Heat, dry weather help cut dengue vector density

Rawalpindi: The existing weather conditions, a severe heat wave hitting most parts of the country and another intense heat wave expected from Sunday, can be termed as the most suitable time for checking breeding of mosquitoes particularly ‘aedes aegypty’ and ‘aedes albopictus’, the vector that causes dengue fever.

According to experts, high environmental temperatures particularly under strong sunlight would not allow larval growth. Extreme hot and dry weather may kill most of the eggs of mosquitoes and render adult vectors, mosquitoes, inactive. The reduction in the number of eggs, larvae and pupae will reduce the number of emerging adult mosquitoes. Experts say that it is time for individuals to benefit from the weather conditions to control the density of dengue fever vectors in and around their residences.

Studies reveal that the optimal temperature for the growth of ‘aedes aegypti’ larvae is 28C. Above this the rate of development is high and below 18C the growth gets prolonged. Above 36C, the larval development is not complete. A good proportion of mosquitoes’ population existing in the environment would not be able to survive in the high temperatures. After the intense heat waves, only a little percentage of aedes aegypti, that survives, would be able to bring its offspring.

Also, the breeding of aedes aegypti is not possible in high temperatures on a number of sites. Many health experts believe that if individuals manage to eliminate possible breeding sites inside homes and at cooler places at the time, there might be less number of mosquitoes during the high transmission season, in July and August.

Experts say that it is the right time for both individuals and the concerned government authorities to give proper attention to check breeding of mosquitoes by eliminating possible breeding sites. Only by elimination of possible breeding sites of mosquitoes from inside homes, offices and indoor environment, the chances of a possible outbreak of dengue fever can be reduced.

Experts say that at this point in time, there may be chances of growth of aedes aegypti in humid parts of the country but the extreme hot and dry weather conditions in this region of the country may not support mosq­uitoes’ growth. All the stakeholders should convince individuals not to allow breeding of mosquitoes at this time and if we manage to check breeding of mos­quitoes in May and June, there would be less chances of a severe dengue fever outbreak in the high transmission season.