Use of orf 5 PCR on tonsil biopsy to monitor for the risk of introducing PRRS virus in seropositive incoming breeding stock

摘要

Introduction of Porcine Reproductive and Respiratory Syndrome (PRRS) virus into swine herds has been linked to introduction of virus positive replacement breeding stock. These animals may shed virus to animals already in the herd, resulting in clinical PRRS. This study estimated the risk of serologically positive stock to introduce and transmit PRRS virus to a breeding herd utilizing tonsil biopsy followed by ORF 7 PCR on (he tissue sample. Comparison was made to EL1SA and SN litres, PCR of buffy coat while blood cells, and PCR of serum. Tissues were selected based on prior research into the transmission of PRRS virus. Zimmerman has utilized tonsil scrapings and virus isolation to follow PRRS infected animals for more than 100 days. Benfield has used PCR on buffy coal white blood cells in experiments describing long term viraemic pigs. Serology is widely used to as a screening toot for replacement breeding stock.