Seropositivity to Dengue virus (DENV) in three neighborhoods in the periphery of a city with a recent history of outbreaks in Argentina: what can we learn from unreported cases?

BackgroundArgentina has experienced several dengue outbreaks since its reemergence in 1998, but cases are underreported due to asymptomatic infections and inadequate access to the healthcare system, particularly in marginalized neighborhoods. MethodsBetween December 2019 and March 2020, we assessed seroprevalence of DENV in three neighborhoods in the periphery of the city of Santa Fe. Serum samples were obtained from one adult per household and analyzed by ELISA for DENV IgG antibodies. Multivariate logistic regression models were used to analyze seropositivity by demographic, socio-economic and environmental variables. ResultsFrom 184 participants,overall seroprevalence was 15.2% (95% CI: 10.7; 21.1%). Proximity to a vacant lot decreased the likelihood of seropositivity by 65% (OR: 0.35; 95% CI: 0.15; 0.80). This aligns with studies suggesting vegetation cover can reduce vector abundance and that DENV transmission is higher in densely populated urban areas. Surprisingly, knowledge of disease symptoms and transmission was not linked to lower seropositivity, echoing findings from other studies. ConclusionsThese findings contribute to building consensus on the factors that increase DENV infection and will be valuable in designing public health interventions in vulnerable neighborhoods during dengue outbreaks.