Anemia Offers Protection Against Malaria in African Children

In Africa, where nine out of 10 deaths of malaria occur, a child dies every minute. In fact, this life-threatening disease accounted for 528,000 deaths in 2013; 78% of them were children who did not live to see the age of five. In this area where malaria is endemic, many of these children are anemic due to nutritional deficiencies.

According to the Centers for Disease Control and Prevention, when it comes to nutritional deficiency, iron deficiency is the most common worldwide, and for children, this can have long-term consequences. Iron supplements have been used as a way to remedy these deficiencies; however, researchers have questioned the safety of these supplements when it comes to children who are living in countries where malaria remains endemic, such as countries in Africa. In fact, previous studies have found that sickle-cell anemia offers a level of protection in children against Plasmodium falciparum (P. falciparum)—one of the species of Plasmodium that cause malaria.

In a recent study published in EBioMedicine, a group of researchers from the University of North Carolina at Chapel Hill, the Medical Research Council Unit in Gambia, Africa, and the London School of Hygiene & Tropical Medicine have taken things a step further in their discovery that iron deficiency anemia actually offers protection against blood-stage malaria and iron supplements may actually decrease that level of protection in the children who take them, giving validation to supplemental concerns.

In their study, funded by the Bill & Melinda Gates Foundation, the researchers sought to find out how anemia works to prevent blood-stage malaria as well as how iron supplements work to diminish this protection. To do this, researchers collected fresh red blood cells from 135 anemic children who were living in Gambia, a small West African country where malaria is endemic; all of these children were 6 to 24 months old. The children were a part of an iron supplementation trial and were given iron (rf12 mg/day) as part of a micronutrient powder for 84 days. At baseline, Day 49 and Day 84, the fresh red blood cells were examined.

According to UNC’s official press release, it has been shown in previous studies that sickle-cell anemia has a “protective effect” in children against malaria. However, in this study, researchers found that, “on a population-wide basis, anemia reduced the blood-stage of malaria by 16% while the sickle-cell trait only reduced it by 4%.”

According to the study’s lead author Morgan Goheen, PhD, a graduate student in the UNC department of Microbiology and Immunology, “Our finding that anemia offers greater natural protection against blood-stage malaria infection than sickle-cell trait has led us to formulate the interesting hypothesis that the widespread prevalence of anemia in people of African descent is a genetic signature of malaria.”

After anemic children received iron supplementation over the course of seven weeks, the researchers found that the supplements actually worked to reverse the “deficits in invasion and growth” of malaria. Based on past studies that the team has conducted, the researchers posit that the, “parasites’ strong preference for young red blood cells” may be the reason for the increased rates of invasion and growth.

“These results confirm and quantify a plausible mechanism by which anemia protects African children against falciparum malaria, an effect that is substantially greater than the protection offered by sickle-cell trait. Iron supplementation completely reversed the observed protection and hence should be accompanied by malaria prophylaxis,” the authors concluded.