Daily US Times: A team of Kenyan and the UK scientists have discovered a microbe that completely protects mosquitoes from being infected with malaria, what they say has “enormous potential” to control the disease.
Malaria is spread by the bite of infected mosquitoes, so protecting them from being infected could in turn protect people.
The scientists are now investigating whether they can use spores to suppress the disease or release infected mosquitoes into the wild.
What is this microbe?
Microsporidia MB, the malaria-blocking bug, was discovered by studying mosquitoes on the shores of Lake Victoria in Kenya. It lives in the genitals and guts of the insects. The researchers could not find a single mosquito carrying the Microsporidia that was harbouring the malaria parasite.
Lab experiments, published in Nature Communication, confirmed the microbe gave the mosquitoes protection.
Microsporidias are fungi, or at least closely related to them, and most are parasites.
The new species, however, may be beneficial to the mosquito and was naturally found in around 5% of the insects studied.
How big the discovery is?
Dr Jeremy Herren, from the International Centre of Insect Physiology and Ecology (icipe) in Kenya, said that the data they have so far suggest it is 100% blockage.
“It will come as a quite a surprise. I think people will find that a real big breakthrough,” Dr Jeremy said.
Every year, more than 400,000 people killed by malaria across the world, most of them children under the age of five.
While huge progress has been made through spraying homes with insecticide and the use of bed nets, this has stalled in recent years. It is widely agreed new tools are needed to tackle malaria.
How does the microbe stop malaria?
The fine details still need to be worked out, but Microsporidia MB could be priming the mosquito’s immune system, so it is more able to fight off infections.
Or the presence of the microbe in mosquitos could be having a profound effect on the insect’s metabolism, making it inhospitable for the malaria parasite.
Microsporidia MB infections appear to be life-long. If anything, the experiments show they become more intense, so the malaria-blocking effect would be long-lasting.
When can this be used against malaria?
In order to make a significant dent in malaria, at the very least, 40% of mosquitoes in a region need to be infected with Microsporidia.
The microbe can be passed from the female to her offspring and also be passed between adult mosquitoes. Microsporidia from spores which could be released en masse to infect mosquitoes.
Male mosquitoes, which don’t bite, could be infected in the lab and released into the environment to infect the female mosquitoes when they have sex.
Prof Steven Sinkins, from the MRC-University of Glasgow Centre for Virus Research, said: “It’s a new discovery. We are very excited by its potential for malaria control. It has enormous potential.”
What happens next?
The researchers need to understand how the microbe spreads, so they plan to perform more tests in Kenya.
However, these approaches are not unprecedented and are relatively uncontroversial because the species is already found in wild mosquitoes and is not introducing something new.
The process would not kill the mosquitoes, so it will not hamper the ecosystem that are dependant on them.
The fecundity and egg to adult survival rate of Microsporidia MB uninfected and infected iso-female lineages were examined. No significant differences were observed in the number of eggs laid by Microsporidia MB uninfected versus infected individuals, which indicates that unlike most other mosquito microsporidians17, Microsporidia MB does not have a sterilizing effect on females.