Molecular Diagnosis of Hepatitis C Virus in Ghanaian Blood Donors

Abstract

The geographical distribution of different types and subtypes and the prevalence of hepatitis C virus (HCV) vary significantly. Identification of HCV genotypes has become increasingly important for the clinical management and prognosis of HCV infections. Available evidence shows that HCV is endemic in West Africa, but there is little data on HCV genotypes present in Ghana. This study therefore set out to identify circulating HCV genotypes in healthy Ghanaians and determine the relationship to genotypes from other geographical regions. Plasma were obtained from 200 blood donors in the year 2002 and tested for antibodies against HCV. RNA was extracted from anti-HCV-positive sera and reverse-transcribed into cDNA. The cDNA preparations were subjected to nested and semi-nested PCR to amplify 5’-untranslated region (5’UTR) and the core sequences, respectively. Nested PCR was then used to identify HCV genotypes using type-specific primers. Semi-nested PCR amplified core sequences were cloned into a TOPO vector (Appendix I). The clones were transformed into E. coli cells and cultured; DNA was purified from the cells and sequenced. HCV cDNA sequences were analysed and compared for intra- and interdonor differences and with reported sequences for similarity with those from other regions. HCV RNA was detected in only 2 of 13 (15.4%) HCV seropositive donors. Genotype 2 was the only genotype found and subtypes 2a and 2b were detected in one subject while the other had 2a only. Comparison of nucleotide sequences from position 329 to 658 of the HCV genome showed the following characteristics: (i) the nucleotide sequence similarity was 95 to 96%; (ii) intra- / inter-donor difference in nucleotide sequences observed was 30% and an intra- / inter-donor similarity was at least 94%. The phylogenetic analyses of the core region indicated that collectively, the Ghanaian HCV RNA extracts formed a diverse single phylogenetic group. The existence of rapid genotype variation within a single individual was observed. This study also shows that HCV genotype 2a is prevalent in Ghana.