Mosquito breeding has gone up marginally in upmarket central Delhi and fallen in south and east Delhi — the usual hotbeds of dengue and malaria outbreaks — says data collected by the New Delhi Municipal Council (NDMC) and the municipal corporations from 60 lakh homes and commercial premises across Delhi.
The annual survey is done to check the growth of the larvae of the anopheles mosquito that causes malaria and aedes aegypti that causes dengue. The data is used to initiate measures to check mosquito breeding ahead of the monsoon. The sample size for the survey was much larger this year than previous years.
Mosquito larvae were found in 3.08 % (216 homes) of the 7,000 properties surveyed in NDMC areas in 2013, which is almost the same as 2.6% in 2012 and 3.2% in 2011.
In areas under the municipal corporations, 2,216 of the 59.3 lakh households and offices surveyed had larval breeding. In 2012, 19 of the 23,344 properties surveyed were affected by breeding. In 2011, out of 70,354 households surveyed, breeding was detected in 15.
“The number is more or less the same every year. This year, the sample size was larger and we included Moti Bagh, Netaji Nagar, Sarojini Nagar and Laxmi Bai Nagar. In most cases, mosquitoes were found breeding in overhead tanks,” said a senior NDMC official.
The NDMC has advised residents to make sure that lids of overhead tanks remain tightly shut. Though the number of dengue and other cases of mosquito-borne diseases is less in winter, the disease does not die out completely. The civic bodies reported 69 dengue cases in December last year.
“In winter, mosquitoes go into hibernation. Therefore, we see a few cases of dengue and other mosquito-borne diseases. The disease never dies out completely and it is not unusual to get mosquito-related diseases in winters,” said Dr SP Byotra, chairman, department of internal medicine, Sir Ganga Ram Hospital.
Two new cases of dengue have been reported since January this year. “This is the time when we start anti-larval measures, and this year, too, we have begun the exercise,” said the official.