There are very few ways to infect yourself with toxo, the only secure one is digging in the cats litter box and not washing your hands afterwards.
Besides that, between 1/3 and half of humanity already carry the protozoon in them, even if they have no cats, mostly by eating infected meat. There are studies that are pretty convincing like Torda A (2001). "Toxoplasmosis. Are cats really the source?".
Aust Fam Physician (sorry don't think it is available online) that dispute a necessary cat link. What is certain is that cats are much more resistant to the bug and therefore more likely to have it symptomless than other large mammals.
Of you want to make sure have your cat tested during your next vet visit and a simple Clindamycin treatment can kill the dormant disease.
And remember: If you keep your pets healthy so will you be.
Edited by questionmark, 07 September 2012 - 04:51 PM.