Science

Warming ocean waters may be spreading 'flesh-eating bacteria'

"Flesh-eating" bacteria that live in the ocean may be spreading to previously unaffected beach waters thanks to climate change, according to a new report.

In the study, published on June 18 in the journal Annals of Internal Medicine, the authors described five cases of severe flesh-eating bacterial infections in people who were exposed to water or seafood from the Delaware Bay, which sits between Delaware and New Jersey.

The culprit is called Vibrio vulnificus, a species of Gram-negative, motile, curved rod-shaped (bacillus), pathogenic bacteria of the genus Vibrio. The bacterium is found in marine environments such as estuaries, brackish ponds, or coastal areas where the water temperatures are above 55 degrees Fahrenheit (13 degrees Celsius). V. vulnificus is related to V. cholerae, the causative agent of cholera.

Being found in the Delaware Bay is unusual because the bacterium prefers warmer waters, such as those in the Gulf of Mexico, where it is endemic to the region and where most cases of V. vulnificus in the U.S. have occurred in the past.

Warming ocean waters may be spreading 'flesh-eating bacteria'

Fresh blue crabs in the market. wpopp

People can become infected with V. vulnificus in one of two ways - Either by eating undercooked or raw seafood or if they have an open wound that comes into direct contact with seawater containing the bacteria. Generally, most people will develop mild infections.

However, some people can develop life-threatening skin or bloodstream infections. V. vulnificus can cause necrotizing fasciitis, a rare "flesh-eating" infection that rapidly destroys skin and muscle tissue. This can result in amputations or even death.

According to Live Science, the authors noted that from 2008 to 2016, their hospital - Cooper University Hospital in Camden, New Jersey - saw just one case of V. vulnificus infection. But in the summers of 2017 and 2018, that number jumped to five cases.

Warming ocean waters may be spreading 'flesh-eating bacteria'

Satellite photo of the Delaware Bay on January 3, 2011. NASA

In all the cases, the patients had either gone crabbing in the Delaware Bay or consumed seafood from the area, and all of the patients developed necrotizing fasciitis. One patient died.

According to the Centers for Disease Control and Prevention (CDC), people with compromised immune systems, especially those with chronic liver disease, are more likely to get vibriosis. Of the five cases described in the new report, three individuals had hepatitis B or C and one had diabetes.

Dr. Katherine Doktor, an infectious disease specialist at Cooper University Health Care, told NBC News she wants doctors to be aware of the bacteria's spread to facilitate more rapid diagnosis, which is key in treating patients infected with V. vulnificus.

Warming ocean waters may be spreading 'flesh-eating bacteria'

Vibriosis causes an estimated 80,000 illnesses in the United States every year. CDC

“As a result of our experience, we believe clinicians should be aware of the possibility that V. vulnificus infections are occurring more frequently outside traditional geographic areas,” said Doktor.

Multistate outbreak of gastrointestinal illnesses linked to oysters

The CDC investigated an outbreak of gastrointestinal illnesses coming from oysters imported from Estero El Cardon estuary in Baja California Sur, Mexico in May this year.

Sixteen ill people from five states have been reported as part of the outbreak. Illnesses started on dates ranging from December 16, 2018, to April 17, 2019. Two people have been hospitalized. No deaths have been reported. The CDC found multiple organisms causing the infections, with some people having more than one organism.

Warming ocean waters may be spreading 'flesh-eating bacteria'

Doktor explained that climate anomalies and increasing water temperatures over recent decades have provided favorable growth conditions for Vibrio in areas that were traditionally considered too cool for its growth. CDC