PLASMODIUM-FALCIPARUM - MALARIA MORBIDITY IS ASSOCIATED WITH SPECIFICMEROZOITE SURFACE-ANTIGEN-2 GENOTYPES

Plasmodium falciparum merozoite surface antigen 2 (MSA2) is considered a vaccine candidate in a subunit vaccine against blood stage malaria. In order to test if a specific genotype of the highly polymorphic MSA 2 is associated with disease, we conducted a case-control study in a m alaria endemic area of Papua New Guinea involving 227 individuals, mos tly children under the age of 10 years, All cases and controls were ge notyped by polymerase chain reaction for their respective MSA2 genotyp es. We report that at the time of the study parasites carrying the FC2 7-like genotype were twice as likely to be found in symptomatic malari a cases than in asymptomatic controls. Mixed genotype infections were significantly less frequent in symptomatic malaria infections. One ind ividual allele (WOS10) of the FC27 family was found only in cases. Thi s may be a form of P. falciparum infrequently encountered and may caus e morbidity due to lack of immunity to it. This study provides evidenc e that MSA2 is involved in the morbidity of malaria and supports the i nclusion of MSA2 in a subunit vaccine. (C) 1995 Academic Press, Inc,