Emergence of genetically variant Hepatitis C virus population in response to increased antiviral drug pressure, Pakistan.

Mutations in NS5B gene of Hepatitis C virus (HCV) have been reported in patients undergoing antiviral therapy. In the present study, we report emerging clade of HCV-3a in patients administered with IFN plus ribavirin therapy for 24 weeks and having low viral loads (<250 IU/mL). Mutations D/N244E, K304R, N/K307G, Q/T329V, and A338V were found associated with these emerging strains. This distinct HCV could be associated with the increased antiviral drug pressure.