By Amy Woolfolk

MISSISSIPPI STATE -- Americans eat about 50 million pounds of oysters every year, but some people may risk illness if the oysters are not prepared properly.

Cathy Hollomon, environmental education program assistant at Mississippi State University's Coastal Research and Extension Center in Biloxi, said healthy adults run little risk of contracting illness from oysters. Anyone with a weakened immune system is susceptible to a potentially fatal infection from a bacteria called Vibrio Vulnificus sometimes found in raw or partially cooked oysters.

"The risk for a healthy adult is minimal, but individuals with a weakened immune system are at high risk for contracting this bacterial infection," Hollomon said. "People at risk should eat only thoroughly cooked oysters."

Some conditions that can cause weakened immune systems and put individuals at risk of contracting this bacteria include liver and kidney disease, cancer, diabetes, stomach problems, and HIV or AIDS.

"Vibrio Vulnificus is a bacteria commonly found in warm coastal waters like those in the Gulf of Mexico," Hollomon said. "Because it is not the result of pollution, it can be present in waters approved for legal harvest of oysters. The bacteria does not change the appearance or taste of oysters, making it difficult to detect."

Symptoms of infection can occur within 16 hours of eating the oysters and may include nausea, chills, confusion, weakness, and clear or blood-filled blisters on the legs. Death from the infection can occur within 48 to 72 hours, Hollomon said.

The specialist offered these tips for safe preparation of oysters.

For oysters in the shell, boil three to five minutes after shells open. Discard any oysters that do not open during boiling.

• To steam oysters, put in an already steaming cooker for four to nine minutes.
• Allow shucked oysters to boil or simmer until the edges curl.
• If baking oysters, do so for 10 minutes at 450 degrees.
• Fry or broil oysters for at least three minutes.

Hollomon said always buy live oysters in tightly closed shells and store them properly.

"Do not store live oysters in water or in an airtight container. Cover containers with a clean, damp cloth and refrigerate," Hollomon said.

The specialist cautioned against falling victim to myths about oyster safety.

"Alcohol and hot sauce do not kill bacteria, only thorough cooking does," she said. "Also just because oysters come from a reputable store or restaurant does not mean they are safe. The bacteria is difficult to detect because it is not the result of pollution. The best way to be safe is to eat only thoroughly cooked oysters."