Gérardin and others1 in a hospital-based study carried out in Senegal reported that thrombocytopenia in African children can predict the severity of malaria caused by Plasmodium falciparum and the prognosis of the disease. In this study, a significant association between median platelet counts and malarial death was found. These investigators concluded that thrombocytopenia could be used as a valid prognostic indicator for P. falciparum malaria in African children living in areas of low transmission.
We wish to express our concern regarding the validity of applying such findings in all settings. We believe that in countries where the prevalence of human immunodeficiency virus (HIV) is high (i.e., 10% or more), the positive predictive value of thrombocytopenia for a poor outcome of malaria still remains to be established. Indeed, thrombocytopenia associated with HIV is a common finding2,3 that is immunemediated and clinically expressed through purpura. Moreover, immune thrombocytopenia as a complication of infection with HIV frequently occurs in childhood.4 In neonates, thrombocytopenia is used as a marker of exposure to HIV in utero. In a cross-sectional study carried out in South Africa, 34 neonates exposed to HIV (HIV-positive by an enzyme-linked immunosorbent assay) were identified. Sixteen (47%) had thrombocytopenia and no underlying cause other than HIV was identified.5 Thrombocytopenia has also been described as a common manifestation in children up to 13 years of age in a systematic review on HIV infection in children.6
As the prevalence of HIV infection continues to increase in many African malaria-endemic countries, HIV infection should be considered as a major confounding factor in the association between thrombocytopenia and poor outcome of P. falciparum malaria in children.
Gérardin P, Rogier C, Ka AS, Jouvencel P, Brousse V, Imbert P, 2002. Prognostic value of thrombocytopenia in African children with falciparum malaria. Am J Trop Med Hyg 66 :686–691.
Monpoux F, Kurzenne J, Sirvent N, Cottalorda J, Boutte P, 1999. Partial splenectomy in a child with human immunodeficiency virus-related immune thrombocytopenia. J Pediatr Hematol Oncol 21 :441–443.