Genetically Engineered Mosquitoes Prevent Transmission of Dengue Fever

Researchers have genetically engineered a line of mosquitoes so that the females of the next generation, which normally carry and transmit the dengue fever virus, are unable to fly and die before they can spread the disease or reproduce.

The mosquito Aedes aegypti is the major vector of dengue and dengue hemorrhagic fever, which are increasing public health problems with an estimated 50-100 million new infections each year. The virus is spread by the bite of the female mosquito, and currently no vaccine or treatment is available.

Eliminating the insect vector could be an effective way of controlling the disease. To this end, investigators from the University of California, Irvine (USA) and the biotechnology company Oxitec, Ltd. (Oxford, United Kingdom) have explored the possibility of using genetic engineering techniques to reduce or eliminate transmission of the disease.

In an article published in the February 22, 2010, online edition of the journal Proceedings of the [U.S.] National Academy of Sciences (PNAS) they reported that they had succeeded in engineering male mosquitoes to carry one or more genes that result in the females of the next generation being unable to fly. Flightless females die quickly in the wild, and curtailing the number of mosquitoes seriously disrupts dengue transmission. Males of the strain can fly but do not bite or convey disease. These strains therefore eliminate the need for sterilization by irradiation, permit male-only release, and enable the release of eggs instead of adults.

"The technology is completely species-specific, as the released males will mate only with females of the same species,” said senior author Dr. Luke Alphey, chief scientific officer at Oxitec. "It is far more targeted and environmentally friendly than approaches dependent upon the use of chemical spray insecticides, which leave toxic residue. Another attractive feature of this method is that it is egalitarian: All people in the treated areas are equally protected, regardless of their wealth, power, or education.”

Related Links:
University of California, Irvine
Oxitec