Malaria may be helping spread the AIDS virus across Africa, the continent hardest hit by the incurable disease. The way the two diseases interact greatly expands the prevalence of both among people in sub-Saharan Africa, a team of scientists said in a study in the journal Science.
Malaria, a mosquito-borne disease caused by a parasite, greatly boosts viral load — the amount of human immunodeficiency virus in the blood of infected people — making them more likely to infect a sex partner with HIV, they stated.
“Higher viral load causes more HIV transmission, and malaria causes high HIV viral load,” said lead study author Laith Abu-Raddad of the Fred Hutchinson Cancer Research Center in Seattle and the University of Washington.
Abu-Raddad, an AIDS researcher, estimated that malaria has helped HIV infect hundreds of thousands and perhaps millions of people in sub-Saharan Africa. AIDS was first identified a quarter century ago.
At the same time, HIV fuels malaria’s spread because HIV-infected people are more susceptible to malaria as a result of HIV ravaging the immune system, the body’s natural defenses, the researchers said.
AIDS and malaria are concentrated in sub-Saharan Africa. Abu-Raddad said scientists were puzzled when they realized that the risky sexual behavior by people in the region was not by itself sufficient to explain the swift spread of HIV, so other factors must be involved.
They focused their work on Kisumu, a Kenyan city by Lake Victoria where HIV and malaria are both common. They said 5 percent of HIV infections can be blamed on the increased HIV viral load due to malaria, and 10 percent of adult malaria cases can be blamed on HIV.
Since 1980, 8,500 more people got HIV infections, and there were 980,000 more episodes of malaria (a person can get it more than once) in a city whose adult population is 200,000, the study found.