Malaria in infants below six months of age: retrospective surveillance of hospital admission records in Blantyre, Malawi

BACKGROUND: Information on the burden of malaria in early infancy is scarce. Young infants are relatively protected against clinical malaria during the first six months of life due to the presence of maternal antibodies and foetal haemoglobin, and have received relatively little attention with respect to research and treatment guidelines. The World Health Organization provides treatment guidelines for children from six months onwards, without specific treatment guidelines for the younger infants. A number of recent reports however suggest that the burden in this young age group may be underestimated. METHODS: A retrospective review of paediatric hospital records at the Queen Elizabeth Central Hospital in Blantyre from 1998 to 2008 from three data sources was carried out. The number of admitted infants <6 months and ≤ 15 years was obtained from the registry books of the Paediatric-Nursery-Department and the Malaria Research Laboratory. For the period 2001 - 2004, more detailed malaria related admission information was available as part of an ongoing study on severe malaria, allowing a calculation of the proportion of infants < 6 months of age among admissions in children < 5 years. RESULTS: Retrospective analysis of hospital records showed that over the course of these years, the average annual proportion of paediatric admissions in children ≤ 15 years with confirmed malaria aged <6 months was 4.8% and ranged between 2.8%-6.7%. This proportion was stable throughout the seasons. Between 2001-2004, 9.9% of admissions with confirmed malaria in children <5 years occurred in infants <6 months, with numbers increasing steadily during the first six months of life. CONCLUSIONS: These findings are consistent with recent reports suggesting that the burden of malaria during the six first months of life may be substantial, and highlight that more research is needed on dose-optimization, safety and efficacy of anti-malarials that are currently used off-label in this vulnerable patient group.