Parasite Viability as a Superior Measure of Antimalarial Drug Activity in Humans

Abstract

Background: Artemisinin derivatives are the leading class of antimalarial drugs due to their rapid onset of action and rapid clearance of circulating parasites. The parasite clearance half-life measures the rate of loss of parasites from blood after treatment, and this is currently used to assess antimalarial activity of novel agents and to monitor resistance. However, a number of recent studies have challenged the use of parasite clearance to measure drug activity, arguing that many circulating parasites may be nonviable. Methods: Plasmodium falciparum-infected subjects (n = 10) in a malaria volunteer infection study were administered a single dose of artesunate (2 mg/kg). Circulating paras..