Rawalpindi:The temperature has started decreasing in this region of the country though it is still much suitable for transmission of dengue fever however with the further fall in mercury, mosquitoes including ‘aedes aegypti’, the vector that causes dengue fever would not be able to hatch its eggs that would certainly result in decline in dengue fever incidences.
Also the fall in temperature particularly below 13.8 degree centigrade affects the biting ability and physiological functions of ‘aedes aegypti’. The mercury has already started falling in the twin cities of Islamabad and Rawalpindi and their surroundings that hints that the severe dengue fever outbreak in the region would most probably be under control within next two to three weeks.
According to health experts, the existing adult ‘aedes aegypti’ in the environment may continue transmission of the infection but its rate would most probably be decreased within a week or so depending on the fall in mercury in the region.
It is important that only mature female ‘aedes aegypti’ or ‘aedes albopictus’ mosquitoes infected with dengue virus transmit the disease and the whole life cycle of the species does not long for over 28 days and if temperature falls to a certain degree, there would not be adult mosquitoes after four weeks.
Studies reveal that breeding of the mosquito may not be possible at temperature below 13 to 14 degree centigrade and further fall in temperature would certainly affect the breeding of mosquito particularly in outdoor environment.
What is important at the time is to clear places inside homes from possible breeding sites of mosquito as temperature inside homes does not fall below 14 degree centigrade normally, said epidemiologist Dr Muhammad Najeeb Durrani who is Member Global Outbreak Alert and Response Network (GOARN).
Dr. Durrani who is former District Health Officer Islamabad explained that the fall in temperature slows down larvae production of ‘aedes aegypti’ from eggs however; the mosquito may resist the fall in temperature from five to zero degree centigrade but it would not be able to mount and feed on humans at low temperature.
He added that as soon as the temperature starts falling below 20 to 18 degree centigrade, there would be an obvious drop in number of patients being reported in hospitals and it happens normally in the month of November in this region.
The mosquitoes’ activity is decreased in outdoor environment in low temperature and they are not able to bite because of less energy in joints as it do not let them to make a firm stand on the body of a person before sucking blood, he said.