Geographic and temporal distribution of primary and secondary dengue cases in Burkina Faso from 2023-2025: a hospital-based cross-sectional study

Geographic and temporal distribution of primary and secondary dengue cases in Burkina Faso from 2023-2025: a hospital-based cross-sectional study | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Geographic and temporal distribution of primary and secondary dengue cases in Burkina Faso from 2023-2025: a hospital-based cross-sectional study Louis Robert Wendyam Belem, Arsène Zongo, Raymond Karlhis Yao, and 10 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9140004/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background Dengue virus (DENV) is the main prevalent arbovirus in Burkina Faso, with significant morbidity and mortality. Discrimination between primary and secondary dengue infections is important for public health decision-making. This study aimed to characterize the spatiotemporal distribution of primary and secondary dengue infections, as well as pre-vaccination screening. Methods This study was conducted in 2023, 2024, and 2025 in Bobo-Dioulasso, Houndé, Ouagadougou, and Gaoua. Blood sample was collected from each suspected case. DENV detection was performed using a rapid diagnostic test, enzyme-linked immunosorbent assay (ELISA), and molecular techniques. Results In 2023, the primary and secondary infection rates were 75.40% (92/122) and 24.6% (30/122), respectively. In 2024, 77.17% (71/92) of primary infections and 22.83% (21/92) of secondary infections were reported. In 2025, primary and secondary infection accounted for 68.83% (53/77) and 31.17% (24/77), respectively. Across the 2023–2025 period, abdominal pain occurred in 7.87% (17/216) and persistent vomiting in 2,31% (5/216) of dengue primary infection cases, while 92.13% (199/216) showed no warning signs. Among patients with secondary dengue infection, abdominal pain was reported in 54.66% (41/75) and persistent vomiting in 29.33% (22/75), although 45.43% (34/75) presented without warning signs. In 2023, DENV-3 was the predominant serotype, accounting for 76.23% (93/122) of cases. In contrast, DENV-1 predominated in 2024 and 2025, representing 69.57% (66/92) and 71.42% (55/77) of cases, respectively. Conclusions Primary infection predominated in all years, with year-to-year variation in DENV serotype distribution, and warning signs were associated with secondary infection. Qdenga (TAK-003) vaccine may be a relevant option in the Burkina context Geographic temporal primary secondary dengue Burkina Faso Figures Figure 1 Figure 2 Figure 3 Introduction Dengue virus (DENV) is the most widely distributed arbovirus worldwide, primarily due to population growth and urbanization. Globalization and climate change facilitate the geographic spread of both the mosquito vector and the pathogen to previously unaffected areas[ 1 ]. According to the World Health Organization (WHO), over 5 million dengue cases and 3,000 deaths were reported in early December 2025 in several regions, including the Americas, Asia, and Africa [ 2 ]. In Burkina Faso, DENV is responsible for outbreaks characterized by high prevalence and substantial morbidity and mortality. Between August and November 2023, Burkina Faso reported important DENV outbreaks with 146,878 suspected cases and 688 deaths [ 3 , 4 ]. DENV belongs to the Flaviviridae family, its genome is ribonucleic acid (RNA), and is classified into four genetically different serotypes (DENV1-4) [ 5 , 6 ]. Dengue is transmitted by the bite of infected Aedes mosquitoes, mainly Aedes (Ae) aegypti and Ae. albopictus [ 7 ], and represents a major public health problem in tropical and subtropical regions [ 8 , 9 ]. DENV infection can vary in presentation, ranging from asymptomatic cases or mild illness with symptoms to severe disease. Severe dengue is characterized by vascular permeability, plasma leakage, massive bleeding, and, in some cases, liver compromise, organ impairment, and even death [ 10 ]. Although primary infection with a single DENV serotype induces long-term homologous protective immunity, subsequent infection with a different serotype is associated with more severe clinical outcomes [ 11 ]. A secondary heterotypic DENV infection has been recognized as a key driver of disease severity, primarily through antibody-dependent enhancement (ADE). In this immunopathological process, immunoglobulin G (IgG) complexes promote enhanced viral replication, leading to the release of proinflammatory cytokines and chemokines that increase vascular permeability and can ultimately result in shock [ 12 ]. During primary infection, immunoglobulin M (IgM) antibodies are the first immunoglobulin isotype to appear. Anti-dengue IgM antibodies are detectable in only a few patients between days 2 and 4 after symptom onset. By day 5 of illness, approximately 80% of patients exhibit detectable IgM, increasing to 93–99% between days 6 and 10 post-onset. Anti-dengue IgM may persist for more than 90 days. Low levels of anti-dengue IgGs become detectable by the end of the first week of illness and can persist for several months, potentially remaining detectable for life. In secondary dengue infection, IgG antibodies are rapidly produced and represent the dominant isotype from the onset of symptoms, while IgM levels are low or often undetectable during the acute phase [ 1 , 11 ].Primary and secondary DENV infections can be distinguished by analyzing dengue specific immunoglobulin responses during the acute phase of the infection, defined as the first eight days of symptom onset[ 12 ]. Although two dengue vaccines (Dengvaxia® CYD-TDV and Qdenga®TAK-003) have been approved by the WHO, their efficacy and safety are influenced by serotype, pre-existing dengue immunity, and age, which limits their broader implementation [ 13 ]. Therefore, accurate diagnosis during the early febrile phase of dengue is critical to prevent unnecessary and costly diagnostic procedures, avoid potentially harmful antibiotic use, ensure timely and appropriate interventions at both primary and secondary care levels, and facilitate early detection of outbreaks. In resource-limited settings, rapid diagnostic test (RDT) kits are the primary diagnostic tool as they do not require costly laboratory equipment and remain stable under suboptimal storage conditions [ 1 ]. However, false-positive results have been reported, representing a limitation of dengue diagnosis [ 14 ]. Molecular diagnostics are considered the gold standard for dengue detection [ 15 ]. Combining molecular techniques with RDTs and enzyme-linked immunosorbent assays (ELISAs) can facilitate early diagnosis, determination of DENV serotypes, discrimination between primary and secondary infections, and assessment of endemicity. These data are essential for public health decision-making, forecasting severe dengue risk, and, given that vaccine efficacy depends on baseline serostatus, for predicting the impact of dengue vaccination at the population level [ 16 ]. To date, no spatiotemporal characterization of dengue primary and secondary infections has been conducted in Burkina Faso, and no dengue vaccine has yet been introduced. Differentiating primary from secondary DENV infections is crucial for elucidating dengue transmission dynamics and epidemiology in Burkina Faso. This study aimed to determine the geographic and temporal distribution of primary and secondary DENV infections, and to incorporate differentiation of infection status into diagnostic, surveillance, and pre-vaccination screening protocols. Methods Study sites This study was conducted during June to September of 2023, 2024, and 2025 across three regions of Burkina Faso, including four cities: Bobo-Dioulasso, Houndé, Ouagadougou, and Gaoua (Fig. 1). Burkina Faso, a West African country, has a tropical climate with distinct dry (November to May) and wet seasons (June to October). Bobo-Dioulasso, the economic capital and capital of the Guiriko region, is located in Houet province (11°11′00″ North, 4°17′00″ West). Houndé, a city in Tuy province, is also located within the Guiriko region (11°30′ North, 3°31′ West). Ouagadougou, the national capital and largest city of Burkina Faso, lies in the Kadiogo region, at the heart of the intertropical zone (12° 21′ 58″ North, 1° 31′ 05″ West). Gaoua is located in the Djôrô region (10° 20′ 00″ north, 3° 11′ 00″ west). Study participants were recruited from the Centers with Surgical Antenna (CMA) of DO and Eureka Medical Center in Bobo-Dioulasso, the CMA of Houndé, the Progrès Medical Laboratory in Ouagadougou, and the Regional Hospital (CHR) of Gaoua. Study design Participants were enrolled based on the presence of clinical symptoms, including fever, headache, chills, abdominal pain, rash, joint and muscle pain, vomiting, conjunctival hyperemia, and retroorbital pain. Persisting vomit and abdominal pain were considered to be warning signs that can lead to severe disease. Whole blood sample (3-5 mL) was collected from each participant into serum separation tubes and centrifuged at 1500 rpm for 5 minutes to separate the serum. The resulting serum was aliquoted into two separate vials (200 µl/vial) and stored at -80°C before analysis, including RDTs, RNA extraction, ELISA, and DENV molecular detection. RDTs were performed using Dengue Non-Structural 1 (NS1) Antigen and IgG/IgM Antibody kits (Colloidal Gold, Wondfo, China). Primary and secondary infections were distinguished based on serological and molecular results: cases positive by RT-PCR with detectable anti-DENV IgM but negative anti-DENV IgG were classified as primary infections, whereas RT-PCR positive cases with detectable anti-DENV IgG, regardless of IgM status, were classified as secondary infections. These criteria have been widely adopted in previous studies [10,17–19]. Molecular detection of DENV1-4 The viral RNA was extracted from 140 µL of human serum using the QIAamp Viral RNA Mini Kit (Qiagen, Hilden, Germany). Detection of DENV serotypes 1-4 was performed using the PrimeScript One Step RT-PCR Kit (Takara Bio Inc) following the protocol previously described [20]. Data management and statistical analysis Proportions and ratios were calculated for categorical variables, including sex, age, geographic area, clinical manifestations, dengue infection status (primary or secondary), and DENV serotype. Fisher's exact test was applied for categorical variables with expected counts less than five, while the Chi-square test was performed for variables with expected counts of five or more. Statistical significance was defined as p ≤ 0.05. All analyses were conducted using R version 4.3.1. Results and discussion Patient’s characteristics and geographic distribution of primary and secondary dengue infection Among suspected cases, molecular testing confirmed 122, 92, and 77 dengue cases in 2023, 2024, and 2025, respectively. The distribution of primary and secondary infections varied by location and year. In 2023, primary infections accounted for 76.56% (49/64) and secondary infections 23.44% (15/64) at the CMA of DO (Bobo-Dioulasso), 77.27% (17/22) and 22.73% (5/22) at the CMA of Houndé; and 72.22% (26/36) and 27.78% (10/36) at the Progrès Medical Laboratory in Ouagadougou (Table 1). The median age of primary infection cases was 33 years, with 42.62% (52/122) male and 32.8% (40/122) female, with a sex ratio of male to female of 1.3. For secondary infections, the median age was 24 years, with 14.00 % (17/122) male and 10.58% (13/122) female, with a male-to-female ratio of 1.3 (Table 1). In 2024, primary infections accounted for 67.44% (29/43) and secondary infections 32.56% (14/43) at the Eureka Medical Center (Bobo Dioulasso); 73.68% (14/19) and 26.32% (5/19) at the CMA of Houndé; and 93.33% (28/30) and 6.67 % (2/30) at the CHR of Gaoua (Table 1). The median age of primary infection cases was 27 years; 42.39% (39/92) were male, and 34.78% (32/92) were female, with a male-to-female ratio of 1.2 (Table 1). For secondary infection cases, the median age was 32 years, with 13.04% (12/92) male and 9.79% (9/92) female, for a male-to-female ratio of 1.3 (Table 1). In 2025, primary infections accounted for 68.18 % (15/22) and secondary infections 31.82% (7/22) at the Eureka Medical Center (Bobo-Dioulasso); 72.72% (8/11) and 27.27% (3/11) at the CMA of Houndé, 65.38% (17/26) and 34.62% (9/26) at the Progrès Medical Laboratory, 72.22% (13/18) and 27.78% (5/18) at the CHR of Gaoua (Table 1). The median age of primary infection cases was 31 years, with 32.46% (25/77) male and 36.36% (28/77) female, with a male-to-female ratio of 0.8. For secondary infection, the median age was 33 years, with 16.88% (13/77) male and 14.3% (11/77) female, with a male-to-female ratio of 1.1 (Table 1). In this study, primary dengue infection predominated over secondary infection during the three-years (2023, 2024, 2025), with 2023 recording the highest number of confirmed cases. This peak corresponds to the dengue outbreaks reported in Burkina Faso between August and November 2023 [3,4]. The highest prevalence of primary infection was observed in the 21-30-year age group, followed by the 31-40-year age group. Age stratification is essential for dengue management as disease expression varies across age groups. Previous studies have shown that primary DENV infections in young children are often asymptomatic, whereas adults experiencing a first infection are more likely to develop symptomatic dengue fever. In contrast, dengue hemorrhagic fever (DHF) rates are higher among children than in adults during secondary DENV-2 infection, potentially due to age-related differences in susceptibility to vascular permeability. Additionally, elderly individuals may be at increased risk of disease complications [21,22]. In our study, males constituted the majority of both primary and secondary dengue cases. No significant sex differences were observed in the distribution of infection status in 2023 and 2025; however, a significant difference was identified in 2024. Sex has been reported to influence dengue severity, with girls older than four years having a higher risk of developing severe dengue compared with boys of any age [21]. In this study, primary dengue infection predominated across all study sites, with the highest proportions observed in Bobo-Dioulasso and Ouagadougou, the economic and political capitals of Burkina Faso, respectively. These major urban centers experience substantial population movement because the road linking Ouagadougou to Bobo-Dioulasso and continuing to Côte d'Ivoire strongly supports migration and economic growth, which may facilitate dengue transmission [23]. Dengue is strongly linked to the urban environment due to the proliferation of mosquito vectors, particularly A. aegypti , whose breeding is promoted by inadequate waste management, prolonged water storage in domestic containers for routine household use, high population density, and human mobility. These factors contribute to increased transmission in urban compared with rural settings [24,25]. Assessing the geographic distribution of dengue primary and secondary infections is essential for identifying outbreak-prone areas, optimizing clinical management to reduce mortality, and implementing targeted vector control strategies to limit disease spread. Furthermore, understanding the spatial distribution of prior DENV exposure is critical for informing vaccination strategies, as current dengue vaccines are recommended primarily for individuals with previous infection[17]. Table 1 Demographic characteristics and primary and secondary dengue infection distribution 2023 2024 2025 Confirmed dengue (N=122), n Primary dengue (N=92), n (%) Secondary dengue (N=30), n (%) Confirmed dengue (N=92), n Primary dengue (N=71), n (%) Secondary dengue (N=21), n (%) Confirmed dengue (N=77), n Primary dengue (N=53), n (%) Secondary dengue (N=24), n (%) Sex Male 69 52 (42.62) 17 (14.00) 56 39 (42.39) 12 (13.04) 38 25 (32.46) 13 (16.88) Female 53 40 (32.8) 13 (10.58) 36 32 (34.78) 9 (9.79) 39 28 (36.36) 11 (14.3) P Value 1 0.07426 0.7469 Age (year) Median 32 33 24 28 27 32 32 31 33 Age groups ]5-20] 19 15 (78.95) 4 (21.05) 20 14 (70.00) 6 (30.00) 13 10 (76.92) 3 (23.08) [21-30] 37 24 (64.86) 13 (35.14) 33 30 (91.00) 3 (9.00) 22 15 (68.18) 7 (31.82) [31-40] 31 22 (70.97) 9 (29.03) 20 14 (70.00) 6 (30.00) 19 11 (57.89) 8 (42.11) [41-50] 21 18 (85.71) 3 (14.29) 8 7 (87.5) 1 (12.5) 12 9 (75.0) 3 (25.0) ≥ 51 14 13 (92.86) 1 (7.14) 11 8 (72.72) 3 (27.28) 11 8 (72.72) 3 (27.27) P Value 0.125 0.3865 0.8238 Sites CMA DO 64 49 (76.56) 15 (23.44) NA NA NA NA NA NA EUK NA NA NA 43 29 (67.44) 14 (32.56) 22 15 (68.18) 7 (31.82) CMA Houndé 22 17 (77.27) 5 (22.73) 19 14 (73.68) 5 (26.32) 11 8 (72.72) 3 (27.27) Progrès Lab 36 (100) 26 (72.22) 10 (27.78) NA NA NA 26 17 (65.38) 9 (34.62) CHR of Gaoua NA NA NA 30 28 (93.33) 2 (6.67) 18 13 (72.22) 5 (27.78) P Value 0.8485 0.1576 0.9851 NA: not applicable Warning clinical manifestations associated with dengue infection status Warning signs were markedly less frequent in primary dengue infection than in secondary infection. Among patients with primary dengue (n=216), abdominal pain was reported in 7.87 % (17/216) and persistent vomiting in 2,31% (5/216), while 92.13% (199/216) presented without warning signs (Fig. 2). In contrast, among patients with secondary dengue infection (n=75), abdominal pain occurred in 54.66% (41/75) and persistent vomiting in 29.33% (22/75), although 45.43 % (34/75) had no warning signs (Fig. 2). The differences between primary and secondary infections were highly significant for both abdominal pain (P< 2.2 10 -16 ) and persistent vomiting (P< 1.85 10 -11 ). Overall, warning signs were significantly more frequent in secondary dengue infection than primary infection. These findings are consistent with previous reports [26–28]. Secondary infection is associated with an increased risk of severe dengue, potentially mediated by antibody-dependant enhancement (ADE) [12]. Severe complications, including hemorrhagic manifestations, occur more commonly in secondary infections. Therefore, early differentiation between primary and secondary dengue infection has important prognostic and clinical implications. Incorporating this distinction into the dengue diagnostic algorithm could improve risk profiling, optimize patient management, and reduce the risk of severe outcomes and mortality, particularly among vulnerable populations such as older adults with comorbidities and children. Temporal distribution of dengue virus serotypes In 2023, among laboratory-confirmed dengue cases, DENV-1 accounted for 20.5% (25/122), DENV-2 for 3.27% (4/122), and DENV-3 for 76.23% (93/122) (Fig. 3). In 2024, DENV-1 predominated, representing 69.57% (66/92) of confirmed cases, followed by DENV-3 at 27.17% (25/92), and DENV-2 at 3.26% (3/92) (Fig. 3). In 2025, DENV-1 remained the most prevalent serotype at 71.42% (55/77), while DENV-2 and DENV-3 accounted for 15.58% (12/77) and 13% (10/77) of cases, respectively (Fig. 3). DENV-4 was not detected during the study period. Burkina Faso is currently experiencing dengue outbreaks characterized by dynamic shifts in circulating DENV serotypes. In 2023, the country reported a major outbreak marked by the predominance of DENV-3, followed by DENV-1. In 2024, DENV-1 became the dominant serotype, with DENV-3 detected at lower frequency. This trend persisted in 2025, when DENV-1 remained predominant, followed by DENV-2. These temporal changes in serotype distribution likely contributed to the high proportion of primary dengue infections observed during the study period. Infection with a given DENV serotype confers long-term immunity against that specific serotype; however, it does not provide cross-protective immunity against the other serotypes, leaving individuals susceptible to subsequent heterologous infections [11]. Prior to 2023, DENV-1 and DENV-2 were the principal circulating serotypes in Burkina Faso [29]. The emergence and predominance of DENV-3 in 2023 consequently represent a significant epidemiological shift, which may explain the increase in primary dengue cases that year. Notably, secondary dengue infections were also particularly frequent in 2023. The increased severity of dengue reported during this period may be attributable to the high rate of secondary infections in combination with the predominance of DENV-3, a serotype previously associated with more severe clinical outcomes[30]. The concurrent circulation of multiple serotypes in this study suggests sustained viral introduction and/or endemic transmission, which may progressively shift the immune landscape toward an increasing proportion of secondary infections over time. Historically, DENV-2 predominated in 2016 and 2017[29,31]. In 2021 and 2022, all four DENV serotypes co-circulated in Burkina Faso, with DENV-1 predominating[32]. Sporadic cases of DENV-4 were reported between 2020 and 2022 [32,33]. In the present study, however, DENV-4 was not detected, consistent with the findings reported by Ouattara et al. (2025) [32]. This study provides critical evidence to inform dengue diagnostic strategies, clinical management, and vaccine implementation policies in Burkina Faso. Dengue incidence has increased in recent years in this setting, likely reflecting the combined effects of tropical climatic conditions, vector breeding, and competence and enhanced viral circulation. The high prevalence of primary DENV infections observed, together with the circulation of multiple serotypes, underscores an elevated risk for future severe disease and has important implications for the timing and targeting of dengue vaccination strategies. Serological status is a key determinant of vaccine eligibility and performance, as individuals with prior dengue exposure (seropositive) may derive greater benefit from vaccination. Dengvaxia was the first dengue vaccine approved by WHO for use in seropositive children. However, its use in dengue-naïve individuals has been associated with an increased risk of severe dengue, limiting its applicability in populations with low baseline seroprevalence [34]. Moreover, Qdenga (TAK-003) was recently approved by the WHO. According to Tricou et al. (2024), its five-year cumulative efficacy was 61.2% against virologically confirmed dengue and 84.1% against dengue-related hospitalization. In those with prior DENV exposure, TAK-003 showed favorable efficacy and safety against all four serotypes (DENV1 to DENV-4), while in seronegative individuals, it provided protection against DENV-1 and strong protection against DENV-2, but no significant efficacy against virologically confirmed dengue or dengue-related hospitalization due to DENV-3 and DENV-4 [35]. Borja-Tabora et al. (2024) further reported that TAK-003 effectively prevented dengue in children and adolescents aged 4–16 years living in endemic areas [36]. The findings of this study provide evidence that can inform the Burkina Faso Ministry of Health in strengthening dengue diagnostic capacity and surveillance systems, as well as in guiding decisions regarding the introduction of the dengue vaccine in the country’s two big largest urban centers. In particular, the tetravalent dengue vaccine Qdenga (TAK-003) may be a relevant option in the Burkinabe context, based on the sero-epidemiological patterns observed. Given reports of homotypic reinfections with DENV serotypes [37,38] ,implementation of vaccination could contribute to reducing the risk of severe dengue and related complications, especially among children and other high-risk groups, thereby strengthening public health protection. This study has some limitations. The analysis did not include samples from all regions of the country, did not cover all months of the year, and lacked convalescent sera from previously confirmed dengue cases. However, as a pilot investigation focused on acute dengue patients, it provides important preliminary insights. Future studies will include nationwide sampling, year-round data collection, and the analysis of convalescent sera. In addition, molecular characterization of DENV genotypes will be undertaken to better understand serotype diversity, viral evolution, and transmission dynamics. Conclusion This study reports the highest prevalence of primary dengue infection in Burkina Faso, predominantly in the urban centers of Ouagadougou and Bobo-Dioulasso, and documents temporal variation in circulating DENV serotypes across different years. Given the association between warning signs and secondary dengue infection, these findings highlight the need for strengthened surveillance using early detection, distinction between primary and secondary dengue infection for disease control, and vaccine implementation. Qdenga (TAK-003) vaccine may be a relevant option in the Burkina context Declarations Acknowledgments We sincerely thank the Director and staff of Eureka Medical Center, CMA of DO, CMA of Houndé, the Progrès Medical Laboratory, and the Regional Hospital (CHR) of Gaoua for study approval and their hard work in patient’s enrolment. Author contributions Conceptualization: Louis Robert Wendyam Belem, Arsene Zongo, Adama Sanou, Antoinette Kaboré. Methodology: Louis Robert Wendyam Belem, Raymond Karlhis Yao, Christel Lankouandé, Armand Vital Wenceslas TAITA, Philippe Kaboré, Abdoul Bamogo, Mireille Dsouza, Yacouba Kouadima. Data curation: Louis Robert Wendyam Belem, Raymond Karlhis Yao, Tarwendpanga François Xavier Ouédraogo. Writing – original draft: Louis Robert W. Belem. Writing – review & editing: Adama Sanou, Arsene Zongo, Dieudonne Tialla. Supervision: Louis Robert Wendyam Belem, Adama Sanou, Antoinette Kaboré. Funding This research was supported by the Fond National de la Re­cherche et de l’Innovation pour le Devéloppement of Burkina Faso (Grant No. FONRID/AAP-Spécial-Jeunes/NCP/PCD/2022) and Cen­tre d’Excellence Africain en Innovations Biotechnologiques pour l’Elimination des Maladies à Transmission Vectorielle of Burkina Faso (Grant No.2020 − 000178/MESRSI/SG/UNB/P). Data availability Data are included in this manuscript, and data base can be provided if request. Ethics approval and consent to participate This study was approved by the Regional Health Department of Guiriko (No. 2021-0294/MS/RHBS/DRS) and the Health Science Research Institute of Burkina Faso Ethics Committee (No. A026-2023/CEIRES/IRSS). Written informed consent was obtained from all participants, and confidentiality was strictly maintained. For minors included in this study, consent was provided by the parents or legally authorized representatives. Consent for publication Not applicable. Competing interests The authors declare no competing interests. References Blessmann J, Winkelmann Y, Keoviengkhone L, Sopraseuth V, Kann S, Hansen J, et al. Assessment of diagnostic and analytic performance of the SD Bioline Dengue Duo test for dengue virus (DENV) infections in an endemic area (Savannakhet province, Lao People’s Democratic Republic). PLoS One. 2020;15(3). https://doi.org/10.1371/journal.pone.0230337. OMS. 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Glob Transit. 2026 ;8(1):10–21. https://doi.org/10.1016/j.glt.2025.08.003. Lovera D, Martínez-Cuellar C, Galeano F, Amarilla S, Vazquez C, Arbo A. Clinical manifestations of primary and secondary dengue in Paraguay and its relation to virus serotype. J Infect Dev Ctries. 2019;13(12):1127–34. https://doi.org/10.3855/jidc.11584. Aggarwal C, Ahmed H, Sharma P, Reddy ES, Nayak K, Singla M, et al. Severe disease during both primary and secondary dengue virus infections in pediatric populations. Nat Med. 2024 Mar 1;30(3):670–4. https://doi.org/10.1038/s41591-024-02798-x. Shih HI, Wang YC, Wang YP, Chi CY, Chien YW. Risk of severe dengue during secondary infection: A population-based cohort study in Taiwan. Journal of Microbiology, Immunology and Infection. 2024 Oct 1;57(5):730–8. https://doi.org/10.1016/j.jmii.2024.07.004. Tarnagda Z, Cissé A, Bicaba BW, Diagbouga S, Sagna T, Ilboudo AK, et al. Dengue Fever in Burkina Faso, 2016. Emerg Infect Dis. 2018 ;24(1):170–2. https://doi.org/10.3201/eid2401.170973. Soo KM, Khalid B, Ching SM, Chee HY. Meta-analysis of dengue severity during infection by different dengue virus serotypes in primary and secondary infections. PLoS One. 2016 ;11(5). https://doi.org/10.1371/journal.pone.0154760. Letizia AG, Pratt CB, Wiley MR, Fox AT, Mosore M, Agbodzi B, et al. Retrospective Genomic Characterization of a 2017 Dengue Virus Outbreak, Burkina Faso. Emerg Infect Dis. 2022;28(6):1198–210. https://doi.org/10.3201/eid2806.212491. Bello SOT, Tapsoba ASA, Zoure AA, Bassole YJR, Yogo WLSK, Bado P, et al. Molecular Characterization of the Four Serotypes (DENV-1, DENV-2, DENV-3 and DENV-4) of Dengue Virus Circulating in Ouagadougou, Burkina Faso. Open J Epidemiol. 2024;14(04):565–78. https://doi.org/10.4236/ojepi.2024.144040. Tinto B, Patindé D, Kaboré A, Kania D, Samdapawindé Kagoné T, Kiba-Koumaré A, et al. Serological Evidence of Zika Virus Circulation in Burkina Faso. 2022; 11(7) 741. https://doi.org/10.3390/pathogens11070741. Woodland DL. Dengue Vaccines. Viral Immunology. Mary Ann Liebert Inc.; 2019;6(32)235. https://doi.org/10.1089/vim.2019.29039.dlw. Tricou V, Yu D, Reynales H, Biswal S, Saez-Llorens X, Sirivichayakul C, et al. Long-term efficacy and safety of a tetravalent dengue vaccine (TAK-003): 4·5-year results from a phase 3, randomised, double-blind, placebo-controlled trial. Lancet Glob Health. 2024 ;12(2):e257–70. https://doi.org/10.1016/S2214-109X(23)00522-3. Borja-Tabora C, Fernando LK, Lopez Medina E, Reynales H, Rivera L, Saez-Llorens X, et al. Immunogenicity, Safety, and Efficacy of a Tetravalent Dengue Vaccine in Children and Adolescents: An Analysis by Age Group. Clinical Infectious Diseases. 2025;80(1):199–206. https://doi.org/10.1093/cid/ciae369. Waggoner JJ, Balmaseda A, Gresh L, Sahoo MK, Montoya M, Wang C, et al. Homotypic Dengue Virus Reinfections in Nicaraguan Children. Journal of Infectious Diseases. 2016 ;214(7):986–93. https://doi.org/10.1093/infdis/jiw099. Anggriani N, Tasman H, Ndii MZ, Supriatna AK, Soewono E, Siregar E. The effect of reinfection with the same serotype on dengue transmission dynamics. Appl Math Comput. 2019 ;349:62–80. https://doi.org/10.1016/j.amc.2018.12.022. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted 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-9140004","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":610196895,"identity":"537857d3-891e-4156-9ee5-f5e1392c56ec","order_by":0,"name":"Louis Robert Wendyam 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Nazi Boni, Bobo-Dioulasso, Burkina Faso","correspondingAuthor":false,"prefix":"","firstName":"Yacouba","middleName":"","lastName":"Kouadima","suffix":""},{"id":610196922,"identity":"7be2d7e0-4d77-432f-bb97-6d412e571816","order_by":10,"name":"Dieudonne Tialla","email":"","orcid":"","institution":"Laboratoire de Microbiologie-Epidémiologie, de Zoonoses et de One Health, Institut de Recherche en Sciences de la Santé, Ouagadougou, Burkina Faso","correspondingAuthor":false,"prefix":"","firstName":"Dieudonne","middleName":"","lastName":"Tialla","suffix":""},{"id":610196925,"identity":"64cf6885-035b-4662-9cbd-db2bd936001e","order_by":11,"name":"Antoinette Kaboré","email":"","orcid":"","institution":"Laboratoire Central de Référence, Institut National de Santé Publique (LNR/INSP), Ouagadougou, Burkina Faso","correspondingAuthor":false,"prefix":"","firstName":"Antoinette","middleName":"","lastName":"Kaboré","suffix":""},{"id":610196929,"identity":"195b485b-174c-413a-9b9f-39737f4f0223","order_by":12,"name":"Adama Sanou","email":"","orcid":"","institution":"Ecole Doctorale Sciences Naturelles et Agronomiques (ED-SNA), Université Nazi Boni, Bobo-Dioulasso, Burkina Faso","correspondingAuthor":false,"prefix":"","firstName":"Adama","middleName":"","lastName":"Sanou","suffix":""}],"badges":[],"createdAt":"2026-03-16 15:55:30","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9140004/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9140004/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":105319134,"identity":"907e2594-06ca-4ed6-a76e-c8a4559e6da3","added_by":"auto","created_at":"2026-03-24 16:59:10","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":356044,"visible":true,"origin":"","legend":"\u003cp\u003eStudy areas location\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-9140004/v1/0089850120ac940e462860d3.png"},{"id":105319132,"identity":"ea2f9cdf-6cab-4ef2-aedc-2c82360c0319","added_by":"auto","created_at":"2026-03-24 16:59:10","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":87764,"visible":true,"origin":"","legend":"\u003cp\u003eDengue infection status and warning signs distribution\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-9140004/v1/845158d6ea3f78f0931186cf.png"},{"id":105319131,"identity":"a9640b1a-0e19-48b5-ab23-2bcbb1250bcc","added_by":"auto","created_at":"2026-03-24 16:59:10","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":66480,"visible":true,"origin":"","legend":"\u003cp\u003eDistribution of dengue virus serotypes over time\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-9140004/v1/1c9e4bc2e6d573d0b5648b92.png"},{"id":107869402,"identity":"2ec65161-a725-4acb-9069-78b6355fc353","added_by":"auto","created_at":"2026-04-27 07:36:58","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":739033,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9140004/v1/97663bf4-6886-4999-9037-ece1e7cf2acc.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Geographic and temporal distribution of primary and secondary dengue cases in Burkina Faso from 2023-2025: a hospital-based cross-sectional study","fulltext":[{"header":"Introduction","content":"\u003cp\u003eDengue virus (DENV) is the most widely distributed arbovirus worldwide, primarily due to population growth and urbanization. Globalization and climate change facilitate the geographic spread of both the mosquito vector and the pathogen to previously unaffected areas[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. According to the World Health Organization (WHO), over 5\u0026nbsp;million dengue cases and 3,000 deaths were reported in early December 2025 in several regions, including the Americas, Asia, and Africa [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. In Burkina Faso, DENV is responsible for outbreaks characterized by high prevalence and substantial morbidity and mortality. Between August and November 2023, Burkina Faso reported important DENV outbreaks with 146,878 suspected cases and 688 deaths [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. DENV belongs to the \u003cem\u003eFlaviviridae\u003c/em\u003e family, its genome is ribonucleic acid (RNA), and is classified into four genetically different serotypes (DENV1-4) [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Dengue is transmitted by the bite of infected \u003cem\u003eAedes\u003c/em\u003e mosquitoes, mainly \u003cem\u003eAedes (Ae) aegypti\u003c/em\u003e and \u003cem\u003eAe. albopictus\u003c/em\u003e [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e], and represents a major public health problem in tropical and subtropical regions [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. DENV infection can vary in presentation, ranging from asymptomatic cases or mild illness with symptoms to severe disease. Severe dengue is characterized by vascular permeability, plasma leakage, massive bleeding, and, in some cases, liver compromise, organ impairment, and even death [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Although primary infection with a single DENV serotype induces long-term homologous protective immunity, subsequent infection with a different serotype is associated with more severe clinical outcomes [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. A secondary heterotypic DENV infection has been recognized as a key driver of disease severity, primarily through antibody-dependent enhancement (ADE). In this immunopathological process, immunoglobulin G (IgG) complexes promote enhanced viral replication, leading to the release of proinflammatory cytokines and chemokines that increase vascular permeability and can ultimately result in shock [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eDuring primary infection, immunoglobulin M (IgM) antibodies are the first immunoglobulin isotype to appear. Anti-dengue IgM antibodies are detectable in only a few patients between days 2 and 4 after symptom onset. By day 5 of illness, approximately 80% of patients exhibit detectable IgM, increasing to 93\u0026ndash;99% between days 6 and 10 post-onset. Anti-dengue IgM may persist for more than 90 days. Low levels of anti-dengue IgGs become detectable by the end of the first week of illness and can persist for several months, potentially remaining detectable for life. In secondary dengue infection, IgG antibodies are rapidly produced and represent the dominant isotype from the onset of symptoms, while IgM levels are low or often undetectable during the acute phase [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e].Primary and secondary DENV infections can be distinguished by analyzing dengue specific immunoglobulin responses during the acute phase of the infection, defined as the first eight days of symptom onset[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eAlthough two dengue vaccines (Dengvaxia\u0026reg; CYD-TDV and Qdenga\u0026reg;TAK-003) have been approved by the WHO, their efficacy and safety are influenced by serotype, pre-existing dengue immunity, and age, which limits their broader implementation [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. Therefore, accurate diagnosis during the early febrile phase of dengue is critical to prevent unnecessary and costly diagnostic procedures, avoid potentially harmful antibiotic use, ensure timely and appropriate interventions at both primary and secondary care levels, and facilitate early detection of outbreaks. In resource-limited settings, rapid diagnostic test (RDT) kits are the primary diagnostic tool as they do not require costly laboratory equipment and remain stable under suboptimal storage conditions [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. However, false-positive results have been reported, representing a limitation of dengue diagnosis [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Molecular diagnostics are considered the gold standard for dengue detection [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. Combining molecular techniques with RDTs and enzyme-linked immunosorbent assays (ELISAs) can facilitate early diagnosis, determination of DENV serotypes, discrimination between primary and secondary infections, and assessment of endemicity. These data are essential for public health decision-making, forecasting severe dengue risk, and, given that vaccine efficacy depends on baseline serostatus, for predicting the impact of dengue vaccination at the population level [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. To date, no spatiotemporal characterization of dengue primary and secondary infections has been conducted in Burkina Faso, and no dengue vaccine has yet been introduced. Differentiating primary from secondary DENV infections is crucial for elucidating dengue transmission dynamics and epidemiology in Burkina Faso. This study aimed to determine the geographic and temporal distribution of primary and secondary DENV infections, and to incorporate differentiation of infection status into diagnostic, surveillance, and pre-vaccination screening protocols.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003e\u003cstrong\u003eStudy sites\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was conducted during June to September of 2023, 2024, and 2025 across three regions of Burkina Faso, including four cities: Bobo-Dioulasso, Hound\u0026eacute;, Ouagadougou, and Gaoua (Fig. 1). Burkina Faso, a West African country, has a tropical climate with distinct dry (November to May) and wet seasons (June to October). Bobo-Dioulasso, the economic capital and capital of the Guiriko region, is located in Houet province (11\u0026deg;11\u0026prime;00\u0026Prime; North, 4\u0026deg;17\u0026prime;00\u0026Prime; West). Hound\u0026eacute;, a city in Tuy province, is also located within the Guiriko region (11\u0026deg;30\u0026prime; North, 3\u0026deg;31\u0026prime; West). Ouagadougou, the national capital and largest city of Burkina Faso, lies in the Kadiogo region, at the heart of the intertropical zone (12\u0026deg; 21\u0026prime; 58\u0026Prime; North, 1\u0026deg; 31\u0026prime; 05\u0026Prime; West). Gaoua is located in the Dj\u0026ocirc;r\u0026ocirc; region (10\u0026deg; 20\u0026prime; 00\u0026Prime; north, 3\u0026deg; 11\u0026prime; 00\u0026Prime; west). Study participants were recruited from the Centers with Surgical Antenna (CMA) of DO and Eureka Medical Center in Bobo-Dioulasso, the CMA of Hound\u0026eacute;, the Progr\u0026egrave;s Medical Laboratory in Ouagadougou, and the Regional Hospital (CHR) of Gaoua.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStudy design\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eParticipants were enrolled based on the presence of clinical symptoms, including fever, headache, chills, abdominal pain, rash, joint and muscle pain, vomiting, conjunctival hyperemia, and retroorbital pain. Persisting vomit and abdominal pain were considered to be warning signs that can lead to severe disease. \u0026nbsp;Whole blood sample (3-5 mL) was collected from each participant into serum separation tubes and centrifuged at 1500 rpm for 5 minutes to separate the serum. The resulting serum was aliquoted into two separate vials (200 \u0026micro;l/vial) and stored at -80\u0026deg;C before analysis, including RDTs, RNA extraction, ELISA, and DENV molecular detection. RDTs were performed using Dengue Non-Structural 1 (NS1) Antigen and IgG/IgM Antibody kits (Colloidal Gold, Wondfo, China). Primary and secondary infections were distinguished based on serological and molecular results: \u0026nbsp;cases positive by RT-PCR with detectable anti-DENV IgM but negative anti-DENV IgG were classified as primary infections, whereas RT-PCR positive cases with detectable anti-DENV IgG, regardless of IgM status, were classified as secondary infections. These criteria have been widely adopted in previous studies [10,17\u0026ndash;19].\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMolecular detection of DENV1-4\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe viral RNA was extracted from 140 \u0026micro;L of human serum using the QIAamp Viral RNA Mini Kit (Qiagen, Hilden, Germany). Detection of DENV serotypes 1-4 was performed using the PrimeScript One Step RT-PCR Kit (Takara Bio Inc) following the protocol previously described [20].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;Data management and statistical analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eProportions and ratios were calculated for categorical variables, including sex, age, geographic area, clinical manifestations, dengue infection status (primary or secondary), and DENV serotype. Fisher\u0026apos;s exact test was applied for categorical variables with expected counts less than five, while the Chi-square test was performed for variables with expected counts of five or more. Statistical significance was defined as p \u0026le; 0.05. All analyses were conducted using R version 4.3.1.\u003c/p\u003e"},{"header":"Results and discussion","content":"\u003cp\u003e\u003cstrong\u003ePatient\u0026rsquo;s characteristics and geographic distribution of\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eprimary and secondary dengue infection\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAmong suspected cases, molecular testing confirmed 122, 92, and 77 dengue cases in 2023, 2024, and 2025, respectively. The distribution of primary and secondary infections varied by location and year. \u0026nbsp;In 2023, primary infections accounted for 76.56% (49/64) and secondary infections 23.44% (15/64) at the CMA of DO (Bobo-Dioulasso), 77.27% (17/22) and 22.73% (5/22) at the CMA of Hound\u0026eacute;; and 72.22% (26/36) and 27.78% (10/36) at the Progr\u0026egrave;s Medical Laboratory in Ouagadougou (Table 1). The median age of primary infection cases was 33 years, with 42.62% (52/122) male and 32.8% (40/122) female, with a sex ratio of male to female of 1.3. \u0026nbsp;For secondary infections, the median age was 24 years, with 14.00 % (17/122) male and 10.58% (13/122) female, with a male-to-female ratio of 1.3 (Table 1).\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;In 2024, primary infections accounted for 67.44% (29/43) and secondary infections 32.56% (14/43) at the Eureka Medical Center (Bobo Dioulasso); 73.68% (14/19) and 26.32% (5/19) at the CMA of Hound\u0026eacute;; and 93.33% (28/30) and 6.67 % (2/30) at the CHR of Gaoua (Table 1). The median age of primary infection cases was 27 years; 42.39% (39/92) were male, and 34.78% (32/92) were female, with a male-to-female ratio of 1.2 (Table 1). For secondary infection cases, the median age was 32 years, with 13.04% (12/92) male and 9.79% (9/92) female, for a male-to-female ratio of 1.3 (Table 1).\u003c/p\u003e\n\u003cp\u003eIn 2025, primary infections accounted for 68.18 % (15/22) and secondary infections 31.82% (7/22) at the Eureka Medical Center (Bobo-Dioulasso); 72.72% (8/11) and 27.27% (3/11) at the CMA of Hound\u0026eacute;, 65.38% (17/26) and 34.62% (9/26) at the Progr\u0026egrave;s Medical Laboratory, 72.22% (13/18) and 27.78% (5/18) at the CHR of Gaoua (Table 1). The median age of primary infection cases was 31 years, with 32.46% (25/77) male and 36.36% (28/77) female, with a male-to-female ratio of 0.8. For secondary infection, the median age was 33 years, with 16.88% (13/77) male and 14.3% (11/77) female, with a male-to-female ratio of 1.1 (Table 1).\u003c/p\u003e\n\u003cp\u003eIn this study, primary dengue infection predominated over secondary infection during the three-years (2023, 2024, 2025), with 2023 recording the highest number of confirmed cases. This peak corresponds to the dengue outbreaks reported in Burkina Faso between August and November 2023 [3,4]. The highest prevalence of primary infection was observed in the 21-30-year age group, followed by the 31-40-year age group. Age stratification is essential for dengue management as disease expression varies across age groups. \u0026nbsp;Previous studies have shown that primary DENV infections in young children are often asymptomatic, whereas adults experiencing a first infection are more likely to develop symptomatic dengue fever. In contrast, dengue hemorrhagic fever (DHF) rates are higher among children than in adults during secondary DENV-2 infection, potentially due to age-related differences in susceptibility to vascular permeability. Additionally, elderly individuals may be at increased risk of disease complications [21,22].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIn our study, males constituted the majority of both primary and secondary dengue cases. \u0026nbsp;No significant sex differences were observed in the distribution of infection status in 2023 and 2025; however, a significant difference was identified in 2024. Sex has been reported to influence dengue severity, with girls older than four years having a higher risk of developing severe dengue compared with boys of any age [21].\u003c/p\u003e\n\u003cp\u003eIn this study, primary dengue infection predominated across all study sites, with the highest proportions observed in Bobo-Dioulasso and Ouagadougou, the economic and political capitals of Burkina Faso, respectively. These major urban centers experience substantial population movement because the road linking Ouagadougou to Bobo-Dioulasso and continuing to C\u0026ocirc;te d\u0026apos;Ivoire strongly supports migration and economic growth, which may facilitate dengue transmission \u0026nbsp;[23]. Dengue is strongly linked to the urban environment due to the proliferation of mosquito vectors, particularly \u003cem\u003eA. aegypti\u003c/em\u003e, whose breeding is promoted by inadequate waste management, prolonged water storage in domestic containers for routine household use, high population density, and human mobility. These factors contribute to increased transmission in urban compared with rural settings [24,25]. Assessing the geographic distribution of dengue primary and secondary infections is essential for identifying outbreak-prone areas, optimizing clinical management to reduce mortality, and implementing targeted vector control strategies to limit disease spread. Furthermore, understanding the spatial distribution of prior DENV exposure is critical for informing vaccination strategies, as current dengue vaccines are recommended primarily for individuals with previous infection[17].\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 1\u003c/strong\u003e Demographic characteristics and primary and secondary dengue infection distribution\u003c/p\u003e\n\u003ctable style=\"width: 5.8e+2pt\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\"\u003e\n \u003cp\u003e\u003cstrong\u003e2023\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\"\u003e\n \u003cp\u003e\u003cstrong\u003e2024\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\"\u003e\n \u003cp\u003e\u003cstrong\u003e2025\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eConfirmed dengue (N=122), n\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003ePrimary dengue (N=92), n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eSecondary dengue (N=30), n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eConfirmed dengue (N=92), n\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003ePrimary dengue (N=71), n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eSecondary dengue (N=21), n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eConfirmed dengue (N=77), n\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003ePrimary dengue (N=53), n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eSecondary dengue (N=24), n (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eSex\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eMale\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e69\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e52 (42.62)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e17 (14.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e56\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e39 (42.39)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e12 (13.04)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e38\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e25 (32.46)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e13 (16.88)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eFemale\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e53\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e40 (32.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e13 (10.58)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e36\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e32 (34.78)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e9 (9.79)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e39\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e28 (36.36)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e11 (14.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eP Value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\"\u003e\n \u003cp\u003e0.07426\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\"\u003e\n \u003cp\u003e0.7469\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eAge (year)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eMedian\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e32\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e33\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e24\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e28\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e27\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e32\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e32\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e31\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e33\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eAge groups\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e]5-20]\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e19\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e15 (78.95)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e4 (21.05)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e20\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e14 (70.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e6 (30.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e13\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e10 (76.92)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e3 (23.08)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e[21-30]\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e37\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e24 (64.86)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e13 (35.14)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e33\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e30 (91.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e3 (9.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e22\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e15 (68.18)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e7 (31.82)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e[31-40]\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e31\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e22 (70.97)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e9 (29.03)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e20\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e14 (70.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e6 (30.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e19\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e11 (57.89)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e8 (42.11)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e[41-50]\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e21\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e18 (85.71)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e3 (14.29)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e8\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e7 (87.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1 (12.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e12\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e9 (75.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e3 (25.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026ge; 51\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e14\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e13 (92.86)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1 (7.14)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e11\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e8 (72.72)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e3 (27.28)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e11\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e8 (72.72)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e3 (27.27)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eP Value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\"\u003e\n \u003cp\u003e0.125\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\"\u003e\n \u003cp\u003e0.3865\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\"\u003e\n \u003cp\u003e0.8238\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eSites\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eCMA DO\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e64\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e49 (76.56)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e15 (23.44)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eEUK\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e43\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e29 (67.44)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e14 (32.56)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e22\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e15 (68.18)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e7 (31.82)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eCMA Hound\u0026eacute;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e22\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e17 (77.27)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e5 (22.73)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e19\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e14 (73.68)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e5 (26.32)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e11\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e8 (72.72)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e3 (27.27)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eProgr\u0026egrave;s Lab\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e36 (100)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e26 (72.22)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e10 (27.78)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e26\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e17 (65.38)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e9 (34.62)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eCHR of Gaoua\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eNA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e28 (93.33)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e2 (6.67)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e18\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e13 (72.22)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e5 (27.78)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eP Value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\"\u003e\n \u003cp\u003e0.8485\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\"\u003e\n \u003cp\u003e0.1576\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\"\u003e\n \u003cp\u003e0.9851\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eNA: not applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eWarning clinical manifestations associated with\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003edengue infection status\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;Warning signs were markedly less frequent in primary dengue infection than in secondary infection. Among patients with primary dengue (n=216), abdominal pain was reported in 7.87 % (17/216) and persistent vomiting in 2,31% (5/216), while \u0026nbsp; 92.13% (199/216) presented without warning signs (Fig. 2). In contrast, among patients with secondary dengue infection (n=75), abdominal pain occurred in 54.66% (41/75) and persistent vomiting in 29.33% (22/75), although 45.43 % (34/75) had no warning signs (Fig. 2). \u0026nbsp;The differences between primary and secondary infections were highly significant for both abdominal pain (P\u0026lt; 2.2 10\u003csup\u003e-16\u0026nbsp;\u003c/sup\u003e) and persistent vomiting (P\u0026lt; 1.85 10\u003csup\u003e-11\u003c/sup\u003e). Overall, warning signs were significantly more frequent in secondary dengue infection than primary infection. \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;These findings are consistent with previous reports [26\u0026ndash;28]. Secondary infection is associated with an increased risk of severe dengue, potentially mediated by antibody-dependant enhancement (ADE) [12]. Severe complications, including hemorrhagic manifestations, occur more commonly in secondary infections. Therefore, early differentiation between primary and secondary dengue infection has important prognostic and clinical implications. Incorporating this distinction into the dengue diagnostic algorithm could improve risk profiling, optimize patient management, and reduce the risk of severe outcomes and mortality, particularly among vulnerable populations such as older adults with comorbidities and children.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTemporal distribution of dengue virus serotypes\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn\u0026nbsp;2023, among laboratory-confirmed dengue cases, DENV-1 accounted for 20.5% (25/122), DENV-2 for 3.27% (4/122), and DENV-3 for 76.23% (93/122) (Fig. 3). In 2024, DENV-1 predominated, representing 69.57% (66/92) of confirmed cases, followed by DENV-3 at 27.17% (25/92), and DENV-2 at 3.26% (3/92) (Fig. 3). In 2025, DENV-1 remained the most prevalent serotype at 71.42% (55/77), while DENV-2 and DENV-3 accounted for 15.58% (12/77) and 13% (10/77) of cases, respectively (Fig. 3). DENV-4 was not detected during the study period.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;Burkina Faso is currently experiencing dengue outbreaks characterized by dynamic shifts in circulating DENV serotypes. In 2023, the country reported a major outbreak marked by the predominance of DENV-3, followed by DENV-1. In 2024, DENV-1 became the dominant serotype, with DENV-3 detected at lower frequency. \u0026nbsp;This trend persisted in 2025, when DENV-1 remained predominant, followed by DENV-2.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThese temporal changes in serotype distribution likely contributed to the high proportion of primary dengue infections observed during the study period. Infection with a given DENV serotype confers long-term immunity against that specific serotype; however, it does not provide cross-protective immunity against the other serotypes, leaving individuals susceptible to subsequent heterologous infections [11]. Prior to 2023, DENV-1 and DENV-2 were the principal circulating serotypes in Burkina Faso [29]. The emergence and predominance of DENV-3 in 2023 consequently represent a significant epidemiological shift, which may explain the increase in primary dengue cases that year. Notably, secondary dengue infections were also particularly frequent in 2023. The increased severity of dengue reported during this period may be attributable to the high rate of secondary infections in combination with the predominance of DENV-3, a serotype previously associated with more severe clinical outcomes[30]. The concurrent circulation of multiple serotypes in this study suggests sustained viral introduction and/or endemic transmission, which may progressively shift the immune landscape toward an increasing proportion of secondary infections over time. \u0026nbsp;Historically, DENV-2 predominated in 2016 and 2017[29,31]. \u0026nbsp; In 2021 and 2022, all four DENV serotypes co-circulated in Burkina Faso, with DENV-1 predominating[32]. Sporadic cases of DENV-4 were reported between 2020 and 2022 [32,33]. \u0026nbsp;In the present study, however, DENV-4 was not detected, consistent with the findings reported by Ouattara et al. (2025) [32].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThis study provides critical evidence to inform dengue diagnostic strategies, clinical management, and vaccine implementation policies in Burkina Faso. Dengue incidence has increased in recent years in this setting, likely reflecting the combined effects of tropical climatic conditions, vector breeding, and competence and enhanced viral circulation. The high prevalence of primary DENV infections observed, together with the circulation of multiple serotypes, underscores an elevated risk for future severe disease and has important implications for the timing and targeting of dengue vaccination strategies. Serological status is a key determinant of vaccine eligibility and performance, as individuals with prior dengue exposure (seropositive) may derive greater benefit from vaccination. Dengvaxia was the first dengue vaccine approved by WHO for use in seropositive children. However, its use in dengue-na\u0026iuml;ve individuals has been associated with an increased risk of severe dengue, limiting its applicability in populations with low baseline seroprevalence [34]. Moreover, Qdenga (TAK-003) was recently approved by the WHO. According to Tricou et al. (2024), its five-year cumulative efficacy was 61.2% against virologically confirmed dengue and 84.1% against dengue-related hospitalization. \u0026nbsp;In those with prior DENV exposure, TAK-003 showed favorable efficacy and safety against all four serotypes (DENV1 to DENV-4), while \u0026nbsp; in seronegative individuals, it provided protection against DENV-1 and strong protection against DENV-2, but no significant efficacy against virologically confirmed dengue or dengue-related hospitalization due to DENV-3 and DENV-4 [35]. Borja-Tabora et al. (2024) further reported that TAK-003 effectively prevented dengue in children and adolescents aged 4\u0026ndash;16 years living in endemic areas [36].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe findings of this study provide evidence that can inform the Burkina Faso Ministry of Health in strengthening dengue diagnostic capacity and surveillance systems, as well as in guiding decisions regarding the introduction of the dengue vaccine in the country\u0026rsquo;s two big largest urban centers. In particular, the tetravalent dengue vaccine Qdenga (TAK-003) may be a relevant option in the Burkinabe context, based on the sero-epidemiological patterns observed. Given reports of homotypic reinfections with DENV serotypes [37,38] ,implementation of vaccination could contribute to reducing the risk of severe dengue and related complications, especially among children and other high-risk groups, thereby strengthening public health protection. \u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThis study has some limitations. The analysis did not include samples from all regions of the country, did not cover all months of the year, and lacked convalescent sera from previously confirmed dengue cases. However, as a pilot investigation focused on acute dengue patients, it provides important preliminary insights. Future studies will include nationwide sampling, year-round data collection, and the analysis of convalescent sera. In addition, molecular characterization of DENV genotypes will be undertaken to better understand serotype diversity, viral evolution, and transmission dynamics.\u0026nbsp;\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThis study reports the highest prevalence of primary dengue infection in Burkina Faso, predominantly in the urban centers of Ouagadougou and Bobo-Dioulasso, and documents temporal variation in circulating DENV serotypes across different years. Given the association between warning signs and secondary dengue infection, these findings highlight the need for strengthened surveillance using early detection, distinction between primary and secondary dengue infection for disease control, and vaccine implementation. Qdenga (TAK-003) vaccine may be a relevant option in the Burkina context\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgments\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe sincerely thank the Director and staff of Eureka Medical Center,\u0026nbsp;CMA of\u0026nbsp;DO, CMA\u0026nbsp;of Hound\u0026eacute;, the Progr\u0026egrave;s Medical Laboratory, and the Regional Hospital (CHR) of Gaoua for study approval and\u0026nbsp;their hard work in patient\u0026rsquo;s enrolment.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eConceptualization: Louis Robert Wendyam Belem,\u0026nbsp;Arsene Zongo,\u0026nbsp;Adama Sanou,\u0026nbsp;Antoinette\u0026nbsp;Kabor\u0026eacute;. Methodology: Louis Robert Wendyam Belem,\u0026nbsp;Raymond Karlhis Yao, Christel Lankouand\u0026eacute;, Armand Vital Wenceslas TAITA, Philippe\u0026nbsp;Kabor\u0026eacute;,\u0026nbsp;Abdoul Bamogo,\u0026nbsp;Mireille Dsouza, Yacouba Kouadima. Data curation: Louis Robert Wendyam Belem,\u0026nbsp;Raymond Karlhis Yao, Tarwendpanga Fran\u0026ccedil;ois Xavier Ou\u0026eacute;draogo. Writing\u0026nbsp;\u0026ndash;\u0026nbsp;original draft: Louis Robert W. Belem. Writing\u0026nbsp;\u0026ndash;\u0026nbsp;review \u0026amp; editing: Adama Sanou,\u0026nbsp;Arsene Zongo, Dieudonne Tialla. Supervision: Louis Robert Wendyam Belem, Adama Sanou, Antoinette\u0026nbsp;Kabor\u0026eacute;.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThis research was supported by the Fond National de la Re\u0026shy;cherche et de l\u0026rsquo;Innovation pour le Dev\u0026eacute;loppement of Burkina Faso (Grant No. FONRID/AAP-Sp\u0026eacute;cial-Jeunes/NCP/PCD/2022) and Cen\u0026shy;tre d\u0026rsquo;Excellence Africain en Innovations Biotechnologiques pour l\u0026rsquo;Elimination des Maladies \u0026agrave; Transmission Vectorielle of Burkina Faso (Grant No.2020 \u0026minus; 000178/MESRSI/SG/UNB/P).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eData are included in this manuscript, and data base can be provided if request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was approved by the Regional Health Department of Guiriko (No. 2021-0294/MS/RHBS/DRS) and the Health Science Research Institute of Burkina Faso Ethics Committee (No. A026-2023/CEIRES/IRSS). Written informed consent was obtained from all participants, and confidentiality was strictly maintained. For minors included in this study, consent was provided by the parents or legally authorized representatives. \u0026nbsp;\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\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eBlessmann J, Winkelmann Y, Keoviengkhone L, Sopraseuth V, Kann S, Hansen J, et al. Assessment of diagnostic and analytic performance of the SD Bioline Dengue Duo test for dengue virus (DENV) infections in an endemic area (Savannakhet province, Lao People\u0026rsquo;s Democratic Republic). PLoS One. 2020;15(3). https://doi.org/10.1371/journal.pone.0230337. \u003c/li\u003e\n\u003cli\u003eOMS. 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Clinical Infectious Diseases. 2025;80(1):199\u0026ndash;206. https://doi.org/10.1093/cid/ciae369. \u003c/li\u003e\n\u003cli\u003eWaggoner JJ, Balmaseda A, Gresh L, Sahoo MK, Montoya M, Wang C, et al. Homotypic Dengue Virus Reinfections in Nicaraguan Children. Journal of Infectious Diseases. 2016 ;214(7):986\u0026ndash;93. https://doi.org/10.1093/infdis/jiw099. \u003c/li\u003e\n\u003cli\u003eAnggriani N, Tasman H, Ndii MZ, Supriatna AK, Soewono E, Siregar E. The effect of reinfection with the same serotype on dengue transmission dynamics. Appl Math Comput. 2019 ;349:62\u0026ndash;80. https://doi.org/10.1016/j.amc.2018.12.022. \u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Geographic, temporal, primary, secondary, dengue, Burkina Faso","lastPublishedDoi":"10.21203/rs.3.rs-9140004/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9140004/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eDengue virus (DENV) is the main prevalent arbovirus in Burkina Faso, with significant morbidity and mortality. Discrimination between primary and secondary dengue infections is important for public health decision-making. This study aimed to characterize the spatiotemporal distribution of primary and secondary dengue infections, as well as pre-vaccination screening.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eThis study was conducted in 2023, 2024, and 2025 in Bobo-Dioulasso, Hound\u0026eacute;, Ouagadougou, and Gaoua. Blood sample was collected from each suspected case. DENV detection was performed using a rapid diagnostic test, enzyme-linked immunosorbent assay (ELISA), and molecular techniques.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eIn 2023, the primary and secondary infection rates were 75.40% (92/122) and 24.6% (30/122), respectively. In 2024, 77.17% (71/92) of primary infections and 22.83% (21/92) of secondary infections were reported. In 2025, primary and secondary infection accounted for 68.83% (53/77) and 31.17% (24/77), respectively. Across the 2023\u0026ndash;2025 period, abdominal pain occurred in 7.87% (17/216) and persistent vomiting in 2,31% (5/216) of dengue primary infection cases, while 92.13% (199/216) showed no warning signs. Among patients with secondary dengue infection, abdominal pain was reported in 54.66% (41/75) and persistent vomiting in 29.33% (22/75), although 45.43% (34/75) presented without warning signs. In 2023, DENV-3 was the predominant serotype, accounting for 76.23% (93/122) of cases. In contrast, DENV-1 predominated in 2024 and 2025, representing 69.57% (66/92) and 71.42% (55/77) of cases, respectively.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003ePrimary infection predominated in all years, with year-to-year variation in DENV serotype distribution, and warning signs were associated with secondary infection. Qdenga (TAK-003) vaccine may be a relevant option in the Burkina context\u003c/p\u003e","manuscriptTitle":"Geographic and temporal distribution of primary and secondary dengue cases in Burkina Faso from 2023-2025: a hospital-based cross-sectional study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-03-24 16:59:05","doi":"10.21203/rs.3.rs-9140004/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"32cb2444-224b-4dfb-aa3c-79f80eaf4439","owner":[],"postedDate":"March 24th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-04-24T14:56:31+00:00","versionOfRecord":[],"versionCreatedAt":"2026-03-24 16:59:05","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9140004","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9140004","identity":"rs-9140004","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}