Vector-borne diseases like malaria and dengue can spread from the most innocuous of places simply because of water stagnation. Most would normally expect open drains to be the primary sources forgetting others which are closer home- air coolers, specifically water tanks in air coolers. Interestingly, there exist government sponsored studies
on the role of coolers in breeding of vectors. Thanks to some ingenious thinking by Dr V K Saxena, Dr T G Thomas and Dr Shiv Lal of National Institute of Communicable Diseases (NICD), an effective solution may be at hand at competitive prices. Here’s an article from the Times of India giving the details of the invention and the reason that triggered its creation:
“A cooler with almost 100% efficiency at preventing mosquitoes from entering it and laying eggs will now spearhead India’s fight against vector-borne diseases like dengue and chikungunya. After over six months of research, scientists at Delhi’s National Institute of Communicable Diseases (NICD) have developed a “Mosquito Proof Cooler” (MPC). This new machine, developed jointly by Dr V K Saxena, Dr T G Thomas and NICD director Dr Shiv Lal, has several advantages. Unlike conventional coolers that require continuous cleaning to check for mosquito larvae, MPC needs a clean-up only once in three months. Moreover, it is compact and does not have a single hole for vectors to get through unlike conventional coolers with three detachable sides. The cooler also has a modified water tank and water inlet to takes care of water problems. Unlike conventional coolers which require water to be filled every day, MPC will require refill once in three weeks, even during peak summer months. This is because a special in-built technology does not allow stored water inside the cooler to evaporate.
Saxena, NICD joint director, told TOI that the machine would be a boon, especially in Haryana, Punjab, UP, Delhi, MP, Gujarat, Rajasthan and Maharastra where coolers are extensively used to beat summer’s scorching heat. These states also account for the highest number of dengue cases in the country. Stored water in the cooler tanks is the most favoured breeding place for the deadly Aedes mosquito, which causes dengue. NICD has already applied for a patent for the new invention and is in the midst of talks with two leading cooler manufacturers for transfer of this indigenous technology.
Saxena said: “We took three months to create the prototype. Field experiments over two months found it to be nearly 100% effective. While malaria and dengue vectors were found to be breeding in two conventional coolers used in the trials, not a single mosquito could enter the MPC and lay eggs. To be doubly sure, we introduced juvenile larvae in the water tank of the MPC to see if they emerged as adult mosquitoes. After one week, we found they did emerge but failed to escape from the cooler. Dead mosquitoes were found. This means even if by any chance a dengue or malaria carrying vector does enter the cooler, it won’t be able to come out.”
Saxena added: “A metallic barrier has been put above the tank to prevent mosquitoes from entering. Side shutters have been done away with. Once in the market, the price will vary. It will cost a maximum of Rs 300 more than conventional coolers.”
Dengue is endemic in several parts of the country. In 2006, 3,288 dengue cases and 38 deaths were reported out of which 1,951 cases were from Delhi. Over 10,000 people were infected with dengue in 1996 and 423 persons had died. Dr N K Yadav, health officer of Municipal Corporation of Delhi (MCD), said: “Over 90% of dengue mosquito breeding is found to be in coolers, especially during September-November. Till now, we have challaned 18,248 households for not maintaining cleanliness. Till November 7, Delhi recorded 502 dengue cases while the suburbs accounted for an additional 43 cases and one death
Let’s hope that we may have finally gotten rid of a bugging problem!