Michael, there is also a time vs temp equation for killing bacteria. You can pasteurize with high temp (165F and up) almost instantly, or you can slow kill over time at lower temps (above 130F).
Sous vide brings up an interesting issue with low temp cooks, like the steak I cooked the other day was 45 min at 129F. 129 is below the minimum kill temp, and 45 is no where near long enough to pasteurize at the minimum temp. The grace there is that whole muscle is less risky since bacteria live on the surface and can't penetrate the meat and that I sear with a blowtorch. Ground, on the other hand, every bit of it is exposed to air during the grind and could become contaminated.
I don't know the numbers of cases, but according to my contact who runs the butcher program at the university, most cases of bacterial food poisoning are due to improperly handled and improperly cooked (under-done) ground beef. Most people are scared enough of salmonella on chicken and turkey that they over cook those ground meats. Beef, people think of medium rare hamburgers. While they taste great, they are, unfortunately, potential risks. Almost no one gets bacterial food poisoning from a medium rare or even rare steak though.