Five of nine Louisiana residents who contracted a nasty flesh-eating bacteria died this year, reflecting a steady increase in infection rate and severity that prompted advisories from health officials.

The Louisiana Department of Health said that during the same reporting period over the previous 10 years, the state recorded an average of seven cases and one death from the Vibrio vulnificus bacteria.

“Some species, including Vibrio vulnificus, can cause severe and life-threatening infections,” the agency wrote in a statement, adding that “people with severe infections may require intensive care or limb amputation.” 

“About one in five people with Vibrio vulnificus infection dies, sometimes within a day or two of becoming ill.”

The bacteria is naturally present in warm coastal waters and is typically found in higher concentrations from May to October when water temperatures are warmest.

Infections can occur when an open wound is exposed to brackish or salt water, or if a person consumes undercooked seafood, particularly oysters. 

Illness resulting from a general Vibrio bacterial infection can populate as gastrointestinal stress, wound infection or blood poisoning — severe infections could require hyper-intensive care or limb amputation.

Patients with underlying health conditions like HIV, cancer, thalassemia are at higher risk of severe or fatal infection.