Four cases of people have been infected with the illness-causing bacteria Vibrio vulnificus, according to health officials in Mobile County, Alabama.
One case happened in March of this year when someone went out of the state, ate raw oysters, and became infected with Vibrio, said J. Mark Bryant, the public information officer for the Mobile County Health Department.
Another case occurred in April after a local resident consumed raw oysters in Mobile County.
"Then in June, we had two people that went into the waters south of Mobile County, and also were infected," Bryant said.
Vibrio vulnificus is a natural bacteria found in coastal gulf waters, particularly when water temperatures are warm. Other types of Vibrio bacteria that can live in the water are Vibrio parahaemolyticus and Vibrio alginolyticus.
Infection with any form of these Vibrio bacteria causes vibriosis, the symptoms of which include watery diarrhea, abdominal cramping, nausea, vomiting, fever and chills. If Vibrio infects an open wound, it can cause pain, redness and swelling. Skin rashes have also been reported.
Most people contract the infection by consuming raw oysters and other shellfish harboring the bacteria, or when open wounds are exposed to brackish or salt water where the bacteria is present.
Symptoms can be especially severe in people with weakened immune systems, and those who have cancer, diabetes, liver disease or other chronic conditions.
Bryant said all four cases in Mobile County were mild because they were identified and treated early.
A fifth case was reported recently in a Mississippi woman who contracted the infection while fishing on a pier in Baldwin County, Alabama.
Dr. Karen Landers, assistant state health officer for the Alabama Department of Public Health, said that despite the infection occurring in Alabama, it is being investigated by the Mississippi State Department of Health.
In an email to CNN, Dr. Paul Byers, Mississippi state epidemiologist, said, "the Mississippi State Department of Health does not provide specific details regarding individual cases to protect personal information and to avoid patient identification."
But Byers confirmed that the Mississippi State Department of Health did recently receive notice of a new Vibrio case, bringing the total number of cases reported in Mississippi in 2017 to nine.
The Alabama Department of Public Health has reported 30 cases of vibriosis in Alabama in the last 12 months. The US Centers for Disease Control and Prevention estimates 80,000 people become ill and 100 people die from vibriosis each year nationwide.
Landers said the most important thing people can do to avoid Vibrio infections is to be "wound and water aware," especially during the summer months when the amount of Vibrio bacteria in the water is at a higher concentration.
"The overarching message is that we must have a specific awareness for our own health and our own safety," said Landers.
"Let's say you sustain a wound in the water. You need to watch for signs and symptoms of illness," she said.
Landers asks that anyone showing signs of infection, such as redness or swelling, wash the wound and then immediately go and see their healthcare provider.
"Even though Vibrio is not very common, if treated early, severe illness can be avoided," she said.
The Alabama Department of Public Health and Mississippi State Department of Health are advising anyone with open wounds or cuts to stay out of the water and those with compromised immune systems or chronic conditions to avoid eating raw shellfish.