Vibrio Infections

Vibrio vulnificus (V. vulnificus) and Vibrio parahaemolyticus (V. parahaemolyticus) are bacteria that occur naturally in warm coastal areas, such as the Gulf of Mexico. These bacteria are found in higher concentrations in the summer months when water gets warmer.

Vibrios typically cause disease in people who eat contaminated seafood.

• V. parahaemolyticus typically causes non-bloody diarrhea. 
• In persons with liver disease, cancer, or another immune-compromising condition, V. vulnificus typically infects the bloodstream, causing a  life-threatening illness. About half of V. vulnificus bloodstream infections are fatal, and death can occur within two days. In addition to transmission by raw shellfish, V. vulnificus can enter the body via a wound that is exposed to warm seawater.

Sources	Raw or undercooked shellfish, particularly raw oysters
Incubation Period	V. vulnificus: 1-7 days  V. parahaemolyticus: 2-48 hours
Symptoms	In healthy individuals: Diarrhea, vomiting, abdominal pain  In high-risk individuals: Sudden chills, fever, shock, skin lesions
Duration of Illness	2-8 days
What Do I Do?	If you develop severe illness within a few days after eating raw or undercooked shellfish or after being exposed to warm coastal water, contact your doctor.
How Can I Prevent Illness?	Avoid eating raw or undercooked shellfish.

General Information on Vibrio Infections

Vibrio vulnificus and Vibrio parahaemolyticus (CDC)
General information about these illnesses

Vibrio vulnificus and Vibrio parahaemolyticus (FDA)
From the Bad Bug Book; provides basic facts, including associated foods, frequency of disease, complications, and target populations.

Risks of Eating Raw Oysters

Certain health conditions put people at high risk for serious illness or death from V. vulnificus infections. These conditions include:

• Liver disease (from hepatitis, cirrhosis, alcoholism, or cancer)
• Iron overload disease (hemochromatosis)
• Diabetes
• Cancer (including lymphomas, leukemia, Hodgkin's disease)
• Stomach disorders
• Any illness or medical treatment that weakens the body's immune system, including HIV infection

Tips for Preparing Oysters

• Eating oysters in restaurants: Order oysters fully cooked.
• Preparing oysters in the shell:
  • Before cooking: Discard any oysters with open shells
  • During cooking: Boil for 3-5 minutes after shells open.
  • After cooking: Discard any oysters with shells that did not open.
• Preparing shucked oysters:
  • Boil or simmer for at least 3 minutes or until the edges curl.
  • Fry at 375 degrees for at least 3 minutes.
  • Broil 3 inches from heat for 3 minutes.
  • Bake at 450 degrees for 10 minutes.

More Information on Oysters

Raw Oysters Contaminated With Vibrio vulnificus Can Cause Illness and Death (FDA)
Explains the risks associated with eating raw oysters and how to prevent serious illness.

Raw Oyster Myths (FDA)
Hot sauce does not kill harmful bacteria in raw oysters; neither does alcohol. Get the facts behind the myths.