COMPARATIVE-EVALUATION OF IN-VITRO AND IN-VIVO ASSAYS FOR THE DETECTION OF AVIAN INFECTIOUS-BRONCHITIS VIRUS AS A CONTAMINANT OF LIVE POULTRY VACCINES

A reverse transcriptase polymerase chain reaction (RT-PCR) assay speci fic for identifying avian infectious bronchitis virus (IBV) in poultry vaccines, ind the serological response to IBV induced by the inoculat ion of chicks with a Newcastle disease vaccine spiked with the Massach usetts strain of IBV, were compared for their ability to detect IBV as a contaminant of avian vaccines. The sensitivity of the IBV-RT-PCR as say provided results which were at least equivalent to the biological effect produced by the inoculation of chicks, allowing this assay to b e considered a valid alternative to animal testing in the quality cont rol of avian immunologicals. This procedure can easily be adapted to d etect a number of contaminants for which the in vivo test still repres ents the only available method of detection.