Malaria species moves into previously resistant population

Malaria species moves into previously resistant population

A significant portion of the human population long thought to be resistant to the most common species of malaria is no longer protected from the disease. Since the early 1920s, people with a "Duffy negative" blood type were thought to be resistant to Plasmodium vivax (P.vivax) malaria—one of the five malaria parasite species that infects humans. But in a recent study by the School of Medicine, the Pasteur Institute and the Madagascar Ministry of Health that examined more than 600 people in Madagascar, researchers found that 10 percent of those infected with P.vivax were Duffy negative.

While researchers have speculated that P. vivax has made its way into the blood of Duffy-negative people, verifying these suspicions had not been possible until now.

The study confirms that P. vivax is able to invade red blood cells, whether the Duffy antigen is present or not. The evolution of new parasite strains and population mixing seem to be behind this development, according to Peter A. Zimmerman, PhD, the study's senior author and professor of international health, genetics and biology with the Center for Global Health and Diseases at the medical school.