BOSTON – The Massachusetts Department of Public Health (DPH) issued an alert on Wednesday, Aug. 15, warning residents and visitors of the potential danger of Vibrio bacteria after the identification of a rare case of human infection.
According to the DPH, a Massachusetts resident likely contracted the Vibrio vulnificus infection in coastal waters at a beach in Buzzards Bay.
Between 2015 and 2025, DPH detected an average of 88 cases per year, with a high of 127 in 2024 and a low of 62 in 2020. However, most of those infections resulted from consuming shellfish, especially raw oysters. Infection may also occur through exposure via an open wound.
In 2025, DPH reports 71 confirmed and probable cases detected so far.
Infections are more common along the Gulf Coast. Both 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.”
Infection can occur in anyone exposed to the bacteria. Those with liver disease, cancer, diabetes, HIV, thalassemia, or those receiving immunosuppressive therapy are at greater risk of severe disease.
Tips to Prevent Infection
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.
Individuals with an open wound already exposed to coastal waters should monitor for symptoms of infection for seven days. Those symptoms include fever, chills, dangerously low blood pressure, blistering skin lesions or any redness, pain, swelling, warmth, discoloration, or discharge at the site of the wound.
Vibrio bacteria infections can also occur through eating raw or undercooked seafood, particularly oysters. The infection can cause gastrointestinal (GI) illness. Individuals taking medication designed to decrease stomach acid levels or recently had stomach surgery are at increased risk.
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.
The U.S. Centers for Disease Control and Prevention provides additional information.
