Flesh-Eating Bacteria

Residents in Gulf Coast states are being warned by health officials to beware of the flesh-eating bacteria known as Vibrio vulnificus.  32 cases related to coastal waters have been reported: 17 in Louisiana (4 deaths), 13 in Florida (4 deaths) and single non-fatal cases in Alabama and Mississippi. The bacterium is known to cause a disease called “necrotizing fasciitis.” It destroys soft tissues from skin down to connective tissue known as “fascia.”

Fasciitis caused by Vibrio not new. It’s thought that up to 200 cases are reported every year. Often, people are infected from swimming in Vibrio-contaminated marine waters; others are sickened after eating raw oysters. Fishermen who have hook mishaps or are impaled by fin spines are also vulnerable. Fatalities occur in about 20 percent of cases.

MORE ABOUT VIBRIO VULNIFICUS

Vibrio is a well-known family of bacteria which includes the pathogen that causes cholera. V. vulnificus, however, is a different bug altogether. It normally occurs in warm salt or brackish water near the Gulf of Mexico, but can be found in higher concentrations up north from May to October when the weather is warm. If you spend time in the ocean or eat seafood, you should know how to recognize it and how it spreads.

SIGNS AND SYMPTOMS OF NECROTIZING FASCIITIS CAUSED BY VIBRIO

If bad oysters are the culprit, common symptoms appear somewhat similar to cholera: You’ll see watery diarrhea, stomach cramps, vomiting, fever, and chills.

If an open wound is the mode of entry for the bacteria, you’ll see the typical early symptoms of any infected wound: It’ll present as a red, swollen, painful area that’s warm to the touch. Expect signs to appear quickly, usually within the first 12-24 hours of infection.

As necrotizing fasciitis continues to develop, you’ll see:

• Fever and chills
• Low blood pressure
• Ulcers, blisters, or black spots on the skin
• Pus or other drainage
• Diarrhea and/or nausea and vomiting
• Altered mental status

The infection can spread quickly enough to kill the victim within a couple of days. Death occurs more commonly in older people.

HOW DOES VIBRIO “EAT FLESH”?

So why is infection with V. vulnificus “flesh-eating”? Because the disease process of necrotizing fasciitis degrades the soft tissue around the point of entry. This includes the skin, fat, blood vessels, nerves, and muscles.  It does this by:

• Producing toxins: vulnificus releases potent toxins called “hemolysins” and “cytolysins” which rapidly cause the death of cells.
• Secreting enzymes: Vibrio produces enzymes that break down proteins, collagen, and connective tissues in the skin and muscles.
• Evading the immune system: The bacterium’s capsule helps it evade the immune system, allowing unchecked spread.
• Triggering inflammation: The infection triggers a major inflammatory response.

It also travels through the blood (septicemia) to sites distant from the wound, damaging extremities to the point that amputation may be required. in some cases, more than one limb is lost.

(Note: In the TV series “The Walking Dead,” a character underwent an amputation of a lower limb bitten by a zombie in order to prevent the pathogen from spreading. With necrotizing fasciitis, the strategy isn’t much different if standard medicines fail.)

THE CASE OF A YOUNG GIRL

In my wound care classes, I often mention the case of a young girl named Aimee. She fell from a zipline in Georgia more than a decade ago, sustaining a laceration on her thigh that was closed by 22 staples in the local emergency room.  Unfortunately, closing the wound only sequestered the flesh-eating bacteria in her soft tissues, which traveled to different parts of her body. She ended up with both hands amputated, as well as parts of both legs.

Strangely enough, people who take stomach-acid reducing drugs like Prilosec, Pepcid, and others may be at increased risk for infection because stomach acid helps kill harmful germs.

OTHER ORGANISMS THAT CAUSE NECROTIZING FASCIITIS

Other bacteria are known to cause necrotizing fasciitis. They include:

• Group A streptococcus
• Aeromonas hydrophila
• Clostridium
• coli
• Klebsiella
• Staphylococcus aureus

TREATMENT OF NECROTIZING FASCIITIS

Luckily, there’s no evidence that necrotizing fasciitis is transmissible from person to person. It’s not contagious and can be treated without major risk to the caregiver.

People with less severe stomach infections usually recover on their own after a few days. Standard treatment for diarrhea is the usual treatment: keep the patient as well hydrated as possible.

For wound cases, a doctor prescribes antibiotics such as doxycycline or ciprofloxacin early in the disease process. In the worst cases, surgical removal of non-viable tissue (called “debridement”) or amputation is required. Access to intensive care gives the best chance of survival.

PREVENTION OF VIBRIO INFECTION

Given the severe nature of necrotizing fasciitis, it’s important to know how to prevent a vibrio infection:

-Those with open wounds such as scrapes, cuts, recent tattoos or piercing should avoid swimming or wading in warm marine waters.

-If exposure to marine waters is unavoidable, cover any open wounds with a waterproof bandage.

-Wear shoes if wading to avoid cuts from rocks or shells on the bottom.

-Avoid direct contact with floating algae like sargassum, especially in South Florida, where V. vulnificus has been identified.

-Don’t consume raw shellfish taken from warm coastal waters during the summer months. Cook them instead. Boil shucked oysters at least three minutes, or fry them in oil at least 10 minutes at 375°F.

-Wear gloves when handling raw shellfish; wash with soap and water when done.

good idea to wear gloves when handling ocean fish

One interesting fact is that there’s apparently a connection between hurricanes and vibrio infections. Cases spike during and after flooding events from hurricanes, especially in the region of the Gulf of Mexico. In 2022, there were 38 cases (and 11 deaths) attributed to Hurricane Ian despite warnings to avoid contact with floodwaters, particularly for those with open wounds. Spikes in cases also occurred after Hurricane Katrina in 2005 and Hurricane Irma in 2017, according to the CDC.

Fortunately, necrotizing fasciitis caused by Vibrio vulnificus is very rare. The family medic , however, should recognize when their family’s at risk and take preventive measures as needed.