Vibrio infections, caused by a type of bacteria found in warm, brackish coastal waters, are on the rise in the Chesapeake Bay. One Maryland resident, Vernon Spear, contracted a Vibrio vulnificus infection after scratching his arm on a crab pot in the Choptank River. He was fortunate to survive and keep his arm, but many others have not been so lucky.

Climate Change and Vibrio Infections

Scientists say that climate change is contributing to the increase in Vibrio infections. As the Chesapeake Bay warms, its waters become more hospitable to the bacteria. The average water temperature in the Bay has increased by 1.8 degrees over the past 30 years, making it an ideal environment for Vibrio to thrive.

Vibrio vulnificus, the type of bacteria that infected Spear, can enter the body through open wounds or even scratches exposed to bacteria-infested waters. If not treated promptly, the infection can lead to sepsis, a dangerous overreaction of the immune system that can kill human tissue, shut down organs, and cause death.

According to the U.S. Centers for Disease Control and Prevention (CDC), there are about 80,000 Vibrio infections each year nationwide. While most are food-borne illnesses, some can be contracted through contact with contaminated water.

In Maryland and Virginia, the number of Vibrio cases has more than doubled in recent years. In 2025, there were over 400 reported cases, with 260 in Maryland and 151 in Virginia. The CDC estimates that one in five people infected with Vibrio vulnificus will die, sometimes within a day or two of becoming ill.

Original reporting: Baltimore Fishbowl — read the source article.