Effect of intermittent treatment with amodiaquine on anaemia and malarial fevers in infants in Tanzania: a randomised placebo-controlled trial.

Background: Malaria is a major cause of infant morbidity and mortality in sub-Saharan Africa, and is often complicated by severe anaemia. Resistance of Plasmodium falciparum to most affordable antimalarial drugs is an impediment to intermittent chemotherapy. We investigated the effect of presumptive intermittent treatment with amodiaquine and daily iron supplementation in infants on malarial fevers and anaemia, in a holoendemic area of Tanzania where malaria is largely resistant to chloroquine and sulfadoxine/ pyrimethamine.

Methods: 291 infants aged 12-16 weeks who attended three clinics were randomised to receive amodiaquine, iron supplementation, amodiaquine plus iron supplementation, or placebo. Over 6 months, we gave amodiaquine three times with intervals of 60 days; oral iron supplementation was given daily. Malarial fevers and anaemia were monitored at bimonthly treatment visits and by self-reporting to health centres.

Findings: The protective efficacy of intermittent amodiaquine treatment in prevention of malarial fevers and anaemia was 64.7% (95% CI, 42.4-77.2) and 67.0% (95% CI, 34.5-83.4), respectively. Protective efficacy was similar in the group receiving amodiaquine plus iron supplementation. Infants receiving iron supplementation only were partly protected against anaemia (protective efficacy 59.8%; 95% CI, 23.4-78.9), but not against malarial fevers. 4 months' follow-up did not show rebound morbidity. We noted no haematological or clinical adverse effects.

Interpretation: Presumptive intermittent treatment for malaria with amodiaquine reduced malarial fevers and anaemia in infants, in an area with high resistance to other antimalarials. Intermittent treatment strategies for malaria in highly endemic areas could be of great benefit to public health.