Estimation of Aedes aegypti (L.) (Diptera: Culicidae) productivity in households and public spaces in a dengue endemic city in Colombia

Abstract

Introduction: Aedes aegypti is a vector for the dengue virus in Colombia. Its productivity can be estimated using pupal counts.

Objective: To determine Ae. aegypti productivity in households and public spaces in Girardot (Colombia) during both wet and dry seasons.

Materials and methods: The amount of Ae. aegypti pupae was evaluated in 20 randomly selected clusters in Girardot, each consisting of 100 households and public spaces. Inspections were performed during the rainy (February-May, 2011), and dry (August-September, 2011) seasons. House, container, Breteau, person and hectare pupae indices were estimated.

Results: During the rainy season households contributed 94% to the total number of pupae (n=7,098) while only 6% (n=482) were found in public spaces. In the dry season, 98% (n=9,138) of pupae were found in households and 2% (n=223), in public spaces. Low water-storage tanks and tanks for washing purposes provided >87% of pupae in households, whereas jars, tires and sinks contained most pupae in public spaces. High pupal densities were observed in public spaces during the rainy season and in streets and schools in the dry season. There were no significant differences in the index per person (rainy season=1.0; dry season=1.3) or per hectare (rainy season=0.96, dry season=0.45) between seasons.

Conclusions: High Ae. aegypti pupal densities were found inside households in low water-storage tanks and tanks for washing purposes during both the dry and rainy seasons. Public spaces provided more aquatic habitats during the rainy season. Vector control strategies targeting these containers could allow a more rational use of resources and increase efficiency.