LEONARDTOWN, MD (October 7, 2025) – Ongoing reports of illness in St. Mary’s County to the St. Mary’s County Health Department (SMCHD) suggest the county is experiencing more cases of Vibrio infection than in prior years. SMCHD advises community members to take preventive measures when recreating or working in natural waters and when handling raw seafood. 

Vibrio are bacteria that occur naturally in brackish water such as the Chesapeake Bay and its tributaries, and are more common when the waters are warmer, such as the months of May through October. 

Vibrio infection can occur from contact with the water or when people cut themselves on objects or shellfish that have come from the water. This sometimes happens when people handle live crabs or crab traps. Multiple types of Vibrio infection can also come from eating raw or undercooked shellfish, often oysters. Vibrio infection this way can lead to abdominal pain, vomiting, and diarrhea, but may also become more severe. 

When Vibrio bacteria come into contact with an open wound, they can cause serious infections. Wounds can get unusually red, swollen, and have drainage. Severe infection can even lead to intensive care, limb amputation, or death. People with liver disease, diabetes, weakened immune systems, iron overload disease (hemochromatosis), and those taking stomach acid reducers are at increased risk of severe infection.

Some best practices for preventing Vibrio include: 

• Avoid contact with natural waters if you have any skin wounds or infections; if water contact is unavoidable make sure to fully cover any open wounds with waterproof bandages.
• Avoid cuts while in the water – wear water shoes, and use extra caution and waterproof gloves if possible when handling crabbing equipment, live crabs, and oysters.
• Carry soap and clean water so that wounds that occur during water contact can be thoroughly cleansed immediately. If soap and clean water are initially unavailable, wash with hand sanitizer and re-clean the wound when soap and clean water become available.
• Always shower following contact with natural waters.
• Avoid eating raw or undercooked shellfish (e.g., oysters) especially if you are at increased risk for severe Vibrio infection. Adding hot sauce or lemon juice to raw oysters does not prevent vibriosis. Drinking alcohol while eating raw oysters does not prevent vibriosis.
• If you develop a wound with unusual or expanding redness, swelling, or drainage, seek medical attention immediately and let your health care provider know if you recently came into contact with natural waters.

For more information on Vibrio, visit smchd.org/vibrio.  

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