Submitted to: Applied and Environmental Microbiology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 8/23/2004
Publication Date: 1/1/2005
Citation: Calci, K.R., Tezloff, R.C., Kingsley, D.H., Meade, G.K. 2005. High pressure inactivation of hepatitis a virus withih oysters. Applied and Environmental Microbiology. Vol. 71. No.1 Interpretive Summary: High hydrostatic pressure has previously been shown to inactivate hepatitis A virus (HAV), a virus which can be transmitted through contact with human waste and through consumption of raw oysters and clams. To evaluate the potential of high hydrostatic pressure to function as a sanitation method for raw shellfish, live oysters were exposed to HAV under simulated natural conditions. After accumulation of HAV to >10,000 virus particles per oyster, the performance of high pressure against HAV directly within oysters was evaluated. Results indicate that > 10-, 100- and 1,000-fold reductions of HAV will occur after 1-min treatments at 51,700 pounds per square inch (psi), 55,500 psi, and 59,400 psi, respectively. Since shellfish treated at pressures as high as 59,400 psi are reported to be acceptable to consumers, this work suggests that high pressure treatment of shellfish may be a viable method for inactivating hepatitis A virus in potentially-contaminated and uncooked shellfish.
Technical Abstract: Previous results demonstrated that hepatitis A virus (HAV) could be inactivated by high hydrostatic pressure (HHP); however, direct evaluation of HAV inactivation within contaminated oysters was not performed. In this publication, we report confirmation that HAV within contaminated shellfish is inactivated by high hydrostatic pressure. Shellfish were initially contaminated with HAV using a flow-through system. PFU reductions of > 1, > 2, and > 3 log10 were observed for 1 min treatments at 350, 375, and 400 Megapascals (MPa), respectively, within a temperature range of 8.7 to 10.3 ºC. Bioconcentration of nearly 6-log10 PFU of HAV per oyster was achieved under simultated natural conditions. These results suggest that HHP treatment of raw shellfish will be a viable strategy for reduction of infectious HAV.