Molecular Epidemiology of Hepatitis E Virus Genotypes in Pregnant Women and Swine Populations in Plateau State: A Zoonotic Interface Analysis

Hepatitis E virus (HEV) is a leading cause of acute viral hepatitis globally, with genotype 1 predominantly causing waterborne epidemics in developing countries while genotype 3 and 4 are zoonotic, transmitted through pig meat and direct animal contact. In Nigeria, HEV epidemiology is poorly characterized at the animal-human interface. This study investigated HEV genotype distribution in pregnant women and domestic swine populations in Plateau State, North Central Nigeria, applying a zoonotic interface analysis framework. Serum samples were collected from 150 pregnant women attending antenatal clinics at Jos University Teaching Hospital, and fecal and blood samples were collected from 80 domestic pigs at five swine farms in Jos and Shendam LGAs. HEV RNA was detected by RT-PCR targeting the ORF2 capsid gene. Positive samples were subjected to partial ORF2 sequencing, and phylogenetic analysis was conducted using the HEV reference sequences from GenBank. HEV RNA was detected in 11.3% of pregnant women, with all sequenced human isolates clustering within genotype 1. In swine, HEV RNA prevalence was 26.3%, with swine isolates clustering exclusively within genotype 3. Phylogenetic analysis revealed no direct genetic linkage between human and swine HEV strains, suggesting separate transmission pathways in the study setting. Genotype 1 HEV in pregnant women was associated with a history of flood exposure. These findings provide the first genotype-resolved HEV zoonotic interface data from Plateau State. Keywords: Hepatitis E virus, genotype, pregnant women, swine, Plateau State.