Dip in temp killing mosquito larvae, say health officials
LUCKNOW: Civic officials in the state capital are upbeat about the multiple sightings of dead mosquito larvae over the past few days. The reason, they speculate, could not be the effectiveness of anti-larval measures, but the drop in daily temperatures.
“For the past two days, dead (mosquito) larvae are being spotted across the district. This could be happening due to the dip in the mercury levels. This means, the mosquito population will reduce significantly over the coming week as temperature falls further, particularly at night,” said Ritu Sriavstava, district malaria officer (DMO) who also heads the team responsible for mosquito containment in Lucknow.
“We have made sure that the larvae didn’t die from chemicals. Hence, falling temperature is a safe option to bet,” she added. Dr PK Gupta, a microbiologist and former president of the local unit of Indian Medical Association, said the survival of larva is temperature-dependent. “Mosquito multiply at temperatures above 25 degrees Celsius. Anything below 25 degrees is adverse for mosquito breeding. The falling temperatures will add to the efforts taken by the health department in controlling dengue spread.” The city has been experiencing a gradual fall in temperature since November 17.
“The mosquito that causes dengue can survive up to 21 days. This means that there is still a threat of getting bitten by a mosquito that is carrying the infection, especially since the dip in temperatures (in which the larvae can’t survive) is being observed only recently,” said Dr Abhishek Shukla, secretary general of the Association of International Doctors. The state has reported over 12,000 dengue cases this year, out of which 1,450 were from the state capital alone. A majority of the cases were reported in Prayagraj, Jaunpur and Varanasi.
On where the dead larvae were spotted, Srivastava said: “Our teams conduct ‘first-response’ exercise near the houses of dengue patients every morning. The process included source reduction, such as cleaning stagnant water and the likes. Larvae, if found, were also eliminated.”