Improving the diagnosis of severe malaria in African children using platelet counts and plasma HRP2 concentrations.

Severe malaria caused by is difficult to diagnose accurately in children in high-transmission settings. Using data from 2649 pediatric and adult patients enrolled in four studies of severe illness in three countries (Bangladesh, Kenya, and Uganda), we fitted Bayesian latent class models using two diagnostic markers: the platelet count and the plasma concentration of histidine-rich protein 2 (HRP2). In severely ill patients with clinical features consistent with severe malaria, the combination of a platelet count of ≤150,000/μl and a plasma HRP2 concentration of ≥1000 ng/ml had an estimated sensitivity of 74% and specificity of 93% in identifying severe falciparum malaria.

Plasma Plasmodium falciparum Histidine-rich Protein 2 Concentrations in Children With Malaria Infections of Differing Severity in Kilifi, Kenya.

Background: Most previous studies support a direct link between total parasite load and the clinical severity of Plasmodium falciparum malaria infections.

Methods: We estimated P. falciparum parasite loads in 3 groups of children with malaria infections of differing severity: (1) children with World Health Organization-defined severe malaria (n = 1544), (2) children admitted with malaria but without features of severity (n = 200), and (3) children in the community with asymptomatic parasitemia (n = 33).