Infective Dose Size Studies on Cryptosporidium parvum Using Gnotobiotic Lambs

Natural waterbourne transmission of cryptosporidiosis was studied by a simulation using low-level accxamulative dosing. Gnotobiotic lambs were fed on a diet artificially contaminated to a predetermined level with Cryptosporidium parvum oocysts and the faecal output of cysts was measured. Results indicate a minimum infectious dose as low as one oocysts.