September 4, 2007
Cure the Mosquito, Cure Malaria
In America, you would have to be at least in your 70s or 80s to remember that parts of the country once had a problem with malaria. In the first half of the 20th century, the disease was systematically eliminated by a program of medication, wetland drainage and chemical mosquito control.
Nearly 40 percent of the rest of the world's population, however, remains threatened by the disease.
Scientists have long known that malaria is spread to humans by mosquito bites but, recently, a team from Rensselaer Polytechnic Institute (RPI) in upstate New York identified a key link in the chain of events that causes malarial infection.
If this knowledge can be used to prevent mosquitoes from becoming infected, then malaria itself could be eradicated without any swamps being drained, insecticides being sprayed or humans having to take a drug.
It turns out that both humans and the mosquitoes share the same complex carbohydrate, heparan sulfate. Heparan sulfate is a receptor for the malaria parasite — it binds to the parasite and gives it quick and easy ride through the body.
According to RPI's Robert J. Linhardt, "The discovery allows us to think differently about preventing the disease," Linhardt said. "If we can stop heparan sulfate from binding to the parasite in mosquitoes, we will not just be treating the disease, we will be stopping its spread completely."
The malaria parasite is extremely finicky about its hosts and needs a perfect match at the molecular basis to spread from one species to another. Researchers have long understood this deadly partnership but the molecular basis for the match had never been determined.
"The discovery marks a paradigm shift in stopping malaria," Linhardt said "Now, we can work to develop an environmentally safe, inexpensive way to block infection in mosquitoes and not have to worry about drug side effects in humans."
Malaria kills over one million people around the world, mostly young children. And the problem is growing. As the Earth heats up because of global warming, outbreaks of malaria are being reported farther up the coast of South America and Mexico each year.
This research was published in the August 31, 2007 edition of the Journal of Biological Chemistry.