Mutant mosquitoes latest weapon in malaria war

Scientists in the US have used gene-editing to produce a strain of mosquitoes that blocks the transmission of the malaria parasite. The mutant mosquitoes are the latest weapon in a battle against the life-threatening disease that kills over 438,000 people each year.


Mosquito Image by dr_relling / CC BY 2.0

The United Nations World Health Organisation estimates there will be 214 million cases of malaria worldwide in 2015, with some 3.2 billion people at risk of contracting the disease.

Malaria is transmitted to people through the bite of an infected female mosquito. Travellers to Sub-Saharan Africa, India, parts of Oceania and the Amazon area will be familiar with traditional prevention techniques: mosquito nets, loose clothing, DEET-spray, and anti-malarial drugs. But scientists from the University of California hope they have found a more effective way to reduce, if not completely eradicate, the risk of transmission to humans, by breeding their genetically modified mozzies with wild populations.

Using gene-editing, a technique in which DNA can be inserted, replaced or deleted from a genome, the scientists were able to create mosquitoes with genes that prevent malaria transmission by producing malaria-blocking antibodies. Laboratory tests show the malaria-blocking antibodies from the genetically modified mosquitoes were passed on to 99.5% of their offspring.

The spread of the malaria-blocking antibodies through wild populations could happen surprisingly quickly. University of California-San Diego biologist Valentino Gantz told Reuters: "It can spread through a population with great efficiency, increasing from 1% to more than 99% in 10 generations, or about one season for mosquitoes."

The scientists used the Anopheles stephensi species of mosquito, which spreads malaria in urban India, for their tests. And while University of California-Irvine molecular biologist Professor Anthony James warns the mutant mosquitoes will not eradicate the spread of the disease completely, when used alongside traditional prevention techniques, they could play a major role in the elimination of the disease.

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