Ten-year persistence and evolution of Plasmodium falciparum antifolate and anti-sulfonamide resistance markers pfdhfr and pfdhps in three Asian countries.

Despite the fact that SP therapy was discontinued in Thailand, Cambodia, and Laos decades ago, parasites retained the pfdhfr and pfdhps mutations. Numerous haplotypes were found to be prevalent among the parasites. Frequent monitoring of pfdhfr and pfdhps in these areas is required due to the relatively rapid evolution of mutation patterns.