Purpose: A potential source of contamination is the consumption of porcine produce or food contaminated by an environmental source. As suggested by the CDC and EFSA, the objective of the study was to evaluate the prevalence of hepatitis E virus (HEV) in food samples, not only evaluating pork produce.
Methods: A global method for HEV detection in environmental or food samples was set up. Based on methods developed for norovirus detection in food samples, standard protocols have been developed and validated. The kit hepatitisE@ceeramTools was used for real time RT-PCR detection. A large prevalence study was then conducted on 440 food samples collected worldwide in food companies in 2011. These samples include pork liver sausages (4), shellfish (36), fruits (77), vegetables (12), herbs and spices (230), process water (62), and ready-to-eat food (20). These samples were also tested for norovirus GI, GII and hepatitis A virus (HAV).
Results: A limit of quantification for the global method of 500 genome copies was obtained whatever the samples. Below this limit, a sample is considered positive but not quantifiable with reliability. The prevalence levels for norovirus GI, GII and HAV were of 2.95%, 8.6% and 0.45%, respectively. The results obtained for HEV demonstrate a prevalence of 0.9% with positive samples including pork liver sausage, pepper and laurel powder.
Significance: To our knowledge, this is the first large study conducted on HEV prevalence in food samples. Our results demonstrate a prevalence for HEV in food samples, in the same range as hepatitis A virus. These results confirm that hepatitis E virus should be included in prevalence studies concerning foodborne virus safety issues.