Evaluation of a blocking ELISA using monoclonal antibodies for the detection of porcine epidemic diarrhea virus and its antibodies.

Two blocking enzyme-linked immunosorbent assays (ELISAs) involving the use of monoclonal antibodies (MAb) as capture and detecting agents and an indirect fluorescence test (IFT) were used for the detection of porcine epidemic diarrhea virus (PEDV) antigen or its antibodies. In the ELISA for viral antigen detection, the blocking step is accomplished by incubation of fecal samples, in duplicate wells, with PEDV-specific positive or negative serum, whereas in the ELISA for antibody detection the blocking step is accomplished by incubation of serum samples with a gut-origin virus suspension. All the methods developed were used to monitor an experimental infection in piglets with the CV-777 strain of PEDV and a natural PED outbreak in a swine fattening unit. The antigen-detection ELISA was able to detect PEDV shedding for a longer time than have previously described methods. The blocking ELISA for antibody detection was able to detect the serum antibody response sooner after PEDV infection than did IFT.