Genetic Diversity of Hepatitis C Virus Among Blood Donors and Patients with Clinical Hepatitis in Ibadan, Nigeria

Abstract

Hepatitis C virus (HCV) infection is responsible for liver diseases and hepatocellular carcinoma in chronically-infected patients. Owing to high sequence variability in HCV genome, numerous subtypes have emerged. This study determined HCV strains among patients with clinical hepatitis and blood donors in Ibadan. Blood samples were collected from consented 176 subjects who tested positive to HCV IgM antibodies, including 99 patients with clinical hepatitis and 77 apparently healthy blood donors. Viral RNA was extracted from blood samples, while presence of HCV was tested by amplifying the NS5B gene using polymerase chain reaction (PCR). The amplified NS5B gene was sequenced and sequences were aligned on MEGA 7.0. Phylogenetic tree was constructed with Neighbor-Joining method. Data were analyzed using descriptive statistics at P<0 .05. The NS5B gene was amplified in 38 samples, of which 29 were successfully sequenced. Phylogenetic analysis revealed three of seven known genotypes of HCV including genotypes / subtypes 1a (34.5%), 1b (17.2%), 2b (13.8%), 2c (3.6%) and 5a (31.3%). Subtypes 1b and 2b were found among patients with clinical hepatitis, while the single 2c was found among donors. Although subtype 1a was detected among both populations, its rate was higher among blood donors (P = 0 .003). Subtype 5a was found among the two groups (P= 1. 00). HCV subtypes 1a and 5a are the predominant strains in Ibadan. The diversity of HCV observed has implications for treatment of patients and design of a broadly protective vaccine against the virus.