Health Department Advises High-Risk Persons to Avoid Raw Shellfish

COURT HOUSE — Each year millions of Americans enjoy eating raw shellfish. However, some people with certain medical conditions are at high risk for becoming seriously ill and dying from eating raw oysters, clams and other infected shellfish.
“Persons with liver disease, diabetes, cancer, stomach disorders, and other illnesses or treatments that weaken the immune system are more susceptible to infection with vibrio bacteria and should not eat these foods,” advises Health Officer Kevin Thomas. These “high-risk” persons should only eat cooked shellfish because cooking kills the bacteria.
There are several types of vibrio bacteria that cause illness, including Vibrio cholerae, Vibrio vulnificus, Vibrio parahaemolyticus, and Vibrio alginolyticus. Symptoms can include gastrointestinal illness (diarrhea, abdominal pain), wound infections, and septic blood infections. There were 17 non-cholera vibrio infections reported in New Jersey in 2008.
Of all foodborne diseases, infection with Vibrio vulnificus is one of the most severe. V. vulnificus is a bacterium that occurs naturally in warm coastal areas, such as the Gulf of Mexico. It is found in higher concentrations in the summer months as water becomes warmer. Oysters feed by filtering water-surrounding areas where vibrios may thrive and as a result concentrate the bacteria in their tissues. When a person eats these shellfish raw or undercooked, the bacteria enter the digestive tract and multiply rapidly. In addition to ingestion, people can become infected when cuts, burns, or sores come in contact with seawater containing vibrio bacteria.
While not potentially life-threatening to most healthy people, symptoms of V. vulnificus infection may occur within 24 to 48 hours of ingestion and may include sudden chills, fever, nausea, vomiting, diarrhea, shock, and skin lesions. Fifty percent of high-risk individuals who are infected with V.vulnificus die. Anyone showing signs of these symptoms after eating raw oysters should seek medical attention immediately and inform the healthcare professional that they’ve eaten raw oysters.
“You can’t tell if shellfish is contaminated with Vibrio vulnificus by looking at it or by smelling it,” says Thomas. “Nor does the freshness of the shellfish mean it is safe from bacteria because it may be present in the water where they feed. Therefore, only heat can kill the bacteria, so next time you want to enjoy shellfish, cook them thoroughly when dining at home, or order them cooked when eating out,” advises Thomas.
The Cape May County Department of Health investigates all reported cases of vibrio infection and works with the New Jersey Department of Health and Senior Services to trace-back where shellfish was harvested to determine if harvest waters are contaminated.
Additional information is available at www.cdc.gov and www.fda.gov.