See, chicken pox is a good thing (one from the "Death isn't everything series")

Brenden Hall just became Paralympic champion in the 400m Freestyle S9, beating the runner up by a full 7 seconds. The 19 year old Australian is already competing in his second Paralympic Games after having been the youngest male athlete on the 2008 Australian Team in Beijing.

The reason he can compete in the Paralympic Games is that he had to have his right leg amputated due to complications of chicken pox at the age of 6. He also lost 70% of his hearing. Hall had just started swimming competitively before he contracted chicken pox at the end of first grade, which landed him in hospital for 6 weeks - he describes his illness:

"It was during December, 1999, I sort of just finished grade one and I contracted chicken pox, I got DVT* in my lower right limb.
They (the hospital) rang my parents up and said, 'You better get in here, we've got a decision to make'.
It was either my leg or my life, because the day before, I'd flatlined for about 29min, roughly. I was in cardiac arrest for 29min in hospital before they decided to take my leg off, due to the blood clot because it was in one of the main veins going back to my heart." *deep vein thrombosis

This is not a common complication and it did end in something good besides Paralympic medals for Brenden Hall - he says:

"I had a specialist come over from Canada onto my case, because (the doctors here) hadn't seen anything like it before, but they had a case overseas.
Two months later, because of my case, they brought the chicken pox vaccine out to Australia to start distributing for kids.
It's (chickenpox) something for kids to experience, but there definitely are those rare situations behind it that you don't want to risk."

Indeed!