Malaria in Papua New Guinean infants: a prespecified analysis of a randomised postpartum antimalarial treatment trial

BACKGROUND: There are scant and variable data concerning the incidence of malaria in infants in endemic areas. This study evaluated the impact of maternal antimalarial treatment given postpartum on malaria incidence and growth/development in infants from coastal Papua New Guinea (PNG). METHODS: In an open-label, randomised controlled trial conducted in Madang Province, PNG, 183 mothers were randomised to no treatment (NT) or to artemisinin combination therapy (ACT) with further random allocation to artemether-lumefantrine or dihydroartemisinin-piperaquine. Their infants were assessed monthly over the next 6 months including for malaria identified by microscopy and/or polymerase chain reaction (PCR). RESULTS: Of 151 infants who completed study procedures, 2 developed slide-positive malaria (1 Plasmodium falciparum, 1 Plasmodium vivax; 1.3% [95% confidence interval {CI} 0.2 to 5.2]). Three others had PCR-detected infections (two P. falciparum, one P. vivax). The overall 6-month incidence of slide-/PCR-positive malaria was 3.3% (95% CI 1.2 to 8.0). Four of the five cases occurred in infants whose mothers were randomised to NT. There were no statistically significant between-group differences in infant growth and developmental milestones. CONCLUSIONS: The risk of malaria in early infancy in coastal PNG is low and infections are typically asymptomatic. Postpartum maternal ACT did not influence infant growth or development.