Detection of pseudorabies virus DNA in individual single-reactor pigs found in certified pseudorabies-free herds.
During monitoring of certified pseudorabies (PRV)-free herds to confirm their PRV -free status, occasional individual gE-seropositive pigs are detected. These single-reactor pigs remain gE-seropositive when further serum samples are collected and tested. For the eradication programme to proceed, it is important to determine whether these pigs are only false positives or are; in fact, infected with field PRV. The purpose of this study was to determine whether the polymerase chain reaction (PCR) could detect field PRVDNA in single-reactor pigs and so confirm positive reactions in the serologic monitoring programme. First, DNA samples of various tissues from 15 single-reactor pigs all from different herds were examined for field PRV by PCR. Additionally, serum samples from these pigs were analyzed in a gE-confirmation enzyme linked immunosorbent assay (gE-confirmation ELISA). PCR detected PRVDNA in five of the 15 pigs, and these results were confirmed by the gE-confirmation ELISA. The remaining 10 pigs that tested negative in the PCR also tested negative in the gE- confirmation ELISA. We conclude that PCR can be used to discriminate between true and false serological positive single-reactor pigs and, moreover, that the gE-confirmation ELISA confirms these PCR results.
Jacobs
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L
Institute for Animal Science, Health Department of Mammalian Virology, PO BOX 65, Lelystad, AB, NL-8200, The Netherlands.
Voets
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Bianchi
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D000818:Animals; D004279:DNA, Viral / Q000302:isolation & purification*; D005189:False Positive Reactions; D016133:Polymerase Chain Reaction / Q000662:veterinary; D011557:Pseudorabies / Q000235:genetics*; D013552:Swine / Q000821:virology*
D004279:DNA, Viral