Distribution and heterogeneity of hepatitis C genotypes in hepatitis patients in Cameroon.

Hepatitis C virus infects humans world-wide. The virus genome varies greatly and it has several genotypes. HCV infection is highly prevalent in Central Africa and Cameroon. Initial studies on the genetic variability of HCV showed infection with HCV genotypes 1, 2, and 4. We have now sequenced the NS5b and E2 regions of 156 HCV isolates collected from patients presenting for diagnosis in Yaounde and used the data to describe the distribution of HCV genotypes and subtypes in patients with hepatitis in Cameroon. Genotype 1 was more frequent than Genotypes 4 and 2. Genotypes 1 and 4 were highly heterogeneous, containing many subtypes described previously (1b, 1c, 1e, 1h, 1l, 4f, 4t, 4p, 4k) and unsubtyped groups. There was a systematic phylogenetic concordance between NS5b and E2 sequence clustering. The Genotype 2 sequences did not vary. Neither subject age nor gender influenced HCV distribution. HCV Genotypes 1 and 4 are very heterogeneous in Cameroon, perhaps due to ancient infections. The homogeneity of HCV Genotype 2 indicates its more recent introduction from western Africa.