A Kenya-UK team of researchers have announced the discovery of a microbe that seems to protect mosquitoes from being infected with malaria, something that has “enormous potential” to control the disease – more than 400,000 people are killed by malaria each year, most of them children under the age of five. Malaria is spread by the bite of infected mosquitoes; however, at least 40% of mosquitoes in a region need to be infected with the microbe in order to make a significant dent in malaria.

The malaria-blocking bug, Microsporidia MB (Microsporidia), was identified by studying mosquitoes on the shores of Lake Victoria in Kenya. Although Microsporidias are mostly parasites, this new species was naturally found in around 5% of the mosquitos studied – it lives in their gut and genitals – and may be beneficial to the insects.

As the researchers could not find a single mosquito carrying the Microsporidia harbouring the malaria parasite, they think the Microsporidia could be priming the mosquito’s immune system to fight off other infections, or affect the mosquito’s metabolism, making it inhospitable for the malaria parasite. Microsporidia infections also appear to be life-long and more intense over time, so the malaria-blocking effect would be long-lasting.

“The data we have so far suggests a very severe blockage of malaria – a 100% blockage,” said Dr. Jeremy Herren, from the International Centre of Insect Physiology and Ecology (ICIPE) in Kenya.

The researchers first need to understand how the microbe spreads and can then decide whether to release infected mosquitoes into the wild.Male mosquitoes, which don’t bite, could be infected with the microbe in the lab and released into the wild to infect the females; the microbe can also be passed from the female to her offspring.

Otherwise, the researchers can use Microsporidia form spores which could be released en masse to infect mosquitoes and suppress malaria. Currently, insecticides and mosquito nets are used to protect against the disease.