Beach Bacteria: A Deadly Threat for Some

One expert warns of a rare but potentially deadly infection found in seawater.

June 26, 2008 — -- Last week, a patient of mine — a 60-year-old gentleman with diabetes — came in for a cut on his shin that occurred the day before when he scraped his leg on an open dishwasher. The cut had not entirely healed, but was not infected.

I reassured him that it looked fine and that he should simply keep it clean with warm, soapy water, to which he replied: "I won't worry about it. I am going to the beach this weekend, and the salt water will be good for it."


Very, very wrong.

In the most recent e-publication of the Journal of Microbiology, Karen Blackwell and James Oliver of the University of North Carolina at Charlotte review the presence of the dangerous vibrio bacteria species in estuarine and sea water in North Carolina.

Vibrio bacteria, also known as marine vibrios, are responsible for a number of severe infections in people exposed to sea water or raw shellfish, particularly oysters. Infections from this germ, which multiplies extremely rapidly, are particularly dangerous among people with altered immune systems, such as those with diabetes and liver disease.

These bacteria are found in seawater around the world, but particularly in warmer climates during the summer time.

Unfortunately, many people have the false impression that seawater is good for cuts and wounds. This simply is not true.

Others believe that oysters are safe — true for most people, but not those with chronic medical conditions that affect a person's immune system.

Although infections from marine vibrios are not common, the results can be devastating. In the medical journal Lancet Infectious Disease this month, Chih-Hsin Lee, M.D., and colleagues reported a severe infection in both legs in a patient with cirrhosis of the liver, caused by the marine vibrio, Vibrio vulnificus. The patient had eaten raw oysters three days previously. He came to the hospital in shock and had extensive operations on both legs to clean out the dying leg tissue, but he died within 36 hours of admission.

Rare Infection, Serious Consequences

The Centers for Disease Control and Prevention notes that patients with pre-existing medical conditions were 80 times more likely to develop vibrio infections than healthy people. However, even healthy people can develop this disease.

Marine vibrios can infect the bloodstream, causing potentially fatal illness. In fact, infections caused by Vibrio vulnificus are deadly 50 percent of the time once the bacteria become blood-borne.

Skin infections, which occur when open wounds are exposed to sea water, can lead to large areas of blistering as well as deep skin and muscle infections. These also are extremely dangerous and often fatal.

Vibrio infections are diagnosed by blood or wound cultures for the bacteria. However, doctors might not think about culturing for this germ.

Health care providers and patients should at least consider a vibrio infection in anyone with vomiting, diarrhea, fever or abdominal pain after eating raw seafood or with a wound infection that has been exposed to seawater. This is especially true for patients with chronic medical illnesses such as liver disease or diabetes.

My patient decided to go to the beach, but to stay out of the water. This certainly will put a damper on his vacation. On the other hand, it is better than a marine vibrio, which could cost him limb — or life.

Dr. John Spangler is director of tobacco-intervention programs and a professor of family medicine at Wake Forest University School of Medicine.