Entomological investigations with special attention to pupal indicators of Aedes vectors during outbreaks of dengue in coastal Odisha, India.

is caused by the dengue virus (DENV) (Family: Flaviviridae) comprising four serotypes and is transmitted by the bite of female Aedes mosquito, mainly Ae. aegypti and Aedes albopictus1, 2. Spread of the mosquito vector and the virus has led to the resurgence of dengue epidemics and the emergence of dengue in new areas. Due to unavailability of any vaccine/drug against DENV, vector control currently is the only way to curb the spread of dengue3. Vector control is presently evaluated using surveillance techniques based on larval indices to determine risk and to guide mosquito control activities4. However, recently there has been a movement towards pupal indices, considering early instars as too immature to be the representative of true mosquito productivity, because survival from early stage larvae to pupae is variable and a majority of larvae do not survive to adulthood, whereas most pupae survive to emerge as adults5. Moreover, pupal surveys provide an accurate estimate of adult population density resulting in more useful infestation indices, such as pupae per person (PPP) and pupae per house (PPH)6, 7. During epidemics, some containers produce more pupae than others. Hence, targeting and eliminating such containers will greatly aid in source reduction during epidemics8. Therefore, entomological surveys targeting the most productive containers that contribute maximum pupae during outbreaks can rapidly alleviate the vector density thereby reducing the force of transmission9. Odisha state of India is divided into four distinct physiogeographical regions; northern plateau, central tableland, coastal plains and eastern ghats. As per the State Health Department, most parts of Odisha had been affected by periodic outbreaks of dengue since 2011, out of which Bhograi block in Balasore district of coastal region has been the most affected and reported >70 dengue cases from June to August 2012. Bhograi block is a suburban area, located besides the sea, having a rich vegetation of forests with a population of about 40,521 (Census 2011). Due to its proximity to sea, people from nearby Bangladesh and other places often migrate to this region, J Vector Borne Dis 50, June 2013, pp. 147–150