Evaluation of the analytical sensitivity of a polymerase chain reaction assay for the detection of chicken infectious anemia virus in avian vaccines

Chicken infectious anemia virus (CAV) is a ubiquitous pathogen of chickens causing significant disease in commercial flocks worldwide. During CAV outbreaks, the Center for Veterinary Biologics requires manufacturers of veterinary biologicals to test materials derived from infected flocks for extraneous CAV by polymerase chain reaction (PCR). The analytical sensitivity of a PCR assay for detection of CAV was determined and the applicability of a CAV DNA standard as a positive control for assay validity was evaluated. The analytical sensitivity of the CAV PCR assay was assessed to be 100 copies per reaction for the DNA standard and 1 × 10^1.9 TCID₅₀/reaction for infectious virus. Establishing the analytical sensitivity of this CAV PCR assay and the inclusion of internal and external positive controls for validity provide a basis for determining whether suspect materials are safe for use in the production of veterinary biologics.