We've all heard the stories, a simple cut rapidly turns into a life threatening infection that destroys muscle, skin, and tissue. Flesh eating bacteria, how worried should you be?

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Today's topic is:

Flesh-eating bacteria: It's not just a flesh wound

I first heard of flesh-eating bacteria as a youngmicrobiology student.  It is pretty scarystuff.  It starts out as a minor scrapeor cut and within a few days can result in a gruesome death.

Take for instance the 2008 case of a 5-year-old Wisconsinboy.  He fell off his bike and skinnedhis chin and bit his lip.  Not anuncommon event in the life of a five-year-old. One day later, he was in the ICU fighting for his life againstflesh-eating bacteria.  Over the nextthree days, he underwent five different surgeries to remove dying and infectedtissue.  As his body fought theinfection, his blood pressure began to drop precipitously.  As the illness progressed, it became increasinglylikely that he might not survive.  Thanksto aggressive antibiotic therapy and surgical interventions, after a week inthe hospital, his condition began to improve and eventually he recoveredcompletely. https://www.livescience.com/19722-flesh-eating-bacteria-early-treatments.html

Flesh eating bacteria: also known as necrotizing fasciitis

The medical term for the disease caused by flesh-eatingbacteria is “necrotizing fasciitis”. While many different organisms have caused necrotizing fasciitis, themost common bacterial cause is group A Streptococcus.  This is the same organism that causes strepthroat, however, the infection takes a completely different course.

Flesh eating bacteria is the same organism that causes strep throat

Within 24 hours of infection, the symptoms are readilyapparent.  The area of the cut orabrasion becomes red, warm, and swollen. There is a significant amount of pain at the site of the infection, muchmore than you would normally associate with a minor cut or scrape. 

The redness and swelling can begin to travel to other partsof the body.  Other symptoms includediarrhea, nausea, fever, dizziness, weakness and intense thirst.

If not treated immediately, within 3-4 days the symptoms canbecome much more severe.  Swellingincreases, often accompanied by a purplish rash.  This rash can spread, then it transforms intoblisters filled with a dark, foul-smelling liquid.  The skin begins to discolor, flake and evenpeel away as it dies.  If not treatedaggressively death can occur in four to five days due to a drop in bloodpressure, toxic shock, and organ failure. https://www.webmd.com/skin-problems-and-treatments/necrotizing-fasciitis-flesh-eating-bacteria#2

While the most shocking cases are those who are otherwisehealthy, most individuals who acquire the illness have underlying medicalconditions that weaken the immune system. These secondary causes include diabetes, kidney disease, cirrhosis of theliver, cancer and occasionally chickenpox in young children.

Invasive strep infections

The CDC estimates 11,000-13,000 cases of invasive group Astrep occur every year in the US.  Ofthose 1100-1600 people die.  In additionto necrotizing fasciitis, these illnesses also include cellulitis, pneumonia,and toxic shock syndrome.  That’s roughlya 10% case fatality rate. https://www.cdc.gov/groupastrep/surveillance.html

Flesh eating strep fatalities

As a class, group A strep becomes more prevalent as people age.  For the 18-34 age group, 0.005% of people are likely to acquire the illness, while the 85+ age group had a prevalence of 0.02%.  Even with the increased prevalence associated with aging, group A strep diseases are relatively rare.  https://www.cdc.