Other people at higher risk of severe infection who should not to eat raw oysters include those with cancer, AIDS or other conditions that weaken or compromise the immune system. The risk of Vibrio vulnificus , which is killed by heat, can be reduced by thoroughly cooking oysters. Undercooked oysters, such as those that are lightly steamed or prepared as oysters Rockefeller, may also pose a health risk. Vibrio vulnificus infections can cause fever, chills, nausea, vomiting and abdominal pain. The onset of symptoms is generally about 24 hours after eating contaminated shellfish.
Death can occur within one to three days in highly susceptible individuals.
Since 1991, DHS has required restaurants, markets and other retailers that sell Gulf Coast oysters to conspicuously display a warning about the risk of eating this product. Regulations prohibit retailers from receiving raw oysters if their origin is not clearly identified and require the retailer to retain shellfish identification tags for 90 days. In addition, state regulations require all dealers and retailers to maintain proper records, which allows for the rapid identification of shellfish sources linked to illnesses. Questions on where oysters were harvested should be asked of the retailer or oyster supplier. DHS warns consumers that all foods of animal origin pose some risk when eaten raw.