Concerned over sudden spurt in cases of vector borne diseases, North Delhi Municipal Corporation (NMC) in order to contain mosquito breeding and proliferation of related diseases has decided to promote eco-friendly measures such as dengue free coolers, 'Agave Americana' plant on war footing. The civic body has also stepped up in to curb the mosquito menace and fight vector-borne diseases by putting mosquito larvae-eating fish Gambusia in water-bodies and fountains in its areas.
Dr Pramod Verma, District Health Officer (DHO), City Zone said that the introduction of the concept of dengue free cooler is an environment-friendly initiative and will be taken up at war footing to generate awareness among the people. "The concept was developed by experts of health department after years of research and experience practical approach to deal with mosquitoes menace. The maximum breeding of Aedes mosquito, which causes dengue and Chikungunya takes place in desert coolers so we have already instructed manufacturers to sell Dengue-free cooler. This initiative would help in containing the number of cases of these diseases," he said.
The conventional desert coolers are being used in many parts of the country as a cooling device in households, offices and industrial establishments. The conventional desert cooler retains water for a longer period and becomes potential breeding grounds for dangerous mosquitoes, he said, adding that more than 50 per cent of breeding places of dengue vectors are contributed by these conventional coolers as the water tank is of the open type which is very suitable for mosquitoes to lay eggs.
"Now the concept is to cover water tanks to prevent the entry of mosquitoes into it for laying of eggs. There is thus no risk of disease transmission due to coolers and no weekly cleaning of the water tank is required. Even if the breeding still takes place inside the cooler and eggs fall in the water tank and develop, the mosquitoes can't come out due to cover over the water tank," he said.
Talking about idea of dropping Gambusia fishes to water bodies, he said that there are more mosquitoes in parks and gardens as they tend to have more stagnant water. Controlling the mosquito population by using Gambusia is a well-documented method and is quite easy to do as these fish are prolific breeders.
The young fish breed twice in a season while the older females may breed six times in a season. A season lasts for about 30 days. A single female may produce between 900 and 1,200 offspring during its life span. Gambusia breeds throughout the year after maturity, especially in tropical conditions, so is ideal for the purpose of curbing the mosquito menace, he added
A senior NMC official said that anticipating possible outbreak of vector-borne diseases, the civic body has grown eco-friendly plant 'Agave Americana' in huge (thousands) numbers in its nurseries to eliminate the chances of mosquitoes breeding.
The plant's extract can be poured into cooler to prevent mosquito breeding in place of insecticides to root out mosquitoes. The leaf extract of "Agave Americana' has a "larvicidal efficacy". The leaf extracts of Agave Americana is, also known as Century Plant or Kamal Cactus.
Explaining about it further, entomologists associated with NMC, said that when mosquitoes are exposed to the leaf extract of this plant at the larval stage they die within hours. They also said that the plant does not have any harmful effect on the environment or mankind compared to synthetic insecticides used for spraying.