Researchers led by the University of Oxford's Dominic Kwiatkowski identified three subpopulations of the malaria-causing parasite Plasmodium falciparum that appear to be resistant to artemisinin, as they report in Nature Genetics this week. Kwiatkowski and his team genotyped 86,158 coding SNPs in 825 parasite samples obtained from locations in Burkina Faso, Ghana, Mali, The Gambia, Cambodia Thailand, and Vietnam.
The Cambodian samples, isolated from four different spots in the country, contain three drug-resistant subpopulations, and also appear to harbor greater genetic diversity than the other parasite samples. Further, the samples from western Cambodia, where resistance was detected, differ from each other as well as from eastern Cambodian samples and from other Southeast Asian or African samples.
"For the first time we have identified the emergence of sub-populations associated with a drug resistance to artemisinin," first author Olivo Miotto tells the New Scientist.
New Scientist adds that Cambodia is thought to be a hotspot for resistance, possibly due to how malaria was generally treated there.