The breeding habitat of Aedes aegypti is associated with inadequate water supply, unplanned urbanization, water storage practices and poor environmental management. Dengue is an emerging disease which has spread in urban and rural areas of India. It has been assessed that more than 390 million dengue infections occur annually, out of which India contributes one third of load of dengue infections. The larval indices varied from 5.6 to 37.2 in various schools and colleges of Delhi during 2016. While it varied from 5.9 to 67.9 in hospitals during 2017. The criteria for selection of study sites was based on the maximum number of dengue cases reported in 2015 outbreak in Delhi and National Capital Region (NCR).
Entomological survey was carried out in different educational institutions and hospitals of Delhi and NCR throughout the year from 2016 to 2017 in order to study the vector prevalence in Delhi-NCR and to identify high risk areas prone to dengue outbreak. House index (HI), container index (CI) and Breteau index (BI) are Aedes larval indices used to predict the degrees of larval prevalence. Plastic containers were the prominent habitats for larval breeding in Rohini and Najafgarh (Delhi) and Faridabad (NCR). Main breeding sites were coolers, flower vessels, earthen pot and plastic/tin containers. Desert coolers were the prominent habitats for larval breeding in Shahadara (Delhi) and Ghaziabad (NCR).