The story lines are horrific. A Texas grandfather goes swimming at the beach and four days later his leg is amputated due to necrotizing fasciitis — an infection caused by flesh-eating bacteria that were in the water. A 24-year-old Georgia woman lost her left leg, right foot and both hands to flesh-eating bacteria after being infected through a cut on her leg during a zip-lining accident. And Slayer guitarist Jeff Hanneman nearly lost his right arm when he contracted the disease through a spider bite.

As its name implies, necrotizing fasciitis can destroy the muscles, skin and underlying tissue of the body. The word "necrotizing" refers to something that causes body tissue to die. According to the National Institutes of Health (NIH):

"Necrotizing soft tissue infection develops when the bacteria enters the body, usually through a minor cut or scrape. The bacteria begins to grow and release harmful substances (toxins) that kill tissue and affect blood flow to the area. As the tissue dies, the bacteria enters the blood and rapidly spreads throughout the body."

The good news is that this type of infection is rare. But the bad news is that it's also deadly. Necrotizing fasciitis is actually caused by several kinds of bacteria. In some instances, it's the same bacteria that cause other, more common infections such as strep throat and impetigo.

How does this deadly infection occur? You can get necrotizing fasciitis when bacteria enter the body, usually through a minor cut, insect bite or scrape. But rest assured, it is very rare.

In the case of the Georgia woman, Aimee Copeland, doctors described it as a tragic "perfect storm" of conditions that led to her infection: the bacteria was present in the water over which Copeland was zip-lining; her accident caused her to fall into the water and cut her calf; and for whatever reason, her body is just the right host for this type of bacteria, allowing the infection to take off.

One thing to keep in mind is that the symptoms of necrotizing fasciitis are similar to those of a less-severe infection: pain, fever, swelling, redness and nausea. However, the symptoms are likely to be much worse than you would expect from the size of the wound. The NIH says symptoms may include a painful bump on the skin that spreads, a bruise-like area that grows rapidly or skin that breaks open.

It can be hard to gauge pain levels with kids — some cry at every paper cut while others stoically push broken bones back through the skin. But doctors say one way to tell the difference between this deadly infection and more common infections is that kids with an infected wound are likely to be grumpy or angry, whereas as kids with necrotizing fasciitis are much weaker and sicker.

If you do suspect an infection of any kind, seek out the advice of your health care professional. If it is necrotizing fasciitis, the odds of survival improve when the condition is recognized early.

Editor's note: This story has been revised since it was originally published in May 2012.

What is necrotizing fasciitis?
What you need to know about necrotizing fasciitis, a rare and deadly infection caused by flesh-eating bacteria.