Intermittent preventive treatment for malaria control administered at the time of routine vaccinations in Mozambican infants: a randomized, placebo-controlled trial

Abstract

Background: There is an urgent need to deploy and develop new control tools that will reduce the intolerable burden of malaria. Intermittent preventive treatment in infants (IPTi) has the potential to become an effective tool for malaria control.

Methods: We performed a randomized, double-blind, placebo-controlled trial of sulfadoxine-pyrimethamine (SP) treatment in 1503 Mozambican children. Doses of SP or placebo were given at 3, 4, and 9 months of age. The intervention was administered alongside routine vaccinations delivered through the Expanded Program on Immunization (EPI). Hematological and biochemical tests were done when infants were 5 months old. Morbidity monitoring through a hospital-based passive case-detection system was complemented by cross-sectional surveys when infants were 12 and 24 months old.

Results: IPTi was well tolerated, and no adverse events associated with SP were documented. During the first year of life, intermittent SP treatment reduced the incidence of clinical malaria by 22.2% (95% confidence interval [CI], 3.7%-37.0%; P=.020) and the rate of hospital admissions by 19% (95% CI, 4.0%-31.0%; P=.014). Although the incidence of severe anemia (packed cell volume of <25%) did not differ significantly between the 2 groups (protective effect, 12.7% [95% CI, -17.3% to 35.1%]; P=.36), there was a significant reduction in hospital admissions for anemia during the month after dosing for both the first and second dose. The serological responses to EPI vaccines were not modified by the intervention.

Conclusions: IPTi with SP has been shown to moderately reduce the incidence of clinical malaria in Mozambican infants without evidence of rebound after stopping the intervention or of interactions with EPI vaccines. Its recommendation as a malaria control strategy in Mozambique needs to be balanced against the scarcity of affordable control tools and the burden of malaria in children.