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Abstract Background Urban arboviruses pose a significant global burden, particularly in tropical regions like Brazil. São Sebastião, a lower-middle-class urban area just 26 km from the Brazilian capital, is a hyperendemic area for dengue cases. However, asymptomatic cases may obscure the actual extent of the disease. In this study, we measured the seroprevalence of dengue, Zika virus, and chikungunya, and compared these findings with surveillance data. Methods A cross-sectional study was conducted involving 1,535 households. ELISA serological tests were performed to detect IgM and IgG antibodies against dengue, Zika virus, and chikungunya. History of previous exposure to arbovirus, data on age, gender, and education level were collected through a questionnaire. Participants testing positive for IgM and/or IgG were classified as positive. Statistical analyses included tests for normality, associations, mean comparisons, and correlations. Positive serological results were compared with cases captured by local epidemiological surveillance. Results The study included 1,405 individuals, divided into two groups related to pre-pandemic and pandemic COVID-19 phases. Among participants, 0,7% to 28,8% self-reported history of dengue, Zika, or chikungunya. However, the estimated overall seroprevalence was 64.3% (95% CI: 61.8–66.7) for dengue virus, 51.4% (95% CI: 48.8–53.9) for Zika virus, and 5.4% (95% CI: 4.4–6.7) for chikungunya virus. Multiple arboviruses were noted at 4.0% (95% CI: 3.1–5.1). Advancing age and lower education were associated with higher exposure to arboviruses (p < 0.05). The number of urban arboviral cases was 84 times higher than reported. Conclusions The underreporting of arbovirus cases in the evaluated area reveals a substantial deficiency in epidemiological surveillance. Addressing these gaps is crucial for effective resource allocation and implementation of public health interventions.
Nobre et al. (Sun,) studied this question.