Press Release  Department of Public Health alerts public to rare Vibrio vulnificus bacteria in coastal waters

Boston — The Massachusetts Department of Public Health (DPH) is alerting residents and visitors to the potential danger of Vibrio bacteria in coastal waters. The alert is being issued after the identification of an extremely rare case of Vibrio vulnificus infection in Massachusetts, which the individual likely acquired from exposure to coastal water at a beach on Buzzards Bay. There have been seven confirmed Vibrio vulnificus cases among Massachusetts residents in the last several years, including four that were likely exposed in Massachusetts.

Vibrio vulnificus infections are more common in the warm waters of the Gulf Coast, and Louisiana and Florida have reported unusually large numbers of cases this year.

“Vibrio bacteria normally live in warm, salt or brackish waters along the Atlantic coast,” said Public Health Commissioner Robbie Goldstein, MD, PhD. “Heat waves and above-average water surface temperatures create favorable conditions for Vibrio bacteria to grow, making May through October generally the peak season for these bacteria. People with open wounds who spend time in the water, or those who consume contaminated shellfish, can develop an infection when the bacteria enter the body. Sometimes these infections can spread through the bloodstream and cause severe, even life-threatening illness.”

Several species of Vibrio bacteria can cause human illness, including V. parahaemolyticus, V. alginolyticus, V. fluvialis, and V. vulnificus. In Massachusetts, between 2015 and 2024, there were an average of 88 cases of Vibrio infection per year (ranging between 62 in 2020 and 127 in 2024). Most of these infections were the result of people consuming shellfish contaminated with the bacteria.

Among the various Vibrio bacteria species, 71 confirmed and probable Vibrio cases have been reported among Massachusetts residents so far in 2025; 30 percent have reported hospitalization, and there have been no verified Vibrio-related deaths.

Anyone exposed to the bacteria can get a Vibrio infection. Individuals with liver disease, cancer, diabetes, HIV, or thalassemia, and those receiving immunosuppressive therapy for the treatment of disease are at greater risk for severe disease from Vibrio following exposure.

To prevent Vibrio wound infections:

• If you have an open wound (including from a recent surgery, piercing, or tattoo), cut, or scrape: cover your wound with a waterproof bandage or stay out of coastal waters when engaging in activities such as wading, swimming, and fishing.
• Wounds should also be covered when handling raw seafood, its drippings, or its juices.
• Immediately wash wounds and cuts thoroughly with soap and clean running water after contact with coastal waters.
• If you are at increased risk for infection, wear clothes and shoes that protect you from cuts and scrapes when in coastal waters.
• People with wounds, whether covered or not, should avoid handling raw seafood, its drippings, or its juices.

People who have an open wound that has been exposed to warm, coastal waters are advised to monitor for signs and symptoms of infection for seven days and are advised to seek medical attention if they develop fever, chills, dangerously low blood pressure, blistering skin lesions or any redness, pain, swelling, warmth, discoloration, or discharge at the site of the wound.

In addition to wound infections, Vibrio bacteria can also cause gastrointestinal (GI) illness when a person eats raw or undercooked seafood, particularly oysters. Individuals taking medicine to decrease stomach acid levels or with recent stomach surgery are at increased risk for gastrointestinal infection acquired through the consumption of contaminated seafood.

To prevent GI illness from Vibrio bacteria:

• People handling raw seafood, its drippings, or its juices should immediately wash their hands afterwards to avoid cross-contamination of other foods or food contact surfaces.
• Use caution when deciding whether to consume raw or undercooked seafood, such as oysters, if you are at increased risk of infection and severe illness.  Instead, thoroughly cook seafood to kill any Vibrio bacteria that may be present before consuming.

For more information about Vibrio infections, see the Centers for Disease Control and Prevention Vibrio website.

###