Infectious Diseases

19 June 2019

Another climate change threat: More 'flesh-eating' bacteria?

A US patient recently had to have all his limbs removed at the elbows and knees due to a severe bacterial infection.

Flesh-eating bacteria have migrated into the Delaware Bay between Delaware and New Jersey, drawn north by the warmer waters of climate change, doctors say.

Five cases of infection with Vibrio vulnificus occurred in 2017 and 2018 along the Delaware Bay, compared to one infection with the devastating bacteria in the eight years prior, researchers said.

Pre-existing health problems

The infections resulted in one death and multiple rounds of surgery to save the other patients. One had all his limbs removed at the elbows and knees due to severe bacterial infection, said Dr Katherine Doktor, an infectious disease specialist at Cooper University Hospital in Camden, New Jersy.

"In order to stop the infection, the person needs antibiotics and they need to be taken to the OR [operating room] quickly so any infected tissue can be removed, so it doesn't spread further," she said.

But Doktor added that the bacteria tend to strike hardest at people with pre-existing health problems like liver disease, diabetes, kidney failure or a compromised immune system.

"Just going to the beach or going to the bay is not going to make you sick," she said. "These people usually have a cut and the infected water gets into the cut, or they eat raw seafood that's infected."

Vibrio bacteria cause an estimated 80 000 illnesses and 100 deaths in the United States each year, with most infections in May through October when water temperatures are warm, according to the US Centers for Disease Control and Prevention.

One in five people with this type of infection die, sometimes within days of becoming ill, the CDC warns.

Tainted seafood

Because the bacteria thrive in warmer, salty water, it's usually found mostly in southern waters, Doktor said.

But cases of Vibrio infection began showing up in emergency rooms along the Delaware Bay a few years back, Doktor and her colleagues reported in the Annals of Internal Medicine.

Four of the cases involved middle-aged or older men who had been crabbing in the bay or eating crabs taken from the bay, the doctors said. The fifth case involved a man who worked at a seafood restaurant in New Jersey.

Wound infections affecting a person's limbs occur through breaks in the skin, while eating tainted seafood can cause intestinal and bloodstream infections, the researchers said. Large blood blisters start popping up at sites where skin cells are dying off, Doktor explained.

"On average, people need to be taken back to the OR two to four times to remove any tissue that has died," she said.

It's not just in the United States that Vibrio is migrating northward, Doktor said. In Europe, infections with the bacteria have extended as far north as Norway.

Temperature changes

Dr Amesh Adalja is a senior scholar at the Johns Hopkins Center for Health Security, in Baltimore. He said, "Vibrio vulnificus infections contracted in the Delaware Bay, an area not known to be endemic for the bacteria, should serve as an important reminder that infectious diseases can expand from their traditional areas so long as the environment is hospitable to them." Adalja was not involved with the new report.

"If certain bodies of water have had temperature changes that allow Vibrio vulnificus to flourish in a new region, it will be important that clinicians have heightened awareness of this serious, and sometimes fatal, infection in order to diagnose and treat it appropriately," Adalja added.

Doktor advised that shellfish lovers should exercise caution when having a seafood meal, especially if they have a health condition that compromises their body's ability to stave off infection.

"Some people, when they shuck the crabs, they use gloves," she said. "I would protect your skin by wearing gloves."

You might want to think twice about hitting the raw bar, too.

"As an infectious disease physician, I don't think people should be eating raw seafood," Doktor said. "But if you don't have any of these risk factors, the chance of infection is much, much lower."

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