MEROZOITE SURFACE-ANTIGEN-1 AND 2 GENOTYPES AND RESETTING OF PLASMODIUM-FALCIPARUM IN SEVERE AND MILD MALARIA IN LAMBARENE, GABON

We present a case-control study to investigate the distribution of Pla smodium falciparum genotypes in patients with severe and mild malaria. We compared clinical and parasitological data with the parasites' gen otype and resetting. The study group consisted of 100 children sufferi ng severe malaria, defined as severe anaemia and hyperparasitaemia. Th ese children were matched by age, sex and provenance with 100 children with mild malaria. For characterization of the parasites we used the polymerase chain reaction to determine merozoite surface antigen (MSA) 1 and 2 genotypes and the phenomenon of rosette formation. We found a significant association between rosette formation and disease severit y, and a significant association of severe anaemia with the presence o f the MSA-1 allele K1. Infections with 2 genotypes in the severely aff ected group were significantly associated with severe anaemia and the presence of MSA-1 allele K1. Comparison with the findings of other gro ups led to the conclusion that the occurrence of P. falciparum genotyp es seems to differ geographically.