There were few things that Jerome Rodio, a retired Philadelphia police officer, loved more than fishing.

On a dock last week on Chesapeake Bay, Rodio watched as an older man worked to bring up several crab traps. Rodio, 75, offered to help. A trap scratched the inside of Rodio's arm as he lifted it out of the shallow water.

Three days later, Rodio, of Oxford, Chester County, was dead.

"At one point he showed me the scratch and we laughed about it," said son Gene, who accompanied his father on a boat that morning to reel in perch. "It was only two inches, like a nasty cat had taken a swing at him."

The injury wasn't deep. Jerome Rodio washed it out with bay water, which apparently harbored the bacteria that led to his death.

Vibrio vulnificus kills about 20 people in the United States each year. In contrast, one person dies of a shark attack every other year.

The microorganism thrives in warm, salty water, where it is often ingested by oysters and other sea dwellers. When people eat the contaminated seafood, they're sickened with food poisoning within a day.

But the bacteria, which are related to cholera, can also enter the body through open wounds. A V. vulnificus skin infection, though rare, can spread rapidly. The infection attacks the layers of a membrane known as the fascia, which are the connective bands of tissue that surround muscles, nerves and blood vessel, according to the Centers for Disease Control and Prevention.

The toxins released by the bacteria kill the body's soft tissues, resulting in what doctors call necrotizing fasciitis. The infection can cause sepsis, require the amputation of limbs, or cause death.

People with compromised immune systems, liver disease, or who are being treated for cancer are at greatest risk, said Cliff S. Mitchell, a physician and environmental health director of the Maryland Department of Health and Mental Hygiene.

"I don't like the term flesh-eating bacteria because it conjures up a lot of unnecessary images," Mitchell said. "In reality, necrotizing fasciitis is a very scary and serious condition by itself. Flesh-eating bacteria can refer to several different infections."

In previous years, the State of Maryland has issued advisories warning of the presence of Vibrio in Chesapeake Bay.

"Should you worry about Vibrio?" said Mitchell. "That's a question I get asked a lot."

The number of people affected each year is very small, he said. To avoid Vibrio food poisoning or a skin infection, Mitchell advises common sense.

"I wouldn't recommend eating oysters from warm waters on a hot summer day," he said. "And if you have an open cut, avoid contact with water where Vibrio could live, especially if you are on immune suppressing drugs."

Jerome Rodio, who was also a Navy veteran, had been treated for cancer but was symptom-free, said his son.

The morning after he was scratched, he felt sick and drove to a Veterans Affairs outpatient clinic. The VA transferred Rodio to Harford Memorial Hospital in Havre de Grace, Md. When he didn't respond to treatment, he was taken by helicopter to the University of Maryland Medical Center, where doctors operated to remove the infected tissue.

Rodio, who was expected to become mayor of Oxford next year, never regained consciousness.

A Funeral Mass will be celebrated at 10 a.m. Wednesday at Stella Maris Church, 2901 S. 10th St.