Hepatitis C virus infection and genotypes in Antananarivo, Madagascar.

The prevalence of hepatitis C virus (HCV) genotypes in Madagascar is not well known. Serum samples were obtained from 2,169 individuals selected by random sampling in the population living in Antananarivo city. Using HCV antibody test (Monolisa anti-HCV Plus version 2), 36 (1.7%) of the 2,169 samples were positive. The presence of HCV RNA was determined by using reverse transcription polymerase chain reaction amplifying the 5'-untranslated region (UTR): HCV RNA was detected in 17 of the 36 HCV antibodies positive samples. The genotype was determined using BLAST tool with another 5'-UTR fragment. The phylogenetic analysis of the polymerase (NS5b) and envelope (E1/E2) fragment sequences showed a low level of diversity compared to the high diversity in other African countries: subtype 1b (nine cases, 52.9%) and genotype 2 (eight cases, 47.1%) including subtype 2b (six cases), subtype 2k (one case), and one unclassified subtype. BLAST search with the 5'-UTR fragment sequence of this unclassified subtype identified that strain as subtype 2a.