Dengue vector abundance and diversity of breeding habitats in Puducherry, South India

ABSTRACT

Puducherry had reported regular dengue outbreaks since 2003 with many-fold increase in number of cases every year. This study was done to assess the intensity of dengue vector breeding and diversity of breeding habitats. Aedes surveys were conducted in 8 Primary Health Centres (PHCs) representing both rural and urban areas of Puducherry district throughout the year 2012. Containers inside and outside randomly (simple) selected houses and vacant sites around houses were examined for presence of Aedes mosquitoes. The containers containing water with immature larvae were designated as positive containers (PC), while the containers holding only water were designated as wet containers and all the larvae/pupae from the positive containers were collected and entomological indices were determined using standard WHO methods. The vectors, Aedes aegypti and Ae. albopictus were encountered in the survey, with Ae. aegypti present in high numbers in urban as well as rural areas. The plastic containers were found as the most productive indoor breeding habitat as the 27.2% of the total pupae collected was contributed by plastic containers followed by flower vase (22.8%) and grinding stone (17.6%). Larval indices were found to vary throughout the year and highest indices were recorded during the months of October and November indicating the potential risk of dengue fever during this period.