Relationship between ABO blood groups and malaria

A total of 736 patients with fever was tested for malaria and classified according to ABO blood group. Of these, 476 cases had patent parasitaemia at the time of investigation. The distribution of blood groups in this group was significantly different from that in 1300 controls from the same area. While group A was found to be more common in malaria cases than in normals, the reverse situation was found for group O. Possible explanations for this are discussed.