A multistate salmonella outbreak may be linked to oysters. What people should know

A multistate outbreak of salmonella infections likely linked to raw oysters has sickened more than 60 people across 22 states, according to a US Centers for Disease Control and Prevention health advisory.

Health officials are working to identify the source of those contaminated raw oysters, the advisory issued December 23 said.

What is salmonella, and how does it make people sick? How do oysters become contaminated, and is it ever safe to eat them? What should you know if oysters are on the menu for upcoming social gatherings? Which groups of people are most vulnerable to severe illness? What other types of seafood can carry similar risks, and how can you reduce your chances of getting sick?

To help with these questions, I turned to CNN wellness expert Dr. Leana Wen. Wen is an emergency physician and clinical associate professor at George Washington University. She previously was Baltimore’s health commissioner, with responsibilities that included overseeing food safety.
Dr. Leana Wen: Salmonella is a group of bacteria that causes one of the most common foodborne infections in the United States. People usually become infected after eating food contaminated with the bacteria. Once inside the body, salmonella triggers inflammation that leads to gastrointestinal illness.

Salmonella is often associated with undercooked poultry, eggs and contaminated produce, but it can also be found in seafood, including oysters. Because the bacteria are invisible and do not change the smell or taste of food, people typically have no warning that what they are eating may make them sick.

Symptoms of salmonella infection usually begin within six hours to several days after exposure. Common symptoms include diarrhea, stomach cramps, fever, nausea and vomiting. Many people also feel fatigued and dehydrated. In most healthy adults, symptoms last four to seven days and resolve on their own without specific treatment.

Care is primarily supportive in nature. The most important step is staying well-hydrated, especially if diarrhea is frequent. Oral rehydration solutions can help replace lost fluids and electrolytes. Over-the-counter fever reducers such as acetaminophen or ibuprofen can help manage discomfort as long as they are used appropriately and do not exceed recommended amounts. Antibiotics are not recommended except for people with severe illness or at high risk for complications because they may prolong the time someone carries the bacteria.