How the malaria parasite "hails a cab" to reach more victims
The battle against malaria is taking place on many fronts. We've seen solar powered traps; efforts to genetically engineer mosquitoes to make them immune to the disease-causing parasites; methods of making mosquitos infertile; and, of course, insecticides and vaccines. But the issue with those last two is that the malaria parasites and mosquitoes that carry them can evolve to develop resistance to the chemicals meant to kill them or ward off the disease. New research from Stockholm University, however, might now give the world another method of trying to beat back the disease that still caused about 429,000 deaths in 2015.
The researchers discovered that the mosquitos that spread malaria prefer feeding on people who are infected with the disease. They believe the reason is due to a molecule produced by the malaria parasite known as HMBPP, which it uses to grow. When that molecule comes in contact with red blood cells in the human body, it causes them to release "more carbon dioxide and volatile compounds with an irresistible smell to malaria mosquitoes," says Ingrid Faye at Stockholm University.
In short, an infected person becomes like pizza fresh from the oven to a mosquito, which is why changing the way we smell might someday be a way to combat them.
What's more, the researchers found that when mosquitos latch on to a malaria-infected host, they drink more, which leads them to suck up more malaria parasites, which in turn gives them a more severe – and transmissible – infection.
"HMBPP is a way for the malaria parasite to hail a cab, a mosquito, and successfully transfer to the next host," SU's Noushin Emami explains.
"This seems to be a well-functioning system, developed over millions of years, which means that the malaria parasite can survive and spread to more people without killing the hosts," adds Faye, referring to the fact that an overabundance of parasites in a human body would kill it. But by figuring out how to get mosquitos to take more parasites onboard, the parasite has developed a tricky hitchhiking system that still accomplishes its goal of increasing its population.
Now that the researchers have uncovered this mechanism, they say it might be useful as a way to kill disease-causing mosquitoes. If a device could be made that gives off the same odor that HMBPP causes, malaria mosquitoes could be lured to it, trapped and killed, which would eliminate the need to spray poisonous insecticides.
The research has been published in the journal Science.
Source: Stockholm University