To determine whether an antibody response is generated to CAV, we analyzed 34 serum samples collected at different time points from 5 individuals who had stool samples that were CAV positive by PCR. The serum samples were collected between 1 month prior to the episode that was CAV PCR positive to 11 months after the episode. A commercial, competitive binding CAV serological ELISA assay was used. None of the samples were found to contain antibodies against CAV. As no serological assays are currently available for AGV2/HGV; GyV3 or GyV4, we could not assess the immune response to these viruses.