Pattern of hepatitis C virus genotypes and subtypes circulating in war-stricken Khyber Pakhtunkhwa,Pakistan: Review of published literature

Infection due to hepatitis C virus(HCV) is a major cause of fibrosis and hepatocellular carcinoma in Pakistan. In the current review, pattern of HCV genotypes and subtypes in Khyber Pakhtunkhwa province was ascertained in light of the available literature. After thorough analysis, genotype 3(58.27%) was determined to be the leading HCV genotype,followed by genotypes 2(12.39%), 1(9.54%) and 4(0.86%). The proportions of genotypes 5 and 6 were recorded as 0.09% and 0.22% respectively. Subtype wise, 3 a accounted for 48.67%, followed by subtype 2 a(10.91%), 3 b(9.43%), 1 a(5.84%), 1 b(3.66%), 2 b(1.45%) and genotype 4 with its undefined subtypes contributed a portion of0.86%. The cumulative share of subtypes 1 c, 2 c, 3 c, 5 a and 6 a was less than 1%. In11.51% cases, the subtype was untypeable while in 7.17% cases mixed subtypes were recorded. Gender wise, proportions of most HCV subtypes were marginally higher among males as compared to females. On the basis of studied groups, 3 a was pervasive among all groups except in intravenous drug users where 2 a was the major HCV subtype.Similarly, based on various geographical locations(provincial divisions), subtype 3 a revealed a ubiquitous distribution. Conclusively, HCV 3 a persists to be the principal subtype across the province of Khyber Pakhtunkhwa. The considerable number of untypeable subtypes in most studies urges for an improved genotyping system on the basis of local sequence data and practice of sequencing for determination of underlying subtype in untypeable cases. Further, studies on identification of subtypes transmission pattern are imperative for assessment of transmission origin and reinforcement of efficient control strategies. In addition, the current review emphasizes the need of attention toward HCV risk groups and ignored southern side of Khyber Pakhtunkhwa province for better holistic understanding of HCV genotype distribution pattern in the province.