Comparative clinical characteristics and response to oral antimalarial therapy of children with and without Plasmodium falciparum hyperparasitaemia in an endemic area.

The clinical characteristics and the responses to oral antimalarial therapy of 104 children presenting consecutively with or without Plasmodium falciparum hyperparasitaemia (HP) were investigated in an endemic area. At presentation, although the 52 children with HP were significantly younger and had significantly higher heart rates than the 52 without, there were no significant differences between the two groups in their symptoms or in any other clinical feature of their malaria. Responses to oral antimalarial drugs were similar in both groups. Analysis of the disposition kinetics of parasitaemia, using a non-compartmental model similar to that used in characterizing drug disposition, showed that the two groups had similar half-lives of parasitaemia (t1/2pd), volumes of blood completely cleared of parasites per unit time (CLBpd), and parasite-clearance-time:t1/2pd ratios. Three children in the HP group, all aged < 3 years, progressed to cerebral malaria within 8 h of presentation, and another HP child presented with isolated trunkal ataxia, indicative of cerebellar involvement. No child in the non-HP group had any of the features of severe malaria. Although the clinical characteristics and responses to oral therapy of children with and without HP are therefore very similar, young children with HP appear to have an increased risk of developing other features of severe malaria.