Recent HIV infections and associated risk factors among newly diagnosed individuals in South Korea (2016–2023)

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We assessed populations at increased risk of HIV infection and identified those with delayed diagnosis by analyzing the proportion of recent infections among newly diagnosed individuals. HIV-antibody avidity assays were used to distinguish recent from longstanding infections among newly diagnosed cases in 2016–2023. Logistic regression analysis was used to assess risk factors among demographic and behavioral data, including age, nationality, region, transmission mode, marital status, HIV-testing purpose, and occupation. We investigated 7,545 individuals, representing 85.0% of the 8,875 newly diagnosed HIV-positive cases in 2016–2023. The average proportion of recent HIV infections (RHIs) throughout the study was 26.1%, being significantly higher among males (26.9%, P = 0.034), individuals aged < 30 years (38.8%, P < 0.001), and Korean nationals (27.3%, P < 0.001). Among testing purposes, blood donation screening yielded the highest proportion of RHIs (45.8%). Male sex, age below 30 years, and Korean nationality were identified as main risk factors for HIV infection. The RHI proportion serves as a key indicator of HIV prevention effectiveness in Korea and can inform development of effective prevention strategies. Biological sciences/Microbiology Health sciences/Diseases Health sciences/Health care Health sciences/Medical research HIV recency assay risk factors HIV-antibody avidity assays South Korea Figures Figure 1 Figure 2 Figure 3 Introduction Despite significant advancements in prevention programs and treatments, human immunodeficiency virus (HIV) infection remains a major global public health challenge. According to the Joint United Nations Programme on HIV/acquired immunodeficiency syndrome (AIDS) (UNAIDS) estimations, in 2023, approximately 1.3 million new HIV infections were reported worldwide, reflecting a 39% decline since 2010. Additionally, AIDS-related deaths decreased by 51%, with 630,000 deaths recorded. Currently, approximately 39.9 million people are living with HIV infection, of whom 86% are aware of their status and 77% are receiving antiretroviral therapy (ART) [ 1 ]. In South Korea, 1,005 new HIV cases were reported in 2023. Despite South Korea’s low HIV prevalence, annual new infections continue to range between 1,000 and 1,200. Among the reported cases, 89.9% were men and 10.1% were women, with the highest incidence found in individuals aged 30–39 (35.4%) and 20–29 (28.7%) years. Korean nationals accounted for 74.5% of the new infection cases, while the proportion of foreign nationals (25.5%) who are newly infected has been steadily increasing each year [ 2 ]. Achieving the UNAIDS 95–95–95 targets requires prioritization of early HIV detection, as timely diagnosis facilitates prompt ART initiation, viral load suppression, and reduced transmission. However, the proportion of early-stage diagnoses remains low, largely due to the asymptomatic nature of many recent infections, which contributes to silent transmission. According to UNAIDS, globally, 14% of people living with HIV (5.4 million) remain undiagnosed. In Korea, as of 2020, approximately 37.47% of people living with HIV were undiagnosed, with a median infection-to-diagnosis time of 6.96 years [ 3 ]. Data from the Korea HIV/AIDS Cohort Study further revealed that from 2013 to 2015, 17.4% of participants had a CD4 + T-cell count < 200 cells/mm³ at cohort enrollment, while the median CD4 + count at ART initiation was 273 cells/mm³ [ 4 ]. These findings highlight the urgent need for early diagnosis and timely treatment to improve health outcomes and prevent further transmission. In March 2024, as part of its commitment to global efforts to end AIDS by 2030, the Korea Disease Control and Prevention Agency (KDCA) announced the implementation of a 5-year program, The 2nd National Action Plan on HIV/AIDS Prevention and Control (2024–2028) , aiming to halve the levels of new HIV infections in South Korea by 2030, relative to 2023 levels. This plan includes key measures, such as infection prevention, active case identification, rapid and sustained treatment, and health rights assurance. Additionally, the plan emphasizes strengthening the foundation for HIV prevention and management, aligning national efforts with global objectives, while addressing local challenges [ 5 ]. Testing for recent HIV infections (RHIs) using recency assays plays a crucial role in HIV surveillance and prevention, enabling targeted interventions and improving health outcomes. The World Health Organization (WHO) and UNAIDS advocate for recent infection testing algorithms (RITAs) to estimate HIV incidence and guide public health policies [ 6 , 7 ]. By incorporating recency data, countries can identify transmission hotspots and allocate resources more effectively. In the United States, programs such as the National HIV Surveillance System use advanced technologies, such as the limiting antigen avidity assay, to distinguish recent from longstanding infections. The Centers for Disease Control and Prevention (CDC) highlights their value in identifying high-transmission networks and evaluating prevention strategies, including pre-exposure prophylaxis and community-based testing [ 8 – 10 ]. Similarly, the United Kingdom integrates recent infection assays into national surveillance, focusing on key populations, such as men who have sex with men (MSM) and African communities. Molecular epidemiology further supports efforts to track transmission patterns and inform HIV prevention strategies [ 11 – 12 ]. Since 2015, the KDCA has performed confirmatory testing for early HIV diagnosis by integrating HIV-1 p24 antigen neutralization and HIV-1 RNA tests with the conventional antibody-based western blot assay. This approach utilizes HIV RNA and the p24 antigen as diagnostic biomarkers, which appear before anti-HIV antibodies fully develop. Consequently, the confirmed HIV positivity rate increased significantly from 10.3% in 2014 to 33.3% in 2017, while the proportion of indeterminate test results declined sharply. The adoption of HIV RNA testing allowed previously indeterminate cases, often diagnosed with western blot assays in cases in the acute phase of infection due to immature antibody development, to be reported as positive. This initiative is part of a broader testing enhancement policy aimed at identifying individuals in the early acute phase of HIV infection and linking them to treatment programs [ 13 ]. In 2011, South Korea introduced the RITA system to implement nationwide RHI surveillance among newly diagnosed individuals. The testing methods have been continuously refined. Initially, the AxSYM/ARCHITECT Ag/Ab Combo kit was used to perform avidity assays, while the BED HIV-1 Incidence Test was simultaneously employed [ 14 ]. Since 2013, the LAg-Avidity Enzyme Immunoassay (EIA) has been utilized for recency assays. To enhance the specificity of recent infection results, the RITA was applied by considering CD4 count values and additional clinical information as recommended in the UNAIDS/WHO guide. A recent study reported that the average proportion of RHIs among individuals newly diagnosed as HIV-positive in 2008–2015 was 20.5%, with particularly higher among younger age groups [ 15 ]. To inform targeted prevention programs, enhance the precision of intervention strategies, and provide evidence to support the implementation of the 2nd National Action Plan, which includes identifying priority groups for enhanced HIV testing efforts, we investigated the proportion and characteristics of RHIs among individuals newly diagnosed in 2016–2023. Using advanced antibody avidity assays, we differentiated recent infections from longstanding infections and analyzed the associated demographic and behavioral risk factors. Methods Study samples This study utilized residual serum or plasma samples used in HIV confirmatory testing that were deemed suitable for experimentation. The inclusion criteria was any specimen tested positive with an HIV confirmatory test; however, only the initial sample from each individual was included. Specimens from individuals previously confirmed as HIV-positive, multiple samples from the same person, and anonymously tested specimens with unverifiable duplication were excluded. From 2016 to 2023, a total of 15,735 HIV-positive specimens in Korea, confirmed through HIV-1 p24 antigen neutralization assay, HIV-1 RNA tests, and antibody-based Western blot assay, were further analyzed using the LAg-Avidity assay to determine RHI. After excluding 7,704 duplicates, previously confirmed cases, and anonymous tests, 8,031 specimens were included for recency testing, representing 90.5% of the 8,875 newly diagnosed HIV-positive cases reported during this period (Fig. 1 ). HIV/AIDS is a legally notifiable disease in South Korea. The HIV/AIDS Supporting Network System is a centralized database managed by the Division of HIV/AIDS Prevention and Control at the KDCA, which maintains data on individuals confirmed to be HIV-positive. For this study, anonymized epidemiological data were obtained from the Division of HIV/AIDS Prevention and Control. The dataset included information on the following variables: date of diagnosis, age, mode of transmission, purpose of HIV testing, marital status, testing institutions, occupation, CD4 + T cell count, and HIV RNA test results. HIV Antibody Avidity Assay Procedure The Sedia ® HIV-1 LAg-Avidity EIA (Sedia Biosciences Corporation, Portland, OR, USA, Cat. No. 1002) was used to identify recent HIV-1 infections among the study participants. This assay measures the avidity of HIV-1-specific IgG antibodies in plasma or serum, differentiating recent infections from long-term infections. The assay was performed according to the manufacturer’s instructions to ensure consistency and reliability [ 16 ]. Plasma or serum specimens are diluted and added to wells coated with a limiting concentration of recombinant HIV-1 gp41 antigens. After incubation at 37°C for 60 min, a dissociation buffer is added to elute low-avidity antibodies, while retaining high-avidity antibodies bound to the antigen. Horseradish peroxidase-conjugated anti-human IgG antibodies are then added to the wells, followed by incubation. After washing, 3,3′,5,5′-tetramethylbenzidine substrate is added to detect bound antibodies. Optical density (OD) values are measured at 450 nm using a microplate reader and normalized with an internal calibrator to calculate the normalized OD (ODn). Samples with an ODn ≤ 1.5 were classified as recent infections, based on a mean duration of recent infection of 130 (95% confidence interval [CI]: 118–142) days. Statistical analysis RHIs were determined using a multi-analysis algorithm integrating CD4 + T-cell counts at HIV diagnosis and AIDS-related mortality within 1 year after diagnosis. To improve accuracy, RITA was applied to cases initially classified as RHIs based on avidity assay results. Cases with a CD4 count of < 200 cells/mm³ or AIDS-related death within 1 year were excluded without reclassification as longstanding infections to eliminate false recent results (FRRs). Of the 2,075 RHIs, 80 cases (3.9%) were excluded through application of a RITA: 67 with CD4 + counts of < 200 cells/mm³, 18 AIDS-related deaths, and 5 with both criteria. Additionally, 406 specimens were excluded due to missing socio-demographic data (e.g., sex, age, region, nationality, testing institute, or HIV testing purpose), including 379 longstanding infections and 27 recent infections. Ultimately, 7,545 specimens were included in the final statistical analysis (Fig. 1 ). The proportion of RHIs was calculated as the percentage of newly diagnosed HIV cases classified as recent infections each year. We analyzed HIV-testing purposes and testing institutions, including public health centers, hospitals/clinics, blood donation centers, military manpower administration, and correctional facilities. Regional distribution was examined by classifying areas as metropolitan, small city, or rural area. HIV testing purposes were categorized into 12 groups: outpatient clinic visits, antenatal testing, preoperative testing, health checkups, voluntary testing (named/anonymous), blood donation screening, military manpower administration screening, foreign resident screening, correctional facility admission screening, routine sexually transmitted infection (STI) screening, and contact tracing for known HIV-positive individuals. For analysis, some categories were combined. Annual trends in the proportion of recent infections were assessed using the Mann–Kendall test for trends. Odds ratios (ORs) for RHIs were estimated via univariable and multivariable logistic regression. Statistical analyses were conducted using R version 4.4.0 software (R Core Team, R Foundation for Statistical Computing, Vienna, Austria), with a significance level at P < 0.05. Ethics approval All authors hereby declare that all experiments have been reviewed and granted an exemption from ethical approval by the appropriate ethics committee (KDCA Institutional Review Board Ethics Committee; approval number: KDCA-2025-01-02-PE-01). Additionally, the requirement for obtaining informed consent from patients for this study was waived by the KDCA Institutional Review Board. Results Characteristics of the study population This study analyzed the data of HIV cases, newly diagnosed with serum samples collected between 2016 and 2023. The study population was predominantly male (Table 1 ). Foreign nationals accounted for less than 20% of the sample. Almost one-third of the study population was aged 30–39 years. The purpose of HIV testing was predominantly outpatient clinic visits. Notably, 70% (252/360) of those who were tested for HIV because of blood donation were aged under 30 years of age. More than one-third of the cases involved male-to-male sexual contact as the mode of transmission. Additionally, almost three-quarters of the individuals were single or unmarried. Table 1 Socio-demographic characteristics of newly diagnosed human immunodeficiency virus (HIV)-positive cases in Korea in 2016–2023 and included in the Recent HIV Infection Study Study variables Category Recency assay results Total Longstanding infection Recent HIV infection N (%) N (%) N (%) Distribution (%) * Overall 7545 5577 (73.9) 1968 (26.1) 100 Sex Male 6918 (91.7) 5057 (73.1) 1861 (26.9) 94.6 Female 627 (8.3) 520 (82.9) 107 (17.1) 5.4 Age ∥ (years) < 20 (16–19) 53 (0.7) 26 (49.1) 27 (50.9) 1.4 20s (20–29) 2332 (30.9) 1433 (61.4) 899 (38.6) 45.7 30s (30–39) 2422 (32.1) 1809 (74.7) 613 (25.3) 31.1 40s (40–49) 1279 (17.0) 1056 (82.6) 223 (17.4) 11.3 50s (50–59) 896 (11.9) 767 (85.6) 129 (14.4) 6.6 ≥ 60 563 (7.5) 486 (86.3) 77 (13.7) 3.9 Nationality Korean nationals 6227 (82.5) 4526 (72.7) 1701 (27.3) 86.4 Foreign nationals 1318 (17.5) 1051 (79.7) 267 (20.3) 13.6 Region (Residency) Metropolitan 4228 (56.0) 3085 (73.0) 1143 (27.0) 58.1 Small city/rural area 3317 (44.0) 2492 (75.1) 825 (24.9) 41.9 Transmission mode MSM 2821 (37.4) 1968 (69.8) 853 (30.2) 43.3 Heterosexual contact 2529 (33.5) 1892 (74.8) 637 (25.2) 32.4 Others 266 (3.5) 205 (77.1) 61 (22.9) 3.1 Not known 1779 (23.6) 1406 (79.0) 373 (21.0) 19.0 No-response 150 (2.0) 106 (70.7) 44 (29.3) 2.2 Marital status Married/Cohabiting 1270 (16.8) 1021 (80.4) 249 (19.6) 12.7 Single/Not married 5585 (74.0) 3996 (71.5) 1589 (28.5) 80.7 Etc./Not recorded 690 (9.2) 560 (81.2) 130 (18.8) 6.6 Occupation Service worker 344 (4.5 245 (71.2) 99 (28.8) 5.0 Production worker 65 (0.9) 55 (84.6) 10 (15.4) 0.5 Student 72 (1.0) 35 (48.6) 37 (51.4) 1.9 Others 122 (1.6) 98 (80.3) 24 (19.7) 1.2 No response 6942 (92.0) 5144 (74.1) 1798 (25.9) 91.4 Testing institute Hospital/clinic 5053 (67.0) 3857 (76.3) 1196 (23.7) 60.8 Blood donation center 395 (5.2) 218 (55.2) 177 (44.8) 9.0 Public health center 1952 (25.9) 1399 (71.7) 553 (28.3) 28.1 Military Manpower Administration 122 (1.6) 86 (70.5) 36 (29.5) 1.8 Correctional facility 23 (0.3) 17 (73.9) 6 (26.1) 0.3 Testing purpose (Combined) Outpatient clinic visits † 3285 (43.5) 2416 (73.5) 869 (26.5) 44.2 Preoperative testing 1062 (14.1) 873 (82.2) 189 (17.8) 9.6 Health checkups 591 (7.8) 482 (81.6) 109 (18.4) 5.5 Voluntary testing ‡ 1644 (21.8) 1154 (70.2) 490 (29.8) 24.9 Blood donation screening 360 (4.8) 195 (54.2) 165 (45.8) 8.4 Military manpower administration screening 147 (2.0) 105 (71.4) 42 (28.6) 2.1 Others § 456 (6.0) 352 (77.2) 104 (22.8) 5.3 Testing purpose (single) Outpatient clinic visits 3262 (43.2) 2396 (73.5) 866 (26.6) 44.0 Antenatal testing 23 (0.3) 20 (87.0) 3 (13.0) 0.2 Preoperative testing 1062 (14.1) 873 (82.2) 189 (17.8) 9.6 Health checkups 591 (7.8) 482 (81.6) 109 (18.4) 5.5 Voluntary named testing 993 (13.2) 688 (69.3) 305 (30.7) 15.5 Voluntary anonymous testing 651 (8.7) 466 (71.6) 185 (28.4) 9.4 Blood donation screening 360 (4.9) 195 (54.2) 165 (45.8) 8.4 Military Manpower Administration screening 147 (2.0) 105 (71.4) 42 (28.6) 2.1 Foreign resident screening 69 (0.9) 59 (85.5) 10 (14.5) 0.5 Correctional facility admission screening 60 (0.8) 52 (86.7) 8 (13.3) 0.4 Routine STI screening 108 (1.5) 74 (68.5) 34 (31.5) 1.7 Contact tracing of known HIV-positive individuals 49 (0.7) 39 (79.6) 10 (20.4) 0.5 Etc. 93 (1.2) 69 (74.2) 24 (25.8) 1.2 No response 77 (1.0) 59 (76.6) 18 (23.4) 0.9 Year of HIV diagnosis 2016 935 (12.4) 669 (71.6) 266 (28.4) 13.5 (Sample collection) 2017 1062 (14.1) 781 (73.5) 281 (26.5) 14.3 2018 1020 (13.5) 808 (79.2) 212 (20.8) 10.7 2019 1059 (14.0) 821 (77.5) 238 (22.5) 12.1 2020 787 (10.4) 563 (71.5) 224 (28.5) 11.4 2021 805 (10.7) 611 (75.9) 194 (24.1) 9.9 2022 927 (12.3) 651 (70.2) 276 (29.8) 14.0 2023 950 (12.6) 673 (70.8) 277 (29.2) 14.1 * Distribution: The percentage occupied by a specific category within a single variable. † Outpatient visits include both outpatient clinic visits and antenatal testing. ‡ Voluntary testing includes both named and anonymous voluntary testing. § Others include military manpower administration screening, foreign resident screening, correctional facility admission screening, routine STI screening, contact tracing of known HIV-positive individuals, and other unspecified categories (N/A). ∥ Median age of study participants: 34 (interquartile range: 28–46) years HIV, human immunodeficiency virus; MSM, men who have sex with men; STI, sexually transmitted infection Proportion of RHIs (2016–2023) Among 7,545 newly diagnosed HIV cases between 2016 and 2023, RHIs accounted for slightly more than one-quarter (Table 1 ). The proportion was higher in males than in females (P 40 years than in younger age groups (P < 0.001). The proportion of RHIs among foreign nationals was significantly lower than that among Korean nationals (P < 0.001). Additionally, individuals diagnosed in metropolitan areas included a higher proportion of RHIs than did those in small cities or rural areas. Regarding transmission mode, MSM had the highest proportion of RHIs. The proportion of RHIs also varied depending on the purpose of testing. The highest proportions of RHIs were identified during testing related to blood donation. In contrast, lower proportions were found during testing related to contact tracing of known HIV-positive individuals, health checkups, preoperative testing, foreign resident screening, correctional facility admission screening, and antenatal testing (Table 1 ). Notably, blood donation consistently showed the highest proportion of RHIs each year. The proportion was lower in tests where HIV infection was likely discovered incidentally, such as antenatal testing, correctional facility admission screening, foreign resident screening, and preoperative testing. The proportion of RHIs also varied by testing institution. Blood donation centers recorded the highest proportion, followed by military manpower administration screening, public health centers, and hospitals. Although the sample size was limited and the statistical significance was uncertain, the occupational analysis showed that students had the highest proportion of RHIs relative to other occupational groups. Service workers comprised the second highest proportion, while production workers comprised the lowest proportion among the analyzed occupational categories. Trends in RHIs among newly diagnosed cases (2016–2023) A comparative analysis of RHIs from 2016 to 2023 found no statistically significant year-to-year changes across any variable. In 2009, the proportion of RHIs was 16.3%, and the rate has remained above 25% since 2016. Although the overall trend has been slightly upward, 2018 (20.8%) and 2019 (22.5%) showed deviations from this pattern (Fig. 2 a). RHIs were consistently about 10% higher in males than in females each year (Fig. 2 b). Additionally, each year, foreign nationals included significantly lower proportions of RHIs than Korean nationals (Fig. 2 c). Age-specific analysis revealed an inverse relationship between age and RHIs, with lower proportions observed in older age groups each year (Fig. 2 d). According to testing purpose, testing related to blood donation consistently involved the highest RHI proportion, exceeding 40% annually, while voluntary testing and military manpower administration screening also exhibited relatively high rates (Fig. 2 e). Factors associated with RHIs The median age of individuals with RHIs was 30 (interquartile range [IQR]: 26–37) years, which was significantly lesser than the age of those with longstanding infections (36, IQR: 29–48 years). Univariate logistic regression identified several epidemiological factors that were statistically significantly associated with RHIs, including sex, age, nationality, region, transmission mode, marital status, testing institution, and testing purpose (Table 2 ). Table 2 Results of univariable and multivariable analyses to identify risk factors associated with recent human immunodeficiency virus (HIV) infections in Korea in 2016–2023 Category Recent HIV infection Univariable model Multivariable model N (%) * cOR † (95% CI) P-value aOR ‡ (95% CI) P-value Total 1968 (26.1) Sex 0.031 Male 1861 (26.9) 1.79 (1.44–2.22) < 0.001 1.29 (1.02–1.63) 0.034 Female 107 (17.1) 1 1 Age § (years) < 0.001 <20 (16–19) 27 (50.9) 6.55 (3.63–11.82) < 0.001 5.49 (2.96–10.18) < 0.001 20s (20–29) 899 (38.6) 3.96 (3.07–5.11) < 0.001 4.16 (3.15–5.48) < 0.001 30s (30–39) 613 (25.3) 2.14 (1.65–2.77) < 0.001 2.32 (1.77–3.05) < 0.001 40s (40–49) 223 (17.4) 1.33 (1.01–1.76) 0.045 1.45 (1.19–1.94) 0.011 50s (50–59) 129 (14.4) 1.06 (0.78–1.44) 0.700 1.10 (0.81–1.50) 0.538 ≥60 77 (13.7) 1 1 Nationality < 0.001 Korean nationals 1701 (27.3) 1 1 Foreign nationals 267 (20.3) 0.68 (0.58–0.78) < 0.001 0.75(0.63–0.88) < 0.001 Region (Residency) Metropolitan 1143 (27.0) 1 - Small city/rural area 825 (24.9) 0.9 (0.81–0.99) 0.038 - Transmission mode MSM 853 (30.2) 1 - Heterosexual contact 637 (25.2) 0.78 (0.69–0.88) < 0.001 - Others 61 (22.9) 0.69 (0.51–0.92) 0.013 - Not known 373 (21.0) 0.61 (0.53–0.70) < 0.001 - No-response 44 (29.3) 0.96 (0.67–1.37) 0.814 - Marital status 0.008 Single/Not married 1589 (28.5) 1.63 (1.41–1.89) < 0.001 0.81 (0.68–0.97) 0.022 Etc./Not recorded 130 (18.8) 0.95 (0.75–1.20) 0.682 0.68 (0.52–0.87) 0.003 Married/Cohabiting 249 (19.6) 1 1 Testing institute Hospital/clinic 1196 (23.7) 1 Blood donation center 177 (44.8) 2.62 (2.13–3.23) < 0.001 - Public health center 553 (28.3) 1.27 (1.13–1.43) < 0.001 - Military manpower administration 36 (29.5) 1.35 (0.91–2.00) 0.136 - Correctional facility 6 (26.1) 1.14 (0.45–2.89) 0.786 - Testing purpose (Combined) < 0.001 Health checkups 109 (18.4) 1 1 Voluntary testing 490 (29.8) 1.88 (1.49–2.37) < 0.001 1.49 (1.17–1.90) 0.001 Outpatient visits 869 (26.5) 1.59 (1.27–1.99) < 0.001 1.65 (1.31–2.07) < 0.001 Preoperative testing 189 (17.8) 0.96 (0.74–1.24) 0.743 1.06 (0.81–1.38) 0.678 Blood donation 165 (45.8) 3.74 (2.79–5.02) < 0.001 2.33 (1.72–3.16) < 0.001 Military manpower administration screening 42 (28.6) 1.77 (1.17–2.68) 0.007 0.91 (0.60–1.39) 0.666 Others 104 (22.8) 1.31 (0.97–1.77) 0.082 1.52 (1.11–2.08) 0.009 Occupation No response 1798 (25.9) 1 1 Service worker 99 (28.8) 1.16 (0.91–1.47) 0.235 1.12 (0.87–1.43) 0.372 Production worker 10 (15.4) 0.52 (0.26–1.02) 0.058 0.56 (0.28–1.12) 0.103 Student 37 (51.4) 3.02 (1.9–4.82) < 0.001 1.63 (1.01–2.63) 0.046 Others 24 (19.7) 0.70 (0.45–1.10) 0.121 0.69 (0.43–1.11) 0.124 * Proportion of recent HIV infections among specimens tested with the recency assay. † cOR: Crude odds ratio ‡ aOR: Adjusted odds ratio (adjusted for sex, age, nationality, marital status, HIV testing purpose, and occupation) § Median age (interquartile range, Q1–Q3) of individuals with recent HIV infection: 30 (26–37) years CI, confidence interval; MSM, men who have sex with men Multivariable logistic regression revealed key risk factors for RHIs. The likelihood of recent infection was higher in males than in females (adjusted OR: 1.29, 95% CI: 1.02–1.63). Younger individuals in the cohort, particularly those aged 20–29 years and those aged 30–39 years had about four-fold and two-fold increased odds, respectively, of having RHIs, than did those aged 60 years and older. Korean nationals were significantly more likely to have RHIs than were foreign nationals (P < 0.001). Testing related to blood donation, outpatient clinic visits, and voluntary testing also showed strong associations with RHIs. The primary risk factors identified by multivariable analysis were being male, a younger age (under 30 years), and Korean nationality, emphasizing the need for targeted prevention strategies for these high-risk groups. Characteristics of RHIs among younger age groups (aged < 30 years) An analysis of RHIs among individuals aged < 30 years from 2016 to 2023 revealed key findings. The study population included 53 individuals aged 16–19 years and 2,332 in their 20s, collectively accounting for 31.6% of all participants (Table 1 ). Due to the small sample size of the 16–19-year-old age group, statistical analyses were limited, and in some cases, data from both the abovementioned groups were combined. The 8-year average proportion of RHIs was 50.9% among individuals aged 16–19 years and 38.6% among those in their 20s; both these values exceeded the overall study average of 26.1%. Among individuals in their 20s, annual RHI proportions ranged from 31.5% in 2018 to 47.2% in 2020 (Fig. 2 d), with no significant temporal trends observed. Among individuals aged under 30 years, RHIs were more prevalent among males (39.4%) than among females (26.7%) and was higher among Korean nationals (40.1%) than among foreign nationals (31.2%). The proportion was 12.7% points higher in males than in females and 8.9% points higher in Korean nationals than in foreign nationals (Fig. 3 a). RHIs were highest among individuals aged under 10 years who were tested during routine STI screening (50.0%), blood donation (49.2%), outpatient clinic visits (42.4%), preoperative testing (39.8%), contact tracing (37.5%), voluntary testing (35.5%), and military manpower administration screening (28.9%). In contrast, foreign resident screening (15.4%) and correctional facility admission screening (9.1%) had significantly lower RHI proportions (Fig. 3 b). Discussion In this study, we analyzed the proportion of RHIs among 7,545 individuals newly diagnosed with HIV in South Korea over the past 8 years (2016–2023), which represented 85% of the 8,875 cases reported to the KDCA during the study period. Among this study population, the average proportion of RHIs was 26.1%, reflecting a 5.6% increase compared to the previously reported proportion of 20.5% for the period 2008–2015. This trend appears to be associated with the rising number of newly diagnosed HIV cases in South Korea annually, which increased from approximately 900 to 1,100–1,200 cases since 2013. Furthermore, our data suggest that HIV diagnostic testing has become more widely implemented within certain high-risk populations. A logistic regression model was employed to identify independent demographic and behavioral risk factors associated with RHIs. This revealed that male sex, younger age (under 30 years), Korean nationals, and specific testing purposes such as blood donation and voluntary testing, were significantly associated with RHIs. The high proportion of RHIs in certain high-risk groups suggests ongoing transmission and frequent HIV testing behaviors. For example, in Singapore, MSM are known to undergo testing more frequently due to heightened awareness attributed to the effectiveness of government-led sexual health campaigns [ 17 ]. Findings from recent infection surveys serve as critical indicators for enhancing early HIV detection and improving diagnostic strategies. The present study identified the following groups with lower proportions of RHIs: females (17.1%), foreign nationals (20.3%), and individuals aged 40 years or older (17.4%, 14.4%, and 13.7% among individuals in their 40s, 50s, and 60s or older, respectively). The lower proportion of RHIs among older age groups may reflect reduced exposure to high-risk sexual behaviors or limited access to HIV testing. Conversely, younger individuals had a significantly higher probability of RHIs, with those aged 16–19 years having a 5.5-fold higher odds and those aged 20–29 years having a 4.2-fold higher odds of having RHIs compared to individuals aged 60 years and older. The highest RHI proportion according to the HIV testing purpose was observed in the blood donation group (45.8%). This may be explained by the fact that individuals under the age of 30 years accounted for 70% of the blood donation group in this study. Furthermore, since blood donation centers perform HIV-1 RNA testing for all samples from the initial stage of HIV screening, they can diagnose HIV infection earlier than institutions that conduct only antigen/antibody testing. The high RHI proportion in the routine STI screening group (31.5%) likely reflects regular annual HIV testing, as this group is legally required to undergo periodic screening. The lower proportion of RHIs among females may be explained by their relatively small representation among newly diagnosed HIV cases in South Korea, where they account for less than 10% of all new diagnoses. Overall, the risk factors identified in this recent infection analysis align with the epidemiological profile of HIV incidence in Korea. Specifically, these findings were consistent with the 2023 HIV/AIDS notification surveillance data, which indicated that 89.9% of newly diagnosed cases were males, while 64.1% of cases were reported among individuals aged in their 20s and 30s. Global efforts to monitor RHIs have revealed significant regional and population-based variability, emphasizing the need for targeted interventions. In the United States, recent infections account for 10–20% of newly diagnosed cases, with higher rates found among MSM and younger individuals. Similarly, in the United Kingdom, 20–25% of new diagnoses are classified as RHIs, particularly among MSM and African communities. Studies from Germany, Ireland, Singapore, Ethiopia, and Kenya have further highlighted the importance of recency testing in identifying transmission trends and informing public health strategies [ 18 – 24 ]. Despite advancements in HIV surveillance, gaps in testing coverage remain, particularly among racial and ethnic minorities in the United States, where late diagnoses continue to be a challenge. Recency testing has played a crucial role in facilitating earlier care and reducing community-level transmission risks. In the United Kingdom, integrating new HIV diagnoses and late HIV diagnoses data into national surveillance systems has optimized resource allocation in high-prevalence areas, supporting progress toward the UNAIDS 95–95–95 targets [ 25 ]. Beyond surveillance, recent infection testing has significant clinical implications. Acute and early HIV infections are associated with high viral loads and increased transmission risk. Individuals in the early stage of infection are up to 26 times more likely to transmit HIV than are those with chronic infection. Notably, 20–50% of total HIV transmissions occur during this early period [ 26 ]. Early identification and treatment can reduce transmission risk, slow disease progression, and prevent complications. The success of public health interventions in the United States and United Kingdom demonstrates the potential for other countries to adopt similar strategies to enhance HIV prevention and control. The proportion of non-Korean individuals among all HIV cases in South Korea has steadily increased, from 19.5% in 2020 to 20.7% in 2021, 22.6% in 2022, and 25.5% in 2023. Despite this upward trend, the relatively low proportion of recent infections among non-Korean individuals observed in this study suggests that this group has limited access to HIV testing, potentially leading to a higher prevalence of undiagnosed cases. Addressing these disparities requires targeted policies and programs that promote voluntary HIV testing among non-Korean populations, to facilitate earlier diagnosis and reduce transmission risk. This study had some limitations. First, to minimize the impact of FRRs when applying a RITA, we adhered to WHO recommendations by incorporating CD4 + T-cell counts and data on individuals who died within 1 year of diagnosis. However, CD4 + T-cell data were available for only 5,607 (74.5%) of the 7,545 samples included in the study, indicating that CD4 test results were limited to these samples. Consequently, some false positives may not have been fully excluded. Nonetheless, all samples analyzed in this study were the first specimens collected from individuals newly diagnosed with HIV, ensuring that they were unaffected by antiretroviral therapy. Second, the WHO/UNAIDS technical guidelines recommend calculating the “proportion recent” by dividing the number of recent infections by the total number of individuals at risk for HIV, which includes both recent infections and those testing HIV-negative, rather than using only the total number of newly diagnosed cases [ 7 , 27 ]. However, due to the study design, which focused exclusively on confirmed positive samples, we were unable to incorporate data on individuals who tested HIV-negative in South Korea. This limitation may affect the generalizability of our findings to the broader population. Finally, the lack of in-depth epidemiological information associated with each variable made it challenging to interpret the causes or environmental changes related to the analyzed RHI results. These interpretations are expected to be feasible after obtaining relevant epidemiological data in future studies. Despite these constraints, this study holds significant value as it was based on national data covering 7,545 (85%) of the 8,875 newly diagnosed HIV cases reported in South Korea during the study period. This extensive coverage enhances the reliability of our findings and their applicability to understanding the HIV epidemic in Korea. Conclusion Between 2016 and 2023, 26.1% of newly diagnosed HIV cases were detected within 130 days of acquisition (median: 118–142 days), indicating that many individuals remained unaware of their infection during the early phase. Expanding education and outreach programs is essential to encourage regular HIV testing among high-risk groups. This study identified young Korean males aged less than 30 years as the most at-risk group for HIV infection, while foreign nationals are more likely to experience delayed diagnosis. Improving access to HIV testing for these populations is crucial to reducing transmission risks and strengthening prevention efforts. Under the 2nd National Action Plan on HIV/AIDS Prevention and Control (2024–2028), the KDCA is expanding HIV testing initiatives for MSM, people who inject drugs, partners of HIV-positive individuals, and foreign nationals to facilitate early detection and linkage to treatment. These efforts align with global goals and support the objective of ending AIDS by 2030. This study underscores the value of recency assays in HIV epidemic control and provides evidence for their importance in public health strategies. Declarations Competing interests The authors declare no competing interests. Ethics declarations All authors hereby declare that all experiments have been reviewed and granted an exemption from ethical approval by the appropriate ethics committee (KDCA Institutional Review Board Ethics Committee; approval number: KDCA-2025-01-02-PE-01). Additionally, the requirement for obtaining informed consent from patients for this study was waived by the KDCA Institutional Review Board. Author Contribution J.-S.W. and M.-G.H. designed and conceived the study, and M.-G.H. supervised all aspects of its implementation. J.-S.W. wrote the first draft of the manuscript. E.J.K., G.K., Y.J.L., H.G.H., and M.K. performed the LAg Avidity assays. N.R.J. and T.-Y.H. analyzed the data. S.K. and H.M.K. coordinated funding for the project. K.K., S.K., and J.Y. operated the national HIV/ AIDS database. All authors have edited and approved the final version of the manuscript. Acknowledgements This research was supported by the Korea Disease Control and Prevention Agency (grant No. 6331-301-210) Data Availability Data are available from the corresponding author upon reasonable request and is subject to restrictions. References Joint United Nations Programme on HIV/AIDS (UNAIDS). Global HIV & AIDS statistics-fact sheet. UNAIDS (2024). https://www.unaids.org/en/resources/fact-sheet Kim, K., Kim, S., Kim, T. & Yu, J. HIV/AIDS Notifications in Korea, 2023. Public. Health Wkly. Rep. 17 , 1737–1749. 10.56786/PHWR.2024.17.41.3 (2024). Lee, E., Kim, J., Lee, J. Y. & Bang, J. H. Estimation of the number of HIV infections and time to diagnosis in the Korea. J. Korean Med. Sci. 35 , e41. 10.3346/jkms.2020.35.e41 (2020). Ryou, S., Lee, J. G., Jeong, O., Go, M. J. & Kim, J. Long term follow-up of HIV patients: Insight and achievement from a 17 years ‘Korea HIV/AIDS cohort study’ (2006–2023). Public. Health Wkly. Rep. 17 , 1720–1736. 10.56786/PHWR.2024.17.41.2 (2024). Kim, S., Kim, E. & Yu, J. The 2nd National Action Plan on HIV/AIDS prevention and control (2024–2028). Public. Health Wkly. Rep. 17 , 2001–2010. 10.56786/PHWR.2024.17.46.3 (2024). UNAIDS. Recent infection testing algorithm technical update—applications for HIV surveillance and programme monitoring. UNAIDS (2018). https://www.unaids.org/en/resources/documents/2018/infection_testing_algorithm UNAIDS and World Health Organization (WHO). Using recency assays for HIV surveillance: 2022 technical guidance. UNAIDS/WHO (2022). https://www.who.int/publications/i/item/9789240064379 Wei, X. et al. Development of two avidity-based assays to detect recent HIV type 1 seroconversion using a multisubtype gp41 recombinant protein. AIDS Res. Hum. Retroviruses . 26 , 61–71. 10.1089/aid.2009.0133 (2010). Duong, Y. T. et al. Detection of recent HIV-1 infection using a new limiting-antigen avidity assay: Potential for HIV-1 incidence estimates and avidity maturation studies. PLoS ONE . 7 , e33328. 10.1371/journal.pone.0033328 (2012). The Centers for Disease Control and Prevention & Publishes New, C. D. C. HIV Surveillance Reports: HIV Surveillance Supplemental Report: Estimated HIV Incidence and Prevalence in the United States, 2018–2022. CDC (2024). https://www.cdc.gov/nchhstp/director-letters/cdc-publishes-new-hiv-surveillance-reports.html Georgios, K. N. & Andreas, G. T. Diagnostics. recent HIV infection: Diagnosis and public health implications. Diagnostics 12 , 2657. 10.3390/diagnostics12112657 (2022). Public health England (the UK Health Security Agency). Progress towards ending the HIV epidemic in the United Kingdom 2018 report. UK Health Secur. Agency (2019). https://assets.publishing.service.gov.uk/media/5d3afad8e5274a401520b532/Progress_towards_ending_the_HIV_epidemic_in_the_UK.pdf Wang, J. S. et al. Effect of a confirmatory testing algorithm on early acute HIV diagnosis in Korea. Medicine 100 , e25632. 10.1097/MD.0000000000025632 (2021). Wang, J. S., Kee, M. K., Choi, B. S. & Kim, S. S. Modification of AxSYM human immunodeficiency virus assay to identify recent human immunodeficiency virus infections in Korean human immunodeficiency virus-positive individuals. Osong Public. Health Res. Perspect. 6 , 184–119. 10.1016/j.phrp.2015.06.002 (2015). Yoo, M. et al. Characteristics of recent HIV infection among individuals newly diagnosed as HIV-positive in South Korea (2008–2015). Sci. Rep. 12 , 10515. 10.1038/s41598-022-13953-0 (2022). Sedia Biosciences Corporation. Sedia HIV-1 LAg-Avidity EIA. Cat. No. 1002, Oregon USA. (2018)/2022. Ang, L. W. et al. Epidemiological factors associated with recent HIV infection among newly-diagnosed cases in Singapore, 2013–2017. BMC Public. Health . 21 , 430. 10.1186/s12889-021-10478-5 (2021). Schwarcz, S. et al. Characteristics of persons with recently acquired HIV infection: application of the serologic testing algorithm for recent HIV seroconversion in 10 US cities. J. Acquir. Immune Defic. Syndr. 44 , 112–115 (2007). Fisher, M. et al. Serological testing algorithm shows rising HIV incidence in a UK cohort of men whohave sex with men: 10 years application. AIDS 21 , 2309–2314 (2007). Alexandra, H. et al. Surveillance of recent HIV infections among newly diagnosed HIV cases in Germany between 2008 and 2014. BMC Infect. Dis. 17, 484; 1186/s12879-017-2585-4 (2011). O’Donnell, K., Moran, J. & Igoe, D. Monitoring recent HIV infection in Ireland, 2018. Dublin: HSE HPSC; HSE Health Protection Surveillance Centre (2020). https://www.hpsc.ie/a-z/hivandaids/hivdataandreports/2018reports/HIV_2018_recentinfection.pdf (2020). Nigatu, A. et al. Recent HIV infection and associated factors among newly diagnosed HIV cases in the Southwest Ethiopia Regional State: HIV case-based surveillance analysis (2019–2022). BMC Infect. Dis. 24 , 609. 10.1186/s12879-024-09481-z (2024). Tefera, A. et al. Recent HIV infection among newly diagnosed cases and associated factors in the Amhara regional state, Northern Ethiopia: HIV case surveillance data analysis (2019–2021). Front. Public. Health . 10 , 922385. 10.3389/fpubh.2022.922385 (2022). Young, P. W. et al. HIV incidence, recent HIV infection, and associated factors, Kenya, 2007–2018. AIDS Res. Hum. Retroviruses . 39 , 57–67. 10.1089/AID.2022.0054 (2023). GOV.UK, UK Health Security Agency. Official Statistics: HIV testing, PrEP, new HIV diagnoses and care outcomes for people accessing HIV services: 2024 report. UK Health Secur. Agency (2024). https://www.gov.uk/government/statistics/hiv-annual-data-tables/hiv-testing-prep-new-hiv-diagnoses-and-care-outcomes-for-people-accessing-hiv-services-2024-report William, C. M., Nora, E. R., Sarah, E. R. & Kimberly, A. Role of acute and early HIV infection in the sexual transmission of HIV. Curr. Opin. HIV AIDS . 5 , 277–282. 10.1097/COH.0b013e32833a0d3a (2010). Godin, A. et al. Inferring population HIV incidence trends from surveillance data of recent HIV infection among HIV testing clients. AIDS 35 , 2383–2388 (2021). Additional Declarations No competing interests reported. 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08:53:29","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6494324/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6494324/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1038/s41598-025-10444-w","type":"published","date":"2025-07-19T16:05:45+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":82310577,"identity":"0d7a610b-8c4a-4baa-b9e7-dceb316a2152","added_by":"auto","created_at":"2025-05-09 01:52:31","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":682217,"visible":true,"origin":"","legend":"\u003cp\u003eFlowchart of sample inclusion and classification in the Recent human immunodeficiency virus (HIV) infection study among newly diagnosed HIV cases in South Korea during 2016–2023.\u003c/p\u003e\n\u003cp\u003eOf the 15,735 HIV-positive specimens collected, 7,704 were excluded due to duplication, prior HIV confirmation, or anonymous testing, leaving 8,031 specimens for recency testing. Among those classified as recent infections, 80 specimens were removed based on the RITA to eliminate false recent results, and 406 specimens were excluded due to missing epidemiological data. Consequently, the final analysis included 7,545 specimens.\u003c/p\u003e\n\u003cp\u003eAIDS, acquired immune deficiency syndrome; RITA, recent infection testing algorithm\u003c/p\u003e","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-6494324/v1/34c1ff394f65e6a5313c441d.jpeg"},{"id":82312310,"identity":"2f8c101f-007d-4032-b330-14af4e45a16f","added_by":"auto","created_at":"2025-05-09 02:08:31","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":90146,"visible":true,"origin":"","legend":"\u003cp\u003eAnnual proportion of recent human immunodeficiency virus (HIV) infections by (\u003cstrong\u003ea\u003c/strong\u003e) annual proportion of recent HIV infections, (\u003cstrong\u003eb\u003c/strong\u003e) sex, (\u003cstrong\u003ec\u003c/strong\u003e) nationality, (\u003cstrong\u003ed\u003c/strong\u003e) age, and (\u003cstrong\u003ee\u003c/strong\u003e) HIV-testing purpose among newly diagnosed HIV-positive individuals in Korea, 2016–2023.\u003c/p\u003e\n\u003cp\u003eHIV, human immunodeficiency virus; RHIs, recent HIV infections\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-6494324/v1/391514de2eede66f06cbdf96.png"},{"id":82310570,"identity":"c35304d8-d2b1-4a18-be4a-e5b044320201","added_by":"auto","created_at":"2025-05-09 01:52:31","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":72403,"visible":true,"origin":"","legend":"\u003cp\u003eProportion of recent HIV infections by demographic and behavioral factors among newly diagnosed individuals aged 16–29 years during 2016–2023.\u003c/p\u003e\n\u003cp\u003e(\u003cstrong\u003ea\u003c/strong\u003e) Sex, nationality, testing institute\u003c/p\u003e\n\u003cp\u003eForeigner, foreign nationals; blood center, blood donation center; public center, public health center; military, manpower administration; prison, correctional facility\u003c/p\u003e\n\u003cp\u003e(\u003cstrong\u003eb\u003c/strong\u003e) Testing purpose\u003c/p\u003e\n\u003cp\u003eVoluntary testing includes both named and anonymous voluntary testing. Outpatient visits include outpatient clinic visits and antenatal testing.\u003c/p\u003e\n\u003cp\u003ePrisoner screening, correctional facility admission screening; military screening, military manpower administration screening; foreigner screening, foreign resident screening; HIV-positive partner, contact tracing of known HIV-positive individuals.\u003c/p\u003e\n\u003cp\u003eHIV, human immunodeficiency virus; RHIs, recent HIV infections\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-6494324/v1/123f79279a96f9273578d31f.png"},{"id":88506900,"identity":"8132bef3-78f2-4f5c-bf15-3f7f7786465b","added_by":"auto","created_at":"2025-08-07 07:35:29","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2154442,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6494324/v1/1ecbd886-ea8f-436c-baa4-6af156dcddbf.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Recent HIV infections and associated risk factors among newly diagnosed individuals in South Korea (2016–2023)","fulltext":[{"header":"Introduction","content":"\u003cp\u003eDespite significant advancements in prevention programs and treatments, human immunodeficiency virus (HIV) infection remains a major global public health challenge. According to the Joint United Nations Programme on HIV/acquired immunodeficiency syndrome (AIDS) (UNAIDS) estimations, in 2023, approximately 1.3\u0026nbsp;million new HIV infections were reported worldwide, reflecting a 39% decline since 2010. Additionally, AIDS-related deaths decreased by 51%, with 630,000 deaths recorded. Currently, approximately 39.9\u0026nbsp;million people are living with HIV infection, of whom 86% are aware of their status and 77% are receiving antiretroviral therapy (ART) [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. In South Korea, 1,005 new HIV cases were reported in 2023. Despite South Korea\u0026rsquo;s low HIV prevalence, annual new infections continue to range between 1,000 and 1,200. Among the reported cases, 89.9% were men and 10.1% were women, with the highest incidence found in individuals aged 30\u0026ndash;39 (35.4%) and 20\u0026ndash;29 (28.7%) years. Korean nationals accounted for 74.5% of the new infection cases, while the proportion of foreign nationals (25.5%) who are newly infected has been steadily increasing each year [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eAchieving the UNAIDS 95\u0026ndash;95\u0026ndash;95 targets requires prioritization of early HIV detection, as timely diagnosis facilitates prompt ART initiation, viral load suppression, and reduced transmission. However, the proportion of early-stage diagnoses remains low, largely due to the asymptomatic nature of many recent infections, which contributes to silent transmission. According to UNAIDS, globally, 14% of people living with HIV (5.4\u0026nbsp;million) remain undiagnosed. In Korea, as of 2020, approximately 37.47% of people living with HIV were undiagnosed, with a median infection-to-diagnosis time of 6.96 years [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Data from the Korea HIV/AIDS Cohort Study further revealed that from 2013 to 2015, 17.4% of participants had a CD4\u003csup\u003e+\u003c/sup\u003e T-cell count\u0026thinsp;\u0026lt;\u0026thinsp;200 cells/mm\u0026sup3; at cohort enrollment, while the median CD4\u003csup\u003e+\u003c/sup\u003e count at ART initiation was 273 cells/mm\u0026sup3; [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. These findings highlight the urgent need for early diagnosis and timely treatment to improve health outcomes and prevent further transmission.\u003c/p\u003e \u003cp\u003eIn March 2024, as part of its commitment to global efforts to end AIDS by 2030, the Korea Disease Control and Prevention Agency (KDCA) announced the implementation of a 5-year program, \u003cem\u003eThe 2nd National Action Plan on HIV/AIDS Prevention and Control (2024\u0026ndash;2028)\u003c/em\u003e, aiming to halve the levels of new HIV infections in South Korea by 2030, relative to 2023 levels. This plan includes key measures, such as infection prevention, active case identification, rapid and sustained treatment, and health rights assurance. Additionally, the plan emphasizes strengthening the foundation for HIV prevention and management, aligning national efforts with global objectives, while addressing local challenges [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eTesting for recent HIV infections (RHIs) using recency assays plays a crucial role in HIV surveillance and prevention, enabling targeted interventions and improving health outcomes. The World Health Organization (WHO) and UNAIDS advocate for recent infection testing algorithms (RITAs) to estimate HIV incidence and guide public health policies [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. By incorporating recency data, countries can identify transmission hotspots and allocate resources more effectively. In the United States, programs such as the National HIV Surveillance System use advanced technologies, such as the limiting antigen avidity assay, to distinguish recent from longstanding infections. The Centers for Disease Control and Prevention (CDC) highlights their value in identifying high-transmission networks and evaluating prevention strategies, including pre-exposure prophylaxis and community-based testing [\u003cspan additionalcitationids=\"CR9\" citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Similarly, the United Kingdom integrates recent infection assays into national surveillance, focusing on key populations, such as men who have sex with men (MSM) and African communities. Molecular epidemiology further supports efforts to track transmission patterns and inform HIV prevention strategies [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eSince 2015, the KDCA has performed confirmatory testing for early HIV diagnosis by integrating HIV-1 p24 antigen neutralization and HIV-1 RNA tests with the conventional antibody-based western blot assay. This approach utilizes HIV RNA and the p24 antigen as diagnostic biomarkers, which appear before anti-HIV antibodies fully develop. Consequently, the confirmed HIV positivity rate increased significantly from 10.3% in 2014 to 33.3% in 2017, while the proportion of indeterminate test results declined sharply. The adoption of HIV RNA testing allowed previously indeterminate cases, often diagnosed with western blot assays in cases in the acute phase of infection due to immature antibody development, to be reported as positive. This initiative is part of a broader testing enhancement policy aimed at identifying individuals in the early acute phase of HIV infection and linking them to treatment programs [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn 2011, South Korea introduced the RITA system to implement nationwide RHI surveillance among newly diagnosed individuals. The testing methods have been continuously refined. Initially, the AxSYM/ARCHITECT Ag/Ab Combo kit was used to perform avidity assays, while the BED HIV-1 Incidence Test was simultaneously employed [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Since 2013, the LAg-Avidity Enzyme Immunoassay (EIA) has been utilized for recency assays. To enhance the specificity of recent infection results, the RITA was applied by considering CD4 count values and additional clinical information as recommended in the UNAIDS/WHO guide. A recent study reported that the average proportion of RHIs among individuals newly diagnosed as HIV-positive in 2008\u0026ndash;2015 was 20.5%, with particularly higher among younger age groups [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eTo inform targeted prevention programs, enhance the precision of intervention strategies, and provide evidence to support the implementation of the 2nd National Action Plan, which includes identifying priority groups for enhanced HIV testing efforts, we investigated the proportion and characteristics of RHIs among individuals newly diagnosed in 2016\u0026ndash;2023. Using advanced antibody avidity assays, we differentiated recent infections from longstanding infections and analyzed the associated demographic and behavioral risk factors.\u003c/p\u003e"},{"header":"Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy samples\u003c/h2\u003e \u003cp\u003eThis study utilized residual serum or plasma samples used in HIV confirmatory testing that were deemed suitable for experimentation. The inclusion criteria was any specimen tested positive with an HIV confirmatory test; however, only the initial sample from each individual was included. Specimens from individuals previously confirmed as HIV-positive, multiple samples from the same person, and anonymously tested specimens with unverifiable duplication were excluded.\u003c/p\u003e \u003cp\u003eFrom 2016 to 2023, a total of 15,735 HIV-positive specimens in Korea, confirmed through HIV-1 p24 antigen neutralization assay, HIV-1 RNA tests, and antibody-based Western blot assay, were further analyzed using the LAg-Avidity assay to determine RHI. After excluding 7,704 duplicates, previously confirmed cases, and anonymous tests, 8,031 specimens were included for recency testing, representing 90.5% of the 8,875 newly diagnosed HIV-positive cases reported during this period (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eHIV/AIDS is a legally notifiable disease in South Korea. \u003cem\u003eThe HIV/AIDS Supporting Network System\u003c/em\u003e is a centralized database managed by the Division of HIV/AIDS Prevention and Control at the KDCA, which maintains data on individuals confirmed to be HIV-positive. For this study, anonymized epidemiological data were obtained from the Division of HIV/AIDS Prevention and Control. The dataset included information on the following variables: date of diagnosis, age, mode of transmission, purpose of HIV testing, marital status, testing institutions, occupation, CD4\u0026thinsp;+\u0026thinsp;T cell count, and HIV RNA test results.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eHIV Antibody Avidity Assay Procedure\u003c/h3\u003e\n\u003cp\u003eThe Sedia\u003csup\u003e\u0026reg;\u003c/sup\u003e HIV-1 LAg-Avidity EIA (Sedia Biosciences Corporation, Portland, OR, USA, Cat. No. 1002) was used to identify recent HIV-1 infections among the study participants. This assay measures the avidity of HIV-1-specific IgG antibodies in plasma or serum, differentiating recent infections from long-term infections. The assay was performed according to the manufacturer\u0026rsquo;s instructions to ensure consistency and reliability [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Plasma or serum specimens are diluted and added to wells coated with a limiting concentration of recombinant HIV-1 gp41 antigens. After incubation at 37\u0026deg;C for 60 min, a dissociation buffer is added to elute low-avidity antibodies, while retaining high-avidity antibodies bound to the antigen. Horseradish peroxidase-conjugated anti-human IgG antibodies are then added to the wells, followed by incubation. After washing, 3,3\u0026prime;,5,5\u0026prime;-tetramethylbenzidine substrate is added to detect bound antibodies. Optical density (OD) values are measured at 450 nm using a microplate reader and normalized with an internal calibrator to calculate the normalized OD (ODn). Samples with an ODn\u0026thinsp;\u0026le;\u0026thinsp;1.5 were classified as recent infections, based on a mean duration of recent infection of 130 (95% confidence interval [CI]: 118\u0026ndash;142) days.\u003c/p\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eRHIs were determined using a multi-analysis algorithm integrating CD4\u003csup\u003e+\u003c/sup\u003e T-cell counts at HIV diagnosis and AIDS-related mortality within 1 year after diagnosis. To improve accuracy, RITA was applied to cases initially classified as RHIs based on avidity assay results. Cases with a CD4 count of \u0026lt;\u0026thinsp;200 cells/mm\u0026sup3; or AIDS-related death within 1 year were excluded without reclassification as longstanding infections to eliminate false recent results (FRRs). Of the 2,075 RHIs, 80 cases (3.9%) were excluded through application of a RITA: 67 with CD4\u003csup\u003e+\u003c/sup\u003e counts of \u0026lt;\u0026thinsp;200 cells/mm\u0026sup3;, 18 AIDS-related deaths, and 5 with both criteria. Additionally, 406 specimens were excluded due to missing socio-demographic data (e.g., sex, age, region, nationality, testing institute, or HIV testing purpose), including 379 longstanding infections and 27 recent infections. Ultimately, 7,545 specimens were included in the final statistical analysis (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe proportion of RHIs was calculated as the percentage of newly diagnosed HIV cases classified as recent infections each year. We analyzed HIV-testing purposes and testing institutions, including public health centers, hospitals/clinics, blood donation centers, military manpower administration, and correctional facilities. Regional distribution was examined by classifying areas as metropolitan, small city, or rural area. HIV testing purposes were categorized into 12 groups: outpatient clinic visits, antenatal testing, preoperative testing, health checkups, voluntary testing (named/anonymous), blood donation screening, military manpower administration screening, foreign resident screening, correctional facility admission screening, routine sexually transmitted infection (STI) screening, and contact tracing for known HIV-positive individuals. For analysis, some categories were combined. Annual trends in the proportion of recent infections were assessed using the Mann\u0026ndash;Kendall test for trends. Odds ratios (ORs) for RHIs were estimated via univariable and multivariable logistic regression. Statistical analyses were conducted using R version 4.4.0 software (R Core Team, R Foundation for Statistical Computing, Vienna, Austria), with a significance level at P\u0026thinsp;\u0026lt;\u0026thinsp;0.05.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eEthics approval\u003c/h3\u003e\n\u003cp\u003eAll authors hereby declare that all experiments have been reviewed and granted an exemption from ethical approval by the appropriate ethics committee (KDCA Institutional Review Board Ethics Committee; approval number: KDCA-2025-01-02-PE-01). Additionally, the requirement for obtaining informed consent from patients for this study was waived by the KDCA Institutional Review Board.\u003c/p\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eCharacteristics of the study population\u003c/h2\u003e \u003cp\u003eThis study analyzed the data of HIV cases, newly diagnosed with serum samples collected between 2016 and 2023. The study population was predominantly male (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Foreign nationals accounted for less than 20% of the sample. Almost one-third of the study population was aged 30\u0026ndash;39 years. The purpose of HIV testing was predominantly outpatient clinic visits. Notably, 70% (252/360) of those who were tested for HIV because of blood donation were aged under 30 years of age. More than one-third of the cases involved male-to-male sexual contact as the mode of transmission. Additionally, almost three-quarters of the individuals were single or unmarried.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eSocio-demographic characteristics of newly diagnosed human immunodeficiency virus (HIV)-positive cases in Korea in 2016\u0026ndash;2023 and included in the Recent HIV Infection Study\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eStudy variables\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eCategory\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e \u003cp\u003eRecency assay results\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eLongstanding infection\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cp\u003eRecent HIV infection\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eN (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eN (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eN (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eDistribution (%)\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOverall\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7545\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e5577 (73.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e1968 (26.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSex\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6918 (91.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e5057 (73.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e1861 (26.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e94.6\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eFemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e627 (8.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e520 (82.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e107 (17.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e5.4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge\u003csup\u003e∥\u003c/sup\u003e (years)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;20 (16\u0026ndash;19)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e53 (0.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e26 (49.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e27 (50.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1.4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e20s (20\u0026ndash;29)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2332 (30.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1433 (61.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e899 (38.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e45.7\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e30s (30\u0026ndash;39)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2422 (32.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1809 (74.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e613 (25.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e31.1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e40s (40\u0026ndash;49)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1279 (17.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1056 (82.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e223 (17.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e11.3\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e50s (50\u0026ndash;59)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e896 (11.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e767 (85.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e129 (14.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e6.6\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026ge;\u0026thinsp;60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e563 (7.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e486 (86.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e77 (13.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e3.9\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNationality\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eKorean nationals\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6227 (82.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e4526 (72.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e1701 (27.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e86.4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eForeign nationals\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1318 (17.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1051 (79.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e267 (20.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e13.6\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRegion (Residency)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMetropolitan\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4228 (56.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e3085 (73.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e1143 (27.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e58.1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eSmall city/rural area\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3317 (44.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2492 (75.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e825 (24.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e41.9\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTransmission mode\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMSM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2821 (37.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1968 (69.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e853 (30.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e43.3\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHeterosexual contact\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2529 (33.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1892 (74.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e637 (25.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e32.4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOthers\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e266 (3.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e205 (77.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e61 (22.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e3.1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNot known\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1779 (23.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1406 (79.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e373 (21.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e19.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNo-response\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e150 (2.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e106 (70.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e44 (29.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2.2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMarital status\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMarried/Cohabiting\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1270 (16.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1021 (80.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e249 (19.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e12.7\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eSingle/Not married\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5585 (74.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e3996 (71.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e1589 (28.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e80.7\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eEtc./Not recorded\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e690 (9.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e560 (81.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e130 (18.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e6.6\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOccupation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eService worker\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e344 (4.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e245 (71.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e99 (28.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e5.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eProduction worker\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e65 (0.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e55 (84.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e10 (15.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.5\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eStudent\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e72 (1.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e35 (48.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e37 (51.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1.9\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOthers\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e122 (1.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e98 (80.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e24 (19.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1.2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNo response\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6942 (92.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e5144 (74.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e1798 (25.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e91.4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTesting institute\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHospital/clinic\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5053 (67.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e3857 (76.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e1196 (23.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e60.8\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eBlood donation center\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e395 (5.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e218 (55.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e177 (44.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e9.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePublic health center\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1952 (25.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1399 (71.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e553 (28.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e28.1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMilitary Manpower Administration\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e122 (1.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e86 (70.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e36 (29.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1.8\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCorrectional facility\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e23 (0.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e17 (73.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e6 (26.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.3\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTesting purpose (Combined)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOutpatient clinic visits\u003csup\u003e\u0026dagger;\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3285 (43.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2416 (73.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e869 (26.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e44.2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePreoperative testing\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1062 (14.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e873 (82.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e189 (17.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e9.6\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHealth checkups\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e591 (7.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e482 (81.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e109 (18.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e5.5\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eVoluntary testing\u003csup\u003e\u0026Dagger;\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1644 (21.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1154 (70.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e490 (29.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e24.9\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eBlood donation screening\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e360 (4.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e195 (54.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e165 (45.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e8.4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMilitary manpower administration screening\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e147 (2.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e105 (71.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e42 (28.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2.1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOthers\u003csup\u003e\u0026sect;\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e456 (6.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e352 (77.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e104 (22.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e5.3\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTesting purpose (single)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOutpatient clinic visits\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3262 (43.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2396 (73.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e866 (26.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e44.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eAntenatal testing\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e23 (0.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e20 (87.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e3 (13.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePreoperative testing\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1062 (14.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e873 (82.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e189 (17.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e9.6\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHealth checkups\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e591 (7.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e482 (81.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e109 (18.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e5.5\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eVoluntary named testing\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e993 (13.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e688 (69.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e305 (30.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e15.5\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eVoluntary anonymous testing\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e651 (8.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e466 (71.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e185 (28.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e9.4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eBlood donation screening\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e360 (4.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e195 (54.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e165 (45.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e8.4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMilitary Manpower Administration screening\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e147 (2.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e105 (71.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e42 (28.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2.1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eForeign resident screening\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e69 (0.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e59 (85.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e10 (14.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.5\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCorrectional facility admission screening\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e60 (0.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e52 (86.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e8 (13.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRoutine STI screening\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e108 (1.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e74 (68.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e34 (31.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1.7\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eContact tracing of known HIV-positive individuals\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e49 (0.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e39 (79.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e10 (20.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.5\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eEtc.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e93 (1.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e69 (74.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e24 (25.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1.2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNo response\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e77 (1.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e59 (76.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e18 (23.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.9\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eYear of HIV diagnosis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2016\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e935 (12.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e669 (71.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e266 (28.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e13.5\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e(Sample collection)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2017\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1062 (14.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e781 (73.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e281 (26.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e14.3\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2018\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1020 (13.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e808 (79.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e212 (20.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e10.7\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2019\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1059 (14.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e821 (77.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e238 (22.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e12.1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2020\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e787 (10.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e563 (71.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e224 (28.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e11.4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2021\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e805 (10.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e611 (75.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e194 (24.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e9.9\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2022\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e927 (12.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e651 (70.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e276 (29.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e14.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2023\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e950 (12.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e673 (70.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e277 (29.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e14.1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003e\u003csup\u003e*\u003c/sup\u003eDistribution: The percentage occupied by a specific category within a single variable.\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003e\u003csup\u003e\u0026dagger;\u003c/sup\u003eOutpatient visits include both outpatient clinic visits and antenatal testing.\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003e\u003csup\u003e\u0026Dagger;\u003c/sup\u003e Voluntary testing includes both named and anonymous voluntary testing.\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003e\u003csup\u003e\u0026sect;\u003c/sup\u003eOthers include military manpower administration screening, foreign resident screening, correctional facility admission screening, routine STI screening, contact tracing of known HIV-positive individuals, and other unspecified categories (N/A).\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003e\u003csup\u003e∥\u003c/sup\u003e Median age of study participants: 34 (interquartile range: 28\u0026ndash;46) years\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003eHIV, human immunodeficiency virus; MSM, men who have sex with men; STI, sexually transmitted infection\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eProportion of RHIs (2016–2023)\u003c/h3\u003e\n\u003cp\u003eAmong 7,545 newly diagnosed HIV cases between 2016 and 2023, RHIs accounted for slightly more than one-quarter (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). The proportion was higher in males than in females (P\u0026thinsp;\u0026lt;\u0026thinsp;0.034). Age-specific analysis showed that RHIs were most prevalent in 16\u0026ndash;19-year-olds compared to the other age groups. The proportion was significantly lower in individuals aged\u0026thinsp;\u0026gt;\u0026thinsp;40 years than in younger age groups (P\u0026thinsp;\u0026lt;\u0026thinsp;0.001). The proportion of RHIs among foreign nationals was significantly lower than that among Korean nationals (P\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Additionally, individuals diagnosed in metropolitan areas included a higher proportion of RHIs than did those in small cities or rural areas. Regarding transmission mode, MSM had the highest proportion of RHIs.\u003c/p\u003e \u003cp\u003eThe proportion of RHIs also varied depending on the purpose of testing. The highest proportions of RHIs were identified during testing related to blood donation. In contrast, lower proportions were found during testing related to contact tracing of known HIV-positive individuals, health checkups, preoperative testing, foreign resident screening, correctional facility admission screening, and antenatal testing (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eNotably, blood donation consistently showed the highest proportion of RHIs each year. The proportion was lower in tests where HIV infection was likely discovered incidentally, such as antenatal testing, correctional facility admission screening, foreign resident screening, and preoperative testing.\u003c/p\u003e \u003cp\u003eThe proportion of RHIs also varied by testing institution. Blood donation centers recorded the highest proportion, followed by military manpower administration screening, public health centers, and hospitals.\u003c/p\u003e \u003cp\u003eAlthough the sample size was limited and the statistical significance was uncertain, the occupational analysis showed that students had the highest proportion of RHIs relative to other occupational groups. Service workers comprised the second highest proportion, while production workers comprised the lowest proportion among the analyzed occupational categories.\u003c/p\u003e\n\u003ch3\u003eTrends in RHIs among newly diagnosed cases (2016–2023)\u003c/h3\u003e\n\u003cp\u003eA comparative analysis of RHIs from 2016 to 2023 found no statistically significant year-to-year changes across any variable. In 2009, the proportion of RHIs was 16.3%, and the rate has remained above 25% since 2016. Although the overall trend has been slightly upward, 2018 (20.8%) and 2019 (22.5%) showed deviations from this pattern (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e2\u003c/span\u003ea). RHIs were consistently about 10% higher in males than in females each year (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e2\u003c/span\u003eb). Additionally, each year, foreign nationals included significantly lower proportions of RHIs than Korean nationals (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e2\u003c/span\u003ec). Age-specific analysis revealed an inverse relationship between age and RHIs, with lower proportions observed in older age groups each year (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e2\u003c/span\u003ed). According to testing purpose, testing related to blood donation consistently involved the highest RHI proportion, exceeding 40% annually, while voluntary testing and military manpower administration screening also exhibited relatively high rates (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e2\u003c/span\u003ee).\u003c/p\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eFactors associated with RHIs\u003c/h2\u003e \u003cp\u003eThe median age of individuals with RHIs was 30 (interquartile range [IQR]: 26\u0026ndash;37) years, which was significantly lesser than the age of those with longstanding infections (36, IQR: 29\u0026ndash;48 years). Univariate logistic regression identified several epidemiological factors that were statistically significantly associated with RHIs, including sex, age, nationality, region, transmission mode, marital status, testing institution, and testing purpose (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eResults of univariable and multivariable analyses to identify risk factors associated with recent human immunodeficiency virus (HIV) infections in Korea in 2016\u0026ndash;2023\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eCategory\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRecent HIV infection\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e \u003cp\u003eUnivariable model\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c6\" namest=\"c5\"\u003e \u003cp\u003eMultivariable model\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eN (%)\u003c/b\u003e \u003csup\u003e\u003cb\u003e*\u003c/b\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003ecOR\u003c/b\u003e\u003csup\u003e\u0026dagger;\u003c/sup\u003e \u003cb\u003e(95% CI)\u003c/b\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003eP-value\u003c/b\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003eaOR\u003c/b\u003e\u003csup\u003e\u0026Dagger;\u003c/sup\u003e \u003cb\u003e(95% CI)\u003c/b\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cb\u003eP-value\u003c/b\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eTotal\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1968 (26.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eSex\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.031\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1861 (26.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.79 (1.44\u0026ndash;2.22)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.29 (1.02\u0026ndash;1.63)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.034\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e107 (17.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eAge\u003c/b\u003e\u003csup\u003e\u0026sect;\u003c/sup\u003e \u003cb\u003e(years)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u0026lt;20 (16\u0026ndash;19)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e27 (50.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6.55 (3.63\u0026ndash;11.82)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e5.49 (2.96\u0026ndash;10.18)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e20s (20\u0026ndash;29)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e899 (38.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3.96 (3.07\u0026ndash;5.11)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4.16 (3.15\u0026ndash;5.48)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e30s (30\u0026ndash;39)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e613 (25.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.14 (1.65\u0026ndash;2.77)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2.32 (1.77\u0026ndash;3.05)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e40s (40\u0026ndash;49)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e223 (17.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.33 (1.01\u0026ndash;1.76)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.045\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.45 (1.19\u0026ndash;1.94)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.011\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e50s (50\u0026ndash;59)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e129 (14.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.06 (0.78\u0026ndash;1.44)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.700\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.10 (0.81\u0026ndash;1.50)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.538\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u0026ge;60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e77 (13.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eNationality\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eKorean nationals\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1701 (27.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eForeign nationals\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e267 (20.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.68 (0.58\u0026ndash;0.78)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.75(0.63\u0026ndash;0.88)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eRegion (Residency)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMetropolitan\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1143 (27.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSmall city/rural area\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e825 (24.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.9 (0.81\u0026ndash;0.99)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.038\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"6\" nameend=\"c6\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eTransmission mode\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMSM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e853 (30.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHeterosexual contact\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e637 (25.2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.78 (0.69\u0026ndash;0.88)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOthers\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e61 (22.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.69 (0.51\u0026ndash;0.92)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.013\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNot known\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e373 (21.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.61 (0.53\u0026ndash;0.70)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo-response\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e44 (29.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.96 (0.67\u0026ndash;1.37)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.814\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eMarital status\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.008\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSingle/Not married\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1589 (28.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.63 (1.41\u0026ndash;1.89)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.81 (0.68\u0026ndash;0.97)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.022\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEtc./Not recorded\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e130 (18.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.95 (0.75\u0026ndash;1.20)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.682\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.68 (0.52\u0026ndash;0.87)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.003\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMarried/Cohabiting\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e249 (19.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eTesting institute\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHospital/clinic\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1196 (23.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBlood donation center\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e177 (44.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.62 (2.13\u0026ndash;3.23)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePublic health center\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e553 (28.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.27 (1.13\u0026ndash;1.43)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMilitary manpower\u003c/p\u003e \u003cp\u003eadministration\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e36 (29.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.35 (0.91\u0026ndash;2.00)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.136\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCorrectional facility\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6 (26.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.14 (0.45\u0026ndash;2.89)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.786\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"5\" nameend=\"c5\" namest=\"c1\"\u003e \u003cp\u003e\u003cb\u003eTesting purpose (Combined)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHealth checkups\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e109 (18.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVoluntary testing\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e490 (29.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.88 (1.49\u0026ndash;2.37)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.49 (1.17\u0026ndash;1.90)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOutpatient visits\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e869 (26.5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.59 (1.27\u0026ndash;1.99)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.65 (1.31\u0026ndash;2.07)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePreoperative testing\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e189 (17.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.96 (0.74\u0026ndash;1.24)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.743\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.06 (0.81\u0026ndash;1.38)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.678\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBlood donation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e165 (45.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3.74 (2.79\u0026ndash;5.02)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2.33 (1.72\u0026ndash;3.16)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMilitary manpower\u003c/p\u003e \u003cp\u003eadministration screening\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e42 (28.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.77 (1.17\u0026ndash;2.68)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.007\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.91 (0.60\u0026ndash;1.39)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.666\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOthers\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e104 (22.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.31 (0.97\u0026ndash;1.77)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.082\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.52 (1.11\u0026ndash;2.08)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.009\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eOccupation\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo response\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1798 (25.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eService worker\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e99 (28.8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.16 (0.91\u0026ndash;1.47)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.235\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.12 (0.87\u0026ndash;1.43)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.372\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eProduction worker\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e10 (15.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.52 (0.26\u0026ndash;1.02)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.058\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.56 (0.28\u0026ndash;1.12)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.103\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStudent\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e37 (51.4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3.02 (1.9\u0026ndash;4.82)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.63 (1.01\u0026ndash;2.63)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.046\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOthers\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e24 (19.7)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.70 (0.45\u0026ndash;1.10)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.121\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.69 (0.43\u0026ndash;1.11)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.124\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003e\u003csup\u003e*\u003c/sup\u003e Proportion of recent HIV infections among specimens tested with the recency assay.\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003e\u003csup\u003e\u0026dagger;\u003c/sup\u003e cOR: Crude odds ratio\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003e\u003csup\u003e\u0026Dagger;\u003c/sup\u003e aOR: Adjusted odds ratio (adjusted for sex, age, nationality, marital status, HIV testing purpose, and occupation)\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003e\u003csup\u003e\u0026sect;\u003c/sup\u003e Median age (interquartile range, Q1\u0026ndash;Q3) of individuals with recent HIV infection: 30 (26\u0026ndash;37) years\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003eCI, confidence interval; MSM, men who have sex with men\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eMultivariable logistic regression revealed key risk factors for RHIs. The likelihood of recent infection was higher in males than in females (adjusted OR: 1.29, 95% CI: 1.02\u0026ndash;1.63). Younger individuals in the cohort, particularly those aged 20\u0026ndash;29 years and those aged 30\u0026ndash;39 years had about four-fold and two-fold increased odds, respectively, of having RHIs, than did those aged 60 years and older. Korean nationals were significantly more likely to have RHIs than were foreign nationals (P\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Testing related to blood donation, outpatient clinic visits, and voluntary testing also showed strong associations with RHIs. The primary risk factors identified by multivariable analysis were being male, a younger age (under 30 years), and Korean nationality, emphasizing the need for targeted prevention strategies for these high-risk groups.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003eCharacteristics of RHIs among younger age groups (aged\u0026thinsp;\u0026lt;\u0026thinsp;30 years)\u003c/h2\u003e \u003cp\u003eAn analysis of RHIs among individuals aged\u0026thinsp;\u0026lt;\u0026thinsp;30 years from 2016 to 2023 revealed key findings. The study population included 53 individuals aged 16\u0026ndash;19 years and 2,332 in their 20s, collectively accounting for 31.6% of all participants (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Due to the small sample size of the 16\u0026ndash;19-year-old age group, statistical analyses were limited, and in some cases, data from both the abovementioned groups were combined. The 8-year average proportion of RHIs was 50.9% among individuals aged 16\u0026ndash;19 years and 38.6% among those in their 20s; both these values exceeded the overall study average of 26.1%. Among individuals in their 20s, annual RHI proportions ranged from 31.5% in 2018 to 47.2% in 2020 (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e2\u003c/span\u003ed), with no significant temporal trends observed.\u003c/p\u003e \u003cp\u003eAmong individuals aged under 30 years, RHIs were more prevalent among males (39.4%) than among females (26.7%) and was higher among Korean nationals (40.1%) than among foreign nationals (31.2%). The proportion was 12.7% points higher in males than in females and 8.9% points higher in Korean nationals than in foreign nationals (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ea). RHIs were highest among individuals aged under 10 years who were tested during routine STI screening (50.0%), blood donation (49.2%), outpatient clinic visits (42.4%), preoperative testing (39.8%), contact tracing (37.5%), voluntary testing (35.5%), and military manpower administration screening (28.9%). In contrast, foreign resident screening (15.4%) and correctional facility admission screening (9.1%) had significantly lower RHI proportions (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eb).\u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eIn this study, we analyzed the proportion of RHIs among 7,545 individuals newly diagnosed with HIV in South Korea over the past 8 years (2016\u0026ndash;2023), which represented 85% of the 8,875 cases reported to the KDCA during the study period. Among this study population, the average proportion of RHIs was 26.1%, reflecting a 5.6% increase compared to the previously reported proportion of 20.5% for the period 2008\u0026ndash;2015. This trend appears to be associated with the rising number of newly diagnosed HIV cases in South Korea annually, which increased from approximately 900 to 1,100\u0026ndash;1,200 cases since 2013. Furthermore, our data suggest that HIV diagnostic testing has become more widely implemented within certain high-risk populations. A logistic regression model was employed to identify independent demographic and behavioral risk factors associated with RHIs. This revealed that male sex, younger age (under 30 years), Korean nationals, and specific testing purposes such as blood donation and voluntary testing, were significantly associated with RHIs.\u003c/p\u003e \u003cp\u003eThe high proportion of RHIs in certain high-risk groups suggests ongoing transmission and frequent HIV testing behaviors. For example, in Singapore, MSM are known to undergo testing more frequently due to heightened awareness attributed to the effectiveness of government-led sexual health campaigns [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eFindings from recent infection surveys serve as critical indicators for enhancing early HIV detection and improving diagnostic strategies. The present study identified the following groups with lower proportions of RHIs: females (17.1%), foreign nationals (20.3%), and individuals aged 40 years or older (17.4%, 14.4%, and 13.7% among individuals in their 40s, 50s, and 60s or older, respectively). The lower proportion of RHIs among older age groups may reflect reduced exposure to high-risk sexual behaviors or limited access to HIV testing. Conversely, younger individuals had a significantly higher probability of RHIs, with those aged 16\u0026ndash;19 years having a 5.5-fold higher odds and those aged 20\u0026ndash;29 years having a 4.2-fold higher odds of having RHIs compared to individuals aged 60 years and older. The highest RHI proportion according to the HIV testing purpose was observed in the blood donation group (45.8%). This may be explained by the fact that individuals under the age of 30 years accounted for 70% of the blood donation group in this study. Furthermore, since blood donation centers perform HIV-1 RNA testing for all samples from the initial stage of HIV screening, they can diagnose HIV infection earlier than institutions that conduct only antigen/antibody testing. The high RHI proportion in the routine STI screening group (31.5%) likely reflects regular annual HIV testing, as this group is legally required to undergo periodic screening.\u003c/p\u003e \u003cp\u003eThe lower proportion of RHIs among females may be explained by their relatively small representation among newly diagnosed HIV cases in South Korea, where they account for less than 10% of all new diagnoses. Overall, the risk factors identified in this recent infection analysis align with the epidemiological profile of HIV incidence in Korea. Specifically, these findings were consistent with the 2023 HIV/AIDS notification surveillance data, which indicated that 89.9% of newly diagnosed cases were males, while 64.1% of cases were reported among individuals aged in their 20s and 30s.\u003c/p\u003e \u003cp\u003eGlobal efforts to monitor RHIs have revealed significant regional and population-based variability, emphasizing the need for targeted interventions. In the United States, recent infections account for 10\u0026ndash;20% of newly diagnosed cases, with higher rates found among MSM and younger individuals. Similarly, in the United Kingdom, 20\u0026ndash;25% of new diagnoses are classified as RHIs, particularly among MSM and African communities. Studies from Germany, Ireland, Singapore, Ethiopia, and Kenya have further highlighted the importance of recency testing in identifying transmission trends and informing public health strategies [\u003cspan additionalcitationids=\"CR19 CR20 CR21 CR22 CR23\" citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eDespite advancements in HIV surveillance, gaps in testing coverage remain, particularly among racial and ethnic minorities in the United States, where late diagnoses continue to be a challenge. Recency testing has played a crucial role in facilitating earlier care and reducing community-level transmission risks. In the United Kingdom, integrating new HIV diagnoses and late HIV diagnoses data into national surveillance systems has optimized resource allocation in high-prevalence areas, supporting progress toward the UNAIDS 95\u0026ndash;95\u0026ndash;95 targets [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eBeyond surveillance, recent infection testing has significant clinical implications. Acute and early HIV infections are associated with high viral loads and increased transmission risk. Individuals in the early stage of infection are up to 26 times more likely to transmit HIV than are those with chronic infection. Notably, 20\u0026ndash;50% of total HIV transmissions occur during this early period [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. Early identification and treatment can reduce transmission risk, slow disease progression, and prevent complications. The success of public health interventions in the United States and United Kingdom demonstrates the potential for other countries to adopt similar strategies to enhance HIV prevention and control.\u003c/p\u003e \u003cp\u003eThe proportion of non-Korean individuals among all HIV cases in South Korea has steadily increased, from 19.5% in 2020 to 20.7% in 2021, 22.6% in 2022, and 25.5% in 2023. Despite this upward trend, the relatively low proportion of recent infections among non-Korean individuals observed in this study suggests that this group has limited access to HIV testing, potentially leading to a higher prevalence of undiagnosed cases. Addressing these disparities requires targeted policies and programs that promote voluntary HIV testing among non-Korean populations, to facilitate earlier diagnosis and reduce transmission risk.\u003c/p\u003e \u003cp\u003eThis study had some limitations. First, to minimize the impact of FRRs when applying a RITA, we adhered to WHO recommendations by incorporating CD4\u003csup\u003e+\u003c/sup\u003e T-cell counts and data on individuals who died within 1 year of diagnosis. However, CD4\u003csup\u003e+\u003c/sup\u003e T-cell data were available for only 5,607 (74.5%) of the 7,545 samples included in the study, indicating that CD4 test results were limited to these samples. Consequently, some false positives may not have been fully excluded. Nonetheless, all samples analyzed in this study were the first specimens collected from individuals newly diagnosed with HIV, ensuring that they were unaffected by antiretroviral therapy. Second, the WHO/UNAIDS technical guidelines recommend calculating the \u0026ldquo;proportion recent\u0026rdquo; by dividing the number of recent infections by the total number of individuals at risk for HIV, which includes both recent infections and those testing HIV-negative, rather than using only the total number of newly diagnosed cases [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. However, due to the study design, which focused exclusively on confirmed positive samples, we were unable to incorporate data on individuals who tested HIV-negative in South Korea. This limitation may affect the generalizability of our findings to the broader population. Finally, the lack of in-depth epidemiological information associated with each variable made it challenging to interpret the causes or environmental changes related to the analyzed RHI results. These interpretations are expected to be feasible after obtaining relevant epidemiological data in future studies. Despite these constraints, this study holds significant value as it was based on national data covering 7,545 (85%) of the 8,875 newly diagnosed HIV cases reported in South Korea during the study period. This extensive coverage enhances the reliability of our findings and their applicability to understanding the HIV epidemic in Korea.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eBetween 2016 and 2023, 26.1% of newly diagnosed HIV cases were detected within 130 days of acquisition (median: 118\u0026ndash;142 days), indicating that many individuals remained unaware of their infection during the early phase. Expanding education and outreach programs is essential to encourage regular HIV testing among high-risk groups.\u003c/p\u003e \u003cp\u003eThis study identified young Korean males aged less than 30 years as the most at-risk group for HIV infection, while foreign nationals are more likely to experience delayed diagnosis. Improving access to HIV testing for these populations is crucial to reducing transmission risks and strengthening prevention efforts. Under the 2nd National Action Plan on HIV/AIDS Prevention and Control (2024\u0026ndash;2028), the KDCA is expanding HIV testing initiatives for MSM, people who inject drugs, partners of HIV-positive individuals, and foreign nationals to facilitate early detection and linkage to treatment. These efforts align with global goals and support the objective of ending AIDS by 2030. This study underscores the value of recency assays in HIV epidemic control and provides evidence for their importance in public health strategies.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eCompeting interests\u003c/h2\u003e \u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e \u003ch2\u003eEthics declarations\u003c/h2\u003e \u003cp\u003eAll authors hereby declare that all experiments have been reviewed and granted an exemption from ethical approval by the appropriate ethics committee (KDCA Institutional Review Board Ethics Committee; approval number: KDCA-2025-01-02-PE-01). Additionally, the requirement for obtaining informed consent from patients for this study was waived by the KDCA Institutional Review Board.\u003c/p\u003e \u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eJ.-S.W. and M.-G.H. designed and conceived the study, and M.-G.H. supervised all aspects of its implementation. J.-S.W. wrote the first draft of the manuscript. E.J.K., G.K., Y.J.L., H.G.H., and M.K. performed the LAg Avidity assays. N.R.J. and T.-Y.H. analyzed the data. S.K. and H.M.K. coordinated funding for the project. K.K., S.K., and J.Y. operated the national HIV/ AIDS database. All authors have edited and approved the final version of the manuscript.\u003c/p\u003e\u003ch2\u003eAcknowledgements\u003c/h2\u003e \u003cp\u003eThis research was supported by the Korea Disease Control and Prevention Agency (grant No. 6331-301-210)\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eData are available from the corresponding author upon reasonable request and is subject to restrictions.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eJoint United Nations Programme on HIV/AIDS (UNAIDS). 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Inferring population HIV incidence trends from surveillance data of recent HIV infection among HIV testing clients. \u003cem\u003eAIDS\u003c/em\u003e \u003cb\u003e35\u003c/b\u003e, 2383\u0026ndash;2388 (2021).\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"HIV, recency assay, risk factors, HIV-antibody avidity assays, South Korea","lastPublishedDoi":"10.21203/rs.3.rs-6494324/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6494324/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eTo develop targeted prevention strategies, identifying the proportion of individuals newly diagnosed with human immunodeficiency virus (HIV) each year, with the infection acquired within 130 days, is essential. We assessed populations at increased risk of HIV infection and identified those with delayed diagnosis by analyzing the proportion of recent infections among newly diagnosed individuals. HIV-antibody avidity assays were used to distinguish recent from longstanding infections among newly diagnosed cases in 2016\u0026ndash;2023. Logistic regression analysis was used to assess risk factors among demographic and behavioral data, including age, nationality, region, transmission mode, marital status, HIV-testing purpose, and occupation. We investigated 7,545 individuals, representing 85.0% of the 8,875 newly diagnosed HIV-positive cases in 2016\u0026ndash;2023. The average proportion of recent HIV infections (RHIs) throughout the study was 26.1%, being significantly higher among males (26.9%, P\u0026thinsp;=\u0026thinsp;0.034), individuals aged\u0026thinsp;\u0026lt;\u0026thinsp;30 years (38.8%, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001), and Korean nationals (27.3%, P\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Among testing purposes, blood donation screening yielded the highest proportion of RHIs (45.8%). Male sex, age below 30 years, and Korean nationality were identified as main risk factors for HIV infection. The RHI proportion serves as a key indicator of HIV prevention effectiveness in Korea and can inform development of effective prevention strategies.\u003c/p\u003e","manuscriptTitle":"Recent HIV infections and associated risk factors among newly diagnosed individuals in South Korea (2016–2023)","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-05-09 01:52:26","doi":"10.21203/rs.3.rs-6494324/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-05-21T06:45:24+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-05-19T11:03:06+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-05-17T15:32:43+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"177894078340798007046627900728568850280","date":"2025-05-03T07:43:26+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"121476870870899856495753766623088734132","date":"2025-05-03T00:41:45+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-05-02T14:19:53+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-04-25T17:57:46+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-04-22T11:04:37+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-04-21T12:07:13+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2025-04-21T08:45:27+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"858bcd2b-8f56-4783-9614-fcf1dcb2f645","owner":[],"postedDate":"May 9th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":48084286,"name":"Biological sciences/Microbiology"},{"id":48084287,"name":"Health sciences/Diseases"},{"id":48084288,"name":"Health sciences/Health care"},{"id":48084289,"name":"Health sciences/Medical research"}],"tags":[],"updatedAt":"2025-08-07T07:29:01+00:00","versionOfRecord":{"articleIdentity":"rs-6494324","link":"https://doi.org/10.1038/s41598-025-10444-w","journal":{"identity":"scientific-reports","isVorOnly":false,"title":"Scientific Reports"},"publishedOn":"2025-07-19 16:05:45","publishedOnDateReadable":"July 19th, 2025"},"versionCreatedAt":"2025-05-09 01:52:26","video":"","vorDoi":"10.1038/s41598-025-10444-w","vorDoiUrl":"https://doi.org/10.1038/s41598-025-10444-w","workflowStages":[]},"version":"v1","identity":"rs-6494324","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6494324","identity":"rs-6494324","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}