The reverse transcription polymerase chain reaction for the diagnosis of porcine reproductive and respiratory syndrome: comparison with virus isolation and serology.
A single-tube reverse transcription polymerase chain reaction (RT-PCR) assay for the detection of porcine reproductive and respiratory syndrome (PRRS) virus in blood samples from infected pigs was developed. This test was assessed for sensitivity and application as a rapid diagnostic tool by comparison with virus isolation and detection of PRRS virus antibody in blood. The RT-PCR test was slightly more sensitive than virus isolation for detection of virus in serum and markedly more sensitive than virus isolation from plasma from experimentally infected pigs. The RT-PCR test was also applicable when using whole blood-impregnated filter paper discs, with 94% of the specimens taken by this procedure being positive when compared to RT-PCR performed on serum. PRRS viral nucleic acid was detected in blood samples as early as 24 h after infection and persisted for some time, whereas circulating antibody to PRRS virus was not detected in the same animals until 9 days after infection. These results indicate that the RT-PCR may be an useful technique for the early identification of PRRS viral nucleic acid in blood samples of infected pigs.
Spagnuolo-Weaver
M
M
m.spagnuolo@alpha1.qub.ac.uk
Walker
I W
IW
McNeilly
F
F
Calvert
V
V
Graham
D
D
Burns
K
K
Adair
B M
BM
Allan
G M
GM
D000818:Animals; D000831:Animals, Newborn; D000914:Antibodies, Viral / Q000097:blood; D019318:Porcine Reproductive and Respiratory Syndrome / Q000097:blood / Q000175:diagnosis*; D019316:Porcine respiratory and reproductive syndrome virus / Q000235:genetics / Q000302:isolation & purification*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods / Q000662:veterinary; D012698:Serologic Tests / Q000379:methods / Q000662:veterinary; D013552:Swine
D000914:Antibodies, Viral