Might medicated nets eliminate malaria in mosquitos?

Although killing mosquitos is certainly one way of keeping them from spreading malaria, the pests can unfortunately develop a resistance to insecticides. Scientists from Harvard University are therefore looking at another approach, in which live mosquitos are made malaria-free simply by landing on a treated surface.

Atovaquone is a chemical that's already used in medications to treat and prevent malaria in humans. In lab-based experiments, Harvard researchers coated glass surfaces with that chemical, covered the glass with an inverted plastic cup, and then placed female Anopheles mosquitos inside of that cup. Immediately before or after sticking the insects in there, the scientists infected them with Plasmodium falciparum, which is the parasite that causes malaria.

Over the course of the study, the mosquitos were trapped in the cup for different amounts of time, and the glass was coated with differing concentrations of atovaquone. Inevitably, the insects ended up landing on the glass, absorbing the chemical through their legs. Ultimately, it was found that when they stood on relatively low concentrations of atovaquone for just six minutes, it was sufficient to eliminate all of the parasites within their bodies.

The insects typically light on mosquito netting around beds for at least six minutes at a time, so it is now hoped that by treating such nets with the chemical (or others similar to it), mosquito populations in given areas could gradually be made malaria-free.

It should also be noted that the atovaquone exposure did not alter the insects' lifespans or ability to reproduce. This could actually be welcome news to many people, who worry that simply killing off large numbers of mosquitos may adversely affect the ecological food chain.

"Mosquitoes are amazingly resilient organisms that have developed resistance against every insecticide that has been used to kill them. By eliminating malaria parasites within the mosquito rather than killing the mosquito itself, we can circumvent this resistance and effectively prevent malaria transmission," says Prof. Flaminia Catteruccia. "Ultimately, the use of antimalarials on mosquito nets could help eliminate this devastating disease. It's a simple but innovative idea that's safe for people who use mosquito nets and friendly to the environment."

A paper on the research was recently published in the journal Nature.

Source: Harvard University