In South-East Asia, Plasmodium falciparum, one of the parasites that transmits malaria, developed resistance to the widely used antimalarial drug artemisinin over a decade ago. Now scientists have discovered that resistance is also starting to become more common in Africa.

A study published in the Lancet Infectious Diseases journal indicates that artemisinin-based combination therapies (ACTs) have not been able to clear malaria parasites from Rwandan children's blood in three days. The paper analysed 224 children with malaria aged six months to five years. In some areas, 15% of children still had detectable parasites after three days, which is the WHO criteria for partial resistance.