Infections with the hepatitis E virus (HEV) annually cause 44,000 human deaths worldwide. People get infected by ingesting food or water containing virus, or by contact with animals such as pigs in temperate climates. Recent reports also showed sporadic occurrence of human infections by a genetically divergent rat-associated HEV.
To better understand the genealogy of the Hepeviridae virus family, Felix Drexler and colleagues mined publicly available genomic data including that of primates, rodents, hooved animals, bats, and shrews in search for hepeviral genes. The authors identified four genetically divergent hepeviruses in rodents and bats. The authors then analyzed >2,000 liver specimens from approximately 100 rodent and shrew species sampled from understudied regions in Africa, Asia, and Latin America.
Combining data mining and fieldwork, genetically divergent hepeviruses in >15 species of rodents, bats and shrews were identified. Rodents hosted the largest diversity of hepeviruses. Evolutionary analyses of the hepeviral genomes revealed that human-associated HEV likely originated recently in hooved animals such as swine or camelids and more distantly in small mammals such as rodents. The data also indicate that hepeviruses that switched hosts predominantly originated from rodents.
These findings highlight the need for increased global surveillance and experimental assessments of the risks that rodent-associated hepeviruses may pose for humans.
Read the full article: Jo et al. Ancient evolutionary origins of hepatitis E virus in rodents. PNAS 2024 Dec 09. doi: 10.1073/pnas.2413665121
Featured Image: Geographic representation of hepeviruses identified in rodents and shrews. Hepevirus evolutionary tree. The northern three-toed jerboa (Dipus sagitta) that hosts ancestors of human hepatitis E virus. Country: Mongolia (Zaaltai Gobi Desert). Image credit: Leonid Lavrenchenko
