Thanks for those figures.
It's quite difficult to determine the percentage of cases that are related to reptiles though, so can't really draw any conclusions. I've had a quick look at a few online journal articles, and have found that they differ quite a lot.
Basically, there is definitely a risk of Salmonella infection when being exposed to reptiles. Anywhere from 30% - 90% of reptiles (data varies widely, but generally sits at the higher end) carry Salmonella, and the percentage of cases of infection in humans that can be linked to reptiles is unknown. Many people may not identify the connection, so no accurate assumptions can be drawn. Also, not all cases of Salmonella are actually recorded.
Symptoms of infection in humans also vary widely, and can range from a mild fever, diarrhea, and cramps, to severe illness or death (rarely, and more common in young children or people with a weakened immune system).
Young children are especially at risk of serious complications after being infected, such as meningitis.
After handling a reptile, touching anything can transfer the bacteria onto that surface. Apparently, the bacteria can survive in these conditions for weeks, and therefore pose a risk (however slight).
I was also just reading somewhere that in the US in the 70's, there was an outbreak of Salmonella cases (approx. 300k cases I think?) related directly to terrapins. The FDA introduced a ban of some sort (can't remember exactly, think it may have been an import/export ban?) and there was a significant reduction in the cases of infection (obviously). This demonstrates that there is indeed a risk.
While the risk of infection may be relatively low, there is definitely a very real risk involved. Simple hygiene is not difficult, and is good practice when keeping any pets. Extra caution should definitely be taken if you have contact with children, or anyone with a weakened immune system. I just don't think it is a risk worth taking when it comes to your own health, and even more so, someone else's.