Artemisinin (qinghaosu)--a new gametocytocidal drug for malaria

Gametocytocidal activity of artemisinin (qinghaosu) has been demonstrated against simian malaria parasite Plasmodium cynomolgi B. Colony-bred Anopheles stephensi were allowed to feed on gametocyte-carrying rhesus monkeys and the mosquito infectivity rate and oocyst count of the infected mosquito gut were recorded on day 8-9 postinfection. Control (pretreatment) feedings of mosquito on gametocyte-carrying monkeys showed good infectivity in different batches of the mosquitoes ranging from 57.14 to 95.0%. Administration of single intramuscular injection of 5 mg/kg artemisinin (suspended in neutralised oil) resulted in complete loss of mosquito infectivity within 24 h of drug administration. This is the first report on the possible use of artemisinin to stop malaria transmission. The drug has no sporontocidal action.