PMID- 11289209
OWN - NLM
STAT- MEDLINE
DCOM- 20010712
LR  - 20190522
IS  - 1040-6387 (Print)
IS  - 1040-6387 (Linking)
VI  - 13
IP  - 2
DP  - 2001 Mar
TI  - Detection and duration of porcine reproductive and respiratory syndrome virus in 
      semen, serum, peripheral blood mononuclear cells, and tissues from Yorkshire, 
      Hampshire, and Landrace boars.
PG  - 133-42
AB  - Because transmission of porcine reproductive and respiratory syndrome virus 
      (PRRSV) can occur through boar semen, it is important to identify persistently 
      infected boars. However, even for boars given the same PRRSV strain and dose, 
      variability in the duration of viral shedding in semen has been observed, 
      suggesting that host factors are involved in PRRSV persistence. To determine 
      whether there are host genetic factors, particularly litter and breed differences 
      related to the persistence of PRRSV, 3 litters from 3 purebred swine breeds were 
      used for this study. It was also determined whether PRRSV could be detected for a 
      longer period of time in serum, semen, or peripheral blood mononuclear cells 
      (PBMC) and if PRRSV could still be detected in tissues after these antemortem 
      specimens were PRRSV negative for a minimum of 2-3 weeks. Three Hampshire, 3 
      Yorkshire, and 2 Landrace PRRSV-naive boars were obtained and inoculated 
      intranasally with a wild-type PRRSV isolate (SD-23983). All boars within each 
      breed were from the same litter, and litters were within 9 days of age. Serum and 
      PBMC were collected twice weekly from each boar and analyzed for the presence of 
      PRRSV by virus isolation and the polymerase chain reaction (PCR). Serum was also 
      used to obtain virus neutralization titers and enzyme-linked immunosorbent assay 
      S/P values. Semen was collected twice weekly from 7 of 8 boars and analyzed by 
      PCR. After all specimens were PRRSV negative for a minimum of 2-3 weeks, each 
      boar was euthanized, and 21 tissues plus saliva, serum, feces, and urine were 
      collected. All postmortem specimens were evaluated by virus isolation. Specimens 
      that were PRRSV negative by virus isolation were then evaluated by PCR. The mean 
      number of days (+/-SD) for the duration of PRRSV shedding in semen was 51+/-26.9 
      days, 7.5+/-4.9 days, and 28.3+/-17.5 days for Landrace, Yorkshire, and Hampshire 
      boars, respectively. Because of small sample sizes and large SDs, the differences 
      in duration of PRRSV shedding in semen between breeds were not considered 
      significant. However, the trend suggested that Yorkshire boars were more 
      resistant to PRRSV shedding in semen than were Landrace boars, requiring further 
      investigation using a larger numbers of boars. PRRSV was detected for a longer 
      period in semen than in serum or PBMC in 4 of 7 boars. Viremia could be detected 
      for a longer period in serum than in PBMC in 6 of 8 boars. After a minimum of 2-3 
      weeks of PRRSV-negative serum, semen, and PBMC, PRRSV could still be detected in 
      the tonsil of 3 of 8 boars by virus isolation, indicating that boars still harbor 
      PRRSV within the tonsil even though antemortem specimens are PRRSV negative.
FAU - Christopher-Hennings, J
AU  - Christopher-Hennings J
AD  - Animal Disease Research and Diagnostic Laboratory, South Dakota State University, 
      Brookings 57007-1396, USA.
FAU - Holler, L D
AU  - Holler LD
FAU - Benfield, D A
AU  - Benfield DA
FAU - Nelson, E A
AU  - Nelson EA
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - J Vet Diagn Invest
JT  - Journal of veterinary diagnostic investigation : official publication of the 
      American Association of Veterinary Laboratory Diagnosticians, Inc
JID - 9011490
RN  - 0 (Antibodies, Viral)
RN  - 0 (DNA Primers)
RN  - 0 (RNA, Viral)
SB  - IM
MH  - Animals
MH  - Antibodies, Viral/isolation & purification
MH  - DNA Primers
MH  - Enzyme-Linked Immunosorbent Assay/veterinary
MH  - Leukocytes, Mononuclear/*virology
MH  - Male
MH  - Polymerase Chain Reaction/veterinary
MH  - Porcine Reproductive and Respiratory Syndrome/prevention & control/*virology
MH  - Porcine respiratory and reproductive syndrome 
      virus/genetics/immunology/*isolation & purification/*pathogenicity
MH  - RNA, Viral/isolation & purification
MH  - Semen/*virology
MH  - Swine/*virology
EDAT- 2001/04/06 10:00
MHDA- 2001/07/19 10:01
CRDT- 2001/04/06 10:00
PHST- 2001/04/06 10:00 [pubmed]
PHST- 2001/07/19 10:01 [medline]
PHST- 2001/04/06 10:00 [entrez]
AID - 10.1177/104063870101300207 [doi]
PST - ppublish
SO  - J Vet Diagn Invest. 2001 Mar;13(2):133-42. doi: 10.1177/104063870101300207.