Investigation of the role of companion animals in the zoonotic transmission of cryptosporidiosis.

Companion animals owned by human patients with cryptosporidiosis (cases) and those animals owned by the wider human population (controls), were studied to determine whether Cryptosporidium was more likely to be excreted by case animals than controls. A total of 280 recently voided faecal samples (114 case animals and 166 control animals) were collected and tested by immunomagnetic separation and immunofluorescent microscopy. A multivariable model was also created to identify pet characteristics, contacts and management factors associated with Cryptosporidium infection in animals, using information collected by a standardized questionnaire. The model was designed to take into account the clustering of samples at the owner level and whether the sampled animal was a case or control.