Kenya-led team discovers microbe that could stop malaria transmission


Scientists in Kenya have discovered a novel method with significant potential to completely stop mosquitos from transmitting the parasites which cause malaria in humans.

The team of scientists mostly from Kenya and the UK plus one from South Africa have been studying mosquitoes on the shores of Lake Victoria in Kenya and discovered that Microsporidia MB, a microorganism that lives in a mosquito’s gut and reproductive tract completely protects the mosquito from being infected with plasmodium the parasite that causes malaria.

Microsporidia are fungi, or at least closely related to them. Like plasmodium, which are protozoans they are also known to live inside mosquitoes as parasites. Mosquitoes inject their saliva into the skin during blood feeding to facilitate blood-feeding. Their saliva sometimes contains plasmodium which is usually injected together with their saliva resulting in malaria transmission. According to the study, the Microsporidia MB reduces the establishment of the Plasmodium falciparum parasite in the guts of the mosquitoes and impairs the colonization of the salivary glands by the parasite.

Malaria prevention and control organizations are optimistic the findings could offer a lasting solution to malaria, a disease that infects about 220 million people a year.

The vast majority of malaria cases occur in Africa and India and are caused by the P. falciparum parasite carried by female Anopheles mosquitoes.

Focusing on P. falciparum, researchers from icipe, the International Centre of Insect Physiology and Ecology, and the University of Glasgow, reported in a study published this week (4 May) that mosquitoes with the fungus do not carry malaria parasites, either in nature or after experimental infection in the lab.

The fungus Microsporidia MB is naturally found at low levels in malaria mosquitoes in Kenya, but the researchers believe there may be ways to increase the number of mosquitoes carrying it, thereby blocking their capacity to transmit malaria. Only female mosquitoes bite people.

Further research will investigate precisely how Microsporidia MB could be used to control malaria in large mosquito populations, but the researchers argue it is scalable and could be delivered to remote areas via plane airdrops of lab-infected mosquitoes or spores.

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