Molecular evolution, virology and spatial distribution of HCV genotypes in Pakistan: a meta-analysis

Hepatitis C, caused by the Hepatitis C Virus (HCV), is the second most common form of viral hepatitis. The geographical distribution of HCV genotypes can be quite complex, making it challenging to ascertain the most prevalent genotype in a specific area. To address this, a review was conducted to determine the prevalence of HCV genotypes across various provinces and as a whole in Pakistan. The scientific literature regarding the prevalence, distribution, genotyping, and epidemiology of HCV was gathered from published articles spanning the years 1996 to 2020. Genotype 1 accounted for 5.1% of the patients, with its predominant subtype being 1a at 4.38%. The frequencies of its other subtypes, 1b and 1c, were observed to be 1.0% and 0.31% respectively. Genotype 2 had a frequency of 2.66%, with the most widely distributed subtype being 2a at 2.11% of the patients. Its other subtypes, 2b and 2c, had frequencies of 0.17% and 0.36% respectively. The most prevalent genotype among all isolates was 3 (65.35%), with the most frequent subtype being 3a (55.15%), followed by 3b (7.18%). The prevalence of genotypes 4, 5, and 6 were scarce in Pakistan, with frequencies of 0.97%, 0.08%, and 0.32% respectively. The prevalence of untypeable and mixed genotypes was 21.34% and 3.53% respectively. Estimating genotypes proves to be a productive method in assisting with the duration and selection of antiviral treatment. Different HCV genotypes can exhibit variations in their response to specific antiviral treatments. Different genotypes may have distinct natural histories, including variations in disease progression and severity. Some genotypes may lead to more rapid liver damage, while others progress more slowly. This information can guide screening and testing strategies, helping to identify individuals at higher risk of developing severe complications. Studying the distribution of HCV genotypes in a population can provide valuable insights into the transmission dynamics of the virus.