title: Probability of detecting Porcine reproductive and respiratory syndrome virus infection using pen-based swine oral fluid specimens as a function of within-pen prevalence.
abstract: Pen-based oral fluid sampling has proven to be an efficient method for surveillance of infectious diseases in swine populations. To better interpret diagnostic results, the performance of oral fluid assays (antibody- and nucleic acid-based) must be established for pen-based oral fluid samples. Therefore, the objective of the current study was to determine the probability of detecting Porcine reproductive and respiratory syndrome virus (PRRSV) infection in pen-based oral fluid samples from pens of known PRRSV prevalence. In 1 commercial swine barn, 25 pens were assigned to 1 of 5 levels of PRRSV prevalence (0%, 4%, 12%, 20%, or 36%) by placing a fixed number (0, 1, 3, 5, or 9) of PRRSV-positive pigs (14 days post PRRSV modified live virus vaccination) in each pen. Prior to placement of the vaccinated pigs, 1 oral fluid sample was collected from each pen. Thereafter, 5 oral fluid samples were collected from each pen, for a total of 150 samples. To confirm individual pig PRRSV status, serum samples from the PRRSV-negative pigs (n = 535) and the PRRSV vaccinated pigs (n = 90) were tested for PRRSV antibodies and PRRSV RNA. The 150 pen-based oral fluid samples were assayed for PRRSV antibody and PRRSV RNA at 6 laboratories. Among the 100 samples from pens containing ≥1 positive pig (≥4% prevalence) and tested at the 6 laboratories, the mean positivity was 62% for PRRSV RNA and 61% for PRRSV antibody. These results support the use of pen-based oral fluid sampling for PRRSV surveillance in commercial pig populations.
authors.affiliation: Veterinary Diagnostic Laboratory, Iowa State University, Ames, IA 50011-1240, USA.
authors.forename: Chris
authors.initials: C
authors.lastname: Olsen
authors.forename: Chong
authors.initials: C
authors.lastname: Wang
authors.forename: Jane
authors.initials: J
authors.lastname: Christopher-Hennings
authors.forename: Kent
authors.initials: K
authors.lastname: Doolittle
authors.forename: Karen M
authors.initials: KM
authors.lastname: Harmon
authors.forename: Sarah
authors.initials: S
authors.lastname: Abate
authors.forename: Apisit
authors.initials: A
authors.lastname: Kittawornrat
authors.forename: Sergio
authors.initials: S
authors.lastname: Lizano
authors.forename: Rodger
authors.initials: R
authors.lastname: Main
authors.forename: Eric A
authors.initials: EA
authors.lastname: Nelson
authors.forename: Tracy
authors.initials: T
authors.lastname: Otterson
authors.forename: Yaowalak
authors.initials: Y
authors.lastname: Panyasing
authors.forename: Chris
authors.initials: C
authors.lastname: Rademacher
authors.forename: Rolf
authors.initials: R
authors.lastname: Rauh
authors.forename: Rohan
authors.initials: R
authors.lastname: Shah
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Zimmerman
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000032:analysis / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D019318:Porcine Reproductive and Respiratory Syndrome / Q000175:diagnosis* / Q000821:virology; D019316:Porcine respiratory and reproductive syndrome virus / Q000302:isolation & purification*; D012367:RNA, Viral / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012463:Saliva / Q000821:virology*; D013552:Swine
chemical_list: D000914:Antibodies, Viral; D012367:RNA, Viral
keywords: Diagnostics; Porcine reproductive and respiratory syndrome virus; enzyme-linked immunosorbent assay; oral fluid; polymerase chain reaction; surveillance