Children who live in areas where malaria is common can mount an immune response to the infection that may enable them to avoid repeated bouts of high fever and illness, according to a study published today in PLOS Pathogens.
The findings may help researchers develop future interventions that prevent or mitigate the disease caused by the malaria parasite.
Each year, approximately 200 million cases of malaria occur worldwide, resulting in roughly 627,000 deaths (mostly children less than the age of 5 years living in sub-Saharan Africa). In 2013, 97 countries had ongoing malaria transmission, according to the World Health Organization. Unlike individuals who are newly exposed to malaria, people living in malaria-endemic regions often do not experience malaria-induced fever and manage to control parasite numbers in the bloodstream. To better understand why, researchers analyzed immune cells from children in Mali who are bitten by malaria-infected mosquitos more than 100 times per year, yet experience malaria fever only two times per year on average. The scientists collected blood samples from children on three occasions: before the start of the six-month malaria season; seven days after each child had been treated for his or her first malaria fever of the season, when symptoms had cleared; and after the subsequent six-month dry season, when little to no malaria transmission occurs.