Plasmodium falciparum infection: Influence on hemoglobin levels in alpha-thalassemia and microcytosis

Plasmodium falciparum malaria, alpha-thalassemia, and anemia are frequent i n African children. In 494 nonhospitalized Nigerian children, P. falciparum infection rates, alpha-globin genotypes, and hematologic parameters were d etermined. II falciparum infection was observed in 78% of the children. The gene frequency of alpha-thalassemia was 0.28. Infection rates and parasite mia were similar for the 3 alpha-globin genotypes, In contrast to nonthalas semic and heterozygous persons, infection in children with homozygous alpha -thalassemia did not influence hemoglobin values. Because microcytosis and anemia are common features of alpha-thalassemia, their significance in P. f alciparum infection was examined. Microcytosis was significantly associated with protection from hemoglobin decrease due to P. falciparum, Moreover, t he rate of infection was lower in microcytic than in normocytic anemia.