Four people in Florida have died and seven others have been sickened this year by a rare but potentially deadly bacterial infection known as Vibrio vulnificus , state health officials confirmed . The bacteria, often referred to as "flesh-eating," lives in warm saltwater and brackish water -- a mix of salt and freshwater -- and can cause a severe illness called vibriosis. In some cases, the infection leads to necrotizing fasciitis, a condition that breaks down skin and soft tissue so rapidly