In vitro susceptibility of Plasmodium falciparum isolates in Vietnam to artemisinin derivatives and other antimalarials

We performed in vitro drug susceptibility assays of ten Plasmodium falciparum isolates collected from Viet Nam in 1995. All isolates were found to be highly sensitive to artesunate, dihydro-artemisinin and artemisinin. They were also sensitive to quinine. All of them were resistant to chloroquine and mefloquine in vitro. This study provides the baseline estimates of in vitro susceptibility levels of the Vietnamese isolates to artemisinin and their derivatives because the data were collected soon after these drugs were introduced countrywide. It also describes some quantitative profiles of the in vitro response of other standard antimalarial drugs in Viet Nam, which is presently limited.