Mosquitoes moving to warmer places indoor

Islamabad

After the significant fall in temperature in the twin cities of Islamabad and Rawalpindi, mosquitoes including dengue fever vector ‘aedes aegypti’ may move to relatively warmer places to rest and bite inside homes and offices and according to health experts, it is time for the individuals to perform indoor residual spraying (IRS) to prevent further spread of dengue fever.

Experts believe that the number of cases of dengue fever would consistently be on the rise at least for another three to four weeks because the fall in temperature would not affect mosquitoes’ activities in indoor environment that would remain warmer enough for mosquitoes to bite and feed on humans at least till the end of November.

The epidemiological findings developed with the help of data available on the subject of incidence of dengue fever and the trends of the disease during the last six years in this region of the country show that decline in number of cases of dengue fever can be attributed to fall in temperature, said Additional District Health Officer at Islamabad Capital Territory Health Department Dr. Muhammad Najeeb Durrani while talking to ‘The News’.

He added that the hospital based surveillance being carried out by the health departments during the outbreaks of dengue fever for the last six years proves that a typical drop in number of confirmed cases of dengue fever is observed in the month of November.

Dr. Durrani who is a member of The Global Outbreak Alert and Response Network (GOARN) said that earlier, in the beginning of October, more than 100 patients were being tested positive daily on average from the federal capital while after fall in temperature in the last two weeks, the number has dropped to below 40 patients per day.

He added the dengue fever outbreak lost its intensity in the first week of November last year, in 2015 and the last cases of the infection from endemic areas were reported till November 6, 2015.

To a query, he said the current status of incidence of dengue fever may continue for another one or two weeks based on the fact that patients who are contracting infection these days would report to the hospitals next week after appearance of signs and symptoms. It is important that the incubation period of dengue fever ranges from two days to a week.

Dr. Durrani, like many other health experts, said that it is time to create awareness among public that the fall in temperature observed recently has caused mosquitoes to move to find comparatively warmer places inside houses and offices and individuals should have to carry out IRS in indoor environments to control dengue fever incidence.

At this time, the mosquitoes including dengue fever vector may be moving from corridors and dormitories to the bedrooms, kitchens and bathrooms and in corners behind the curtains or furniture to rest and bite, he said.

Talking of another technical point, he said it is observed generally that more than one member of a family or the whole family gets infected after bite of dengue fever vector and it is so because the female ‘aedes aegypti’ is known as nervous feeder.

He explained that the female mosquito flies repeatedly during feeding on humans and returns again and again for biting.