Quantitative method to assess Cryptosporidium oocyst shedding in the chicken model.

An unsophisticated and fairly sensitive quantitative method and its grounds are described, which proved useful to assess Cryptosporidium oocyst shedding in the chicken model. The method is based on the rather slow sedimentation of oocysts. A threshold of sensitivity ranging between 5,000 and 10,000 oocysts/g feces was established for this technique. There was good agreement between triplicate assays over a wide range of oocyst concentrations.