Entomological Surveillance and Alternate Methods for Species Identification of Aedes in a Dengue-endemic District of Punjab, India

Abstract

Background: Entomological surveillance is a vital component of vector control programmes as it helps to determine the geographical distribution, density, and species of vector populations in areas at risk of arboviral diseases. Moreover, calculating Stegomyia indices is an integral component of Aedes surveillance in areas which are at high risk of dengue.Methodology: In the year 2018, entomological surveillance was carried out in a high dengue endemic district of Punjab to identify the different species of Aedes through morphological identification on the basis of hypopygium. For this, all artificial and natural containers holding stagnant water were inspected for the presence of immature larvae. The larval indices were also recorded.Results: Aedes breeding was found to be high in urban areas as compared to rural areas. Based on the differences in their morphological characteristics as well as hypopygium structure, three different species of Aedes were identified: Ae. aegypti, Ae. albopictus and Ae. vittatus. Among the three species, the most common species was Ae. aegypti. A positive correlation was recorded between dengue cases and Stegomyia indices.Conclusion: This is the first study which has recorded the presence of species Ae. vittatus in a district of Punjab, India. The present results indicate that for the identification of damaged specimens, other morphological characteristics must be explored.