Necrotizing fasciitis

When reach that age in your life and children suddenly spring up around you realize that 15-20% of all normal school children are carrying group A strep in their throats at any given time, and they never develop symptoms.
Step A is usually a lung and throat disease. It never really gets the chance to enter any other system in your body.

However a simple break in your skin can inadvertently let it in. NF is the result of Step A in your blood. 3cm an hour. 25% mortality rate and aggressive surgical debridement is the only known treatment. (its a 70%+ mortality rate if you don't have immediate treatment)
  Lopping off the infected area, usually a leg or an arm is the best treatment we have.
      And you get a 3/4th a chance that will work.
              A 3/4th grade barely passed me at UW
Don't worry its not Step A that eats through you. They just release tissue dissolving toxins as a byproduct of their survival.They just want to live too, they've been here much longer than us humans, and I'm willing to bet they'll be here long after we're gone too..

• S. pyogenes
• Group A Streptococci
• Group A Staphylococci
• Clostridium spp
• Peptostreptococcus
• Klebsiella
• E. Coli
• Pseudomonas
• Vibrio vulnificus.

Ok, I'm done looking at necrotic flesh images on Google. There's a list of bacterium that if your friend says they might have, try not to have them cough on your open cuts.