Vibriosis is an infection caused by Vibrio bacteria. These bacteria live in certain coastal waters and are present in higher concentrations between May and October, when water temperatures are warmer. Most people become infected with vibriosis by eating raw or undercooked shellfish, particularly oysters.

People with compromised immune systems are more likely to get vibriosis. Eating raw seafood can increase a person's chance for getting vibriosis. Most people with a mild case of vibriosis recover after about 3 days with no lasting effects.

A health care provider may suspect vibriosis if a patient has watery diarrhea and has recently eaten raw or undercooked seafood, or when a wound infection occurs after exposure to seawater. A health care provider diagnoses an infection with a laboratory test to find Vibrio bacteria in the stool, wound, or blood of a patient. Treatment is unnecessary in mild cases, but patients should drink plenty of liquids. Antibiotics are sometimes used in severe or prolonged illness.


Symptoms of vibriosis occur within 24 hours of ingesting contaminated seafood. Symptoms usually last about 3 days. Severe illness is rare and usually occurs in people with weakened immune systems. Common vibriosis symptoms include:

  • Diarrhea


  • Stomach Ache

    Stomach Cramping

  • Nausea


  • Vomiting


  • Fever



You can reduce your risk of vibriosis by following these tips:

  • Do not eat raw or undercooked oysters or other shellfish.
  • Always wash your hands with soap and water after handling raw shellfish.
  • Avoid contaminating cooked shellfish with raw shellfish.
  • Stay out of salt or brackish (mixture of salt and fresh) water if you have a wound.
  • Wash wounds and cuts thoroughly with soap and water if they have been exposed to seawater or raw seafood.

Tips for Cooking Shellfish:

Before cooking, discard any shellfish with open shells.

For shellfish in the shell, either:

  • Boil until the shells open and continue boiling another 3-5 minutes, or
  • Add to a steamer when water is already steaming, and cook for another 4-9 minutes.

Only eat shellfish that open during cooking. Throw out any shellfish that do not open fully after cooking.

For shucked oysters, either:

  • Boil for at least 3 minutes,
  • Fry in oil for at least 3 minutes at 375°F,
  • Broil 3 inches from heat for 3 minutes, or
  • Bake at 450°F for 10 minutes.

Information for Health Care Professionals

  • US CDC Information for Health Care Professionals
  • US CDC Vibriosis Surveillance
  • Maine Vibriosis Surveillance Reports 2019 | 2020 | 2021 | 2022 (PDF)
  • Vibriosis Publications
  • Vibriosis Outbreaks