Objective To evaluate the effects of intermittent preventive treatment for malaria in infants (IPTi) with sulfadoxine-pyrimethamine in an area of intense, seasonal transmission.
Design Cluster randomised placebo controlled trial, with 96 clusters allocated randomly to sulfadoxine-pyrimethamine or placebo in blocks of eight.
Interventions Children received sulfadoxine-pyrimethamine or placebo and one month of iron supplementation when they received DPT-2, DPT-3, or measles vaccinations and at 12 months of age.
Main outcome measures Incidence of malaria and of anaemia determined through passive case detection.
Results
89% (1103/1242) of children in the placebo group and 88% (1088/1243)
in the IPTi group completed follow-up to 24 months of age. The
protective efficacy of IPTi against all episodes of malaria was 24.8%
(95% confidence interval 14.3% to 34.0%) up to 15 months of age. IPTi
had no protective effect against malaria between 16 and 24 months of
age (protective efficacy -4.9%, -21.3% to 9.3%). The incidence of
high parasite density malaria (
5000 parasites/µl) was higher in the IPTi group than in the placebo
group between 16 and 24 months of age (protective efficacy -19.5%,
-39.8% to -2.2%). IPTi reduced hospital admissions with anaemia by
35.1% (10.5% to 52.9%) up to 15 months of age. IPTi had no
significant effect on anaemia between 16 and 24 months of age
(protective efficacy -6.4%, -76.8% to 35.9%). The relative risk of
death up to 15 months of age in the IPTi group was 1.26 (95%
confidence interval 0.81 to 1.96; P = 0.31), and from 16 to 24 months
it was 1.28 (0.77 to 2.14; P = 0.35).
Conclusions Intermittent preventive treatment for malaria with sulfadoxine-pyrimethamine can reduce malaria and anaemia in infants even in seasonal, high transmission areas, but concern exists about possible rebound in the incidence of malaria in the second year of life.