Or eating out.. handling anything in places where items have been handled by other people a lot - people are
nasty!
I honestly believe I picked up C. diff from where I was working... someone actually handed me a dvd case with feces smeared on the back of it. I didn't know until I grabbed it.

I don't know if that feces was animal or human - though I think it looked like animal, maybe dog.
The bad thing about clostridium bacteria and others like it is that alcohol hand sanitizers and even soap and water doesn't do much. Only the harshest cleaners do. So if an area gets contaminated people risk getting it.

(still wash your hands as soap makes your hand slippery and helps stuff wash away so lesser amounts are there)
So you can pick them up anywhere there's been fecal contamination on something that gets in your mouth. Then you're a carrier and if your gut flora is disrupted you can get an overgrowth.
Have you been taking antibiotics or any medications lately? How do you feel? Fever? Chills? Like death warmed over?

If you're feeling really bad already, don't wait - go get fluids in the ER and make them take a stool sample before treating you with anything (I know, it's icky).
Always remember that such infections can go both ways. You can actually infect your cats with these. Do not let cats ever drink out of the toilet, wash toilets and sinks down with bleach or lysol to deactivate endospores and protozoa. Especially be doing this at home if you live with someone older or who has compromised health already!
Oh, and in the meantime - drink some gatorade if you can.