Vibrio vulnificus in post-harvest shellstock and processed Gulf coast oysters

Cases of primary septicemia attributed to Vibrio vulnificus usually occur between April and October and are generally associated with oysters consumed from the half-shell rather than oysters purchased as a shucked product. The levels of V. vulnificus in post-harvest shellstock oysters vary directly with the water temperature in the harvest area, and temperature abuse during shellstock transport may lead to multiplication of V. vulnificus . Levels of V. vulnificus in shell oysters collected from processing plants during winter and early spring months were low and often undetectable. During summer months V. vulnificus levels frequently exceeded 110,000 MPN/g. Processing of oysters which included shucking and washing had little effect on the levels of V. vulnificus in oysters. Iced storage of shucked oyster meats reduced the level of culturable V. vulnificus by greater than 99%.