Burden and Molecular Epidemiology of Hepatitis E Virus at the Livestock-Human Interface in North Central Nigeria

Hepatitis E virus genotype 3 and 4 are zoonotic variants transmitted from swine to humans, and their burden at the livestock-human interface in North Central Nigeria is largely uncharacterized. This study investigated the burden and molecular epidemiology of hepatitis E virus at the pig-human interface in Benue, Niger, and Plateau States, North Central Nigeria. A cross-sectional design enrolled 250 pigs from commercial and backyard farms and 200 humans from three occupational groups comprising pig farmers, slaughterhouse workers, and consumers. Pig fecal samples and human serum samples were tested by enzyme-linked immunosorbent assay and quantitative reverse transcriptase PCR. Positive samples were sequenced for ORF2 phylogenetic analysis. A structured questionnaire assessed consumption habits and pig exposure behaviors. Hepatitis E virus seroprevalence was 48.6% in pigs and 23.5% in humans, with highest rates in slaughterhouse workers at 38.7%. Sequencing confirmed genotype 3 in both pig and human samples. Phylogenetic analysis identified shared clades between pig and occupationally exposed human strains, providing genetic confirmation of zoonotic transmission. Consumption of undercooked pork and slaughterhouse employment were independent risk factors in multivariable logistic regression. The study establishes that hepatitis E virus genotype 3 zoonotic transmission at the pig-human interface is occurring at substantial rates in North Central Nigeria and provides the first phylogenetically confirmed zoonotic transmission evidence from this region. Keywords: Hepatitis E virus, zoonotic transmission, pig-human interface, North Central Nigeria, molecular epidemiology