2. Material and methods
2.1. Study area
This study is carried out in Dhaka, the capital of Bangladesh. Our pre- vious study showed that Dhaka is the highest risk area for dengue trans- mission in Bangladesh and the underlying cause of increased risk of dengue in this location remains unknown, which requires further inves- tigation (Banu et al., 2012). Dhaka is located in central Bangladesh at 23°42′ north latitude and 90°22′ east longitude with an area of 1464 km2. Dhaka along with its metropolitan area had a population of 11.8 million (2011 census), making it the biggest city in Bangladesh. Dhaka has a hot, wet and humid tropical climate. The city is within the monsoon climate zone, with an annual average temperature of 25 °C and monthly means varying between 18 °C in January and 29 °C in August. Nearly 80% of the annual average rainfall of 1854 mm occurs between May and September.