Absence of Hepatitis E Virus (HEV) in Italian Lagomorph Species Sampled between 2019 and 2021

SIMPLE SUMMARY: Hepatitis E is an emerging zoonosis. In the European Union, human cases are mainly caused by foodborne infections linked to the consumption of raw or undercooked food containing liver from pigs or wild boars infected by the hepatitis E virus (HEV). Some animal species are suspected to be a reservoir of zoonotic HEV genotypes 3 and 4. Among the HEV-3 genotype, viral strains infecting rabbits (HEV-3ra) are strictly related to the zoonotic genotype detected in pigs and humans. However, the transmission of rabbit HEV to humans is still debatable. To better evaluate the risk of transmission of rabbit HEV to humans, it is important to assess its prevalence in lagomorph populations. The aim of this study was to evaluate the presence of HEV in 328 Italian hares and 59 farmed rabbits collected in 3 Italian macro-areas (North, North-Central, and South-Central) between 2019 and 2021. For this purpose, liver samples were tested to detect HEV RNA using broad-range PCR, which was able to detect both HEV-3 and HEV-3ra. Neither HEV RNA nor anti-HEV antibodies were detected. The circulation of HEV-3ra in Italy may be limited to some geographical regions, as confirmed by its absence in our study and by the lack of human cases reported so far. ABSTRACT: The zoonotic hepatitis E virus genotype 3 (HEV-3) causes most autochthonous human hepatitis E cases in Europe, which are due to the consumption of raw or undercooked food products of animal origin. Pigs and wild boars are considered the main reservoirs of this genotype, while rabbits are the reservoir of a distinct phylogenetic group named HEV-3ra, which is classified within the HEV-3 genotype but in a separate clade. Evidence for the zoonotic potential of HEV-3ra was suggested by its detection in immunocompromised patients in several European countries. HEV-3ra infection was found in farmed and feral rabbit populations worldwide and its circulation was reported in a few European countries, including Italy. Furthermore, Italy is one of the major rabbit meat producers and consumers across Europe, but only a few studies investigated the presence of HEV in this reservoir. The aim of this study was to assess the presence of HEV in 328 Italian hares and 59 farmed rabbits collected in 3 Italian macro-areas (North, North-Central, and South-Central), between 2019 and 2021. For this purpose, liver samples were used to detect HEV RNA using broad-range real-time RT-PCR and nested RT-PCR. Using 28 liver transudates from hares, the ELISA test for anti-HEV IgG detection was also performed. Neither HEV RNA nor anti-HEV antibodies were detected. Further studies will be conducted to assess the HEV presence in Italian lagomorphs to establish the role of this host and the possible risk of transmission for workers with occupational exposure, to pet owners and via food.