Chennai: Guess what you should be worrying about when you swat that mosquito with your ‘bat’ and pray that you don’t contract dengue? Climate change. Yes, experts suggest that the pesky mosquito is undergoing entomological changes due to erratic climate change. They also attribute pollution for the growing threat from the vectors.
Loyola College Entomology Research Institute (ERI), former director, Father Ignasimuthu, told News Today that a research conducted by his team showed the resurgence and invasion of certain kinds of mosquito species, and Aedes aegypti is said to be one among them.
“The primary reason that can be attributed to the aggressive entomological change is the erratic climate change and atmospheric pollution that has become a breeding ground for the mosquito species,” stated Fr Ignasimuthu.
He also said mosquitoes cannot survive below 15 degrees Celsius and owing to global warming, the species have acclimatised themselves to survive in varying weather patterns. “Since the temperature in hilly areas are very low, mosquitoes did not survive there which is not the case now,” he observed.
Explaining about resistance, Ignasimuthu continued, “The mosquitoes have even built resistance towards larvicide. The lifespan of an average mosquito is between 48 and 65 days and it has the capacity to break down the chemicals in just 25 generations as the alteration in the DNA molecule is also easy.”
Department of Public Health and Preventive Medicine, retired director, Dr S Ilangovan, told News Today, “In the last few years, we have witnessed a rapid spread and breeding of mosquitoes in the country. Dengue was not a common phenomenon in New Delhi a decade ago and now, many States, including Tamilnadu, are experiencing increased number of fever incidence reported in government and private hospitals.”
He added that the mosquitoes have invaded several isolated districts in the State which were not affected by severe maladies in the past.
“A few years ago, districts like Madurai, Nagercoil and even Chennai were not threatened by vector-borne diseases. The mosquitoes that act as vector for transmitting disease-causing conditions were predominantly found in forests; later, they began to invade the interior regions. The infiltration of Aedes species dominated the Anopheles carrier that led to a dip in malaria and rise in dengue fever,” he added.
Dr Ilangovan also observed anatomy-related changes in the vector that gave the Aedes mosquito an upper hand over the Anopheles mosquito.
“The dengue carriers are heavy, bred in polluted water in the past whereas the malarial vectors are light in weight, transparent and commonly found in freshwater. During the transition period, the mosquito accultured itself to the fluctuating environmental conditions that has made it possible to survive and proliferate efficiently in fresh source of water,” pointed out the doctor.
When the observation was taken to the knowledge of Department of Public Health and Preventive Health Medicine director, Dr Kolandaiswamy, he stated that the malarial insurgence was effectively tackled by vaccines.
“There were several air-borne and water-borne conditions in the past; constant promotion of hygiene has led to complete eradication of cholera, small pox, etc.,” the director stated.
“The entomological changes do not create any significant impact, as far as healthcare is concerned. A hygienic environment can prevent breeding of insects. If people adhere to basic values, diseases can be prevented,” he added.
WAY FORWARD
Though the Department of Health and Family Welfare, Government of Tamilnadu and Greater Chennai Corporation have been undertaking active measures to control breeding of female Aedes mosquito experts opine that a lot more needs to be done.
Loyola College Entomology Research Institute former director, Father Ignasimuthu goes with the suggestion provided by the government in maintaining a clean atmosphere and discarding unwanted materials that could lead to mosquito breeding.
Adding his weight to the argument, Dr Ilangovan stated that the Aedes mosquitoes have to be stamped out in a single go. “An amount of Rs 20 lakh for a period of four years should be allocated to annihilate the life-threatening vector with suggestions taken from experts,” he said.