The U.S. Center for Disease Control has issued an emergency alert in early September over a flesh-eating pathogen after at least six people have died from the infection along the country’s East Coast this summer, health officials say.
Vibrio vulnificus, a bacterium known to kill one-in-five people — typically in one to two days — is present in certain regions of warm brackish water or saltwater. As ocean temperatures continue to rise, experts say the pathogen may be migrating further north.
While a handful of deaths are usually recorded in U.S. Gulf states every year, it’s unusual to see a spike in fatalities along the country’s East Coast — prompting the CDC to issue an alert warning doctors, public health departments and other health workers to be on the lookout.
In the U.S., around 150 to 200 cases of Vibrio vulnificus are reported to the CDC annually, the agency said. The vast majority of these occur around the Gulf of Mexico — but the CDC said the pathogen has been spreading further north every year.
It’s even been detected in Canada in recent years, according to Health Canada. Here’s what you need to know.
Is the flesh-eating bacteria in Canada?
While rare, infections of the flesh-eating disease have been detected in Canada, a spokesperson for Health Canada told the Star. So far, at least one case has been reported to the agency in 2023, but there may be more — as vibriosis, the illness caused by Vibrio vulnificus, is not a “nationally notifiable disease,” cases are not required to be reported to Health Canada.
That said, the federal agency launched a targeted study into commercially available, Canadian seafood from 2018-2019, during which several vibrio species “were isolated from raw shelled oysters and mussels,” the spokesperson continued.
Meanwhile, at least six Vibrio vulnificus infections in Canada were reported to the government agency since 2019, Health Canada said.
As ocean temperatures continue to warm, infections have been detected increasingly further north. It’s possible cases may become more common in Canada as a result of human-driven climate change, an expert told the Star.
How can you catch flesh-eating bacteria?
According to Dr. Adrienne Chan, an infectious diseases physician and clinician investigator at Toronto’s Sunnybrook Health Sciences Centre, Vibrio vulnificus most commonly enters the body through “breaks in the skin or cuts” while swimming in warm saltwater or brackish water.
“Infections after exposure (to Vibrio vulnificus) are extremely rare … but can, in affected patients, be rapidly progressing and life-threatening — and hence the interest in its spread,” Chan told the Star.
It can also be contracted by eating raw or undercooked shellfish, especially oysters, Health Canada added. Exposing open wounds to raw seafood or seafood juices may also spread the disease.
As a result, the agency recommends you buy shellfish from reputable suppliers only, and to thoroughly cook them, especially oysters, before eating. Avoid saltwater or brackish water if you have a wound. Cuts exposed to this water, or raw seafood, should be immediately cleaned with soap and clean water.
Symptoms of Vibrio vulnificus
Most infamously, Vibrio vulnificus is capable of causing necrotizing fasciitis upon entering a wound — commonly known as “flesh-eating disease” — which causes the fast-spreading destruction of skin and soft body tissues, according to Chan.
Many patients experiencing this may “require intensive care or surgical tissue removal,” according to the U.S. CDC in its alert. “ … Prompt treatment is crucial to reduce mortality from severe (infection).”
Meanwhile, treatment of Vibrio vulnificus wound infections may require different antibiotics than usual necrosis, Chan said, reiterating the importance of educating doctors about the disease.
Other common symptoms include watery diarrhea, often alongside stomach cramping, fever, nausea and vomiting. For wound infections, redness, pain, swelling, warmth, discoloration and fluid discharge may also occur, the CDC continued.
According to Health Canada, the bacteria also “often causes” an infection in the bloodstream, which can be fatal. Symptoms of blood infection include fever, chills, “dangerously low blood pressure and blistering skin lesions,” wrote the CDC.
Vibrio vulnificus is migrating north with climate change
According to recent research, the northern geographic range of the bacteria has grown by 48 kilometres every year from 1988 to 2018. During the same time period, infections in the eastern U.S. increased eightfold.
The CDC attributed part of the bacteria’s spread to “increasing water temperatures and extreme weather events” associated with climate change in its alert.
“What is concerning is that the CDC has now noted reported cases as far north as Connecticut and New York over the summer, suggesting some geographical drift northwards,” Chan said.
“It would be reasonable to postulate that with ongoing population growth along the coasts, warming temperatures making coastal waters warmer for longer, the geographical location of cases may continue to change over time.”