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U.S. Department of Health and Human Services


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Letter to Health Professionals Regarding the Risk of Vibrio vulnificus Septicemia Associated with the Consumption of Raw Oysters

June 2005

Dear Health Professional:

We are sending you this letter to ask your help in alerting your patients about the risk of Vibrio vulnificus septicemia associated with the consumption of raw oysters. Some raw oysters may be contaminated with the bacterium V. vulnificus that can cause a potentially fatal septicemia in individuals with liver disease or in individuals whose immune systems are compromised by other diseases, such as AIDS; chronic alcohol abuse; stomach or blood disorders; cancer; diabetes; and kidney disease. Individuals with these health conditions should only eat oysters fully cooked.

How does V. vulnificus septicemia occur?

V. vulnificus is a bacterium that can be found in warm coastal waters, especially those of the Gulf of Mexico between April and October. It occurs naturally, rather than as a result of pollution.

Oysters can accumulate the bacterium as they filter the water in which they live. Because V. vulnificus is a naturally-occurring organism, efforts taken by the government and industry to protect oysters from sewage and other sources of pollution do not prevent the bacterium from being present in shellfish harvesting waters.

Certain individuals can develop V. vulnificus septicemia by consuming oysters that contain the bacterium. At greatest risk for V. vulnificus septicemia are those affected by AIDS; chronic alcohol abuse; liver, stomach, or blood disorders; cancer; diabetes; or kidney disease.

Additionally, individuals can develop V. vulnificus septicemia through contact between a wound and seawater containing the bacterium.

How can you avoid V. vulnificus septicemia?

Cooking destroys the bacterium. Therefore, persons at-risk for V. vulnificus septicemia should only eat oysters that have been fully cooked.

Individuals in the at-risk group should also avoid swimming in seawater if they have an exposed, open wound.

If you would like additional information on this and related topics, it may be found on the following websites: Seafood Information and Resources and the Interstate Shellfish Sanitation Conference. A course for physicians, entitled, "Diagnosis, Treatment, & Prevention of Vibrio vulnificus Infection", is also available.

We thank you for your help on this important matter.




David W. K. Acheson, M.D.
Chief Medical Officer and Director
Office of Food Safety, Defense, and Outreach
Center for Food Safety and Applied Nutrition
U.S. Food and Drug Administration