Aedes Distribution and Meteorological Effect on Ovitrap Index in Coastal Area of Besut, Terengganu: An Entomological Study

Abstract

INTRODUCTION:_Aedes_ species are a major public health concern due to their ability to be efficient vectors of dengue and other arboviruses. An Ovitrap is an entomological surveillance tool designed to measure the density of _Aedes_. Ovitraps used for monitoring can detect _Aedes_ mosquito populations, thus acting as an early warning system to prevent dengue outbreaks. Meteorological factors such as temperature and rainfall play a great role in affecting the abundance of _Aedes_ mosquitoes. This study aimed to assess the presence and abundance of _Aedes_ species and to determine the correlation of meteorological factors with the Ovitrap index. METHODOLOGY: A cross-sectional study was conducted in the coastal area of Besut district, Terengganu state of Malaysia. The study samples were 3120 Ovitraps placed in only occupied premises. Data were collected from the Besut Meteorological Department database and respective Ovitrap sentinel stations. The independent variables were environmental temperature and rainfall density, while the dependent variable was the Ovitrap index, which served as the indicator for _Aedes_ density. Descriptive and correlation analyses were employed for assessing the Ovitrap index and determining the correlation of the Ovitrap index with temperature and rainfall distribution. A p-value <0.05 was considered statistically significant. RESULTS: The _Aedes_ distribution study showed that _Aedes aegypti_ were more prevalent than _Aedes albopictus_, with 2,383 larvae of Aedes aegypti being recorded compared to 2,198 larvae of Aedes albopictus. The findings also revealed a significant correlation between the Ovitrap index and temperature (r=0.82, p=0.03), but the analysis showed no statistically significant correlation between the Ovitrap index and the rainfall distribution, with (r=0.15, p=0.62). CONCLUSION: Temperature plays an important role in determining Aedes distribution. The high population of Aedes aegypti highlights the need for proper control actions such as Aedes source reduction.