Vibrio Vulnificas

Hemochromatosis and Risky Raw Oysters

If you have liver disease and also happen to love raw oysters, you need to know about a life-threatening illness for those with liver conditions including hemochromatosis. Thoroughly cooked oysters will not harm you, but if you eat them raw, you could become a statistic.

The same conditions that make for plump, tasty oysters also create an ideal environment for Vibrio vulnificus , the bacterium that lives inside oysters harvested from the Gulf of Mexico . Surveillance Epidemiologist Colleen Crowe, with the Centers for Disease Control and Prevention, explains that oysters feed by filtering their surrounding water where vibrio bacteria thrive. When people with liver disease feast on raw oysters, they may unknowingly feast on Vibrio vulnificus as well, setting up a situation where the bacteria can multiply explosively within the body.

Most healthy individuals experience only mild symptoms such as diarrhea, abdominal pain or vomiting. Because liver disease leaves the body vulnerable to rapidly progressing infection, for those with liver conditions Vibrio vulnificus infection often ends in death.

Dr. Paul Gulig, a microbiologist with the University of Florida , is using animal models to study why vibrios are so devastating to those with liver disease. The latest thinking is that the high levels of iron in the blood may impair the white blood cells ability to fight infection. Visualize your white blood cells as your immune system's first line of defense in combating infection. When your immune system is operating efficiently, you are healthy, but when you have liver disease, the white blood cells may be weakened and Vibrio vulnificus has a heyday.

Although Dr. Gulig questions when the vibrios actually start the damage, the end result is always the same: massive infection. The vibrio bacteria move from the sea, which provides a fairly limited environment, to inside the human body, which, he says, “is like coming upon a banquet.” The bacteria then multiply extremely rapidly. ”In fact, he adds, “I tell my students that vibrios grow faster than any bacteria I've ever seen.”

In addition, he explains, those with liver disease filter blood more poorly than the general population. It's like living with dirtier blood, much like how a used oil filter in a car wouldn't do nearly as good a job as a clean filter. Once in the body, the bacteria migrate to the bloodstream where they multiply so quickly that they overwhelm the white blood cells. The victim can experience extensive soft tissue damage and septicemia (blood poisoning). According to the Food and Drug Administration's “Bad Bug Book”, only about 50% of those who experience septicemia survive.

The good news is that you don't have to give up eating oysters entirely. While raw oysters are strictly taboo, cooked oysters are much safer. Thorough cooking destroys Vibrio vulnificus and other harmful bacteria as well. The U.S. Food and Drug Administration recommends that you boil oysters until the shells open and then continue cooking five more minutes. If you steam them, wait until the shells open and time additional steaming for nine more minutes. If you are cooking shucked oysters, boil them at least three full minutes or fry them in oil at least ten minutes at 375 degrees. Never mix cooked oysters with the juice from raw ones and eat the cooked oysters soon after preparing them. Be sure to refrigerate any leftovers.

Oyster lovers may shudder at the idea of heating oysters at all, saying that cooking spoils the experience. The thrill, they claim, is in sliding the cold, sea-infused oyster down the throat. But the risk is too high. If you have liver disease, cooking your oysters thoroughly is your only defense for an already hard-working liver.

For more information on this topic, go to:

http://www.cdc.gov/ncidod/dbmd/diseaseinfo/vibriovulnificus_g.htm

http://issc.org/EDU/Links/Links.htm

For informational brochures for patients and healthcare providers on this topic, click here.

Informational Brochure

Fact Sheet for Healthcare Providers