Experts warn of dengue outbreak in Chennai following waterlogging due to incessant rains

Rajani M. Nambiar, who is a Professor in a private medical college at Chennai in the department of Community Medicine, told IANS: "The puddles of water and waterlogging in several parts of Chennai would lead to the multiplication of mosquito larvae and unless the Greater Chennai Corporation take preventive measures, city is in for a major dengue outbreak."

She also said that an entomologist with statutory powers needs to be immediately appointed in the corporation and fumigation and spraying of larvicide is important.

Rajani also said that a centralised lab has to be constituted at the earliest with three labs for prevention, monitoring, and research.

At present, the Greater Chennai Corporation is relying on a few insect catchers who bring larvae and mosquitoes from different areas of the city, and then it is analysed.

Tamil Nadu, according to entomologists and vector control experts, has four broad species of mosquito that spread dengue-armigers, Anopheles, Aedes and culex. This according to vector control experts is an important measure to rely on advanced technologies to bring out policies for preventive measures.

Sulakshna Ramakrishnan, who is an entomologist and teacher at a University in the United Kingdom told IANS: "Scientific journals have given detailed study reports that the Aedes mosquito that is the main causative agent for dengue can breed in dirty water including sewage water and the vector behavioural changes have to be taken into account before arriving at a policy at the micro-level."

During the incessant rains that lashed Chennai, water mixed with sewage water had logged up in many parts of the city and the Aedes mosquito were not breeding in dirty waters. However, recent studies have revealed that the larvae can grow even in sewage water and that is a matter of concern.

State Health Minister Ma Subramanian told IANS, "The state government has taken effective measures to prevent the outbreak of any vector diseases following waterlogging and we have effectively implemented fumigation and spraying larvicides in pools of water."

However, Rajani said that the Greater Chennai Corporation (GCC) does not have a proper detail of the mosquito fauna in the city and adjoining areas. She said that the GCC is not properly studying the changing patterns of mosquito larvae and the corporation has to first implement a vector lab.

The vector monitoring app of the GCC is also not being used and even the drones are also not being used to spray larvicide.

Several cases related to dengue have been reported from almost all the wards of the corporation and the city and the adjoining areas and health experts are of the opinion that unless a control measure based on scientific study is conducted and implemented at the grass-root levels, things would go out of hands.

GCC officials were not available for comments.