Author(s): Rocha, Nildimar Honorio ; Codeço, Cláudia Torres ; Alves, F. C. ; Magalhães, Mônica de Avelar Figueiredo Mafra ; Oliveira, Ricardo Lourenço de
Date: 2010
Origin: Oasisbr
Subject(s): population dynamics; Aedes Aegypti; meteorological variables; dengue; traps
Laboratório de Transmissores de Hematozoários, Instituto Oswaldo Cruz - Fiocruz
Programa de Computação Científica - Fiocruz
Secretaria Municipal de Saúde do Rio de Janeiro - Fundação Nacional de Saúde
Instituto de Comunicação e Informação Científica e Tecnológica em Saúde - ICICT - Fiocruz,
Laboratório de Transmissores de Hematozoários, Instituto Oswaldo Cruz - Fiocruz
Dengue dynamics in Rio de Janeiro, Brazil, as in many dengue-endemic regions of the world, is seasonal, with peaks during the wetÐhot months. This temporal pattern is generally attributed to the dynamics of its mosquito vector Aedes aegypti (L.). The objectives of this study were to characterize the temporal pattern of Ae. aegypti population dynamics in three neighborhoods of Rio de Janeiro and its association with local meteorological variables; and to compare positivity and density indices obtained with ovitraps and MosquiTraps. The three neighborhoods are distinct in vegetation coverage, sanitation, water supply, and urbanization. Mosquito sampling was carried out weekly, from September 2006 to March 2008, a period during which large dengue epidemics occurred in the city. Our results show peaks of oviposition in early summer 2007 and late summer 2008, detected by both traps. The ovitrap provided a more sensitive index than MosquiTrap. The MosquiTrap detection threshold showed high variation among areas, corresponding to a mean egg density of 25Ð52 eggs per ovitrap. Both temperature and rainfall were signiÞcantly related to Ae. aegypti indices at a short (1 wk) time lag. Our results suggest that mean weekly temperature above 22Ð24 C is strongly associated with high Ae. aegypti abundance and consequently with an increased risk of dengue transmission. Understanding the effects of meteorological variables on Ae. aegypti population dynamics will help to target control measures at the times when vector populations are greatest, contributing to the development of climate-based control and surveillance measures for dengue fever in a hyperendemic area.
