BATON ROUGE — A flesh-eating bacteria found naturally in warm coastal waters has infected nine people in Louisiana this year, sending all of them to the hospital and killing five of them, according to the Louisiana Department of Health.

LDH officials said the number of Vibrio vulnificus infections is running above the state's historical average this year.

"During the same period over the previous 10 years, Louisiana reported an average of seven cases and one death," the department said Thursday. 

All nine cases this year were linked to wounds exposed to seawater and all patients had underlying health conditions, according to LDH.

The health department said Vibrio bacteria are more common from May to October, when water temperatures are warmer. Infection can happen when an open wound is exposed to brackish or salt water or when a person eats raw or undercooked seafood, particularly oysters.

Some species, including Vibrio vulnificus, can cause severe and life-threatening infections requiring intensive care or limb amputation. Approximately one in five people with Vibrio vulnificus infection dies, sometimes within a day or two of becoming ill, according to LDH.

People with liver disease, cancer, diabetes, HIV or thalassemia, those receiving immune-suppressing treatment, those taking medicine that reduces stomach acid and those who have recently undergone stomach surgery are all at higher risk of severe complications.

Signs of a wound infection include fever, redness, pain, swelling or warmth around the wound, skin discoloration and drainage or discharge. Signs of a bloodstream infection include fever, chills, dangerously low blood pressure and blistering skin lesions.

LDH said anyone whose wound was exposed to brackish or salt water and becomes red, swollen, painful, warm or discolored should seek medical care immediately and tell their health care provider.

To reduce the risk of infection, health officials recommend staying out of brackish or salt water if you have an open wound. The department said people should cover wounds with waterproof bandages when near coastal water or raw seafood and wash wounds thoroughly with soap after possible exposure.

People in high-risk groups are also advised to wear protective clothing and footwear in coastal water and gloves when handling raw seafood.

LDH said that starting this week, it will publish Vibrio vulnificus case data weekly on the Public Health Data Spotlight webpage.