Short report: severe malaria associated with blood group

Abstract

The ABO blood groups are not linked to the incidence of simple malaria infection but have been associated with rosette formation. In an effort to see if clinically severe malaria is associated with blood group, 489 patients were studied in Zimbabwe. Patients with malaria and group A blood had lower hemoglobin levels and more risk of coma than did infected patients with other blood groups. In this population, severe malaria is associated with blood group.

PIP: Clinical experience in Zimbabwe suggests that severe malaria is more frequent in individuals in the non-O blood groups. In a study conducted by the authors in 1995--a relatively light malaria season--the 27 patients with non-O blood had a mean hemoglobin level of 11.7 g/dl compared with 12.3 g/dl in the 26 patients with group O blood and were more likely to have jaundice or central nervous system symptoms. The present study evaluated 489 patients with positive malaria smears recruited from the Sanyati Baptist Hospital in Kadoma, Zimbabwe, during the 1996 rainy season. Overall, 266 had group O blood, 104 had group A, 103 had group B, and 16 had group AB. The mean hemoglobin levels were 11.8 +or- 2.8, 11.2 +or- 2.6, 11.4 +or- 2.4, and 12.4 +or- 2.7 g/dl, respectively. Coma was more frequent in patients with group A blood (9/104) than in those with non-A blood (11/385). Again, these findings suggest patients with group A blood are at greatest risk of clinically severe malaria. Cerebral malaria has been linked to the ability of Plasmodium falciparum to trigger formation of red blood cell rosettes, especially in those with group A blood. It is unclear, however, whether blood group, through its influence on rosette formation, is causally related to severe malaria or merely serves as a marker for other host-parasite interactions that provoke the severe manifestations of malaria.