In this study, a polymerase chain reaction (PCR) assay was used for
the detection of bovine viral diarrhea virus (BVDV) persistent
infections in cattle. BVDV RNA's from individual serum, milk and
semen clinical specimens from persistently infected (PI) cattle were
transcribed to cDNA using reverse transcriptase. Using a set of
oligonucleotide primers complementary to nucleotide sequence within
the conserved 5' untranslated region (UTR) of the BVDV genome, a
246 base pair target sequence from BVDV cDNA from clinical
samples was successfully amplified by PCR. The sensitivity of PCR
detection of BVDV nucleic acid was 10 times more than that of BVDV
isolation from serum of PI animals. The results suggest that PCR
amplification assay may be a useful addition in developing new rapid
and sensitive tests for detection of BVDV in clinical samples from PI
animals. The speed and the sensitivity of this method might be of value
for perusing studies on pathogenesis and epidemiology of persistent
infection of cattle with BVD virus.