The interaction between malaria and human immunodeficiency virus infection in severely anaemic Malawian children: a prospective longitudinal study

ObjectiveMalaria and human immunodeficiency virus (HIV) infection are co-prevalent in sub-Saharan Africa and cause severe anaemia in children. Interactions between these infections occur in adults, although these are less clear in children. The aim of study was to determine their interaction in a cohort of severely anaemic children. MethodsSeverely anaemic Malawian children were enrolled, tested for HIV and malaria, transfused and followed for 18months for malaria incidence. Antiretrovirals were not widely available in Malawi during the study period. ResultsOf 381 children (haemoglobin <5g/dl), 357 consented for HIV testing, 12.6% were HIV-infected, and 59.5% had malaria parasitaemia. At enrolment, HIV-infected children had similar malaria parasitaemia prevalence (59.1% vs. 58.7%; P=0.96) and parasite density (geometric mean [parasites/l] 6903 vs. 12417; P=0.18) as HIV-negative children. There were no differences in mean CD4%, or prevalence of severe immunosuppression, between those with and without malaria parasitaemia. Plasma viral load correlated negatively with log parasitaemia (r=-0.78; P=0.01). During follow-up, HIV-infected children did not experience more frequent parasitaemias or symptomatic malaria episodes. Adjusted risk estimates (95% CI) for malaria parasitaemia in HIV-infected children at 6 and 18months follow-up were 0.39 (0.13-1.14) and 0.40 (0.11-1.51), respectively. ConclusionsSeverely anaemic HIV-infected children showed no increased susceptibility to asymptomatic or symptomatic malaria during or following their anaemic episode, although all experienced lower parasite prevalence during follow-up. This contrasts with data in adults and may relate to the malaria immunity of young children which is insufficiently developed to be impaired by HIV. The negative correlation between viral load and malaria parasitaemia remains unexplained