Malaria parasites were detected and counted by microscopy following Giemsa staining of thick and thin blood films [15] . Children with severe malaria were recruited on admission from the Otunba Tunwase Children's Emergency Ward (OTCHEW). Children with uncomplicated malaria were recruited as part of a daily routine malaria parasite screening at the Children's Outpatient Clinics (CHOP). Malaria-negative ill children were recruited either at admission from OTCHEW or from the Department of Paediatrics In-patient wards. Malaria-negative healthy community control children were recruited from local vaccination clinics as well as during school visits across several Ibadan districts.