Dengue vector (Aedes aegypti) larval habitats in an urban environment of Costa Rica analysed with ASTER and QuickBird imagery

Abstract

Dengue fever is transmitted mainly by the mosquito species Aedes aegypti, which breeds in water-filled containers in tropical urban areas. In this study medium- and high-resolution satellite (ASTER and QuickBird) imagery were used to map tree cover and built-up surfaces in Puntarenas, Costa Rica, where dengue fever has been endemic since 1993. Hard and soft image classification algorithms were used to generate these variables, which were analysed with respect to vector habitat distribution as measured by the potential mosquito habitats during the wet season of 2006. A multiple linear regression model revealed that built-up surfaces derived from ASTER imagery explained 63.6% of the variance in the number of larval habitats found during the wet season when transmission and incidence of dengue were highest. The results suggest that elements of urban structure such as built-up surfaces may be used to predict the presence of an important disease vector within urban areas and that medium-resolution satellite imagery may help to inform future prevention and control strategies in Costa Rica and other countries where dengue fever is endemic.

Acknowledgements

We thank Mayra Solano, Adrian Avendaño, students and personnel of the University of Costa Rica, Victoria Sánchez and Rosana Velit, and the Ministry of Health, for facilitating the acquisition of data for Puntarenas and other local information. This research was supported by Grant Number P20 RR020770 from the National Center for Research Resources (NCRR), a component of the National Institutes of Health (NIH), and its content is solely the responsibility of the authors and does not necessarily represent the official view of NCRR or NIH.