In vivo efficacy of chloroquine treatment for Plasmodium falciparum in Malawian children under five years of age

In 1984 the government of Malawi instituted a program to reduce malaria mortality and morbidity in children less than 5 years of age as a part of the Combatting Childhood Communicable Diseases (CCCD) program. To define the appropriate malaria therapy regimen; investigators used a quality assurance design in a simplified 7-day in vivo drug response study with follow-up observations on day 2 (D2) ; D3; and D7 after the initial day of the study (D0). The efficacy of oral chloroquine was assessed in 224 children who were enrolled at 6 sites; 2 in each of the 3 administrative regions of Malawi. Parasitological failure; defined as failure of parasitemia to decrease by 75 percent of the value by D3 or presence of any detectable parasitemia on D7; ranged from 41 percent -65 percent following administration of chloroquine 25 mg (base)/kg. However; only 8 percent of children who were parasitemic on D7 were febrile or judged to be ill. Considering these therapeutic results and the higher cost and limited availability of alternative therapies; chloroquine 25 mg/kg therapy was adopted as the primary therapy for malaria