GM mosquitoes `to tackle dengue fever`

London: Genetically modified mosquitoes could prove effective in tackling dengue fever and other insect-borne diseases, say scientists.

Dengue is caused by a virus transmitted by the Aedes aegypti mosquito as it bites. The World Health Organisation estimates that there may be 50 million cases each year, and the incidence is rising. As yet, there is no vaccine. Now, a UK-based scientific team claims to have found in a dengue-affected part of the Cayman Islands that genetically modified (GM) male mosquitoes mated successfully with wild females, the `BBC` reported. The scientists say such mating has not before been proven in the wild, and could cut the number of disease-carrying mosquitoes. In the research, the scientists from Imperial College London and the Liverpool School of Tropical Medicine released batches of GM mosquitoes in 2009 in an area of Cayman Islands where Aedes aegypti are common, and dengue sometimes present. A proportion of the eggs collected from the study area in subsequent weeks carried the introduced gene, meaning the biotech mosquitoes had mated successfully. The GM males made up 16 per cent of males in the study area, and fathered 10 per cent of the larvae; so they were not quite as successful as the wild males, but not significantly worse. Luke Alphey, a visiting professor at Oxford University, said: "We were really surprised how well they did. For this method, you just need to get a reasonable proportion of the females to mate with GM males -- you`ll never get the males as competitive as the wild ones, but they don`t have to be, they just have to be reasonably good." The findings have been published in the latest edition of the `Nature Biotechnology` journal. PTI