Flesh-Eating Bacteria: Fear vs. Facts

AN UNSTOPPABLE and often lethal bacteria that feeds on human flesh? Sounds like some futuristic plague from a science fiction plot. But, as numerous tragic headlines attest, not only is flesh-eating bacteria a very current medical malady, incidents of this rare disease may be on the rise.

This term is a bit of a misnomer; the bacteria don’t actually eat flesh, but instead release toxins that liquefy tissue (no less horrific). The medical name for the disease is necrotizing fasciitis, or death of the fascia. According to the Centers for Disease Control and Prevention (CDC), roughly a thousand cases are reported annually in the U.S., although this number is likely an underestimate due to misdiagnosis.¹

The Evolution of a Killer Bacteria

Necrotizing fasciitis is an infection from not one but actually several strains of bacterium. These include group A Streptococcus, Klebsiella, Clostridium, Escherichia coli, Staphylococcus aureus and Aeromonas hydrophila. Public health experts consider group A strep to be the most common cause of necrotizing fasciitis, 1 despite that infections from it are typically mild and easy to treat, as in the case with strep throat. But what we’re learning is people infected with a rare strain of it can develop life-threatening infections. Researchers say the reason is the bacteria known as group A strep has undergone four major genetic changes, transforming it into the type that causes necrotizing fasciitis.²

In a 2014 study, James Musser, MD, PhD, a genomic pathologist at Houston Methodist Research Institute in Texas, investigated how changes in the genetic sequence of flesh-eating bacteria enabled it to trigger an epidemic in the late 1980s to early 1990s. He and colleagues discovered four major steps in the microbe’s transition from harmless to potentially fatal. They traced the emergence of the bacterium, identified the toxin that makes it deadly and uncovered the final steps that led to an epidemic.² “For the first time, we really understand precisely the molecular evolutionary genetic events that gave rise to creating a new pathogen, which then caused an epidemic disease,” explains Musser.²

Assessing Points of Entry

Understanding how these bacteria penetrate the body can lead to faster and more accurate diagnosis, and potentially save lives. The most commonly identified way of getting necrotizing fasciitis occurs when the bacteria enter the body through a break in the skin, including cuts, scrapes, burns, insect bites or puncture wounds. “There are often points of entry — a cut that gets the bug through the skin to the deep areas; or sometimes it’s a poke, like a thorn or a needle stick; or on other occasions, it might be an insect bite,” says William Schaffner, an infectious disease specialist at Vanderbilt University Medical Center who has spent decades studying these pathogens. He adds there are times when doctors can’t find a point of entry, making it possible the bacteria can get through nonpunctured skin.³ “These bugs move fast,” he adds. “Infections can spread an inch an hour and quickly cause sepsis, multi-organ failure and even death in as many as one in three of those infected.”

Who Is at Risk?

While deaths from necrotizing fasciitis tend to be highly publicized, it is important to remember that chances of contracting the infection are extremely low. According to CDC, most people who are afflicted with necrotizing fasciitis have other health problems that may lower their body’s ability to fight infection. Some of these conditions include diabetes, kidney disease, cancer and chronic conditions that weaken the body’s immune system.

People with necrotizing fasciitis often display symptoms within a few hours following an injury. The skin may be warm with red or purplish areas of swelling that spread rapidly. Some people get ulcers, blisters or black spots on the skin. Patients often describe their pain as severe. Additional symptoms include fever, chills, fatigue and vomiting. Anyone displaying symptoms of necrotizing fasciitis should seek immediate medical attention.

Is a Vaccine on the Horizon?

Armed with knowledge regarding the evolution of this pathogen, researchers hope to develop vaccines, treatments and improved public health initiatives to combat this frightening disease. While researchers note that one vaccine won’t work against all bacterial strains that can cause necrotizing fasciitis, scientists are currently working on a group A strep vaccine because of the many other health complications these bacteria can cause. If successful, it could potentially prevent certain cases of flesh-eating disease, and move us one step closer to curbing these aggressive infections.³