An evaluation of test and removal for the elimination of porcine reproductive and respiratory syndrome virus from 5 swine farms.
The objective of this field study was to evaluate the protocol of test and removal (T&R) for the elimination of porcine reproductive and respiratory syndrome virus (PRRSV) from 5 chronically infected breeding herds. The T&R protocol involved sampling the entire breeding herd in one day, testing sera by polymerase chain reaction and ELISA to detect previously exposed and/or infected animals, and subsequently removing them from the herd. Following completion of T&R, breeding herds were monitored for 12 consecutive months, using ELISA, for the presence of antibodies to PRRSV. In order to be classified as a PRRSV-negative herd, all samples collected over the 12-month monitoring period were required to be negative by ELISA (s/p ratio < 0.4). At the conclusion of the monitoring period, all 5 farms were PRRSV-negative, according to the defined testing criteria. Approximately 2.2% (74/3408) ELISA false positive samples were detected across all 5 farms during the monitoring period. The diagnostic cost required during the T&R protocol was approximately US $10.66 per animal tested. Limitations of the study were a lack of herds with large (> 2000 sows) breeding herd inventories, and herds with a history of PRRSV vaccination.
Department of Clinical and Population Sciences, University of Minnesota College of Veterinary Medicine, St. Paul 55108, USA. deexx004@tc.umn.edu
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D000822:Animal Husbandry / Q000191:economics / Q000379:methods; D000818:Animals; D003365:Costs and Cost Analysis; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005189:False Positive Reactions; D010865:Pilot Projects; D016133:Polymerase Chain Reaction / Q000662:veterinary; D019318:Porcine Reproductive and Respiratory Syndrome / Q000175:diagnosis* / Q000453:epidemiology / Q000517:prevention & control; D019316:Porcine respiratory and reproductive syndrome virus / Q000276:immunology / Q000302:isolation & purification*; D012680:Sensitivity and Specificity; D013552:Swine; D013997:Time Factors; D014611:Vaccination / Q000662:veterinary