Monitoring of vectors of the genus Aedes sp. during winter in the municipality of Barbacena, Minas Gerais, Brazil ‒ 2018

Abstract

Objective: To estimate oviposition and spatial distribution of Aedes sp. vectors during the winter season and correlate these estimates with climate data from the same period. Methods: Field study conducted in the municipality of Barbacena-MG in 2018. Monitoring, egg collection, and estimation of stegomic indices of Aedes sp. were obtained using ovitraps. The Indices: Egg Density (EDI) and Positive Ovitrap (POI%) were estimated according to climatic seasons and epidemiological weeks. The correlation between meteorological parameters (temperature/rainfall) and stegomic indices (EDI/POI) were determined by the Spearman coefficient. Results: A total of 1,080 ovitraps installed in 39 neighborhoods were analyzed during 10 epidemiological weeks, providing a total of 970 eggs. In the autumn, winter, and spring seasons, 421, 470, and 70 eggs were obtained, respectively. During the autumn, there was a variation in EDI between 14.2–34.2. The POI remained constant at 4.5%. During the winter, the EDI varied between 0.00–47.50 and the POI varied between 0.00%–8.25%. There was a significant negative correlation, respectively, between an increase in monthly precipitation and a decrease in the number of eggs collected (rho=-0.673) and between an increase in monthly precipitation and a decrease in POI (rho=-0.612). The overall value of EDI and POI in the 10 weeks were 22.04 and 4.17%, and in the winter season they were 23.50 and 3.73%, respectively. Conclusion: The findings corroborate the presence of eggs and vectors of the genus Aedes sp. even in adverse climatic conditions for these species and support health management actions throughout the year.