Absence of zoonotic hepatitis E virus infection in Flemish dairy cows

Recently, infectious HEV particles were discovered in milk and fecal samples of dairy cows in China. Given the recent increase of autochthonous HEV infections in Europe, we wanted to assess whether cows constitute an HEV reservoir in this region and hence may be responsible for the advance of HEV through consumption of cow produce. To verify the zoonotic risk cows potentially pose towards European consumers, we screened >10% of dairy milk farms in Flanders, Belgium for the presence of HEV. A quarter of these housed both cows and pigs, the latter a well-known reservoir for HEV. Milk and fecal samples were analyzed for the presence of HEV RNA and HEV-specific antibodies. Despite the fact that HEV is circulating amongst pig farms in Flanders and proof of active HEV infection in the pigs of at least one of the mixed farms included in our study, we could not detect any sign of active or past HEV infection in cows. The HEV prevalence in our study was 0%, with a 99.99% confidence interval (CI) for HEV RNA and anti-HEV antibody of [0%-2.30%] and [0%-4.23%] respectively. Our results suggest that, at least in Flanders, cows are not an HEV reservoir and hence do not pose a major health risk towards humans.