As summer heats up, so does water activity. Visitors flock to the coast for fun and food. But warm waters also bring a potential hazard that beach-goers and shellfish eaters should know.

Vibrio bacteria, such as Vibrio vulnificus and Vibrio parahaemolyticus, are naturally occurring microscopic organisms that are not associated with water pollution. They are found in North Carolina’s coastal waters year-round, but are more abundant during the warm water months of May through October.


These bacteria can cause gastrointestinal illness and are most commonly associated with eating raw or undercooked shellfish, such as oysters, clams, or mussels. People with underlying health conditions such as liver disease, diabetes, cancer, or weakened immune systems are at a higher risk of infection and should avoid eating raw or undercooked shellfish. Symptoms usually include diarrhea, vomiting, abdominal pains, possible fever and chills, and in rare cases, sepsis, shock, and even death. If you are unsure of your risk, consult your health care provider.

Proper harvest and handling of shellfish can reduce the risk of infection through ingestion. Shellfish should only be harvested from approved waters and should be kept cool and free from cross contamination from other raw seafood products such as fish, crabs, and shrimp during transport and storage. They should be placed into refrigeration as soon as possible after harvest and held at 45 degrees Fahrenheit or cooler until ready to be cooked or consumed.

Shellfish harvested commercially require measures such as shading and a maximum time from the start of harvest until refrigeration at a certified dealer (See Proclamation SS-3-2017 and Proclamation SS-4-2017 for the specific regulations). These measures help minimize the post-harvest growth of Vibrio bacteria. Consumers should purchase shellfish only from reputable, certified dealers, retailers, grocers, markets, or restaurants. These facilities are regulated to ensure sanitation and temperature control.

Humans can also contract Vibrio infections through open wounds on the skin and contact with brackish or saltwater through a pinch from a crab, a stick from a fish spine, a prick by a shrimp, or just swimming with an open wound. People who have open wounds should either stay out of these waters or cover the wound with a waterproof bandage. If an open wound is exposed to seawater, it should be cleaned as soon as possible by taking all of the following steps in order:

  1. Flush the wound with sterile water, such as bottled drinking water.
  2. Wash the wound with soap and water.
  3. Flush and clean the wound with hydrogen peroxide and an iodine antiseptic solution, such as Betadine.

Symptoms of a Vibrio infection may include pain, swelling, redness, rash, ulceration, and breakdown of the skin and surrounding tissue. Anyone who experiences these symptoms following contact with brackish or saltwater, should see a healthcare professional.