Association of severe malaria with a specific Plasmodium falciparum genotype in French Guiana

Why severe Plasmodium falciparum malaria occurs in only a small percentage of patients is unclear. The possibility that specific parasite characterist ics contribute to severity has been investigated in French Guiana, a hypoen demic area, where parasite diversity is low and all patients with severe ca ses are referred to a single intensive care unit. Parasite genotyping in ge ographically and temporally matched patients with mild and severe disease s howed that the association of a specific msp-1 allele (B-K1) with a specifi c var gene (var-D) was overrepresented among patients with severe versus mi ld disease (47% vs. 3%, respectively; P < .001). Moreover, this genotype co mbination was consistently observed in the most severe clinical cases. Reve rse-transcription polymerase chain reaction demonstrated programmed express ion of var-D in vivo, which is consistent with its potential implication in severe disease. These results provide field evidence of an association of severe malaria with specific genetic characteristics of parasites and open the way for intervention strategies targeting key virulence factors of para sites.