The National Dengue Control Unit (NDCU) deployed 700 Inspection Teams, in its efforts to combat the spread of the dengue fever(DF)and dengue hemorrhage fever (DHF)in the Western, Northern and Eastern provinces from last Wednesday to Friday (January 17-19). Personnel from the tri-forces, Police or Civil Defense and Public Health Officers comprised the team visiting households in identified high-risk areas. The teams inspected the households for breeding places and larvae, specially of the mosquito Aedes aegypti identified as the main transmitter of DF/DHF in Sri Lanka.
Dengue is knows as an ‘urban disease’ as higher incidence is reported from urban areas. A. aegypti is the reason for this cause. The small mosquito just three millimeters in size is usually found within 100m of human habitats. During daytime, it rests indoors in dark shady areas where the temperature is around 24-25
degrees celcius. Known as a container breeder, the female lays its eggs in both natural (large leaves and crevices and hollows in rocks and trees) and artificial (tanks, pools, vases, bottle caps, polythene bags etc) containers a few at one place, moving to different containers to ensure survival.
However, research around the world has found that Aedes mosquitoes have a very high survival rate since their eggs are resilient to heat, and the larvae to the cold. They can slow their metabolic rates in cold
climates and stay at the same stage for long periods. After mating, the female could lay between 500 to 1000 eggs during its 3 week adult lifetime. The Health and Local Authorities in Sri Lanka use thermal fogging as the main method of eradication of mosquito breeding sites. Raising awareness of the householders in the reduction and minimizing of possible breeding places is also being carried out at the same time.
The Sunday Observer caught glimpses of the Mosquito Inspection Teams deployed at District 1 – Public Health area of the Colombo Municipal Council as they visited the households in Modera and Mattakkuliya two divisions identified as high-risk areas for dengue prevalence.
Pix. By Saman Mendis