Laboratory reporting accuracy of polymerase chain reaction testing for psittacine beak and feather disease virus.

Diagnostic assays that use polymerase chain reaction (PCR) methods are increasingly available to veterinarians. Psittacine beak and feather disease virus (family Circoviridae, genus Circovirus) is a pathogen of clinical importance for which PCR assays have been developed. Several laboratories offer this diagnostic assay in the United States; however, there is little information on the sensitivity, specificity, or accuracy of these assays. In this study, known positive (n = 10) and negative (n = 10) samples were sent to 5 commercial laboratories. Accuracy was 100% for 2 laboratories, 95% for 2 laboratories, and 71% for 1 laboratory; the accuracy of the latter laboratory was affected because of a specificity of 20%. These results suggest that although the results from most laboratories are highly accurate, both false-positive and false-negative results are occasionally reported by at least 2 laboratories. These results also suggest that at least 1 laboratory may be generating large numbers of false-positive results.