In Pakistan, around 11 million people are infected with, at least, six circulating genotypes and subtypes of hepatitis C virus (HCV). The viral burden is still on rise. HCV genotype determination is necessary to devise appropriate antiviral therapy. Previous reports highlight the prevalence circulating untypable (in diagnostic perspectives) HCV subtype in local Pakistani patients. Present study was designed to investigate the epidemiological distribution of genotypes in different districts of Punjab, Pakistan and focuses on prevalence of diagnostically untypable subtype and its possible antiviral therapy. A total of 8,353 HCV patients were included through 2011 to 2016 for determination of HCV prevalent genotypes in the local community. HCV genotyping was carried out using Ohno et al. method, and five cases of diagnostically untypable patients were treated with interferon-based antiviral regimen to find the possible treatment strategy. Of the 8,353 patients, the genotype 3a (n = 6,650, 79.6%) was most significantly prevalent throughout the study period followed by undetermined genotype that is, untypable (n = 1,377, 16.5%). The presence of untypable variants suggested that there are some novel or quasi species prevailing among HCV patients in local community. Five HCV patients infected with untypable genotype had been treated effectively with interferon alpha plus ribavirin therapy for 24 weeks at standard doses and achieved sustained virological response. This study highlighted an important aspect of HCV treatment for local Pakistani HCV patients. Untypable HCV variants could be treated with interferon-based antiviral regimens such as 3a genotype. The study raises the need of characterization of diagnostically untypable HCV variant. On the basis of these results, it can be proposed that until the availability of pangenotypic direct-acting antiviral for HCV treatment in Pakistan, interferon-based antiviral regimens will be of choice for majority of patients infected with 3a or untypable genotypes.
Keywords: HCV; Pakistan; diagnostically untypable HCV variants; epidemiology; genotyping; treatment.