Addressing the Burden and Detection Gap of Latent Tuberculosis Infection in Schoolchildren and Adolescents in China: A Cross-sectional Study

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Previous study and daily surveillance data indicate a LTBI detection gap. The research objective was to evaluate the LTBI burden and detection gap among schoolchildren and adolescents in China. Methods A cross-sectional study was conducted among 69667 schoolchildren and adolescents in Chongqing, China between September 2022 and December 2023 implemented by Chongqing Municipal Institute of Tuberculosis using tuberculin skin test (TST) and creation tuberculin skin test (C-TST). To evaluate the LTBI detection gap, the pulmonary tuberculosis (PTB) screening data implemented by Chongqing Municipal Institute of Tuberculosis have been compared with the data in 2021 implemented by community-level medical and health care institutions. Results the LTBI prevalence rate using TST and C-TST implemented by Chongqing Municipal Institute of Tuberculosis was 12.7% (95%CI, 12.5%-13%) and 6.4% (95%CI, 6%-6.8%) respectively. The LTBI prevalence rate by Chongqing Municipal Institute of Tuberculosis was 9.6% higher than that by community-level medical and health care institutions ( χ 2 = 2931.9, P < 0.001). Conclusions The LTBI detection gap existed among schoolchildren and adolescents in Chongqing, and it also may exist in other similar countries and regions. National screening strategy needs improvement. Regular training and quality assurance could improve the performance of TST and C-TST and close the detection gap of LTBI. Tuberculosis Child Adolescent Latent tuberculosis Tuberculin Test Figures Figure 1 Figure 2 Background Tuberculosis (TB) is the major cause of death in children and adolescents in infectious diseases worldwide. Children and adolescents with LTBI are a large reservoir for active TB, and proactive intervention of LTBI is a key part of the WHO End TB Strategy [ 1 ]. The cumulative number of children treated between 2018 and 2021 was 1.9 million, which was 54% of the five-year target of 3.5 million set at the UN high level meeting in 2018, and preventive treatment target has only been achieved by 42% [ 2 ]. LTBI is defined as a state of being infected with Mycobacterium TB without clinical evidence of active TB [ 3 ]. Sufficient detection of LTBI is the basis of TB prevention and control, especially for schoolchildren and adolescents. China is one of the 30 high TB burden countries, and has the third largest numbers of cases accounting for 7.1% of the global total [ 2 ]. The LTBI burden is still unclear in schoolchildren and adolescents in China. Three national tuberculosis prevalence surveys done in 1990, 2000, and 2010 excluded children under 14 years [ 4 ]. A study has been conducted to estimate the LTBI burden in China in 2021, and the prevalence of LTBI in people five years old and above was 18.1% [ 5 ], but the study did not provide complete LTBI burden in schoolchildren and adolescents. In China, PTB screening in schoolchildren and adolescents is widely carried out at schools. The majority of PTB screening are carried out by community-level medical and health care institutions, which have not received regular standardized training and quality control. This issue has not received adequate attention in provincial tuberculosis prevention and control policies. It was also found that there may be a LTBI detection gap from daily surveillance system and previous investigation. The LTBI burden and detection gap among schoolchildren and adolescents needs comprehensive investigations. Methods Study design This was a cross-sectional study using stratified cluster random sampling, which was conducted among schoolchildren and adolescents in Chongqing, China between September 2022 and December 2023 by Chongqing Municipal Institute of Tuberculosis. A standardized quality control system for active PTB screening was developed. On this basis, we evaluated the LTBI burden and detection gap among schoolchildren and adolescents. According to the local policy of Chongqing, Junior One, Senior One and Senior Two students should be screened for active PTB. The participants were tested using TST or novel skin tests for tuberculosis infection (TBST). TST remains the most widely used tool at a global scale. According to China national diagnostic criteria for TB [ 6 ], the results of TST are divided into four levels: negative(the induration average diameter < 5mm), generally positive(5mm ≤ the induration average diameter < 10mm), moderately positive(10mm ≤ the induration average diameter < 15mm), and strongly positive(the induration average diameter ≥ 15mm). Bacillus Calmette-Guérin (BCG) vaccination at birth is a national policy in China, and coverage has been at a high level, which might interfere with TST reactivity. Considering this, the TST induration cut-off point of ≥ 15mm was used to indicate TB infection in school [ 7 , 8 ]. C-TST is a type of TBST, which uses a new type of recombinant fusion protein that only contains Mycobacterium TB early secretory antigen target six (STAT-6) and culture filtrate protein ten (CFP10), and exposure to previous BCG vaccine will not interfere with the C-TST reactivity. The C-TST induration or erythema cut-off point of ≥ 5mm has been commonly recommended for TB infection. TST or C-TST has been selected according to the wishes of local health department and schools. The annual risk of tuberculous infection (ARTI) was evaluated, which was the probability of acquiring new tuberculous infection over a period of one year. In the classical approach, the annual rate of infection was estimated using the equation: P is the TST strongly positive rate or C-TST positive rate, and age is the mean age of the cohort [ 9 ]. Sample Size According to the the previous PTB screening investigation in schoolchildren and adolescents by Chongqing Municipal Institute of Tuberculosis, the LTBI prevalence rate is about 15%. The sample size was estimated at 13401 schoolchildren and adolescents using the following formula, based on the expected LTBI prevalence rate of 15%, the allowable error of 1%, and the significance level of 5%. Randomisation and Cluster Selection This study used stratified cluster random sampling. According to the division of local government, there were four regions in Chongqing including: the Central Urban Districts, New West Urban Development Districts, Northeast Districts and Southeast Districts. These regions were different in terms of socioeconomic development. Clusters were defined as middle schools located in the four districts. Each cluster had at least 500 participants registered between September 2022 and December 2023. Study participants The inclusion criteria were as follows: (1) participants in school at least ten years old, and (2) participants who can participate in the entire PTB screening process. The exclusion criteria were as follows: (1) participants with allergic constitution, (2) participants with acute infectious diseases or other diseases judged by doctors that TST or C-TST can not be performed, (3) participants who have been vaccinated in the last month, (4) previous TB patients, and (5) TST or C-TST has been implemented in the last three months. According to the inclusion and exclusion criteria, participants were continuously selected from the selected clusters until they were fully enrolled. Procedures Standardized training was provided for all medical workers involved in this study, including public health and clinical theory, as well as TST and C-TST practical skill. The trainees were assessed, and only those who pass the assessment can implement PTB screening. For each enrolled participant, socio-demographic information was collected, including age, gender and educational level. PTB screening mainly includes a consultation on close contact history with PTB patients and suspicious symptoms of PTB, a TST test/C-TST test, and a chest X-ray examination. TST and C-TST were was performed according to the Mantoux technique. When performing TST (Purified Protein Derivative of Tuberculin; Xiang Rui, China or Chengdu Institute of Biology, China), 0.1 mL (5IU) purified protein derivative of tuberculin was injected on the volar surface of the left forearm intradermally. The induration was measured in millimeter after 72 hours at injection sites. When performing C-TST (Recombinant Mycobacterium Tuberculosis Fusion Protein; Zhifei Longcom Biologic Pharmacy Company, Anhui, China), 0.1 mL (5U) recombinant mycobacterium TB fusion protein was injected on the volar surface of the left forearm intradermally. The induration or erythema was measured in millimeter after 48 hours at injection sites. Digital chest radiography was performed on each participant with suspected symptoms of PTB, who was TST strong positive or C-TST positive, and who met the exclusion criteria. Those with abnormal digital chest radiography went to designated medical institutions for further examination. The LTBI detection gap To evaluate LTBI detection gap, we collected PTB screening data implemented by community-level medical and health care institutions in the same schools selected in this study in 2021, which have been compared with the data implemented by Chongqing Municipal Institute of Tuberculosis between September 2022 and December 2023. Statistical analysis We calculated the proportion and 95% CI for the LTBI prevalence rate, which was the proportion of schoolchildren and adolescents with LTBI excluding active PTB. Different LTBI prevalence rates were tested using chi-square test. The trend of rate was tested using chi-square test for linear trend. Some participants were unable to verify the TST or C-TST results due to leave or other reasons, resulting in missing data. To evaluate the impact of missing data, we compared the distribution of gender, grade, region and school type between participants with and without the TST or C-TST results by chi-square test. A two-sided P < 0.05 was taken as statistically significant. Statistical analyses were performed with the SPSS 22.0 software (SPSS, Inc., Chicago, IL, USA). Results The screening process for participants There were 69667 participants in 51 schools in Chongqing between September 2022 and December 2023, and 4786 (6.9%) were excluded for various reasons leaving 64881 (93.1%) participants with TST or C-TST result (Fig. 1 ). There are 41 schools using TST (48583 participants with results), and ten schools using C-TST (16298 participants with results). Participants who were unable to verify the TST or C-TST results due to leave or other reasons were excluded from statistical analysis considering that these missing data were completely random and had a low proportion of 0.4% (279/65160). In addition, there was no difference in the distribution of gender, grade, region and school type between participants with and without the TST or C-TST results (appendix p 2). PTB screening results The LTBI prevalence rate using TST and C-TST was 12.7% (95%CI, 12.5%-13%) and 6.4% (95%CI, 6%-6.8%) respectively (Tables 1 and 2 ). The LTBI prevalence rate using TST was significantly higher than that using C-TST ( χ 2 = 492.7, P < 0.001). Table 1 Schoolchildren and adolescents PTB screening results using TST by our PTB screening team between September 2022 and December 2023 in Chongqing Characteristics Subgroup TST Participants with TST implemented Participants without result TST Strongly Positive Active PTB LTBI prevalence rate 95% CI Gender Male 25295 94 2969 8 11.8% 11.4%-12.2% Female 23487 105 3240 8 13.8% 13.4%-14.3% Grade Junior One 6921 30 575 1 8.3% 7.7%-9% Senior One 20700 88 2475 3 12% 11.6%-12.4% Senior Two 21161 81 3159 12 14.9% 14.5%-15.4% Region Central Urban Districts 18778 84 2382 2 12.7% 12.3%-13.2% New West Urban Development Districts 13875 63 1800 1 13% 12.5%-13.6% Northeast Districts 6755 24 469 3 6.9% 6.3%-7.5% Southeast Districts 9374 28 1558 10 16.6% 15.8%-17.3% School type Public school 33868 150 4096 13 12.1% 11.8%-12.5% Private school 14914 49 2113 3 14.2% 13.6%-14.8% Total 48782 199 6209 16 12.7% 12.5%-13% Table 2 Schoolchildren and adolescents PTB screening results using C-TST by by our PTB screening team between September 2022 and December 2023 in Chongqing Characteristics Subgroup C-TST Participants with C-TST implemented Participants without result C-TST Positive Active PTB LTBI prevalence rate 95% CI Gender Male 8897 45 603 8 6.7% 6.2%-7.2% Female 7481 35 454 3 6.1% 5.5%-6.6% Grade Junior One 746 5 36 0 4.9% 3.3%-6.4% Senior One 7410 45 448 4 6% 5.5%-6.6% Senior Two 8222 30 573 7 6.9% 6.4%-7.5% Region Central Urban Districts 4255 21 162 1 3.8% 3.2%-4.4% New West Urban Development Districts - - - - - - Northeast Districts 2664 14 147 0 5.5% 4.7%-6.4% Southeast Districts 9449 35 748 10 7.8% 7.3%-8.4% School type Public school 11837 54 864 10 7.3% 6.8%-7.7% Private school 4541 26 193 1 4.3% 3.7%-4.8% Total 16378 80 1057 11 6.4% 6%-6.8% The detection rate of active PTB in participants using TST was 32.9 cases per 100000 population (16/48583), and the detection rate of active PTB in participants using C-TST was 67.5 cases per 100000 population (11/16298). There was not a significant difference in detection rate of active PTB in participants using TST or C-TST ( χ 2 = 3.5, P = 0.06). The TST strongly positive rate has increased significantly from 8.3% in Junior One to 15% in Senior Two ( χ 2 trend = 223.6, P < 0.001) .The C-TST positive rate has also increased significantly from 4.9% in Junior One to 7% in Senior Two ( χ 2 trend = 8.6, P = 0.003) . The LTBI detection gap There were 47320 participants with TST result in the same schools of this study in 2021. The LTBI prevalence rate using TST by community-level medical and health care institutions was 3.2% (95%CI, 3.1%-3.4%) in 2021 (Table 3 ). Table 3 Schoolchildren and adolescents PTB screening results using TST by community-level medical and health care institutions in 2021 in Chongqing Characteristics Subgroup TST Participants with result TST Strongly Positive Active PTB LTBI prevalence rate 95% CI χ 2 P ‡ Grade Junior One 7233 201 1 2.8% 2.4%-3.1% 211 < 0.001 Senior One 24397 629 1 2.6% 2.4%-2.8% 1545.8 < 0.001 Senior Two 15690 702 0 4.5% 4.2%-4.8% 1050.2 < 0.001 Region Central Urban Districts 5901 104 0 1.8% 1.4%-2.1% 594.4 < 0.001 New West Urban Development Districts 20659 969 0 4.7% 4.4%-5% 778.7 < 0.001 Southeast Districts 12174 133 2 1.1% 0.9%-1.3% 473.7 < 0.001 Northeast Districts 6718 149 0 2.2% 1.9%-2.6% 857.5 < 0.001 School type Public school 37025 1319 2 3.6% 3.4%-3.7% 1831.8 < 0.001 Private school 10295 213 0 2.1% 1.8%-2.3% 1067.4 < 0.001 Total 47320 1532 2 3.2% 3.1%-3.4% 2931.9 < 0.001 The LTBI prevalence rate by Chongqing Municipal Institute of Tuberculosis was 9.6% higher than that by community-level medical and health care institutions( χ 2 = 2931.9, P < 0.001), and there were also similar trends in LTBI prevalence rate in each subgroup (Fig. 2 ). The risk factors associated with LTBI were analyzed, and the LTBI prevalence rate in Southeast Districts by Chongqing Municipal Institute of Tuberculosis was the highest (appendix p 3). The LTBI detection gap in Southeast Districts was also the greatest, reaching 15.5%. The ARTI of schoolchildren and adolescents the ARTI using TST and C-TST was 0.9% (95%CI, 0.8%-1%) and 0.4% (95%CI, 0.3%-0.5%) respectively ( Table 4 ). Table 4 ARTI in schoolchildren and adolescents between September 2022 and December 2023 in Chongqing Subgroup TST C-TST mean age ± s ARTI 95% CI χ 2 P mean age ± s ARTI 95% CI χ 2 P Male 15.6 ± 1.4 0.8% 0.7%-0.9% 3.4 0.07 15.9 ± 1.1 0.4% 0.3%-0.6% 0.14 0.81 Female 15.5 ± 1.5 1.0% 0.8%-0.11% 15.8 ± 1.1 0.4% 0.3%-0.5% Junior One 12.7 ± 0.9 0.7% 0.5%-0.9% 6.2 0.04 13 ± 1.6 0.4% 0.1%-0.9% 0.1 0.95 Senior One 15.5 ± 0.7 0.8% 0.7%-0.9% 15.6 ± 0.8 0.4% 0.3%-0.6% Senior Two 16.5 ± 0.8 1% 0.8%-1.1% 16.3 ± 0.7 0.4% 0.3%-0.6% Central Urban Districts 15.2 ± 1.7 0.9% 0.8%-1% 23.8 < 0.001 15.9 ± 0.8 0.2% 0.1%-0.4% 6.14 0.04 New West Urban Development Districts 16.1 ± 0.9 0.9% 0.7%-1.1% - - - Northeast Districts 15.9 ± 0.9 0.5% 0.3%-0.6% 16.1 ± 1.1 0.4% 0.1%-0.6% Southeast Districts 15.3 ± 1.6 1.2% 1%-1.6% 15.8 ± 1.2 0.5% 0.4%-0.7% Public school 15.1 ± 1.5 0.9% 0.8%-1% 0.65 0.43 15.9 ± 1.1 0.5% 0.4%-0.6% 3.4 0.08 Private school 16.4 ± 0.8 0.9% 0.8%-1% 15.8 ± 1 0.3% 0.1%-0.4% Total 15.6 ± 1.5 0.9% 0.8%-1% 15.9 ± 1.1 0.4% 0.3%-0.5% There was a significant difference in ARTI using TST among different grades ( χ 2 = 6.2, P = 0.04), and the ARTI in Senior Two was the highest. There was also a significant difference in ARTI using TST in different regions ( χ 2 = 23.8, P < 0.001), and the ARTI in Southeast Districts was the highest. There was also a significant difference in ARTI using C-TST in different regions ( χ 2 = 6.1, P = 0.04), and the ARTI in Southeast Districts was the highest. Discussion One key challenge in TB prevention and control is to accurately find students infected with TB among schoolchildren and adolescents. Through this study, we have obtained accurate LTBI burden among them in Chongqing. In this study, the LTBI prevalence rate conducted by Chongqing Municipal Institute of Tuberculosis using TST between September 2022 and December 2023 was 9.6% higher than the results conducted by community-level medical and health care institutions in the same schools in 2021. The quality of PTB screening implemented by community-level medical and health care institutions may be poor. The reduction of the reported number of TST strong positive schoolchildren and adolescents has significantly decreased the detection of active PTB and LTBI, which may result in more community transmission. According to Statistical Bulletin on National Economic and Social Development in Chongqing of 2021, the total number of middle school students in Chongqing was 1.77 million, which may mean a LTBI detection gap of 0.17 million middle school students who were not detected and intervened timely in Chongqing. This detection gap may not happen only in Chongqing. A study found that the TST strong positive rate was 2.69% among 16795 freshmen in senior high schools and boarding junior high schools in 2019 in Ningbo, Zhejiang Province, China [ 10 ], and the TST strong positive rate was 1.45% among 78102 freshmen in the same population of the same area in 2021 [ 11 ]. The PTB screening among 220269 freshmen in senior high schools and boarding junior high schools showed that the TST strong positive rate was 1.70% from 2016 to 2020 in Liuzhou, Guangxi Province, China [ 12 ]. The TST strong positive rate was 0.36% among 20153 students in Longgang District, Shenzhen, China in 2021 [ 13 ]. Two studies in Beijing showed that the TST strong positive rate was 2.59% among 6187 freshmen in 2018, and 1.86% among 12562 freshmen in 2020 respectively [ 14 , 15 ]. The TST strong positive rates in these studies were lower than our results, which may be due to the lower PTB burden in these regions or the existence of a LTBI detection gap. The reported incidence rate of active PTB was about 48 cases per 100000 population in Chongqing, which currently ranks 13th among all provinces in 2023 in China according to national TB surveillance system, and the reported PTB incidence rate of the above provinces was about 23–68 cases per 100000 population. It was unreasonable to explain such a low TST strong positive rate using the reason that the PTB burden in these regions was far lower than that in Chongqing. Our study conducted standardized training for medical workers. During the training process, it was found that the reasons for this detection gap may include non-standard TST administration and inaccurate TST result reading, and inaccurate TST reading may have the greatest impact on this detection gap, which may be due to the reader's incorrect understanding of the operation rules and rusty practical skills. Research on TST quality control is rare. A study has noticed the limitations of TST quality, which included reader variability and the need for trained personnel to read the results [ 16 ]. A study has found that TST reading results vary very much between readers [ 17 ]. Although a large number of schoolchildren and adolescents underwent TST every year, the TST quality might be seriously underestimated. With the development of information technology, intelligent software for TST or TBST result reading may also be developed to improve the accuracy. Regular training and quality assurance are needed to establish, and maintaining proficiency is equally important. A study has found that mhealth approach using smartphone may be a method that could serve as a TST training and quality control tool in many settings [ 18 ]. This study used two skin test methods, TST and C-TST. However, C-TST was approved for TB diagnosis in China in 2020, and has not been widely used in China. This study obtained the LTBI prevalence rate using C-TST, and the C-TST positive rate was lower than the TST strong positive rate. BCG vaccination might have accounted for a considerable proportion of positive TST [ 19 ]. A study using C-TST showed that the positive rate was 10.14% (14/157) in 2022 in a high school in southeast of Chongqing [ 20 ]. YANG Zhen et al [ 21 ] have found that C-TST positive rate was 9.1% among 1924 college students in 2022 in Beijing, China. MU Tingmei et al [ 22 ] showed that C-TST positive rate was 0.97% among 7416 junior middle school students and 1.1% among 2555 high school students respectively in 2021 in Yaan City, Sichuan Province, China. There were still differences in the C-TST positive rates conducted in different regions, and there was also a possibility of LTBI detection gap. The TST strongly positive rate and C-TST positive rate has increased significantly from Junior One to Senior Two in Chongqing. Other studies have also shown that the TST positive rate has increased with age in schoolchildren and adolescents [ 10 , 11 , 12 , 14 ]. Most provinces of China do not implement PTB screening for Senior Two in high school, and it is important to add a PTB screening in Senior Two, so as to prevent students from being unable to participate in the college entrance examination because of PTB. In 2022, the reported PTB incidence rate of schoolchildren and adolescents aged 10–19 of Chongqing was 23.77 cases per 100000 population per year according to the national TB surveillance system, which was less than the actual incidence rate. In this study, the overall prevalence of LTBI using TST was 12.7% (95% CI, 12.5%-13%) with a corresponding ARTI of 0.9% (95% CI, 0.8%-1%). If we assume 5% rapid progression from recent infection to active TB [ 23 ], and 0.05% annual progression rate from remote infection to active TB [ 24 ], incidence rate can be measured: 0.9%×5%+12.7%×0.05%=51.4 cases per 100000 population per year [ 9 ]. According to a study in Chongqing in 2021, the PTB screening proportion of freshmen in middle school is only 42.4%, indicating that there were still some PTB patients who have not been found in time [ 25 ]. Under these assumptions, the ARTI obtained in this study using TST may reflect the current situation. Using the same method, estimated incidence rate using C-TST was 23.2 cases per 100000 population per year. The estimated incidence rate using C-TST may be underestimated using the Styblo’s rule [ 23 , 26 ]. Considering the universal vaccination of BCG in China and the lower false positive rate of C-TST, the progression rate should be higher than 5% in LTBI using C-TST [ 26 ]. This study has limitations. There were no schools in Northeast Districts that conducted C-TST. The PTB screening in schoolchildren and adolescents has not been systematically implemented before 2022, resulting in the data from routine surveillance system were limited. Lack of gender and some information in routine surveillance system before 2022 made it impossible to conduct related analysis. This study obtained accurate LTBI burden using TST and C-TST in schoolchildren and adolescents in Chongqing, China. The LTBI detection gap existed among schoolchildren and adolescents in Chongqing, and it also may exist in other similar countries and regions, which may lead to more TB infections and morbidity. This situation must attract high attention from decision-makers. The staff of community-level medical and health care institutions need to receive regular standardized training and quality control to maintain the skill proficiency. These measures should be included in national tuberculosis prevention and control policies. Intelligent software for the result reading of TST and TBST should be developed, along with the development of mhealth systems capable of conducting quality control, which could help to enhance the PTB screening capabilities in areas with limited medical resources. In conclusion, obtaining accurate LTBI burden in schoolchildren and adolescents is crucial to develop effective TB prevention and control policies. Taking necessary measures could significantly improve the quality of TST and TBST, and close the detection gap of LTBI. Abbreviations WHO World Health Organization LTBI Latent Tuberculosis Infection TST Tuberculin Skin Test C-TST Creation Tuberculin Skin Test TB Tuberculosis PTB Pulmonary Tuberculosis TBST Novel Skin Tests for Tuberculosis Infection BCG Bacillus Calmette-Guérin STAT-6 Secretory Antigen Target Six CFP10 Culture Filtrate Protein Ten ARTI The Annual Risk of Tuberculous Infection Declarations Ethics approval and consent to participate The study was approved by the ethics committees of Chongqing Municipal Institute of Tuberculosis (202202, 26 September 2022). As we were carrying out a data analysis based on mandatory physical examinations and all individual information was removed before analysis, we were not required to obtain written informed consent from participants. Consent for publication Not applicable. Availability of data and materials The PTB screening data of this study has been stored in the the provincial TB surveillance system but restrictions apply to the availability of these data, which were used under license for the current study, and so are not publicly available. Data are however available from the corresponding author upon reasonable request and with permission of the provincial TB surveillance system. Competing interests The authors declare that they have no competing interests. Funding The data collection and data analysis of the study was supported by Chongqing Science and Health Joint Research Project (2023ZDXM027 and 2023MSXM143), Chongqing Health Commission Medical Science Research Project (2024WSJK08), and Chongqing Public Health Key Specialties (Disciplines) Construction Fund. Authors' contributions JF, JYZ, BW, and YY designed the study. CGW, YLS, YL, JY, QS, ZZ, XH, and MW were involved in conducting the study. BW, YY, JY, QS and YP were involved in data analysis. BW and YY wrote the draft manuscript. BW, YY, JY, and QS had access to and verified the existence of the raw data. All authors read and approved the final manuscript before submission. JF was responsible for the decision to submit the manuscript. Acknowledgments We thank the field workers and the study nurses Jinshan Qian, Jia Luo, Xianhui Feng, Xuemei Feng, Jin Wu, Yanping Feng, Cuimei Yue, Shanshan Liu, Huli Pan, and Yanjun Feng. References Uplekar M, Weil D, Lonnroth K, Jaramillo E, Lienhardt C, Dias HM, et al. WHO’s new end TB strategy. Lancet. 2015;385(9979):1799-801. World Health Oragnization. Global tuberculosis report 2023. Geneva, Switzerland: World Health Organization. 2023. https://www.who.int/publications/i/item/9789240083851. Accessed March 10, 2024. World Health Organization. Latent tuberculosis infection: updated and consolidated guidelines for programmatic management. 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Problems about tuberculin skin test raised from consultations and countermeasures--influence to the interpretation of tuberculin skin test in case of the stoppage of BCG revaccination abolition and the introduction of induration measurement. Kekkaku. 2002;77(10):639-645. Saeedeh MN, Leila B, Olivia O, Chantal V, Mei-Xin L, Jonathon RC. The mTST-An mHealth approach for training and quality assurance of tuberculin skin test administration and reading. PLoS One. 2019;14(4):e0215240. doi: 10.1371/journal.pone.0215240. Ben JM. Mycobacterium tuberculosis infection burden in poor urban communities. Lancet Child Adolesc Health. 2018;2(1):7-8. Su Q, Wang QY, Zhang T, Liu Y. Comparison of recombinant Mycobacterium tuberculosis fusion protein skin test and tuberculin skin test for screening latent tuberculosis infection in school students. Chinese Journal of Infection Control. 2023;22 (5):547-551. Yang Z, Sun Q, Han L, Bao C, Wang X, Zhang ZG. Analysis of recombinant mycobacterium tuberculosis fusion protein in screening for latent tuberculosis infection in college students. Chinese Journal of the Frontiers of Medical Science. 2022;14(07):51-54. Mu TM, Hu QY, Li W, Feng Y, Wang XG. Analysis of recombinant mycobacterium tuberculosis fusion protein in screening for latent tuberculosis infection in college students. Parasitoses and Infectious Diseases. 2022;3:166-170. Styblo K. The relationship between the risk of tuberculous infection and the risk of developing infectious tuberculosis. Bull Int Union Tuberc Lung Dis. 1985;60:117-119. Horsburgh CJ, O’Donnell M, Chamblee S, Moreland JL, Johnson J, Marsh BJ, et al. Revisiting rates of reactivation tuberculosis: a population-based approach. Am J Respir Crit Care Med. 2010;182:420-425. Pang Y, Wu CG, Wang QY, Zhang T. Screening results of tuberculosis among new students in Chongqing Municipality, 2021. Practical Preventive Medicine. 2023;30(02):165-168. Dye C. Breaking a law: tuberculosis disobeys Styblo’s rule.Bull World Health Organ. 2008;86:4. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 16 Sep, 2024 Read the published version in BMC Infectious Diseases → Version 1 posted Editorial decision: Revision requested 29 Apr, 2024 Submission checks completed at journal 27 Apr, 2024 Editor assigned by journal 27 Apr, 2024 First submitted to journal 24 Apr, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-4320976","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":296586212,"identity":"64d68b7a-a461-40fa-ad50-82557213bba9","order_by":0,"name":"Bo Wu","email":"","orcid":"","institution":"Chongqing Municipal Institute of Tuberculosis","correspondingAuthor":false,"prefix":"","firstName":"Bo","middleName":"","lastName":"Wu","suffix":""},{"id":296586214,"identity":"20d06682-3206-4343-a448-b13c93f8140d","order_by":1,"name":"Ya Yu","email":"","orcid":"","institution":"Chongqing Municipal Institute of Tuberculosis","correspondingAuthor":false,"prefix":"","firstName":"Ya","middleName":"","lastName":"Yu","suffix":""},{"id":296586215,"identity":"543f9a9b-7ec2-4cca-9f46-dffccc5f2394","order_by":2,"name":"Chengguo Wu","email":"","orcid":"","institution":"Chongqing Municipal Institute of Tuberculosis","correspondingAuthor":false,"prefix":"","firstName":"Chengguo","middleName":"","lastName":"Wu","suffix":""},{"id":296586223,"identity":"ecae9fb7-135e-449c-a354-cefcae1c2c02","order_by":3,"name":"Yaling Shi","email":"","orcid":"","institution":"Chongqing Municipal Institute of Tuberculosis","correspondingAuthor":false,"prefix":"","firstName":"Yaling","middleName":"","lastName":"Shi","suffix":""},{"id":296586224,"identity":"bf7ed37b-6346-44f8-9e2a-9c749507de4b","order_by":4,"name":"Ying Liu","email":"","orcid":"","institution":"Chongqing Municipal Institute of 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Tuberculosis","correspondingAuthor":false,"prefix":"","firstName":"Zhengyu","middleName":"","lastName":"Zhang","suffix":""},{"id":296586229,"identity":"15992c1b-8ce7-4169-bbcb-3d2764f8c746","order_by":8,"name":"Xueyong Huang","email":"","orcid":"","institution":"Chongqing Municipal Institute of Tuberculosis","correspondingAuthor":false,"prefix":"","firstName":"Xueyong","middleName":"","lastName":"Huang","suffix":""},{"id":296586231,"identity":"0c704cf2-d39c-49ac-96c9-87d754489fa4","order_by":9,"name":"Mei Wang","email":"","orcid":"","institution":"Chongqing Municipal Institute of Tuberculosis","correspondingAuthor":false,"prefix":"","firstName":"Mei","middleName":"","lastName":"Wang","suffix":""},{"id":296586236,"identity":"a4f64eb3-ab65-480e-be94-f7890c32e67a","order_by":10,"name":"Yan Pang","email":"","orcid":"","institution":"Chongqing Municipal Institute of Tuberculosis","correspondingAuthor":false,"prefix":"","firstName":"Yan","middleName":"","lastName":"Pang","suffix":""},{"id":296586238,"identity":"4631403f-72f2-4919-b916-4a06d4898fa9","order_by":11,"name":"Jiyuan Zhong","email":"","orcid":"","institution":"Chongqing Municipal Institute of Tuberculosis","correspondingAuthor":false,"prefix":"","firstName":"Jiyuan","middleName":"","lastName":"Zhong","suffix":""},{"id":296586240,"identity":"715c9a3b-2d5e-43e0-aaed-6e80cabfe05e","order_by":12,"name":"Jun Fan","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA3klEQVRIiWNgGAWjYBACNv7GhgMfKmrk2NibDz5IqKghrIVP4nDjwxlnjhnz8xxLNnhw5hhhLXIM6c3GvG3MiTNn5JhJPmxhJsJhDAfbJGe2sSVuOJBgVpHYwMbA396dgF8Lc2ObxIdzMsYbDhxIu5G4Q4ZB4szZDYRtmVHGJrvhYMOxG4ln2BgMJHIJaUlsk+ZhY2bccJixrSCxjZkoLc3GPG3MijPbmEHaidEicRAWyGzMEglnjvEQ9It8f/sDSFTKv//48QeQwd/ei18LBuAhTfkoGAWjYBSMAqwAAJSOUEv42HPMAAAAAElFTkSuQmCC","orcid":"","institution":"Chongqing Municipal Institute of Tuberculosis","correspondingAuthor":true,"prefix":"","firstName":"Jun","middleName":"","lastName":"Fan","suffix":""}],"badges":[],"createdAt":"2024-04-25 02:36:17","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4320976/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4320976/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s12879-024-09812-0","type":"published","date":"2024-09-16T15:57:19+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":55720819,"identity":"9df3b844-88de-4625-9846-0f1f1f8c72b5","added_by":"auto","created_at":"2024-05-02 08:53:30","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":1254593,"visible":true,"origin":"","legend":"\u003cp\u003eThe flow chat of participants screened for LTBI between September 2022 and December 2023 in Chongqing\u003c/p\u003e","description":"","filename":"Figure1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4320976/v1/ecc6a345b905f26dec0040d5.jpg"},{"id":55720821,"identity":"fe6c5a13-0daa-4d28-b019-748e026f531a","added_by":"auto","created_at":"2024-05-02 08:53:30","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":970822,"visible":true,"origin":"","legend":"\u003cp\u003eThe LTBI detection gap of schoolchildren and adolescents in Chongqing\u003c/p\u003e","description":"","filename":"Figure2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4320976/v1/ad87e2d41003508f759fb8c9.jpg"},{"id":65103984,"identity":"536332a3-7723-45c4-a389-467f63e45cd8","added_by":"auto","created_at":"2024-09-23 16:10:26","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1128887,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4320976/v1/60557a48-ac48-4fad-8544-a6efe6c1f1ce.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Addressing the Burden and Detection Gap of Latent Tuberculosis Infection in Schoolchildren and Adolescents in China: A Cross-sectional Study","fulltext":[{"header":"Background","content":"\u003cp\u003eTuberculosis (TB) is the major cause of death in children and adolescents in infectious diseases worldwide. Children and adolescents with LTBI are a large reservoir for active TB, and proactive intervention of LTBI is a key part of the WHO End TB Strategy [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe cumulative number of children treated between 2018 and 2021 was 1.9\u0026nbsp;million, which was 54% of the five-year target of 3.5\u0026nbsp;million set at the UN high level meeting in 2018, and preventive treatment target has only been achieved by 42% [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. LTBI is defined as a state of being infected with Mycobacterium TB without clinical evidence of active TB [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Sufficient detection of LTBI is the basis of TB prevention and control, especially for schoolchildren and adolescents.\u003c/p\u003e \u003cp\u003eChina is one of the 30 high TB burden countries, and has the third largest numbers of cases accounting for 7.1% of the global total [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. The LTBI burden is still unclear in schoolchildren and adolescents in China. Three national tuberculosis prevalence surveys done in 1990, 2000, and 2010 excluded children under 14 years [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. A study has been conducted to estimate the LTBI burden in China in 2021, and the prevalence of LTBI in people five years old and above was 18.1% [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e], but the study did not provide complete LTBI burden in schoolchildren and adolescents.\u003c/p\u003e \u003cp\u003eIn China, PTB screening in schoolchildren and adolescents is widely carried out at schools. The majority of PTB screening are carried out by community-level medical and health care institutions, which have not received regular standardized training and quality control. This issue has not received adequate attention in provincial tuberculosis prevention and control policies. It was also found that there may be a LTBI detection gap from daily surveillance system and previous investigation. The LTBI burden and detection gap among schoolchildren and adolescents needs comprehensive investigations.\u003c/p\u003e"},{"header":"Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\n \u003ch2\u003eStudy design\u003c/h2\u003e\n \u003cp\u003eThis was a cross-sectional study using stratified cluster random sampling, which was conducted among schoolchildren and adolescents in Chongqing, China between September 2022 and December 2023 by Chongqing Municipal Institute of Tuberculosis. A standardized quality control system for active PTB screening was developed. On this basis, we evaluated the LTBI burden and detection gap among schoolchildren and adolescents.\u003c/p\u003e\n \u003cp\u003eAccording to the local policy of Chongqing, Junior One, Senior One and Senior Two students should be screened for active PTB. The participants were tested using TST or novel skin tests for tuberculosis infection (TBST). TST remains the most widely used tool at a global scale. According to China national diagnostic criteria for TB [\u003cspan class=\"CitationRef\"\u003e6\u003c/span\u003e], the results of TST are divided into four levels: negative(the induration average diameter \u0026lt; 5mm), generally positive(5mm ≤ the induration average diameter \u0026lt; 10mm), moderately positive(10mm ≤ the induration average diameter \u0026lt; 15mm), and strongly positive(the induration average diameter ≥ 15mm). Bacillus Calmette-Guérin (BCG) vaccination at birth is a national policy in China, and coverage has been at a high level, which might interfere with TST reactivity. Considering this, the TST induration cut-off point of ≥ 15mm was used to indicate TB infection in school [\u003cspan class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e8\u003c/span\u003e].\u003c/p\u003e\n \u003cp\u003eC-TST is a type of TBST, which uses a new type of recombinant fusion protein that only contains Mycobacterium TB early secretory antigen target six (STAT-6) and culture filtrate protein ten (CFP10), and exposure to previous BCG vaccine will not interfere with the C-TST reactivity. The C-TST induration or erythema cut-off point of ≥ 5mm has been commonly recommended for TB infection. TST or C-TST has been selected according to the wishes of local health department and schools.\u003c/p\u003e\n \u003cp\u003eThe annual risk of tuberculous infection (ARTI) was evaluated, which was the probability of acquiring new tuberculous infection over a period of one year. In the classical approach, the annual rate of infection was estimated using the equation:\u003c/p\u003e\n \u003cp\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cimg src=\"data:image/png;base64,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\" width=\"198\" height=\"50\"\u003e\u003c/span\u003e\u003cbr\u003e\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eP\u003c/em\u003e is the TST strongly positive rate or C-TST positive rate, and \u003cem\u003eage\u003c/em\u003e is the mean age of the cohort [\u003cspan class=\"CitationRef\"\u003e9\u003c/span\u003e].\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec4\" class=\"Section2\"\u003e\n \u003ch2\u003eSample Size\u003c/h2\u003e\n \u003cp\u003eAccording to the the previous PTB screening investigation in schoolchildren and adolescents by Chongqing Municipal Institute of Tuberculosis, the LTBI prevalence rate is about 15%. The sample size was estimated at 13401 schoolchildren and adolescents using the following formula, based on the expected LTBI prevalence rate of 15%, the allowable error of 1%, and the significance level of 5%.\u003c/p\u003e\n \u003cp\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cimg src=\"data:image/png;base64,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\"\u003e\u003c/span\u003e\u003cbr\u003e\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e\n \u003ch2\u003eRandomisation and Cluster Selection\u003c/h2\u003e\n \u003cp\u003eThis study used stratified cluster random sampling. According to the division of local government, there were four regions in Chongqing including: the Central Urban Districts, New West Urban Development Districts, Northeast Districts and Southeast Districts. These regions were different in terms of socioeconomic development. Clusters were defined as middle schools located in the four districts. Each cluster had at least 500 participants registered between September 2022 and December 2023.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec6\" class=\"Section2\"\u003e\n \u003ch2\u003eStudy participants\u003c/h2\u003e\n \u003cp\u003eThe inclusion criteria were as follows: (1) participants in school at least ten years old, and (2) participants who can participate in the entire PTB screening process. The exclusion criteria were as follows: (1) participants with allergic constitution, (2) participants with acute infectious diseases or other diseases judged by doctors that TST or C-TST can not be performed, (3) participants who have been vaccinated in the last month, (4) previous TB patients, and (5) TST or C-TST has been implemented in the last three months.\u003c/p\u003e\n \u003cp\u003eAccording to the inclusion and exclusion criteria, participants were continuously selected from the selected clusters until they were fully enrolled.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e\n \u003ch2\u003eProcedures\u003c/h2\u003e\n \u003cp\u003eStandardized training was provided for all medical workers involved in this study, including public health and clinical theory, as well as TST and C-TST practical skill. The trainees were assessed, and only those who pass the assessment can implement PTB screening.\u003c/p\u003e\n \u003cp\u003eFor each enrolled participant, socio-demographic information was collected, including age, gender and educational level.\u003c/p\u003e\n \u003cp\u003ePTB screening mainly includes a consultation on close contact history with PTB patients and suspicious symptoms of PTB, a TST test/C-TST test, and a chest X-ray examination.\u003c/p\u003e\n \u003cp\u003eTST and C-TST were was performed according to the Mantoux technique. When performing TST (Purified Protein Derivative of Tuberculin; Xiang Rui, China or Chengdu Institute of Biology, China), 0.1 mL (5IU) purified protein derivative of tuberculin was injected on the volar surface of the left forearm intradermally. The induration was measured in millimeter after 72 hours at injection sites.\u003c/p\u003e\n \u003cp\u003eWhen performing C-TST (Recombinant Mycobacterium Tuberculosis Fusion Protein; Zhifei Longcom Biologic Pharmacy Company, Anhui, China), 0.1 mL (5U) recombinant mycobacterium TB fusion protein was injected on the volar surface of the left forearm intradermally. The induration or erythema was measured in millimeter after 48 hours at injection sites.\u003c/p\u003e\n \u003cp\u003eDigital chest radiography was performed on each participant with suspected symptoms of PTB, who was TST strong positive or C-TST positive, and who met the exclusion criteria. Those with abnormal digital chest radiography went to designated medical institutions for further examination.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\n \u003ch2\u003eThe LTBI detection gap\u003c/h2\u003e\n \u003cp\u003eTo evaluate LTBI detection gap, we collected PTB screening data implemented by community-level medical and health care institutions in the same schools selected in this study in 2021, which have been compared with the data implemented by Chongqing Municipal Institute of Tuberculosis between September 2022 and December 2023.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec9\" class=\"Section2\"\u003e\n \u003ch2\u003eStatistical analysis\u003c/h2\u003e\n \u003cp\u003eWe calculated the proportion and 95% CI for the LTBI prevalence rate, which was the proportion of schoolchildren and adolescents with LTBI excluding active PTB. Different LTBI prevalence rates were tested using chi-square test. The trend of rate was tested using chi-square test for linear trend. Some participants were unable to verify the TST or C-TST results due to leave or other reasons, resulting in missing data. To evaluate the impact of missing data, we compared the distribution of gender, grade, region and school type between participants with and without the TST or C-TST results by chi-square test. A two-sided \u003cem\u003eP\u003c/em\u003e \u0026lt; 0.05 was taken as statistically significant. Statistical analyses were performed with the SPSS 22.0 software (SPSS, Inc., Chicago, IL, USA).\u003c/p\u003e\n\u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\n\u003ch2\u003eThe screening process for participants\u003c/h2\u003e\n\u003cp\u003eThere were 69667 participants in 51 schools in Chongqing between September 2022 and December 2023, and 4786 (6.9%) were excluded for various reasons leaving 64881 (93.1%) participants with TST or C-TST result (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e\n\u003cp\u003eThere are 41 schools using TST (48583 participants with results), and ten schools using C-TST (16298 participants with results). Participants who were unable to verify the TST or C-TST results due to leave or other reasons were excluded from statistical analysis considering that these missing data were completely random and had a low proportion of 0.4% (279/65160). In addition, there was no difference in the distribution of gender, grade, region and school type between participants with and without the TST or C-TST results (appendix p 2).\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e\n\u003ch2\u003ePTB screening results\u003c/h2\u003e\n\u003cp\u003eThe LTBI prevalence rate using TST and C-TST was 12.7% (95%CI, 12.5%-13%) and 6.4% (95%CI, 6%-6.8%) respectively (Tables\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e and \u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e). The LTBI prevalence rate using TST was significantly higher than that using C-TST (\u003cem\u003e\u0026chi;\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;492.7, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001).\u003c/p\u003e\n\u003cdiv class=\"gridtable\"\u003e\n\u003ctable id=\"Tab1\" border=\"1\"\u003e\u003ccaption\u003e\n\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\n\u003cdiv class=\"CaptionContent\"\u003e\n\u003cp\u003eSchoolchildren and adolescents PTB screening results using TST by our PTB screening team between September 2022 and December 2023 in Chongqing\u003c/p\u003e\n\u003c/div\u003e\n\u003c/caption\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eCharacteristics\u003c/p\u003e\n\u003c/th\u003e\n\u003cth rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eSubgroup\u003c/p\u003e\n\u003c/th\u003e\n\u003cth colspan=\"6\" align=\"left\"\u003e\n\u003cp\u003eTST\u003c/p\u003e\n\u003c/th\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eParticipants with TST implemented\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eParticipants without result\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eTST Strongly Positive\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eActive PTB\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eLTBI prevalence rate\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e95% CI\u003c/p\u003e\n\u003c/th\u003e\n\u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eGender\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eMale\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e25295\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e94\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e2969\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e8\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e11.8%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e11.4%-12.2%\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eFemale\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e23487\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e105\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e3240\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e8\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e13.8%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e13.4%-14.3%\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eGrade\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eJunior One\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e6921\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e30\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e575\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e8.3%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e7.7%-9%\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eSenior One\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e20700\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e88\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e2475\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e3\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e12%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e11.6%-12.4%\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eSenior Two\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e21161\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e81\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e3159\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e12\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e14.9%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e14.5%-15.4%\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eRegion\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eCentral Urban Districts\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e18778\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e84\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e2382\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e12.7%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e12.3%-13.2%\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eNew West Urban Development Districts\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e13875\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e63\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1800\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e13%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e12.5%-13.6%\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eNortheast Districts\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e6755\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e24\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e469\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e3\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e6.9%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e6.3%-7.5%\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eSoutheast Districts\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e9374\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e28\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1558\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e10\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e16.6%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e15.8%-17.3%\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eSchool type\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003ePublic school\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e33868\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e150\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e4096\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e13\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e12.1%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e11.8%-12.5%\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003ePrivate school\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e14914\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e49\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e2113\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e3\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e14.2%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e13.6%-14.8%\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eTotal\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e48782\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e199\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e6209\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e16\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e12.7%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e12.5%-13%\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n\u003c/div\u003e\n\u003cdiv class=\"gridtable\"\u003e\n\u003cdiv class=\"colspec\" align=\"left\"\u003e\u0026nbsp;\u003c/div\u003e\n\u003ctable id=\"Tab2\" border=\"1\"\u003e\u003ccaption\u003e\n\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\n\u003cdiv class=\"CaptionContent\"\u003e\n\u003cp\u003eSchoolchildren and adolescents PTB screening results using C-TST by by our PTB screening team between September 2022 and December 2023 in Chongqing\u003c/p\u003e\n\u003c/div\u003e\n\u003c/caption\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eCharacteristics\u003c/p\u003e\n\u003c/th\u003e\n\u003cth rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eSubgroup\u003c/p\u003e\n\u003c/th\u003e\n\u003cth colspan=\"6\" align=\"left\"\u003e\n\u003cp\u003eC-TST\u003c/p\u003e\n\u003c/th\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eParticipants with C-TST implemented\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eParticipants without result\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eC-TST Positive\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eActive PTB\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eLTBI prevalence rate\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e95% CI\u003c/p\u003e\n\u003c/th\u003e\n\u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eGender\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eMale\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e8897\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e45\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e603\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e8\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e6.7%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e6.2%-7.2%\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eFemale\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e7481\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e35\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e454\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e3\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e6.1%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e5.5%-6.6%\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eGrade\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eJunior One\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e746\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e5\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e36\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e4.9%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e3.3%-6.4%\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eSenior One\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e7410\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e45\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e448\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e4\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e6%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e5.5%-6.6%\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eSenior Two\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e8222\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e30\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e573\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e7\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e6.9%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e6.4%-7.5%\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eRegion\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eCentral Urban Districts\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e4255\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e21\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e162\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e3.8%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e3.2%-4.4%\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eNew West Urban Development Districts\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e-\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e-\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e-\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e-\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e-\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e-\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eNortheast Districts\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2664\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e14\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e147\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e5.5%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e4.7%-6.4%\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eSoutheast Districts\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e9449\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e35\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e748\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e10\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e7.8%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e7.3%-8.4%\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eSchool type\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003ePublic school\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e11837\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e54\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e864\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e10\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e7.3%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e6.8%-7.7%\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003ePrivate school\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e4541\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e26\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e193\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e4.3%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e3.7%-4.8%\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eTotal\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e16378\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e80\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e1057\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e11\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e6.4%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e6%-6.8%\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003eThe detection rate of active PTB in participants using TST was 32.9 cases per 100000 population (16/48583), and the detection rate of active PTB in participants using C-TST was 67.5 cases per 100000 population (11/16298). There was not a significant difference in detection rate of active PTB in participants using TST or C-TST (\u003cem\u003e\u0026chi;\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;3.5, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.06).\u003c/p\u003e\n\u003cp\u003eThe TST strongly positive rate has increased significantly from 8.3% in Junior One to 15% in Senior Two (\u003cem\u003e\u0026chi;\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e trend\u0026thinsp;=\u0026thinsp;223.6, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001) .The C-TST positive rate has also increased significantly from 4.9% in Junior One to 7% in Senior Two (\u003cem\u003e\u0026chi;\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e trend\u0026thinsp;=\u0026thinsp;8.6, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.003) .\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e\n\u003ch2\u003eThe LTBI detection gap\u003c/h2\u003e\n\u003cp\u003eThere were 47320 participants with TST result in the same schools of this study in 2021. The LTBI prevalence rate using TST by community-level medical and health care institutions was 3.2% (95%CI, 3.1%-3.4%) in 2021 (Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e\n\u003cdiv class=\"gridtable\"\u003e\n\u003ctable id=\"Tab3\" border=\"1\"\u003e\u003ccaption\u003e\n\u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\n\u003cdiv class=\"CaptionContent\"\u003e\n\u003cp\u003eSchoolchildren and adolescents PTB screening results using TST by community-level medical and health care institutions in 2021 in Chongqing\u003c/p\u003e\n\u003c/div\u003e\n\u003c/caption\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eCharacteristics\u003c/p\u003e\n\u003c/th\u003e\n\u003cth rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eSubgroup\u003c/p\u003e\n\u003c/th\u003e\n\u003cth colspan=\"7\" align=\"left\"\u003e\n\u003cp\u003eTST\u003c/p\u003e\n\u003c/th\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eParticipants with result\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eTST Strongly Positive\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eActive PTB\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eLTBI prevalence rate\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e95% CI\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003e\u0026chi;\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003csup\u003e\u0026Dagger;\u003c/sup\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eGrade\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eJunior One\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e7233\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e201\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e2.8%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e2.4%-3.1%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e211\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eSenior One\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e24397\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e629\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e2.6%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e2.4%-2.8%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e1545.8\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eSenior Two\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e15690\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e702\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e4.5%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e4.2%-4.8%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e1050.2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eRegion\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eCentral Urban Districts\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e5901\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e104\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.8%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e1.4%-2.1%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e594.4\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eNew West Urban Development Districts\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e20659\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e969\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e4.7%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e4.4%-5%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e778.7\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eSoutheast Districts\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e12174\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e133\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1.1%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e0.9%-1.3%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e473.7\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eNortheast Districts\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e6718\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e149\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e2.2%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e1.9%-2.6%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e857.5\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eSchool type\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003ePublic school\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e37025\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1319\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e3.6%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e3.4%-3.7%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e1831.8\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003ePrivate school\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e10295\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e213\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e0\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e2.1%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e1.8%-2.3%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e1067.4\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eTotal\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e47320\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e1532\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e3.2%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e3.1%-3.4%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e2931.9\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003eThe LTBI prevalence rate by Chongqing Municipal Institute of Tuberculosis was 9.6% higher than that by community-level medical and health care institutions(\u003cem\u003e\u0026chi;\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;2931.9, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001), and there were also similar trends in LTBI prevalence rate in each subgroup (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e). The risk factors associated with LTBI were analyzed, and the LTBI prevalence rate in Southeast Districts by Chongqing Municipal Institute of Tuberculosis was the highest (appendix p 3). The LTBI detection gap in Southeast Districts was also the greatest, reaching 15.5%.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec14\" class=\"Section2\"\u003e\n\u003ch2\u003eThe ARTI of schoolchildren and adolescents\u003c/h2\u003e\n\u003cp\u003ethe ARTI using TST and C-TST was 0.9% (95%CI, 0.8%-1%) and 0.4% (95%CI, 0.3%-0.5%) respectively ( Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e\n\u003cdiv class=\"gridtable\"\u003e\n\u003ctable id=\"Tab4\" border=\"1\"\u003e\u003ccaption\u003e\n\u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e\n\u003cdiv class=\"CaptionContent\"\u003e\n\u003cp\u003eARTI in schoolchildren and adolescents between September 2022 and December 2023 in Chongqing\u003c/p\u003e\n\u003c/div\u003e\n\u003c/caption\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth rowspan=\"2\" align=\"left\"\u003e\n\u003cp\u003eSubgroup\u003c/p\u003e\n\u003c/th\u003e\n\u003cth colspan=\"5\" align=\"left\"\u003e\n\u003cp\u003eTST\u003c/p\u003e\n\u003c/th\u003e\n\u003cth colspan=\"5\" align=\"left\"\u003e\n\u003cp\u003eC-TST\u003c/p\u003e\n\u003c/th\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003emean age\u0026thinsp;\u003cem\u003e\u0026plusmn;\u0026thinsp;s\u003c/em\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eARTI\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e95% CI\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003e\u0026chi;\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003emean age\u0026thinsp;\u003cem\u003e\u0026plusmn;\u0026thinsp;s\u003c/em\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003eARTI\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e95% CI\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003e\u0026chi;\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003cth align=\"left\"\u003e\n\u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e\n\u003c/th\u003e\n\u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eMale\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026plusmn;\"\u003e\n\u003cp\u003e15.6\u0026thinsp;\u0026plusmn;\u0026thinsp;1.4\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.8%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e0.7%-0.9%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"char\" char=\".\"\u003e\n\u003cp\u003e3.4\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.07\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e15.9\u0026thinsp;\u0026plusmn;\u0026thinsp;1.1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.4%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e0.3%-0.6%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.14\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.81\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eFemale\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026plusmn;\"\u003e\n\u003cp\u003e15.5\u0026thinsp;\u0026plusmn;\u0026thinsp;1.5\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e1.0%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e0.8%-0.11%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e15.8\u0026thinsp;\u0026plusmn;\u0026thinsp;1.1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.4%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e0.3%-0.5%\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eJunior One\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026plusmn;\"\u003e\n\u003cp\u003e12.7\u0026thinsp;\u0026plusmn;\u0026thinsp;0.9\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.7%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e0.5%-0.9%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"3\" align=\"char\" char=\".\"\u003e\n\u003cp\u003e6.2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"3\" align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.04\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e13\u0026thinsp;\u0026plusmn;\u0026thinsp;1.6\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.4%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e0.1%-0.9%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"3\" align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"3\" align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.95\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eSenior One\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026plusmn;\"\u003e\n\u003cp\u003e15.5\u0026thinsp;\u0026plusmn;\u0026thinsp;0.7\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.8%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e0.7%-0.9%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e15.6\u0026thinsp;\u0026plusmn;\u0026thinsp;0.8\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.4%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e0.3%-0.6%\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eSenior Two\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026plusmn;\"\u003e\n\u003cp\u003e16.5\u0026thinsp;\u0026plusmn;\u0026thinsp;0.8\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e1%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e0.8%-1.1%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e16.3\u0026thinsp;\u0026plusmn;\u0026thinsp;0.7\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.4%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e0.3%-0.6%\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eCentral Urban Districts\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026plusmn;\"\u003e\n\u003cp\u003e15.2\u0026thinsp;\u0026plusmn;\u0026thinsp;1.7\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.9%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e0.8%-1%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"4\" align=\"char\" char=\".\"\u003e\n\u003cp\u003e23.8\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"4\" align=\"char\" char=\".\"\u003e\n\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e15.9\u0026thinsp;\u0026plusmn;\u0026thinsp;0.8\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.2%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e0.1%-0.4%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"4\" align=\"char\" char=\".\"\u003e\n\u003cp\u003e6.14\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"4\" align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.04\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eNew West Urban Development Districts\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026plusmn;\"\u003e\n\u003cp\u003e16.1\u0026thinsp;\u0026plusmn;\u0026thinsp;0.9\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.9%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e0.7%-1.1%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e-\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e-\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e-\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eNortheast Districts\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026plusmn;\"\u003e\n\u003cp\u003e15.9\u0026thinsp;\u0026plusmn;\u0026thinsp;0.9\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.5%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e0.3%-0.6%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e16.1\u0026thinsp;\u0026plusmn;\u0026thinsp;1.1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.4%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e0.1%-0.6%\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eSoutheast Districts\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026plusmn;\"\u003e\n\u003cp\u003e15.3\u0026thinsp;\u0026plusmn;\u0026thinsp;1.6\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e1.2%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e1%-1.6%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e15.8\u0026thinsp;\u0026plusmn;\u0026thinsp;1.2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.5%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e0.4%-0.7%\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003ePublic school\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026plusmn;\"\u003e\n\u003cp\u003e15.1\u0026thinsp;\u0026plusmn;\u0026thinsp;1.5\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.9%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e0.8%-1%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.65\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.43\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e15.9\u0026thinsp;\u0026plusmn;\u0026thinsp;1.1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.5%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e0.4%-0.6%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"char\" char=\".\"\u003e\n\u003cp\u003e3.4\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" align=\"char\" char=\".\"\u003e\n\u003cp\u003e0.08\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003ePrivate school\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026plusmn;\"\u003e\n\u003cp\u003e16.4\u0026thinsp;\u0026plusmn;\u0026thinsp;0.8\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.9%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e0.8%-1%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e15.8\u0026thinsp;\u0026plusmn;\u0026thinsp;1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.3%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e0.1%-0.4%\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003eTotal\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026plusmn;\"\u003e\n\u003cp\u003e15.6\u0026thinsp;\u0026plusmn;\u0026thinsp;1.5\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.9%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e0.8%-1%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e15.9\u0026thinsp;\u0026plusmn;\u0026thinsp;1.1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\n\u003cp\u003e0.4%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"char\" char=\"\u0026minus;\"\u003e\n\u003cp\u003e0.3%-0.5%\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003eThere was a significant difference in ARTI using TST among different grades (\u003cem\u003e\u0026chi;\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;6.2, \u003cem\u003eP\u0026thinsp;=\u003c/em\u003e\u0026thinsp;0.04), and the ARTI in Senior Two was the highest. There was also a significant difference in ARTI using TST in different regions (\u003cem\u003e\u0026chi;\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;23.8, \u003cem\u003eP\u0026thinsp;\u0026lt;\u003c/em\u003e\u0026thinsp;0.001), and the ARTI in Southeast Districts was the highest. There was also a significant difference in ARTI using C-TST in different regions (\u003cem\u003e\u0026chi;\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;6.1, \u003cem\u003eP\u0026thinsp;=\u003c/em\u003e\u0026thinsp;0.04), and the ARTI in Southeast Districts was the highest.\u003c/p\u003e\n\u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eOne key challenge in TB prevention and control is to accurately find students infected with TB among schoolchildren and adolescents. Through this study, we have obtained accurate LTBI burden among them in Chongqing.\u003c/p\u003e \u003cp\u003e In this study, the LTBI prevalence rate conducted by Chongqing Municipal Institute of Tuberculosis using TST between September 2022 and December 2023 was 9.6% higher than the results conducted by community-level medical and health care institutions in the same schools in 2021. The quality of PTB screening implemented by community-level medical and health care institutions may be poor. The reduction of the reported number of TST strong positive schoolchildren and adolescents has significantly decreased the detection of active PTB and LTBI, which may result in more community transmission. According to Statistical Bulletin on National Economic and Social Development in Chongqing of 2021, the total number of middle school students in Chongqing was 1.77\u0026nbsp;million, which may mean a LTBI detection gap of 0.17\u0026nbsp;million middle school students who were not detected and intervened timely in Chongqing.\u003c/p\u003e \u003cp\u003eThis detection gap may not happen only in Chongqing. A study found that the TST strong positive rate was 2.69% among 16795 freshmen in senior high schools and boarding junior high schools in 2019 in Ningbo, Zhejiang Province, China [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e], and the TST strong positive rate was 1.45% among 78102 freshmen in the same population of the same area in 2021 [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. The PTB screening among 220269 freshmen in senior high schools and boarding junior high schools showed that the TST strong positive rate was 1.70% from 2016 to 2020 in Liuzhou, Guangxi Province, China [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. The TST strong positive rate was 0.36% among 20153 students in Longgang District, Shenzhen, China in 2021 [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. Two studies in Beijing showed that the TST strong positive rate was 2.59% among 6187 freshmen in 2018, and 1.86% among 12562 freshmen in 2020 respectively [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. The TST strong positive rates in these studies were lower than our results, which may be due to the lower PTB burden in these regions or the existence of a LTBI detection gap. The reported incidence rate of active PTB was about 48 cases per 100000 population in Chongqing, which currently ranks 13th among all provinces in 2023 in China according to national TB surveillance system, and the reported PTB incidence rate of the above provinces was about 23\u0026ndash;68 cases per 100000 population. It was unreasonable to explain such a low TST strong positive rate using the reason that the PTB burden in these regions was far lower than that in Chongqing.\u003c/p\u003e \u003cp\u003eOur study conducted standardized training for medical workers. During the training process, it was found that the reasons for this detection gap may include non-standard TST administration and inaccurate TST result reading, and inaccurate TST reading may have the greatest impact on this detection gap, which may be due to the reader's incorrect understanding of the operation rules and rusty practical skills.\u003c/p\u003e \u003cp\u003eResearch on TST quality control is rare. A study has noticed the limitations of TST quality, which included reader variability and the need for trained personnel to read the results [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. A study has found that TST reading results vary very much between readers [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. Although a large number of schoolchildren and adolescents underwent TST every year, the TST quality might be seriously underestimated. With the development of information technology, intelligent software for TST or TBST result reading may also be developed to improve the accuracy. Regular training and quality assurance are needed to establish, and maintaining proficiency is equally important. A study has found that mhealth approach using smartphone may be a method that could serve as a TST training and quality control tool in many settings [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThis study used two skin test methods, TST and C-TST. However, C-TST was approved for TB diagnosis in China in 2020, and has not been widely used in China. This study obtained the LTBI prevalence rate using C-TST, and the C-TST positive rate was lower than the TST strong positive rate. BCG vaccination might have accounted for a considerable proportion of positive TST [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. A study using C-TST showed that the positive rate was 10.14% (14/157) in 2022 in a high school in southeast of Chongqing [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. YANG Zhen et al [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e] have found that C-TST positive rate was 9.1% among 1924 college students in 2022 in Beijing, China. MU Tingmei et al [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e] showed that C-TST positive rate was 0.97% among 7416 junior middle school students and 1.1% among 2555 high school students respectively in 2021 in Yaan City, Sichuan Province, China. There were still differences in the C-TST positive rates conducted in different regions, and there was also a possibility of LTBI detection gap.\u003c/p\u003e \u003cp\u003eThe TST strongly positive rate and C-TST positive rate has increased significantly from Junior One to Senior Two in Chongqing. Other studies have also shown that the TST positive rate has increased with age in schoolchildren and adolescents [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Most provinces of China do not implement PTB screening for Senior Two in high school, and it is important to add a PTB screening in Senior Two, so as to prevent students from being unable to participate in the college entrance examination because of PTB.\u003c/p\u003e \u003cp\u003eIn 2022, the reported PTB incidence rate of schoolchildren and adolescents aged 10\u0026ndash;19 of Chongqing was 23.77 cases per 100000 population per year according to the national TB surveillance system, which was less than the actual incidence rate. In this study, the overall prevalence of LTBI using TST was 12.7% (95% CI, 12.5%-13%) with a corresponding ARTI of 0.9% (95% CI, 0.8%-1%). If we assume 5% rapid progression from recent infection to active TB [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e], and 0.05% annual progression rate from remote infection to active TB [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e], incidence rate can be measured: 0.9%\u0026times;5%+12.7%\u0026times;0.05%=51.4 cases per 100000 population per year [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. According to a study in Chongqing in 2021, the PTB screening proportion of freshmen in middle school is only 42.4%, indicating that there were still some PTB patients who have not been found in time [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. Under these assumptions, the ARTI obtained in this study using TST may reflect the current situation.\u003c/p\u003e \u003cp\u003eUsing the same method, estimated incidence rate using C-TST was 23.2 cases per 100000 population per year. The estimated incidence rate using C-TST may be underestimated using the Styblo\u0026rsquo;s rule [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e, \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. Considering the universal vaccination of BCG in China and the lower false positive rate of C-TST, the progression rate should be higher than 5% in LTBI using C-TST [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThis study has limitations. There were no schools in Northeast Districts that conducted C-TST. The PTB screening in schoolchildren and adolescents has not been systematically implemented before 2022, resulting in the data from routine surveillance system were limited. Lack of gender and some information in routine surveillance system before 2022 made it impossible to conduct related analysis.\u003c/p\u003e \u003cp\u003e This study obtained accurate LTBI burden using TST and C-TST in schoolchildren and adolescents in Chongqing, China. The LTBI detection gap existed among schoolchildren and adolescents in Chongqing, and it also may exist in other similar countries and regions, which may lead to more TB infections and morbidity. This situation must attract high attention from decision-makers. The staff of community-level medical and health care institutions need to receive regular standardized training and quality control to maintain the skill proficiency. These measures should be included in national tuberculosis prevention and control policies. Intelligent software for the result reading of TST and TBST should be developed, along with the development of mhealth systems capable of conducting quality control, which could help to enhance the PTB screening capabilities in areas with limited medical resources.\u003c/p\u003e \u003cp\u003eIn conclusion, obtaining accurate LTBI burden in schoolchildren and adolescents is crucial to develop effective TB prevention and control policies. Taking necessary measures could significantly improve the quality of TST and TBST, and close the detection gap of LTBI.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eWHO World Health Organization\u003c/p\u003e\n\u003cp\u003eLTBI Latent Tuberculosis Infection\u003c/p\u003e\n\u003cp\u003eTST Tuberculin Skin Test\u003c/p\u003e\n\u003cp\u003eC-TST Creation Tuberculin Skin Test\u003c/p\u003e\n\u003cp\u003eTB Tuberculosis\u003c/p\u003e\n\u003cp\u003ePTB Pulmonary Tuberculosis\u003c/p\u003e\n\u003cp\u003eTBST Novel Skin Tests for Tuberculosis Infection\u003c/p\u003e\n\u003cp\u003eBCG Bacillus Calmette-Gu\u0026eacute;rin\u003c/p\u003e\n\u003cp\u003eSTAT-6 Secretory Antigen Target Six\u003c/p\u003e\n\u003cp\u003eCFP10 Culture Filtrate Protein Ten\u003c/p\u003e\n\u003cp\u003eARTI The Annual Risk of Tuberculous Infection\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study was approved by the ethics committees of Chongqing Municipal Institute of Tuberculosis (202202, 26 September 2022). As we were carrying out a data analysis based on mandatory physical examinations and all individual information was removed before analysis, we were not required to obtain written informed consent from participants.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe PTB screening data of this study has been stored in the the provincial TB surveillance system but restrictions apply to the availability of these data, which were used under license for the current study, and so are not publicly available. Data are however available from the corresponding author upon reasonable request and with permission of the provincial TB surveillance system.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe data collection and data analysis of the study was supported by Chongqing Science and Health Joint Research Project (2023ZDXM027 and 2023MSXM143), Chongqing Health Commission Medical Science Research Project (2024WSJK08), and Chongqing Public Health Key Specialties (Disciplines) Construction Fund.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eJF, JYZ, BW, and YY designed the study. CGW, YLS, YL, JY, QS, ZZ, XH, and MW were involved in conducting the study. BW, YY, JY, QS and YP were involved in data analysis. BW and YY wrote the draft manuscript. BW, YY, JY, and QS had access to and verified the existence of the raw data. All authors read and approved the final manuscript before submission. JF was responsible for the decision to submit the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgments\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe thank the field workers and the study nurses Jinshan Qian, Jia Luo, Xianhui Feng, Xuemei Feng, Jin Wu, Yanping Feng, Cuimei Yue, Shanshan Liu, Huli Pan, and Yanjun Feng.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eUplekar M, Weil D, Lonnroth K, Jaramillo E, Lienhardt C, Dias HM, et al. WHO\u0026rsquo;s new end TB strategy. Lancet. 2015;385(9979):1799-801. \u003c/li\u003e\n\u003cli\u003eWorld Health Oragnization. Global tuberculosis report 2023. 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Beijing, China: National Health Commission of the People\u0026apos;s Republic of China, Ministry of Education of the People\u0026apos;s Republic of China; 2020.\u003c/li\u003e\n\u003cli\u003eDavid WD, Marcel AB. Are we underestimating the annual risk of infection with Mycobacterium tuberculosis in high-burden settings? Lancet Infect Dis. 2022;22(9):e271-e278. \u003c/li\u003e\n\u003cli\u003eChen T, He TF, Yu M, Che Y, Lin X. Analysis on tuberculin skin test results in 16795 freshmen in Ningbo, Zhejiang. Disease Surveillance. 2023;38(9):1043-1047. \u003c/li\u003e\n\u003cli\u003eLin X, Yu M, He TF, Che Y, Lin L, Cheng T. Tuberculin skin test results among new middle and high school students in Ningbo in 2021. Chinese Preventive Medicine.2023;02:135-138. \u003c/li\u003e\n\u003cli\u003eHuang BY, Wei GL. Tuberculosis screening among freshmen and incidence of tuberculosis among students in Liuzhou from 2016 to 2020. Chinese Youjiang Medical Journal. 2020;10:790-793.\u003c/li\u003e\n\u003cli\u003eLi ML, Liu JY, Zhang XQ, Qiu YH, Huang DH, Zheng TH. Analysis of tuberculosis health examination results in schools in Longgang District, Shenzhen in 2021. Journal of Medical Pest Control. 2023;05:465-469.\u003c/li\u003e\n\u003cli\u003eMa CX, Xu W, Liang YR, Liang RY, Zhang XZ, Wang M. Tuberculosis screening results among new students in Chaoyang district of Beijing in 2020. Disease Surveillance. 2022;37(7):949-953. \u003c/li\u003e\n\u003cli\u003eMeng WL, Li SY, Wang FH, Li HY, Lang Y, Guo JL, et al. Tuberculosis screening results of freshmen in 138 primary and secondary schools. China Tropical Medicine. 2019;19(8):781-783. \u003c/li\u003e\n\u003cli\u003eGina G, Paola M, Francesco NL, Fabrizio P, Sayoki M, Peter M. Tuberculin skin test-Outdated or still useful for Latent TB infection screening? Int J Infect Dis. 2019;80S:S20-S22. \u003c/li\u003e\n\u003cli\u003eKeiko N, Kiminori S, Yuko S, Akimitsu S, Hidetoshi I, Keiichi N. Problems about tuberculin skin test raised from consultations and countermeasures--influence to the interpretation of tuberculin skin test in case of the stoppage of BCG revaccination abolition and the introduction of induration measurement. Kekkaku. 2002;77(10):639-645.\u003c/li\u003e\n\u003cli\u003eSaeedeh MN, Leila B, Olivia O, Chantal V, Mei-Xin L, Jonathon RC. The mTST-An mHealth approach for training and quality assurance of tuberculin skin test administration and reading. PLoS One. 2019;14(4):e0215240. doi: 10.1371/journal.pone.0215240. \u003c/li\u003e\n\u003cli\u003eBen JM. Mycobacterium tuberculosis infection burden in poor urban communities. Lancet Child Adolesc Health. 2018;2(1):7-8.\u003c/li\u003e\n\u003cli\u003eSu Q, Wang QY, Zhang T, Liu Y. Comparison of recombinant Mycobacterium tuberculosis fusion protein skin test and tuberculin skin test for screening latent tuberculosis infection in school students. Chinese Journal of Infection Control. 2023;22 (5):547-551. \u003c/li\u003e\n\u003cli\u003eYang Z, Sun Q, Han L, Bao C, Wang X, Zhang ZG. Analysis of recombinant mycobacterium tuberculosis fusion protein in screening for latent tuberculosis infection in college students. Chinese Journal of the Frontiers of Medical Science. 2022;14(07):51-54.\u003c/li\u003e\n\u003cli\u003eMu TM, Hu QY, Li W, Feng Y, Wang XG. Analysis of recombinant mycobacterium tuberculosis fusion protein in screening for latent tuberculosis infection in college students. Parasitoses and Infectious Diseases. 2022;3:166-170.\u003c/li\u003e\n\u003cli\u003eStyblo K. The relationship between the risk of tuberculous infection and the risk of developing infectious tuberculosis. Bull Int Union Tuberc Lung Dis. 1985;60:117-119.\u003c/li\u003e\n\u003cli\u003eHorsburgh CJ, O\u0026rsquo;Donnell M, Chamblee S, Moreland JL, Johnson J, Marsh BJ, et al. Revisiting rates of reactivation tuberculosis: a population-based approach. Am J Respir Crit Care Med. 2010;182:420-425.\u003c/li\u003e\n\u003cli\u003ePang Y, Wu CG, Wang QY, Zhang T. Screening results of tuberculosis among new students in Chongqing Municipality, 2021. Practical Preventive Medicine. 2023;30(02):165-168.\u003c/li\u003e\n\u003cli\u003eDye C. Breaking a law: tuberculosis disobeys Styblo\u0026rsquo;s rule.Bull World Health Organ. 2008;86:4.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"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":"bmc-infectious-diseases","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"infd","sideBox":"Learn more about [BMC Infectious Diseases](http://bmcinfectdis.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/infd","title":"BMC Infectious Diseases","twitterHandle":"#bmcinfectdis","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Tuberculosis, Child, Adolescent, Latent tuberculosis, Tuberculin Test","lastPublishedDoi":"10.21203/rs.3.rs-4320976/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4320976/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eThe latent tuberculosis infection (LTBI) burden is still unclear in schoolchildren and adolescents in China. Previous study and daily surveillance data indicate a LTBI detection gap. The research objective was to evaluate the LTBI burden and detection gap among schoolchildren and adolescents in China.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eA cross-sectional study was conducted among 69667 schoolchildren and adolescents in Chongqing, China between September 2022 and December 2023 implemented by Chongqing Municipal Institute of Tuberculosis using tuberculin skin test (TST) and creation tuberculin skin test (C-TST). To evaluate the LTBI detection gap, the pulmonary tuberculosis (PTB) screening data implemented by Chongqing Municipal Institute of Tuberculosis have been compared with the data in 2021 implemented by community-level medical and health care institutions.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003ethe LTBI prevalence rate using TST and C-TST implemented by Chongqing Municipal Institute of Tuberculosis was 12.7% (95%CI, 12.5%-13%) and 6.4% (95%CI, 6%-6.8%) respectively. The LTBI prevalence rate by Chongqing Municipal Institute of Tuberculosis was 9.6% higher than that by community-level medical and health care institutions (\u003cem\u003eχ\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;2931.9, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001).\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eThe LTBI detection gap existed among schoolchildren and adolescents in Chongqing, and it also may exist in other similar countries and regions. National screening strategy needs improvement. Regular training and quality assurance could improve the performance of TST and C-TST and close the detection gap of LTBI.\u003c/p\u003e","manuscriptTitle":"Addressing the Burden and Detection Gap of Latent Tuberculosis Infection in Schoolchildren and Adolescents in China: A Cross-sectional Study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-05-02 08:53:26","doi":"10.21203/rs.3.rs-4320976/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2024-04-29T07:24:49+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-04-27T09:10:35+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-04-27T09:10:35+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Infectious Diseases","date":"2024-04-25T02:00:38+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-infectious-diseases","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"infd","sideBox":"Learn more about [BMC Infectious Diseases](http://bmcinfectdis.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/infd","title":"BMC Infectious Diseases","twitterHandle":"#bmcinfectdis","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"85bf25e7-6186-4b40-adc5-cb50784b90d2","owner":[],"postedDate":"May 2nd, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2024-09-23T16:01:08+00:00","versionOfRecord":{"articleIdentity":"rs-4320976","link":"https://doi.org/10.1186/s12879-024-09812-0","journal":{"identity":"bmc-infectious-diseases","isVorOnly":false,"title":"BMC Infectious Diseases"},"publishedOn":"2024-09-16 15:57:19","publishedOnDateReadable":"September 16th, 2024"},"versionCreatedAt":"2024-05-02 08:53:26","video":"","vorDoi":"10.1186/s12879-024-09812-0","vorDoiUrl":"https://doi.org/10.1186/s12879-024-09812-0","workflowStages":[]},"version":"v1","identity":"rs-4320976","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4320976","identity":"rs-4320976","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}