Two cases of potentially fatal Vibrio infections reported in Dare County; bacteria thrives in hot ocean waters

By: - July 25, 2023 5:07 pm

Vibrio bacteria, which can cause serious illness or even death in people who become infected. (Photo: USDA)

Two cases of Vibrio, a potentially serious and sometimes fatal illness, were reported in Dare County from July 20 to 25, the local health department announced today.

The new cases bring the statewide total to 47 so far this year, according to North Carolina health department data. This number is significantly higher than the 31 cases reported for all of 2017. In 2019, the state logged 41 cases.

Vibrio bacteria is found naturally in warm sea water and brackish water. People can contract Vibrio by getting the contaminated water in open wounds, cuts, sores, punctures or burns. For example, people who cut themselves while peeling crabs or stepping on sharp objects on the shore and then coming into contact with the bacteria can be at risk.

People can also become ill with Vibrio after eating raw or undercooked shellfish, especially oysters.

Signs of infection include fever and chills, nausea or vomiting, or a skin infection that appears red and warm to the touch. People should seek medical attention immediately if they are experiencing symptoms after eating shellfish or being exposed to seawater. Those at higher risk for infection and complications include those with compromised immune systems, especially those with chronic liver disease:

A map of the NC Coast showing ocean temperatures ranging from 87 on the Outer Banks to 85 in Wilmington.
Ocean temperatures along the North Carolina coast are running five to seven degrees above average for July. (Map: NOAA)

Most cases of Vibrio in the U.S. occur from May through October, when water temperatures are warm. But climate change is heating up the oceans, lengthening the seasons when the bacteria can thrive — and extending the Vibrio’s range farther north. This summer abnormally hot marine waters have spread from the Gulf of Mexico, the Caribbean and north to the mid-Atlantic. For example, at Oregon Inlet on the Outer Banks the water temperature today is 87.3 degrees, according to federal weather data. The average water temperature for July at that monitoring station is 80.3 degrees.

Farther south in Beaufort, the water is 86.9 degrees, more than seven degrees higher than the monthly average. At 85.5 degrees, Wilmington and Wrightsville are running five to seven degrees hotter than average.

The USDA reported last month that climate change is expected to increase the human and financial costs of Vibrio infections. According to scientific projections, U.S. cases of illness from Vibrio infections could increase 50% by 2090 compared with 1995 because of higher sea surface temperatures associated with moderate increases in greenhouse gas concentrations, the USDA report said. Annual total cost of these illnesses more than doubles from nearly $2.6 billion in 1995 to $6.1 billion in 2090 (in 2022 dollars), based on this scenario. About 95% of total costs are attributable to deaths caused by Vibrio infections, according to the USDA.

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Lisa Sorg
Lisa Sorg

Assistant Editor and Environmental Reporter Lisa Sorg helps manage newsroom operations while covering the environment, climate change, agriculture and energy.