Public service deficiencies and Aedes aegypti breeding sites in Venezuela

Abstract

The 1992 study reported here assessed relationships between potable water supply and trash collection practices and the prevalence of dengue vector mosquito (Aedes aegypti) breeding sites in 30 towns located along the north coast of Venezuela. Within each study town, 100 homes were chosen. At each of these homes the number of water-bearing containers and containers harboring A. aegypti were determined and interviews were conducted to obtain information about the local water supply, trash collection services, and excreta disposal. In general, A. aegypti breeding indexes were high: 55% of the residences were found to harbor A. aegypti immature forms; there was an average of 118 breeding sites per 100 residences; and 24% of the water-bearing receptacles were observed to contain the mosquito. The statistical method of principal component analysis was employed to rank the 30 towns in terms of variables describing public service deficiencies, and correlations existing between the variables studied were determined. Direct correlations were found between two water supply variables (frequency and duration of water supply interruptions), between the excreta disposal and trash collection variables, between the duration of water supply interruptions and the Aedes breeding indexes, and between the duration of water supply interruptions and the mean number of A. aegypti breeding sites found in water storage containers. Overall, the towns with the poorest services were found to have the highest breeding indexes and the greatest numbers of water storage containers harboring the mosquito. It is concluded that public service (water supply and waste disposal) deficiencies were largely responsible for A. aegypti propagation in the study towns. Accordingly, it is recommended that local programs be implemented for recycling containers, constructing water storage tanks that cannot harbor Aedes larvae, and conducting health education and community participation campaigns directed against the mosquito.