Genetically-engineered mosquitoes that cannot transmit malaria could help stop the spread of the illness, according to a report in the The Guardian and other publications.

Replacing wild strains of Anopheles with malaria-resistant GM mozzies could make a huge difference in the fight against malaria. Between 300 and 500 million people contract malaria every year, of which about 1 to 3 million die from the disease. Most of them are children, mostly poor, most living in sub-Saharan Africa.

Engineering malaria resistance into wild mosquitoes could also reduce the amount of insecticides and repellents currently used in human habitations or directly applied for protection against malaria. (I’m spraying myself with DEET as I write these words — an evening ritual for most of us who live in the tropics.)

This development thus raises potentially difficult issues for people deeply opposed in principle to the creation and release into the wild of genetically modified organisms of any kind.

Johns Hopkins University researchers found that the malaria-resistant FM mosquitoes out bred their natural counterparts, suggesting that allowing them to breed with normal insects would spread their resistance through the wild population. The modified mosquitoes have also been given a gene to make their eyes glow red, allowing them to be easily identified.

Trials are unlikely to start for at least five years. Researchers need to do more tests to ensure that the new strain would not lead to more virulent strains of malaria, and that the genes would not spread to other insects.