O-67 High seroprevalence of anti-dengue virus IgG antibodies in the Sud Department of Haiti: a population-based cross-sectional study
Author(s):
C Augustin, MD Louis , W Mathurin, M Joseph , S-T Sully, R Etienne , I Journel, J Alboth Andre, H Denis , E Michel, D Lafontant, M Etheart, J Boncy
Year of Presentation:
2026
Objective: To estimate the seroprevalence of anti-dengue
virus IgG antibodies in the Sud Department of Haiti and
to describe its distribution by sociodemographic and geographic characteristics, in order to inform dengue surveillance and prevention strategies.
Methods: A population-based cross-sectional serological study was conducted in September 2025 in the Sud Department of Haiti. A stratified cluster sampling design was used to select households across arrondissements and communes. After informed consent, participants completed a standardized questionnaire. For children, the questionnaire was administered to a parent or guardian. Venous blood samples were collected. Rapid diagnostic tests detecting dengue NS1 antigen and IgM/IgG antibodies were performed in the field. Anti-dengue IgG antibodies were detected using ELISA at the National Public Health Laboratory. Seroprevalence estimates were calculated with 95% confidence intervals, with stratified analyses by age, sex, and area of residence.
Results: A total of 1,397 individuals were enrolled (median age: 28 years), with females representing approximately 63% of participants. Among 1,171 participants tested using rapid diagnostics, no NS1-positive cases were detected, indicating the absence of acute dengue infection at the time of the survey. ELISA IgG testing was performed on 1,047 samples: 889 yielded definitive results, including 844 positive and 44 negative results. The overall IgG seroprevalence among participants with definitive ELISA results was 94.9% (95% CI ≈ 93–97). When conservatively accounting for missing or non-exploitable samples, the minimum estimated seroprevalence remained approximately 80.6%. Seropositivity increased with age, with substantial exposure already observed among young children.
Conclusion: Dengue virus transmission in the Sud Department of Haiti is intense and sustained, characterized by early-life exposure and near-universal IgG seroprevalence. These findings highlight the limitations of routine passive surveillance and support the use of serological surveys to better characterize dengue burden. Strengthening integrated dengue surveillance, community-level prevention, and outbreak preparedness should be public health priorities in this setting.