Rural–Urban Variation in Dengue Vector Breeding Dynamics in Madurai District, Tamil Nadu, India: A Geo-Medical Study

Abstract

Dengue is one of the most important mosquito-borne viral diseases affecting tropical and subtropical regions worldwide. The principal dengue vectors, Aedes aegypti and Aedes albopictus, exhibit considerable spatial and seasonal variation in their breeding ecology, particularly between rural and urban environments. This study investigated rural–urban variation in dengue vector breeding dynamics in Madurai District, Tamil Nadu, India, using a geo-medical approach. Primary field surveys were conducted in 705 randomly selected households across seven taluks during the dry and wet seasons. Larval and pupal samples were collected from different breeding containers, reared to adulthood, and identified at the ICMR–Vector Control Research Centre, Madurai. Adult mosquito abundance was assessed using the Adult Premise Index (API) and Female per Positive House (FPPH). Principal component analysis (PCA), hierarchical cluster analysis, and heat-map analysis were used to examine seasonal breeding patterns and spatial variation in vector distribution. The results indicated that Ae. aegypti predominated in urban areas, particularly during the dry season, when artificial containers such as tyres, barrels, cisterns, grinding stones, and earthen pots served as major breeding habitats. In contrast, Ae. albopictus was more abundant during the wet season and was more frequently associated with rural and peri-urban environments. Several taluks recorded higher API and FPPH values, indicating spatial variation in adult mosquito density and potential dengue transmission risk. The findings showed that dengue vector ecology differed between rural and urban settings and varied across seasons. These results highlight the importance of location-specific surveillance, source reduction, and integrated vector management strategies for improving dengue prevention and control in Madurai District.