What’s the Deal with Flesh-Eating Bacteria?

Several cases of flesh-eating bacteria have recently made the news. What’s the story of this B-rate horror movie subject come to life?

In the last couple of weeks, a new headline has appeared under health news, with a subject that sounds like it’s straight off the script of a cheaply made horror movie. But although flesh-eating bacteria sounds like a fanciful scare tactic conjured up by a Hollywood screenwriter, it’s a very real — and potentially fatal — condition.

A Texas man dies from flesh-eating bacteria after picking it up in the Gulf of Mexico. A California woman contracted the disease, despite not going into the water. A Kentucky man gets the disease after a camping trip. Another man becomes affected after kayaking in Tennessee. Several individuals have died in Florida from the condition.

What are flesh-eating bacteria, where do they come from, and why are people dying from this condition? Why do these cases seem to be becoming more common?

The Cause Behind Flesh Eating Bacteria

The scientific name for this disease is necrotizing fasciitis, and it’s described as a severe bacterial infection that spreads quickly through the tissue that surrounds our muscles. It’s dangerous because of the speed at which it spreads — the disease can progress from initial infection to death in as few as 12–24 hours.

The disease isn’t caused by a single species of bacteria; bacterial members of the Streptococcus group A family are the most common culprits for the disease, but recent cases have been linked instead to bacteria from the Vibrio family. There are even reports of some cases being linked to multiple different species of bacteria being simultaneously present, or fungal species being the cause of the disease.

Normally, these invaders are rebuffed by the barrier of our skin. When they gain access to our body, however, often through an open cut or sore or a puncture wound, they rapidly grow and spread through our connective tissue, the layer between our skin and our muscles. As they spread, these bacteria may dissolve the connective tissue, produce toxins that inhibit our immune system to keep it from fighting back, and can also drastically reduce oxygen levels in the surrounding area, causing our cells to die from lack of oxygen.

These bacteria that cause the disease are typically encountered in bodies of water, such as in lakes, rivers, and the ocean. While the majority of cases occur in the south, in areas like Florida and Texas, there are more cases now being observed further north. The spread of these bacteria to the north may be linked to global warming, expanding the available habitat range of these pathogens.

Who Gets The Disease?

The CDC says that it gets reports of 700–1200 cases per year, but this number is likely an underestimation. Some people may not report the disease, or it may not be properly identified.

Unfortunately, individuals with weakened immune systems are especially vulnerable to necrotizing fasciitis. This includes individuals going through treatment for cancer, kidney or liver disease, and diabetes. The disease also poses a higher risk to younger children and the elderly, both of whom have weakened immune systems that aren’t as capable at fending off the attack.

What are the Symptoms? What’s the Treatment?

Symptoms of necrotizing fasciitis include:

• Inflamed or swollen areas of the skin, often spreading rapidly
• Changes in skin color
• Fever
• Severe pain from the affected area

Treatment requires immediate hospitalization. Antibiotics are usually regarded as the first line of defense, but they may prove ineffective if the responsible bacteria has developed antibiotic resistance. Staphylococcus infections in particular are may be due to MRSA, or methicillin-resistant Staphylococcus aureus.

A surgeon will usually also be involved. The surgeon will collect samples for testing to determine the responsible pathogen, and may perform operations for drainage of built-up fluid, removal of dead tissue, negative pressure (vacuum) treatment to speed healing, and dealing with secondary complications, which can include organ failure or the need for skin grafts or amputation.

The sooner the disease is caught and treatment begins, the better. Even with treatment, not all patients survive — but survival is strongly linked to how rapidly the disease is detected and treatment starts.

How do I Avoid Necrotizing Fasciitis?

Despite the severity of the disease and the headlines splashed across the news pages, necrotizing fasciitis is fairly rare. Taking proper precautions can further reduce the risk of contracting the condition.

The best solution is avoidance. If you’re planning on exposing yourself to water — swimming, kayaking, heading to the beach, or performing other water-associated activities — it’s best to securely cover any open cuts or sores. If you are at an elevated risk for the disease, such as if you are diabetic or have a compromised immune system, it may be best to avoid the water entirely if you have open cuts or sores.

Necrotizing fasciitis isn’t especially contagious; it’s possible but unlikely to receive the disease from another affected individual. This usually requires direct contact and the breaking of skin, such as if two individuals share a needle.

Because necrotizing fasciitis can spread rapidly, it’s important to not ignore signs of bacterial inflammation and infection. Anyone suffering from the listed symptoms above, such as swelling, fatigue, fever and chills, and unusually high levels of pain in the affected area, should seek medical attention.

The concept of “flesh-eating bacteria” sounds terrifying, and the disease is almost as scary — a deadly bacterial infection that spreads incredibly rapidly. However, contraction of the disease is rare, and taking the proper precautions to avoid exposure, especially if you have a compromised immune system, can minimize your risk of ending up trapped in a horror movie.

Sam Westreich holds his PhD in genetics, focusing on methods for studying the gut-associated microbiome. He currently works at a bioinformatics-focused startup in Silicon Valley. Follow on Twitter at @swestreich.

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