Hepatitis C virus genotypes circulating in district Swat of Khyber Pakhtoonkhaw, Pakistan.

Hepatitis C virus (HCV) is the leading cause of chronic hepatitis worldwide and its subtypes/genotypes are clinically important for clinical management and vaccine development. The present study describes frequency distribution of different HCV genotypes and their treatment status in HCV RNA positive patients from district Swat. A total of 185 HCV infected sera were analyzed by molecular genotyping assay. The most prevalent genotype was 3a (34.1%), followed by 2a (8.1%), 3b (7%) and 1a (5.4%). The samples found untypable by the present method of genotypes was 37.8% while, patients with mixed genotype infections were 7.6%. More than 80% of untypable cases were from those HCV patients who had received interferon plus ribavirin standard therapy in the past and either were non-responders and were relapsed thereafter or were under treatment. In conclusion, genotype 3a is the most prevalent HCV genotype in the region. A high prevalence rate of untypable genotypes is present in treated patients that need further investigation for the successful genotyping by developing new assays or using viral sequencing method. [ABSTRACT FROM AUTHOR]