Genetic characterization of rat hepatitis E virus (Rocahepevirus ratti) in urban brown rats (Rattus norvegicus) in Helsinki, Finland.

We report complete and partial genome sequences of rat hepatitis E virus (RHEV, Rocahepevirus ratti), from archived brown rats captured in Helsinki, Finland. Phylogenetic analysis confirmed the presence of the pathogenic RHEV genotype C1 in the Helsinki region. Finnish strains clustered together with strains from South Korea and Spain. However, the polytomous topology of phylogenetic trees and the large genetic distances between spatially distinct strains suggest that RHEV has remained inadequately sampled on a global scale. Further surveillance of rocahepeviruses is needed to assess their threat to public health and to understand their diversity and evolutionary patterns.