Vibrio v. & Liver Disease

If you have liver disease and happen to love raw oysters, you need to know about a life-threatening bacterium for those with liver disease. 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 often lives inside oysters harvested from warm coastal waters, such as the Gulf of Mexico. Oysters feed by filtering surrounding water where vibrios may thrive. When those with liver disease eat raw oysters, they may unknowingly consume Vibrio vulnificus as well, setting up a situation for the bacteria to multiply inside the body.

For most individuals, the worst that can happen are mild symptoms such as diarrhea, stomachache or vomiting. Liver disease, however, leaves the body vulnerable to rapidly progressing infection that can end in death. High levels of iron in the blood may impair the white blood cells’ ability to fight infection. When your immune system is operating efficiently, you are healthy, but when your liver is damaged, the white blood cells may be weakened and Vibrio vulnificus has a heyday.

In addition, those with liver disease filter blood more poorly than the general population. It’s like living with dirtier blood; much like a used oil filter in a car wouldn’t do nearly as good a job as a clean one. Once in the body, the vibrios 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.

Myth vs. Fact

You might have heard of some tricks to avoid Vibrio vulnificus infection, but here are the facts:

  • Myth: Smother the oysters in hot sauce such as Tabasco.
    Fact: This "technique" has no impact.
  • Myth: If you know your oysters, you can tell a good one from a bad one.
    Fact: Vibrios cannot be tasted, seen or smelled. Even a restaurant with high turnover cannot guarantee that these harmful vibrios are not present.
  • Myth: A few oysters can’t do much damage.
    Fact: There are documented fatalities where only three oysters were consumed.
  • Myth: You don’t have to worry if the oysters are from clean waters.
    Fact: Vibrio vulnificus is a naturally occurring bacterium with no connection to pollution.
  • Myth: Avoid raw oysters during the months without the letter "r" and you don’t have to worry.
    Fact: The CDC cautions that 40% of cases occur during the cooler months, from September through April, even though the bacteria are most abundant during the warmer months.
  • Myth: Alcoholic drinks kill harmful bacteria.
    Fact: Alcohol won’t do any better job than plain water will.

Cooking Kills Vibrio

Thorough cooking destroys Vibrio vulnificus. The 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.

If you have liver disease, cooking oysters thoroughly is your only defense for an already hard-working liver.

Information provided by Interstate Shellfish Sanitation.


Page last updated: April 14, 2017