Much Work Needed to Halt Spread of Hepatitis C Worldwide

Next generation sequencing reveals frequent opportunities for exposure to hepatitis C virus in Africa.
Blood donors in Kumasi, Ghana have a very heterogeneous population of HCV strains, as reported in the online journal PLOS ONE by Joseph Forbi et al.

Next-generation sequencing (NGC) of three HCV genomic regions (5'UTR, HVR1 and NS5B), ascertained that all HCV variants belonged to two genotypes, HCV-1 and HCV-2, with HCV-2 infecting 85% of the tested donors.

HCV Infections in Ghana

The hepatitis C virus is a global health concern, but in Ghana, the prevalence of infection among blood donors exceeds endemic levels with prevalence up to 11.6% among male donors. The demand in Ghana for safe blood exceeds its availability by more than 50%, due partly to the rejection of HCV-infected blood.

The conditions for the effective transmission of the HCV-2 genotype in particular have existed for up to 3 to 4 centuries in Ghana. Major risk factors for exposure to infected blood/blood products include unsafe injection practices, transfusion of untested blood, unsterile medical and dental procedures.

Other recent reports identify traditional circumcision, home birth, tribal scarring, and hepatitis B co-infection as major risk factors.

Study population and DNA sequencing

Serum samples (n=363) were obtained from a random population of recalled male blood donors from a single blood bank in Kumasi Ghana, West Africa. All donors were HPC treatment-naïve. Only samples that were NS5b positives (n=65) were amplified by a nested PCR. Amplicons derived from the PCR amplifications were purified and sequenced after which HCV genotypes were classified.

DNA sequencing of serum samples from 65 blood donors in Kumasi, Ghana determined that the patient population was infected with a remarkably heterogeneous population of HCV strains. All HCV variants belonged to two genotypes, HCV-1 and HCV-2, with HCV-2 infecting 85% of the tested donors. This finding is consistent with previous studies of HCV in Ghana.

Confirming that HCV-2 has a long history in Ghana, the most recent common ancestor (MRCA) for all HCV-2 strains sampled in this study is estimated to have existed approximately 500 years ago. (Although it should be noted that analysis of sequences linked to a limited duration of sample collection could result in estimating tMRCA (time to MRCA) inaccurately.

The significant variety of HCV-2 strains circulating in a single locale in Ghana may be explained by either a single massive introduction of HCV strains or introduction of numerous viral lineages over a long period of time.

Alternatively, Ghana may be, or be part of, the geographic origin of HCV-2, which is consistent with an earlier hypothesis on the origin of this genotype in West Africa.

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