Hepatitis E is a rare human disease in developed countries. It is caused by hepatitis E virus (HEV), which is probably transmitted zoonotically to humans from domestic pigs and wild boars. Multiple reports on the detection of HEV-specific antibodies in rats have suggested the presence of an HEV-related agent; however, infectious virus or a viral genome has not been demonstrated so far. Here, a nested broad-spectrum RT-PCR protocol was developed capable of detecting different HEV types including those derived from wild boar and chicken. Screening of 30 faecal samples from wild Norway rats (Rattus norvegicus) from Hamburg (Germany) resulted in the detection of two sequences with similarities to human, mammalian and avian HEV. Virus particles with a morphology reminiscent of HEV were demonstrated by immunoelectron microscopy in one of these samples and the virus was tentatively designated rat HEV. Genome fragments with sizes of 4019 and 1545 nt were amplified from two samples. Sequence comparison with human and avian strains revealed only 59.9 and 49.9 % sequence identity, respectively. Similarly, the deduced amino acid sequence for the complete capsid protein had 56.2 and 42.9 % identity with human and avian strains, respectively. Inoculation of the samples onto three different permanent rat liver cell lines did not result in detectable virus replication as assayed by RT-PCR with cells of the fifth virus passage. Further investigations are necessary to clarify the zoonotic potential of rat HEV and to assess its suitability to serve in a laboratory rat animal model for human hepatitis E.

Group A rotaviruses (RVAs) are an important cause of diarrhoeal illness in humans, as well as in mammalian and avian animal species. Previous sequence analyses indicated that avian RVAs are related only distantly to mammalian RVAs. Here, the complete genomes of RVA strain 03V0002E10 from turkey (Meleagris gallopavo) and RVA strain 10V0112H5 from pheasant (Phasianus colchicus) were analysed using a combination of 454 deep sequencing and Sanger sequencing technologies. An adenine-rich insertion similar to that found in the chicken RVA strain 02V0002G3, but considerably shorter, was found in the 3′ NCR of the NSP1 gene of the pheasant strain. Most genome segments of both strains were related closely to those of avian RVAs. The novel genotype N10 was assigned to the NSP2 gene of the pheasant RVA, which is related most closely to genotype N6 found in avian RVAs. However, this virus contains a VP4 gene of the novel genotype P[37], which is related most closely to RVAs from pigs, dogs and humans. This strain either may represent an avian/mammalian rotavirus reassortant, or it carries an unusual avian rotavirus VP4 gene, thereby broadening the potential genetic and antigenic variability among RVAs.

Sedoreoviridae is a large family of icosahedral viruses that are usually regarded as non-enveloped with segmented (10–12 linear segments) dsRNA genomes of 18–26 kbp. Sedoreovirids have a broad host range, infecting mammals, birds, crustaceans, arthropods, algae and plants. Some of them have important pathogenic potential for humans (e.g. rotavirus A), livestock (e.g. bluetongue virus) and plants (e.g. rice dwarf virus). This is a summary of the ICTV Report on the family Sedoreoviridae, which is available at ictv.global/report/sedoreoviridae.

Hepatitis E virus (HEV) causes self-limiting acute hepatitis in humans that can eventually result in acute liver failures or progress to chronic infections. While in tropical and sub-tropical areas, HEV infections are associated with important waterborne epidemics, in Northern countries, HEV infections are autochthonous with a zoonotic origin. In the past decade, it has become clear that certain HEV genotypes are zoonotic and that swine, and more generally Suidae, are the main reservoir. Zoonotic transmissions of the virus may occur via direct contact with infected pigs, wild boars or consumption of contaminated meat. This review describes the current knowledge on domestic and wild Suidae as reservoirs of HEV and the evidence of the different routes of HEV transmission between these animals and humans.