Enjoy the Water, but be Smart and Avoid the Vibrios
After the particularly chilly winter of 2014, local residents will head to the water for fishing, swimming, and a host of other water activities that define our lives here on the coast. Most people are unaware of a dangerous flesh eating bacterium, Vibrio vulnificus, which thrives in our coastal salt water. Scientists have identified more than 100 distinct species of Vibrio bacteria.
But only a few are pathogenic and harmful to humans. Among those are
Vibrio cholerae, the bacterium that causes cholera which still kills over 500,000 people annually. CDC states that Vibrio parahaemolyticus causes on average about 45,000 cases of disease in the U.S. each year, 86% of which are food-borne gastorenteritis. By comparison, CDC estimates that Salmonella causes 1 million cases of gastroenteritis annually, Shigella 500,000 and Listeria 1,600. The V. parahaemolyticus death rate is low, about 2% for gastroenteritis and 20-30% for wound-related cases.

The subject of this article, Vibrio vulnificus, can cause both food-borne and wound-related illnesses. The CDC reports a long-term average of 96 cases of serious Vibrio vulnificus infection per year, including food-borne and wound-related. The overall death rate is slightly over 50%, said by many experts to be the highest human fatality rate for any bacterium. According to FDA, 90% of all Vibrio vulnificus illnesses (morbidities and motalities) in the U.S. result from consumption of raw Gulf coast oysters. However, this article focuses on wound-related illness caused by Vibrio vulnificus.
Vibrio vulnificus is not the only Vibrio known to cause wound infections, but it is the most likely to cause disease. During the winter, populations of Vibrio vulnificus are lower and seem almost dormant, so they present little threat to the general public. As temperatures rise, Vibrio vulnificus multiplies. Warmer weather also brings coastal residents and visitors into contact with the water. This increases the chance of encountering the organism. Infections are seasonal; over 85% occur between April and October. Read on to learn about the threat and how to stay safe.
Every Gulf state from Florida to Texas has reported Vibrio vulnificus wound infections. Here in Ocean Springs, Joseph Smith contracted Vibrio while fishing in 2012 and physicians had to remove his leg. In Florida, there were nine deaths in 2012 and 13 deaths in 2011 attributed to the bacterium. Last year in June and July at Grand Isle, Louisiana there were several cases of wound infections of Vibrio vulnificusthat resulted in hospitalization and one death.


The CDC states that Vibrio infections may be under-reported. Since 1988, the CDC has maintained a voluntary surveillance system for culture-confirmed Vibrio infections in Alabama, Florida, Louisiana, Mississippi, and Texas. Between 1988 and 2006, CDC received reports of more than 900 infections from the Gulf Coast states. In 2007, surveillance was expanded to national notification of infections caused by any Vibrio species. Wounds account for approximately 60% of all U.S. Vibrio vulnificus cases.

Dark purple bars show total cases. Light pink bars show cases resulting from eating shellfish. The difference between the two represent wound-related cases. Source: safeoyster.org
Dr. Jay Grimes, Professor of Marine Microbiology at GCRL, reports that with global climate change, Vibrio vulnificus populations are increasing as water temperatures rise. The rising water temperatures promote the increase in Vibrio vulnificus not only in our own coastal waters. New cases of the bacterium are being found in waters where they were not previously perceived as a threat.
Small wounds can happen easily when you are out fishing or enjoying some time on the beaches, for example, getting hooked on your own fishing tackle or stepping on an oyster shell. At the time, it may seem an insignificant injury. But, the Vibrio vulnificus bacterium can enter through a new wound or through an existing wound, like a tiny cut, scratch or even a mosquito bite. For most healthy individuals, any infection or irritation is minor and hardly noticed. The case is different for people who have weakened immune systems. The bacterium invades the bloodstream, potentially causing a severe and life-threatening illness. Vibrio wound infections happen fast; symptoms may become evident in only four hours.
For prevention, people with open wounds should avoid contact with sea water. But, if you have a wound exposed to warm saltwater and see any combination of redness, swelling, fever, chills and experience pain the get to the hospital immediately and be sure to tell the physician that your wound was exposed to salt water. Physicians recommend that you don’t try to “tough it out!" Dr. Ekenna Okechukwu, Infectious Disease Specialist and Doctor of Internal Medicine at Singing River Health Systems, said “The earlier you seek help, the more likely a good outcome is possible. Do not delay in seeking help. Treatment of a Vibrio vulnificus wound infection will usually include antibiotics and surgery in cases of wound infection.
A Vibrio vulnificus infection can be tricky to diagnose and treat. And many clinicians and physicians have not seen a case first-hand. Anybody - young, old, male, or female - can be exposed to this fast-moving infection, but people who have weakened immune systems are at the highest risk. Dr. Ekenna Okechukwu, states “People with underlying diseases like liver cirrhosis or other chronic liver disease, chronic alcoholism, cancer, or persons on treatment with immunosuppressive drugs, including chemotherapy or steroids may be more prone to get sick and complicated infections, especially if they have an open wound.” One study reported that people with compromised immune systems were 80 times more likely to develop Vibrio vulnificus bloodstream infections than healthy people.
Avoid Wounds
When fishing, harvesting oysters, or handling crab traps, use caution and wear gloves where practical to prevent wounds, flush any wounds quickly with sterile water and treat them with hydrogen peroxide and povidone-iodine (e.g., BetadineR). Wear protective coverings on your feet and, in general, use caution when in and around coastal waters. Dr. Grimes emphasizes that an ounce of prevention is worth pounds of cure.
If You Have a Wound
If you get a small wound while you are out enjoying the Gulf Coast or enter the water with a small wound or sore, and begin to see symptoms of an infection, don’t take chances. Immediate medical attention and treatment quickly can be the difference whether you keep all of your limbs and your life. Dr. Grimes recommends that anyone who has a wound exposed to saltwater follow these steps.
Avoid a Vibrio vulnificus Infection in a Wound Exposed to Warm Saltwater
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The Bottom Line
While Vibrio wound infections present a serious danger in warm saltwater, thankfully, they are not common and rarely affect those with healthy immune systems. Dr. Grimes stresses that common sense precautions will help you avoid infections, and that prompt diagnosis and treatment of a Vibrio infection saves lives and limbs.
Resources
- General Information on Vibrio vulnificus and vibriosis, Centers for Disease Control and Prevention
- Safe Oysters.Org, The University of Georgia Marine Extension Service - "Information for Health Care Professionals on Preventing Vibrio vulnificus Infections"
- The DC Bureau, environment and national security news - "Vibrio More Dangerous than Shark Attacks"
- NBC News - "31 in Florida Infected by Bacteria in Salt Water"
- Fox 8 Live News - One dies, three other Louisianans sickened after swimming in Gulf
- WLOX Local News - Man with flesh-eating bacteria loses leg, now helps others
- Louisiana Sportsman - "Gonzales Angler Survives Vibrio Infection" and “How to Help Prevent a Vibrio Infection”
- For medical clinicians and health care providers
- "Bad Bug Book, Handbook of Foodborne Pathogenic Microorganisms and Natural Toxins," U.S. Food and Drug Administration