Fastest growing source of CMS billings over the past 10 years and one of the top 20 causes of death overall. In the US, it seems that nosocomial cases are rising faster than expected (larger proportion of the total) which is especially worrying.

As far as the "old" crowd -- who gets sick most often?! It certainly isn't strapping young men and women, not in any hospital I've ever been in outside of a war zone.

From the wikipedia page, it seems more common than you would think. In the US it is the 10th most common cause of death, and globally kills 200k a year.