Quantitative Risk Assessments of Hepatitis A Virus and Hepatitis E Virus from Raw Oyster Consumption

Abstract A quantitative risk assessment of hepatitis A virus (HAV) and hepatitis E virus (HEV) from raw oyster consumption from farm and retail was evaluated over three seasons. This risk assessment comprises four steps: hazard identification, dose–response assessment, exposure assessment, and risk characterization. We used probabilistic models for prevalence, concentration, and oyster consumption. HEV dose–response (DR) model based on HEV dosing in chimpanzees and used to perform a dose–response assessment of HEV was proposed. Both HAV and HEV were simultaneously enumerated by real‐time PCR to determine viral doses. The probabilistic prevalences of HAV and HEV were in the ranges of 8–20% and 8–40%, respectively. The best‐fit DR model was the beta‐Poisson with alpha and N 50 equal to 216.9 and 3.03 × 10 7 , respectively. After running the Monte Carlo simulation, the annual cases of foodborne hepatitis A and hepatitis E from raw oyster consumption from farms were 9,264–17,526 and 1–604, respectively, while those at retail were 7,694–14,591 and 1–204, respectively. This study suggested that consuming farm oysters poses a significantly higher risk of hepatitis A than hepatitis E. The best‐fit DR model for HEV developed in this study could determine risks of hepatitis E from raw oyster consumption in Thailand.