Arboviral Risk at Brazilian Tourist Destinations.

BACKGROUND

Brazil is a popular travel destination that experiences recurrent outbreaks of dengue, chikungunya, and yellow fever (YF), posing a significant health risk to both residents and international travellers. We aimed to identify high-risk regions for arboviral infections and develop a user-friendly, map-based resource to support clinical decision-making in travel medicine.

METHODS

We analysed laboratory-confirmed cases and deaths from dengue, chikungunya, and YF reported to Brazil's national surveillance system from 2019 to 2024 (from 2015 for YF). Data were aggregated into 133 Intermediate Geographic Regions (IGRs). IGRs without a confirmed case during the studied period were excluded. A composite risk score was calculated for each IGR by combining (i) transmission duration (months with reported cases per year, score 0-12) and (ii) disease burden, based on national quartiles of monthly incidence and mortality (score 1-4). Annual scores were summed to produce risk maps for each arbovirus. High-risk IGRs (defined as the top quartile of composite score) were overlaid with popular tourist destinations to create an intuitive visual guide.

RESULTS

We analysed 4.35 million dengue, 294,921 chikungunya, and 2,312 YF cases, resulting in 7,846, 565, and 794 deaths, respectively. Dengue affected all IGRs, with high-risk IGRs in the Midwest, including the Pantanal. Chikungunya was also identified in all IGRs, with high-risk IGRs in the Northeast, overlapping with popular beaches such as Recife. YF was identified in 38.3% of IGRs, notably in the Southeast, including São Paulo state.

CONCLUSIONS

Arboviruses pose a diverse risk across Brazil. Our spatially integrated map provides a novel tool for travel medicine, enabling healthcare practitioners to offer tailored advice and pre-travel vaccinations to travellers.