Hepatitis E virus in meat and meat products without liver contents – Detection methods, occurrence and implications for public health

Hepatitis E virus (HEV) is the causative agent of an acute or chronic hepatitis in humans. Genotypes 3 and 4 are zoonotic and mainly infect domestic pigs, wild boars and deer. Consumption of liver and liver-containing products from these animals pose a high risk of human infection. However, the role of undercooked meat and meat products in HEV transmission is less clear. This review therefore summarizes the current knowledge on HEV detection in meat and meat products and the infection risks associated with their consumption. Detection of HEV RNA in muscles of experimentally infected pigs and in muscle meat of wild boars was repeatedly reported. The detection rate in pork products was generally lower, but up to 26% in salami-like raw sausages in one study. Detected viral genome amounts were mostly low. In spiking experiments, HEV exhibited a high stability during production and storage of raw meat products. Several case reports and case control studies point to meat and meat products as sources of HEV infection. In conclusion, several lines of evidence indicate a considerable risk of undercooked or raw meat and meat products for HEV transmission, albeit to a lower extent than liver-containing products. Standardized HEV detection methods for meat and meat products are needed to improve comparability of prevalence studies and outbreak investigations. Measures to control HEV, such as improved slaughter hygiene, avoidance of diaphragm in raw sausage production, application of virus-inactivating methods and targeted consumer recommendations, may help to reduce transmission by meat and meat products.