Evolutionary study of potentially zoonotic hepatitis e virus genotype 3 from swine in northeast brazi

Abstract

Hepatitis E virus (HEV), an emerging virus associated with acute hepatic disease, leads to thousands of deaths worldwide. HEV has been already detected in Brazil, however there is a lack of epidemiological and molecular information concerning HEV genetic variability, taxonomy and evolution. It thus remains unclear whether Hepatitis E is a neglected disease in Brazil or whether it is of reduced relevance for the public health in this country. Here we report, for the first time, the presence of HEV in northeast Brazil. Of a total of 119 swine fecal samples screened for the presence of HEV RNA by real-time PCR and further confirmed by conventional RT-PCR, two samples were identified as positive. Molecular evolution analyses based on capsid sequences showed close proximities to HEV sequences belonging to genotype 3 and were genetically related to the subtype 3f isolated in humans. Parsimony ancestral states analysis has inferred gene flow events from HEV cross-species infection, suggesting an important role of pig hosts on viral spillover. HEV’s ability for zoonotic transmission by inter-species host switching as well as its possible adaptation to new animal species remain important issues under one health perspective.