Scientist hopes to block mosquito ‘mating plug’ to prevent spread of malaria

Malaria kills up to a million people each year world-wide. Mortality rates are down by 25 percent over the past decade, according to the World Health Organization, largely thanks to the use of insecticide-treated bed nets and indoor spraying.

But some mosquitoes that carry the disease are becoming resistant to these measures, leading scientists to researcha new generation of malaria control techniques.

The approach being researched by Yale chemist Richard Baxter hinges on a key component of the mating process of malaria mosquitoes.

During mating, the male produces a kind of plug to seal in the sperm he deposits in the female.

Baxter and his team have identified the protein and enzyme that react to form this “mating plug.”  Now, they’re going to start testing substances that might prevent that reaction, and block reproduction.

“What we’re looking for is a potent and specific inhibitor because this could be a compound that we could feed to male mosquitoes,” Baxter said, “instead of having to spray a large area with DDT or another insecticide.”

The research is in early stages, but this so-called “sterile insect” technique has worked before, including on flies plaguing the cattle industry in the U.S.

American Society of Tropical Medicine and Hygiene President Dr. James Kazura said pesticide resistance is prompting promising new research that could give public health experts more tools to fight the disease.

“They’ll find a way around the things that are decreasing their population size,” Kazura said. “So this is a new, novel strategy in which we can actually decrease the reproductive capacity of mosquitoes.”

Baxter presented his research at an American Chemical Society meeting being held in Philadelphia this week.

Kazura said scientists are also looking into why malaria mosquitoes particularly like to bite humans. They hope to develop better insect repellents with that insight.