Genotypic analysis of hepatitis E virus (HEV) from sporadic symptomatic cases in Pakistan.

Pakistan is the fifth most populous nation in the world and faces several challenges, including devastating floods, sub-optimal sanitary conditions, clustered accommodations, and unregulated cross-border movements. These drastic population shifts make it vulnerable to the efficient spread of the Hepatitis E virus (HEV). The current study analyzed the genotypic characteristics and variants of the Hepatitis E virus circulating in the population of Pakistan. A total of 75 ELISA-IgM positive samples were collected from three metropolitan cities: Lahore, Peshawar, and Karachi, and subjected to viral RNA extraction. The amplification of the HEV RNA-dependent RNA polymerase (RdRp) region was done using Nested PCR and degenerate primers. Out of the total, 40% of the samples were positive for HEV RNA. Sequencing and phylogenetic analysis identified the new HEV isolates as Subtype 1 g, a subtype within an existing HEV genotype 1. This shift warrants investigation into its impact on clinical manifestation and disease severity. Importantly, this study marks the first HEV subtype analysis in Pakistan, contributing valuable insights into subtype diversity and prevalence in the region.