Consuming raw or undercooked oysters presents a significant risk of food poisoning, particularly from vibriosis, caused by Vibrio bacteria commonly found in coastal waters where oysters reside. As explained by the CDC, since oysters filter water to feed, they can gather high amounts of Vibrio in their tissues, making them potential carriers of illness. Plus, contrary to popular belief, you can’t tell an infected oyster from a healthy one based on appearance, smell, or taste. Vibriosis can occur throughout the year, but it peaks from May to October when warmer water temperatures facilitate bacterial growth. While most vibrio infections result in mild symptoms like diarrhea and vomiting, vibrio vulnificus infections, although rare, can be severe, causing severe complications that may result in death.
Additionally, per New Health Advisor, oysters can also harbor norovirus, which leads to symptoms like watery diarrhea, nausea, vomiting, and abdominal cramps within 10 to 48 hours of exposure. To prevent vibriosis or norovirus infection, cook oysters and seafood thoroughly. For example, shucked oysters should be boiled for at least 3 minutes or fried at 375 degrees Fahrenheit for 11 minutes. When boiling or steaming whole oysters, continue cooking for 5 and 10 minutes, respectively, after the shells open, and discard those that don’t open while cooking, as this indicates they might be unsafe to consume. Also, remember to separate cooked seafood from raw products and their juices. Lastly, avoid saltwater or brackish water if you have wounds to minimize the risk of infection.