PMID- 12517825
OWN - NLM
STAT- MEDLINE
DCOM- 20030507
LR  - 20210526
IS  - 0095-1137 (Print)
IS  - 1098-660X (Electronic)
IS  - 0095-1137 (Linking)
VI  - 41
IP  - 1
DP  - 2003 Jan
TI  - Duration of infection and proportion of pigs persistently infected with porcine 
      reproductive and respiratory syndrome virus.
PG  - 58-62
AB  - Understanding the dynamics of porcine reproductive and respiratory syndrome virus 
      (PRRSV) persistence in individual pigs is essential to the development of 
      successful control programs. The objectives of this study were to investigate the 
      proportion of inoculated pigs that become persistently infected with PRRSV and 
      the duration of their infection. Additionally, different diagnostic techniques 
      that detect persistent infections were compared. Twenty-eight 35-day-old pigs 
      were inoculated with PRRSV. Serum and tonsil biopsy samples were collected on 
      days 0, 7, 14, and 28 and then approximately monthly thereafter until day 251 
      postinoculation (p.i.). Tonsil, lymph node, and lung samples were collected 
      following euthanasia on day 251 p.i. Virus was isolated from serum and tonsil 
      biopsy samples that had been collected through days 28 and 56 p.i., respectively. 
      Viral RNA was detected by reverse transcription (RT)-PCR in serum and tonsil 
      biopsy samples that had been collected through day 251 p.i., although no serum 
      samples collected from days 84 to 196 p.i. were positive and the presence of 
      infectious PRRSV was not detected by swine bioassay of tissue samples collected 
      at necropsy. The results confirmed that RT-PCR is more sensitive than virus 
      isolation in identifying PRRSV-infected pigs. Six pigs that were persistently 
      infected through days 225 or 251 p.i. remained seropositive throughout the study, 
      although one pig had an enzyme-linked immunosorbent assay sample-to-positive 
      ratio that was only slightly above the cutoff value of 0.40. Twenty of 28 tonsil 
      biopsy samples collected on day 84 p.i. were positive by RT-PCR compared to only 
      1 positive biopsy sample out of 28 collected on day 119 p.i. The study's results 
      indicate that most pigs clear PRRSV within 3 to 4 months, but that some may 
      remain persistently infected for several months.
FAU - Wills, Robert W
AU  - Wills RW
AD  - Department of Veterinary and Biomedical Science, University of Nebraska-Lincoln, 
      Lincoln, Nebraska 68583-0907, USA. willscvm.msstate.edu
FAU - Doster, Alan R
AU  - Doster AR
FAU - Galeota, Judith A
AU  - Galeota JA
FAU - Sur, Jung-Hyang
AU  - Sur JH
FAU - Osorio, Fernando A
AU  - Osorio FA
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, Non-P.H.S.
PL  - United States
TA  - J Clin Microbiol
JT  - Journal of clinical microbiology
JID - 7505564
SB  - IM
MH  - Animals
MH  - Disease Models, Animal
MH  - Female
MH  - Porcine Reproductive and Respiratory Syndrome/*epidemiology/virology
MH  - *Porcine respiratory and reproductive syndrome virus
MH  - Swine
PMC - PMC149563
EDAT- 2003/01/09 04:00
MHDA- 2003/05/08 05:00
PMCR- 2003/01/01
CRDT- 2003/01/09 04:00
PHST- 2003/01/09 04:00 [pubmed]
PHST- 2003/05/08 05:00 [medline]
PHST- 2003/01/09 04:00 [entrez]
PHST- 2003/01/01 00:00 [pmc-release]
AID - 0482 [pii]
AID - 10.1128/JCM.41.1.58-62.2003 [doi]
PST - ppublish
SO  - J Clin Microbiol. 2003 Jan;41(1):58-62. doi: 10.1128/JCM.41.1.58-62.2003.