If you have hepatitis C or a weakened immune system, you should not eat raw oysters or clams. Eat oysters, clams, or other shellfish (mussels, scallops, and cockles) only if they have been cooked thoroughly.

Why is it not safe to eat raw oysters and clams? What is Vibrio ?

Raw oysters, clams, and other shellfish carry Vibrio vulnificus , which is a bacteria that occurs naturally and is commonly found in warm, coastal waters, such as the Gulf of Mexico. Vibrio vulnificus causes the infection called vibriosis. If the level of Vibrio vulnificus in the blood becomes very high and causes serious infection, you can become very ill and it can even cause death. In fact, half of these vibriosis cases result in death.

Who is at risk for vibriosis?

All persons are at risk for vibriosis when they eat raw oysters, clams, or other shellfish. You are at increased risk of infection and serious complications if you have:

· any type of liver disease, such as hepatitis, cirrhosis, alcoholism, or cancer,

· iron overload disease (hemochromatosis),

· diabetes,

· cancer (such as lymphoma, leukemia, and Hodgkin's disease),

· stomach disorders, or

· any other illness or medical treatment that weakens the body's immune system.

How can you tell if an oyster, clam, or other shellfish has Vibrio ?

You cannot tell if an oyster, clam, or other shellfish has Vibrio just by looking at it. Vibrio does not change the look, taste, or smell of an oyster, clam, or other shellfish. They are only safe to eat if they have been thoroughly cooked.

Is eating raw oysters, clams, or other shellfish the only way to get vibriosis?

No. You can also get vibriosis through an open wound, cut, sore, or burn when you swim in warm, coastal waters.

It is also possible to get vibriosis from eating sushi or sashimi, types of Japanese meals that often use raw fish. People with a liver disease, such as hepatitis C, should not eat raw or undercooked fish. Foods made with raw fish may also carry Vibrio bacteria.

What are the symptoms of vibriosis?

Symptoms usually occur within a day or two of exposure. Symptoms include:

• fever or chills
• skin lesions (sores or blisters)
• stomach pain
• nausea
• vomiting
• diarrhea
• shock

If you have symptoms, you must see a doctor right away. Vibriosis can lead to death within two days. You must be treated immediately with antibiotics.

How can you prevent getting vibriosis?

Prevention tips:

• Never eat raw oysters, clams, shellfish, or fish.
• Cook shellfish (oysters, clams, mussels, scallops, cockles) thoroughly.
• Never swim in, wade into, or enter warm coastal waters (such as the Gulf of Mexico) when you have sores, cuts, open wounds, or burns.

For more information on vibriosis, go to www.issc.org or www.cdc.gov .