The CDC has identified a number of pathogens among people who have gotten sick, including Vibrio and Shigella bacteria. The majority of cases have occurred among residents of California, where the oysters were shipped. People who fell ill reported ordering raw oysters from restaurants in California and Nevada.
Experts say oysters can be high-risk because they don’t eat like humans do; instead, they filter water, concentrating bacteria in their tissues. Warmer waters like those around Mexico, as opposed to places like the Pacific Northwest, may also be better environments for bacteria to thrive.
When it comes to the bugs the CDC identified, common symptoms include watery or bloody diarrhea, stomach pain, fever, nausea and vomiting. Symptoms may start within days of infection and last up to a week, the agency said. Those who have other chronic conditions, like weakened immune systems, may be at higher risk.
The CDC recommends cooking raw oysters and shellfish thoroughly before serving them, as well as throwing away oysters whose shells were open before cooking. The agency also stresses the importance of handwashing and disinfecting countertops and utensils that might have come into contact with raw shellfish.