Dados do Trabalho

Name: 57º Congresso da Sociedade Brasileira de Medicina Tropical
Start: 2022-11-13
End: 2022-11-16
Location: Hangar Centro de Convenções e Feiras da Amazônia

Título

Effects of the El Niño and La Niña on Aedes aegypti infestation: a spatiotemporal Bayesian modeling

Introdução

Regional particularities relating to climate and human activity interfere with the population dynamics of the Aedes aegypti mosquito. Understanding these particularities is essential for identifying areas of greatest vector infestation and consequently higher vulnerability to arboviruses.

Objetivo(s)

To examine the spatiotemporal relationship between El Niño/La Niña (ENSO) and the A. aegypti mosquito infestation in a time-series (2008–2018) from a highly endemic dengue region of southeastern of Brazil. Then, following the climate hypothesis, we address whether the local climate variability may account for the observed annual variation patterns of A. aegypti infestation in this tropical epidemiological setting.

Material e Métodos

Using data from the Rapid Survey of A. aegypti Infestation Index (LIRAa), the spatiotemporal trend of infestation levels was assessed from 2009 to 2018. We used hierarchical Bayesian models to analyse the spatiotemporal variability of mosquitoes' infestation, exploiting the concept of spatial and temporal autocorrelation in multilevel structures, through the inclusion of spatial and temporal random effects.

Resultados e Conclusão

Historical assessment of A. aegypti infestation levels in the State of São Paulo clearly show an almost cyclical pattern over the years, with alternating high-risk areas based on information from LIRAa. This entomological condition, resulting from the action of different variables, may become a factor in the future management of major dengue epidemics in the State. Here we focused on characterizing the degree of influence of the ENSO regional event on the temporal A. aegypti infestation dynamics. We found a strong and significant coherence between the temporal pattern of mosquito abundance and that of these variables showing the role that climate plays in driving infestation periodicity. Specifically, we identified a relationship between A. aegypti infestation and the strength of the ENSO phenomenon active in that period: as stronger the El Niño or La Niña effect, the greater the abundance of A. aegypti mosquitoes. Although the entire state has favorable conditions for the proliferation of the vector, some specific areas have a higher tendency toward infestation. These results may increase our understanding of the risk factors for A. aegypti infestation and optimize entomological control actions in the most susceptible areas.