Comparison of the plaque test and reverse transcription nested PCR for the detection of FMDV in nasal swabs and probang samples

In order to compare the sensitivity of assays for the diagnosis of foot-and mouth disease (FMD), a cell suspension plaque test on BHK21-CT cells and a reverse transcription nested PCR (RT-nPCR) were used to examine 485 nasal swabs and 227 probang samples obtained from FMDV-infected cattle during vaccine potency tests. In nasal swabs, FMDV could be detected by both tests before the onset of clinical symptoms. However, after two weeks p.i., FMDV was only detected routinely in the probang samples. Examination of nasal swabs revealed a higher number of infected animals using RT-nPCR than by the use of the plaque test. Both tests gave approximately equivalent results with the probang samples.