Several parts of the city are witnessing a sudden spurt in mosquitoes. The increase is partly due to breeding of culex mosquitoes in the stormwater drain (SWD) network.
After rain, entomologists have been witnessing the breeding of culex mosquitoes in SWDs due to stagnant water. Officials of the Chennai Corporation said while the mosquito menace had increased recently, they were receiving more complaints from areas in north Chennai, specifically from zone IV (Tondiarpet) and zone V (Royapuram).
In the last few weeks, residents of many areas, including Tondiarpet, Korukkupet, Pattalam, Ayanavaram, M.K.B. Nagar, Mylapore, areas adjoining Anna Salai and Kolathur, have experienced an increase in mosquitoes, especially during evening hours.
“The mosquito menace has increased in the last few weeks. We close the door and windows early in the evening so that mosquitoes don’t enter our house,” said a resident of Ayanavaram. Another reisdent of Korukkupet said usually, areas in and around Tondiarpet have plenty of mosquitoes, but the density had increased after intermittent rain.
P. Kuganantham, former city health officer and chairman of the Indian Public Health Foundation, said for the last two decades, SWDs along parts of Anna Salai, such as Nandanam, Luz Corner, Saidapet, Walltax Road, Korukkupet, Otteri and Villivakkam, had been hotspots for culex breeding.
‘No sewer links’
“Chennai city has more than 1,800 km of stormwater drains, but we are yet to find a way for the water to flow out,” he explained.
As long as SWDs are devoid of sewer connections, mosquito breeding will continue, and will remain a public health problem, he added. Illegal sewer connections into waterways — Adyar, Cooum, Buckingham and Virugambakkam canals — also lead to breeding, he said. The mosquitoes carry disease-causing vectors, including filariasis, making them dangerous from a health and sanitation perspective.
B. Dhanraj, former chief vector control officer, Chennai Corporation, pointed out that culex mosquitoes breed throughout the year, but the density rises during this season due to low temperatures. “Culex mostly breeds in waterways and SWDs. It is an engineering task to ensure that water does not stagnate in the SWDs,” he added.
Officials of the Chennai Corporation said they would take up a mass programme for three days.
“Water stagnation in SWDs will be identified and mosquito larvicidal oil will be used for larval control,” an official said.
