Seroprevalence of anti-dengue virus antibodies and associated factors among adults in five communes and wards of Dak Lak Province in 2026

ABSTRACT: Objective: To estimate the seroprevalence of immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies to dengue virus and examine associated factors among adults in five communes and wards in Dak Lak Province in 2026. Methods: This descriptive cross-sectional study included 588 adults aged ≥18 years from Buon Ma Thuot Ward, Tan An Ward, Krong Pak Commune, Ea Knop Commune, and Phu Xuan Commune. Data and serum samples were collected between June and August 2026. Participants were selected by random cluster sampling, with one eligible adult selected per household. Anti-dengue virus IgM and IgG antibodies were detected by enzyme-linked immunosorbent assay (ELISA). Demographic data were obtained using a questionnaire. Data were analyzed using descriptive statistics and chi-square (χ²) tests. Results: IgM seroprevalence was 10.9% (64/588; 95% confidence interval [CI], 8.6–13.7%), and IgG seroprevalence was 43.9% (258/588; 95% CI, 39.9–47.9%). Equivocal results accounted for 6.6% and 17.0% of IgM and IgG results, respectively. Concurrent IgM and IgG positivity was observed in 42 participants (7.1%). IgM seroprevalence was highest in Krong Pak (21.7%) and lowest in Phu Xuan (4.2%), whereas IgG seroprevalence was highest in Buon Ma Thuot (61.5%) and lowest in Ea Knop (21.9%). The distribution of IgM test results differed significantly by ethnicity, educational attainment, occupation, and study site (p < 0.05). The distribution of IgG test results differed significantly by sex, age group, ethnicity, educational attainment, occupation, and study site (p < 0.05). IgG seroprevalence increased from 29.5% among participants aged 18–29 years to 55.3% among those aged ≥60 years. Conclusions: Anti-dengue virus antibodies were detected among adults at all five study sites, with seroprevalence varying by location and population group. These findings may inform serological surveillance and the development of locally appropriate communication strategies for dengue prevention and control in the surveyed communities. Keywords: dengue virus; seroprevalence; IgM; IgG; adults; Dak Lak.