This summer I was working on a rescue case in which
Cryptsporidium baileyi was suspected of sickening a family's reptiles and a 7 year old girl. It was never definitively proved because by the time I got the public health officials to pay attention to my concerns, the animals in question had been dead for months and the fecal smear slides were not properly preserved for molecular testing for either the child or the herps.
The official diagnosis for the child was "parasitic infestation of unknown etiology". We do know that crypto was the cause of death for a bearded dragon and a leopard gecko, both purchased from the same store and acquired from the same large-scale breeder. That breeder is no longer shipping animals to North America and so our worries are over there.
I spent many an hour pouring over info about cryptosporidiosis and found this site particularly helpful.
University of Kansas Parasitology: Cryptosporidiosis
Stuff I gleaned from my reading:
It is extremely rare for humans and reptiles to be sickened by the same strain of crypto. There is only one documented case and that man had an advanced case of AIDS. The strain that sickens reptiles is usually
Cryptosporidium serpentis, which is rarely found in North American water supplies. It is
Cryptosporidium parvum which sickens mammals, and that is the strain most commonly found in North America as a result of runoff water from farms and ranches. Therefore, it is not likely our animals will ever contract crypto unless we ourselves encounter a crypto animal and bring home oocysts to infect our collections. We must use our heads when handling pet shop animals or animals at a show.
Soap and water mechanically removes oocysts from our hands and from underneath our fingernails more effectively than any chemical. The hard coating of the oocysts makes them extremely resistant to penetration by any chemical agent that might kill them, and so chemicals have to be in contact with them for long enough to soak in. Lots of running water is most likely to send them down the drain where they won't harm us or our collection. Hand sanitizers are great for bacterial problems but not very effective for stopping the spread of crypto.
Hope this was helpful.