LEONARDTOWN, MD (August 27, 2025) – St. Mary’s County Health Department (SMCHD) reminds residents about precautions to prevent tick-borne illness and vibrio infections. Though the weather may start to cool down, higher risks for these health conditions in Southern Maryland extend into the fall season.

Vibrio

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. 

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.

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. 

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 becomes 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 mde.maryland.gov/publichealth/Pages/Vibrio.aspx 

Ticks

Ticks are common in Maryland. They can carry viruses, bacteria, and parasites that may cause disease in humans. 

Early symptoms of some common tick-borne illnesses include fever, headache, fatigue, joint pain, and possibly a rash. Not all people recognize or have symptoms. See your healthcare provider if you have any of these symptoms after visiting potentially tick-infested areas, spending time in local outdoor areas such as forests, backyards or trails, or getting a tick bite. Ticks in Maryland can cause a number of health conditions to be aware of, including: 

• Alpha-gal Allergy​ 
• Babesiosis 
• Ehr​lichiosis and Anaplasmosis
• Lyme Disease
• Powassan Virus​ 
• Rocky Mountain Spotted Fever 
• Southern Tick-Associated Rash Illness (STARI) 
• Tularemia​​

Because there are currently no vaccines and limited treatment options for tickborne illness, avoiding tick bites may be the best way to reduce your risk. Tick bite prevention strategies include:

• Look for ticks in late spring through early fall, when they are most active. 
• Limit direct contact with ticks by avoiding wooded and brushy areas with high grass and leaf litter. Wear long pants and long sleeves to help keep ticks off your body.
• Use Environmental Protection Agency (EPA) registered insect repellents containing:
  • DEET​
  • Picaridin
  • IR3535
  • Oil of Lemon Eucalyptus (OLE)
  • Para-menthane-diol (PMD)
  • 2-undecanone 
• Bathe or shower as soon as possible after coming indoors (preferably within two hours) to wash off and find any ticks that are crawling on you.
• Inspect pets and outside gear when going from outdoor environments to indoors 

For more information on tick bites and tickborne illness, visit smchd.org/environmental/animal-nuisance/ticks.