"Don't call it flesh-eating bacteria," state officials in Florida warn, in an effort to control the media message reminiscent of their posture on climate change. The bacteria in question -- Vibrio vulnificus -- inhabit the waters in Florida and the Gulf Coast and have been found most recently in the Chesapeake Bay. Last year, the state of Florida alone reported over 25 cases of infection and five deaths. Often the death toll reaches 50 percent of those infected.
Eating raw shellfish is a frequent cause of illness, though swimming in warm sea waters can also cause infection. While most people do not become ill after exposure, vulnerable consumers include those who are immune compromised due to conditions ranging from cancer and HIV to liver disease, hemochromatosis, or diabetes. Many of those conditions can continue for years undiagnosed, so avoiding raw shellfish harvested from warm waters is advisable for most consumers.
Vibrio vulnificus causes severe life-threatening illnesses, with symptoms that include high fever, skin lesions, and shock. Once someone develops symptoms, he or she often dies, even in the face of aggressive treatment in a hospital. Its reputation as a "flesh-eating bacterium" arises from rare cases in which wound infections advance in as little as two days from a minor cut to gaping untreatable infections. One woman reported that her husband died within 62 hours of exposure after they went crabbing in warm salt water. While in the hospital, her husband's skin turned purple, and "he looked like he had been beaten with a baseball bat," she told the Associated Press.
As frightening as that is, consumers are more likely to be exposed to this pathogen when eating raw or undercooked shellfish than by swimming. A study of Vibrio vulnificus in the marine environment around Tampa, FL, for example, found it more frequently in oysters (70 percent of those sampled) than in seawater (43 percent). Reports by the U.S. Food and Drug Administration show that illnesses sourced to Gulf Coast shellfish occur far from the Gulf Coast. In 2013, for example, illnesses were linked to shellfish consumed in Virginia, Maryland, Tennessee, Oklahoma, and Arizona.
The death toll from Vibrio vulnificus in shellfish has continued unabated for two decades. Unlike other deadly risks in the food supply like Listeria and E. coli O157, FDA has not declared the deadly strain of Vibrio to be an adulterant, despite the fact that it kills about 15 consumers every year. In 2009, when FDA tried to declare it an adulterant (which allows the agency to take action to remove it from the market), they were beat back by the shellfish industry, who intensively lobbied their elected officials to ban FDA's action.
According to the Centers for Disease Control and Prevention (CDC), Vibrio illnesses have increased by 32 percent, (from an average 183 cases per year 2010 to 2012, to 242 cases in 2013), including both vulnificus and its less potent cousin parahaemolyticus. While many consumers face mild symptoms after exposure, like vomiting, diarrhea, and stomach cramps, others progress to septicemia, which often proves fatal.
Consumers in the Mid-Atlantic States like Maryland and Virginia have special reason to be concerned, as warming sea waters may mean that shellfish from those waters also carry Vibrio vulnificus. That fact was underscored by a recent headline in the Maryland Reporter, "Warning: Flesh-eating bacteria in the Chesapeake Bay." So while Florida is trying to call this deadly strain of Vibrio by a different name ("flesh eating" is really necrotizing fasciitis, in medical parlance), Vibrio vulnificus may soon be a crisis for many other public health departments around the country.