Porcine reproductive and respiratory syndrome virus (PRRSV) in serum and oral fluid samples from individual boars: will oral fluid replace serum for PRRSV surveillance?
The purpose of this study was to determine whether oral fluid samples could be used to monitor individually-housed adult boars for porcine reproductive and respiratory syndrome virus (PRRSV) infection. In 3 trials, 24 boars were intramuscularly (IM) inoculated with a modified-live PRRSV (MLV) vaccine (Trial 1), a Type 1 PRRSV isolate (Trial 2), or a Type 2 isolate (Trial 3). Oral fluid samples were collected daily and serum samples were collected twice weekly. Following the completion of the study, samples were randomized and blind-tested for PRRSV by real-time quantitative reverse-transcription polymerase chain reaction (qRT-PCR). PRRSV was detected in oral fluids at DPI 1 and all oral fluid specimens were PRRSV qRT-PCR positive at DPI 4. Although PRRSV was detected in both serum and oral fluid specimens through DPI 21, a comparison of matched samples from individual boars showed that oral fluid was equal to serum for the detection of PRRSV at DPI 7 and more likely to be positive than serum on DPI 14 and 21. Overall, oral fluid was superior to serum for the detection of PRRSV using PCR over the 21-day observation period in this study. The results of this experiment suggest that individually-penned oral fluid sampling could be an efficient, cost-effective approach to PRRSV surveillance in boar studs and other swine populations.
Kittawornrat
Apisit
A
Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA. apisitk@iastate.edu
Prickett
John
J
Chittick
Wayne
W
Wang
Chong
C
Engle
Mark
M
Johnson
Jeremy
J
Patnayak
Devi
D
Schwartz
Trevor
T
Whitney
Daniel
D
Olsen
Chris
C
Schwartz
Kent
K
Zimmerman
Jeffrey
J
D000818:Animals; D019318:Porcine Reproductive and Respiratory Syndrome / Q000175:diagnosis* / Q000821:virology*; D019316:Porcine respiratory and reproductive syndrome virus / Q000302:isolation & purification*; D012367:RNA, Viral / Q000235:genetics / Q000302:isolation & purification; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D012463:Saliva / Q000821:virology*; D044967:Serum / Q000821:virology*; D013552:Swine; D019562:Viral Load; D014773:Virology / Q000379:methods
D012367:RNA, Viral