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VIBRIO BACTERIA ROTS FLESH BUT DOESN'T EAT IT
GABE SEMENZA
Victoria Advocate
Sunday, August 1st, 2004
Vibrio bacteria is dangerous seawater bacteria that has put at least six men in area hospitals in the last few weeks. But it's not "flesh-eating," as it's been commonly described. It's flesh-rotting.
The difference in description may not mean much to victims. Since 1976, when the bacteria was first recognized by scientists, they have had arms, legs or other body parts amputated after the bacteria invaded their bodies.
But to scientists, it is a telling and painful distinction, one that describes fast-spreading seawater bacteria that can stop blood flow to human tissue, and in some cases, cause death.
Dr. John Schwarz, a professor of marine biology at Texas A&M University in Galveston, has worked to understand vibrios for the last 15 years. He said reports of at least six infections in this area may or may not be unusual.
"It's not unusual to see all types of vibrio in a given year," including infections both through open wounds or ingesting tainted seafood, he said in a Thursday telephone conversation. "The fact that they're all right there may be a little unusual, but it may be happenstance."
Late Friday, the Texas Department of Health said the number has increased to 27 cases, 16 by wound. Last year, there were 43 total cases, 20 by wound.
Of the increased percentage in wound infections this year, he said, "It's just a statistical variation. Some years it's up, some years it's down."
Of the 15 types of vibrio bacteria, Schwarz studies what he considers to be the three major varieties - vibrio vulnificus, vibrio parahaemolyticus and vibrio cholerae. Vulnificus and parahaemolyticus naturally occur in nature. Wound infections are often caused by vulnificus. The parahaemolyticus variety causes gastrointestinal problems such as diarrhea, and has been known to be responsible for wound infections. Vibrio cholerae is usually caused by human waste contamination of water sources, and is generally found in Third World nations. It causes cholera, which can cause death if not treated.
Although the parahaemolyticus can be obtained via an open wound, Schwarz focused his discussion on vibrio vulnificus.
"This particular vibrio is naturally occurring - it's been here forever," he said, referring to vibrio vulnificus. "It's not a contaminant. It's not the result of any type of pollution, manmade or otherwise. These are naturally there. The organism loves warm waters. There will be almost nothing you can detect in the wintertime. Then, in late March or early April, when the temperature goes up, you get increasing numbers of vibrio in Texas waters. Expect high numbers from April to October."
He said the bacteria flourishes in water that is not fully fresh or fully salty - water composed of roughly equal parts fresh and equal parts salt, such as most bay water.
He said early summer rain and river runoff can produce prime conditions for an increase in the bacteria by adding freshwater to the saltwater.
"You won't find much of anything in the open ocean, where the water's too salty," he said.
The six people with confirmed cases of infection in recent weeks all reported spending time in bay waters.
"Some people are more susceptible than others," Schwarz said. "The high-risk group is individuals with impaired liver function, diabetes, or those who use alcohol or immunosuppressive drugs - anything that lowers the body's ability to fight off infection. I've never heard of anybody (who became infected) not being in this high-risk group."
While many people associate the flesh-rotting bacteria with eating raw and infected seafood, it appears the men in this area became infected by exposing an open wound to the bacteria.
According to the Web site of the U.S. Food & Drug Administration, "Wound infections result either from contaminating an open wound with seawater harboring the organism, or by lacerating part of the body on coral, fish, etc., followed by contamination with the organism."
Concerning infection from eating, the Web site says, "The ingestion of vibrio vulnificus by healthy individuals can result in gastroenteritis."
Whether the infection comes by ingestion or through a wound, those most at risk from the bacteria are those who have underlying chronic disease, particularly liver disease. If the bacteria in these individuals enter the bloodstream, they can go into septic shock, followed by death in about 50 percent of cases.
All individuals who consume foods contaminated with this organism, however, are susceptible to gastroenteritis. Individuals with diabetes, cirrhosis or leukemia, or those who take immunosuppressive drugs or steroids, are particularly susceptible, and are advised not to consume raw or inadequately cooked seafood or enter seawater with an open wound.
Schwarz said, "Open wound infection is generally not fatal, but there have been deaths. If it's full-blown - that's where somebody has it in their bloodstream - it can shut down organs. If an organism gets inside and establishes a foothold, they're opportunistic. They take advantage of the situation. They grow rapidly, and can double in numbers every 20 to 30 minutes, in ideal growth conditions. Two to three doublings every hour, that's very rapid. That's why prompt medical attention is very critical."
He said when the bacteria get into the body's tissues and capillaries, blood and oxygen to these areas are cut off, and the tissue dies. "It's shutting down the growth of the tissue. The cells are dying because they can't get nutrients in and byproducts out. That's called necrosis - the death of the cells in the tissue. That's why doctors have to remove the tissue."
Once the bacteria get into the bloodstream, they can spread to all parts of the body, and begin "shutting organs down," such as the kidneys and the liver, overwhelming the body's ability to fight infection.
"The liver is very important in this. It has the ability to filter things. If someone is not in this high-risk group, they may not even get the infection. Generally, most vibrio infections are with males, and they would generally be above the age of 40. Kids normally are fine, unless they are diabetic."
Victoria's Dr. T. Adam Kaspar, an infection specialist, has treated two or three dozen cases of this infection. He said the bacteria also thrive on a rich supply of iron.
He also said that those who ingest even one alcoholic drink are susceptible to becoming infected because the alcohol impairs the liver's ability to filter and fight the infection.
"People with chronic liver problems and alcohol problems are at risk," he said. "I can't remember the last time somebody didn't have an alcoholic beverage on the day of injury."
Kaspar said that those in the water can become infected through a cut, but also through a "really big, bad bruise. (The bacteria) causes a rapidly growing infection, and makes a lot of toxins. It causes pain and fever, and destroys flesh with all the toxins it makes."
Even so, Kaspar said this year is no different than most.
"Five people of millions of people who drink alcoholic beverages and jump in the water ... I don't think there's any reason (to fear the bacteria more) this year than most. I haven't been affected at all by this. This hasn't been any deterrent to me."
Kaspar warned those who plan to be in the water not to self-treat with prophylactic antibiotics before fishing or swimming.
"The best antibiotic is doxycyciline," he said. "But the worst thing anyone can do is to take it prophylactically. If it's used indiscriminately, you can cause bigger problems."
He said that by taking the antibiotics before entering bay water, the bacteria could become resistant to the remedy's positive effects, eliminating treatment potential if you were to become infected.
A person suffering a cut or wound in bay water is advised to immediately cleanse the wound with a waterless sanitizer or other antiseptics, such as hydrogen peroxide.
Scott McKenzie of Texas A&M in College Station agrees. McKenzie is a disinfections and decontamination expert.
"If you cut yourself in the water, you're at risk. Simple cleaning and application of antibiotic cream would be the first step," he said. "Now that we're aware of folks having amputations, during the warmer months especially, look for cuts before you go in the water. If you're cut in the water, watch them."
McKenzie suggests applying a triple antibiotic cream to cuts before you go into the water, as well as waterproof bandages, "anything you can do to prevent contact of water with the open wound."
If you're cut in the water, "Use what's in your standard first-aid kits - hydrogen peroxide to disinfecting cream - to clean the wound. Be aware of the status of the wound - redness, pain, if you develop a fever. That should trigger you to seek medical attention."
He added, "Regardless if it's a vibrio or other infection, practicing good wound management is just responsible to do anyway. Whether you get a hook in your hand, or a puncture wound from a fin, or an accidental cut with a knife or scrape from a propeller, it's just good common sense to clean that wound. Add a tube of disinfectant cream to your kit. It can kill the bacteria, or enough of the bacteria so your body's defense can handle the rest."
According to Schwarz, other symptoms of infection to look for include chills and lethargy, a growth in the wound, or general symptoms most people suffer with the flu.
He said the bacteria can be found on fish, but it doesn't feed on fish.
"They eat chitin, exoskeletons of crabs and shrimp, and recycle them," he said. "They are 1 and a half microns long." A micron is 1 millionth of a meter. A meter is 39 inches.
And although the bacteria have very small hair-like tails, they are at the mercy of the bay's currents, he said.
"They won't live out of the water very long. They have to have water to survive. It's hard for them to be concentrated in water. They're not patchy. They're just there. They're not in groups, not like a school of fish. It's just generally distributed throughout. The more you have in an area, the more dangerous it is. The more that gets inside the wound, the more dangerous it is, but more important is the person's physiological state."
He said he doesn't believe it to be more dangerous to become infected on the face than it would be to become infected on the foot.
"It's not good to have it anyplace," he said. "People in the high-risk group should avoid water. If they have a cut, don't go into the water. Clean it out, and if you see redness, go straight to get medical attention. Don't wait. You wouldn't believe what a difference a day can make."