Hepatitis e virus surveillance in ovine bulk milk: a serological and molecular study in central Italy

Hepatitis E virus (HEV) is the most common cause of acute viral hepatitis worldwide and it is able to infect both humans and animals. Outbreaks have been reported in developing and industrialised coun- tries and are mainly linked to consumption of contaminated food and water. Recently, raw milk con- sumption has been identified as a potential foodborne pathway for HEV transmission. While raw pork and wild boar meat are established sources of infection, milk remains a suspected source, strengthen- ing the zoonotic nature of the virus. This study aimed to investigate the presence of HEV antibodies and viral RNA in bulk sheep milk samples collected from 37 farms in Tuscany and Northern Lazio, Italy, in 2023. Sampling included 73 bulk milk samples from farms across seven different provinces. Anti-HEV antibodies were detected using an ELISA assay, with five samples showing optical density values above the cut-off. Subsequent molecular analyses failed to detect HEV RNA. Our findings support the use of bulk sheep milk as a valuable sample for HEV serological surveillance, highlight- ing the need for additional research to evaluate the epidemiological and public health implications of HEV presence in ovine milk.