All reptiles have different strains of Salmonella ssp. in their digestive tracts. Chances are that any tortoise will have the same amount of salmonella in their feces as any other turtle, lizard, or snake. The difference is that an aquatic turtle is constantly defecating in warm water, which gives the salmonella the perfect medium in which to grow and reproduce. If the water isn't cleaned regularly, you can have a full blown germ lab going on. And, the turtle is living and swimming in this petri dish. That would never happen with a tortoise, as salmonella would die in most warm, dry conditions. You should still wash your hands after handling a tortoise, or cleaning up it's feces, but the chance of rampant reproduction of the salmonella bacteria is nowhere near as great, nor is the tortoise as likely to "live" in the bacteria, if that makes sense.
I think turtles are great pets, it's just that a little extra care must be taken. Here in Florida there are plenty of places that loophole the 4" law. So they aren't hard to find.
