ROLLING OUT — In severe cases, Vibrio vulnificus can trigger necrotizing fasciitis, a condition in which tissue around an open wound dies rapidly. In severe cases, Vibrio vulnificus can trigger necrotizing fasciitis, a condition in which tissue around an open wound dies rapidly. Every patient infected in Louisiana this year had at least one underlying health condition, which health officials say is a consistent pattern in serious Vibrio vulnificus cases. Doctors diagnose Vibrio vulnificus bacteria by testing cultures taken from stool, wounds, or blood. Vibrio vulnificus cases have also been reported in Florida and New York this year, suggesting the bacteria increase isn’t isolated to a single state.