Rat Hepatitis E Virus Circulation in Brown Rats from 8 Cities, France, 2021–2023

Rat hepatitis E virus (Rocahepevirus ratti genotype C1, RHEV) is an emerging zoonotic pathogen responsible for acute or chronic hepatitis in patients. To assess RHEV circulation in brown rats (Rattus norvegicus) in France, animals were sampled in eight major cities. Based on RHEV RNA detection in liver, a positivity rate of 30.5% [27.1-34.0] (209/686) was identified. Positive animals were found in all cities, ranging from 9.7% [6. 7-13.8] in parks, to 44% [33.9-55.3] in social housing and sewers. Positivity rate differed by weight class, with 9% [5.8-13.8] in individuals <100g and 40. 7% [36.3-45.2] in those Anti-HEV antibodies were detected in 45% [40.0-51.0] of the samples (144/317). Twenty full genome sequences were obtained, with distinct RHEV strains. High genetic identity was observed between rat and human sequences in France and Europe. RHEV appears to be enzootic in rat populations in French cities, representing a source of zoonotic exposure to humans.