Objective: To determine the burden of congenital malaria in newborns in Nigeria.
Methods: In a prospective multi-centre study, 1875 consecutive mother-baby pairs were enrolled over a continuous 12-month period. Blood smears were prepared from mothers, neonates, placental aspirates and cord blood within 4 h of delivery. Outcome variables were patent parasitaemia in the mother, placenta, cord and neonate in addition to maternal and neonatal haematocrit.
Results: Patent parasitaemia was detected in 95 neonates (5.1%). The occurrence varied between study centres, but was found year round in all sites. The mean parasite density among infected neonates was low (48 asexual forms per microl, range 8-200/microl). Maternal and placental parasitaemia were the most important risk factors for patent neonatal parasitaemia (P < 0.0001). Spontaneous clearance of parasitaemia occurred in 62.1% of neonates before day 2. 33.7% were symptomatic within 3 days of birth.
Conclusion: Congenital malaria is often asymptomatic, clears spontaneously and may not warrant treatment. However, newborns with unexplained fever and refusal to feed in malaria endemic areas should be tested for malaria.