PLASMODIUM-FALCIPARUM - SICKLE-CELL TRAIT IS ASSOCIATED WITH HIGHER PREVALENCE OF MULTIPLE INFECTIONS IN GABONESE CHILDREN WITH ASYMPTOMATIC INFECTIONS

Through PCR amplifications of the gene encoding the merozoite surface antigen 2, utilizing allele-specific 3D7 and FC27 probes, we have exam ined the prevalence of Plasmodium falciparum in children aged from 7 t o 14 years living in a village located in the equatorial forest region of Central Africa (Gabon). Using this technique, 61% (100/163) of the blood samples were shown to be infected with P. falciparum with 24 al leles distinguished by size polymorphism and sequence type. The two ma in families (3D7 and FC27) and hybrid alleles were detected regardless of sex and hemoglobin phenotype. No age-related changes in prevalence of P. falciparum strains were observed; however, the prevalence of in fection (42%) was significantly lower in individuals with the sickle-c ell trait compared with their normal-hemoglobin counterparts (68%). Mi xtures of genetically distinct parasite clones were present in 82% of children carrying the sickle-cell trait but in only 58% of normal-hemo globin carriers. The significance of these observations regarding the design and interpretation of epidemiological investigations is discuss ed in the context of malaria transmission in the region studied. (C) 1 997 Academic Press.