ABSTRACT
A frozen, stillborn alpaca (Lama pacos) was submitted to the Minnesota Veterinary Diagnostic Laboratory for diagnostic purposes. No gross or histopathologic changes of any significance were seen. A pool of lung, liver, and brain tissues was positive for bovine viral diarrhea virus (BVDV) by reverse transcription-polymerase chain reaction. On inoculation in cell cultures, a noncytopathic BVDV (type 1b) was isolated. No evidence of BVDV was seen on immunohistochemical examination of tissues. This indicates the importance of using multiple tests for arriving at a diagnosis and appears to be the first report of BVDV isolation from alpaca.
Subject(s)
Camelids, New World/virology , Diarrhea Viruses, Bovine Viral/isolation & purification , Animals , Diarrhea Viruses, Bovine Viral/pathogenicity , Female , Fetal Death/veterinary , Immunohistochemistry , Pregnancy , Reverse Transcriptase Polymerase Chain ReactionABSTRACT
Detection and elimination of calves and cows persistently infected with bovine viral diarrhea virus (BVDV) is important for the control of this pathogen. Historically, BVDV detection involved cell culture isolation followed by virus detection through immunofluorescence or immunoperoxidase monolayer assay (IPMA) methods. More recently, immunohistochemistry (IHC) has been added as a routine test for BVDV detection. The detection of BVDV by gel-based reverse transcription polymerase chain reaction (RT-PCR) is more sensitive and rapid than by cell culture isolation, but test results can be compromised by sample contamination during nucleic acid amplification. This study was designed to develop a closed-tube format of BVDV nucleic acid amplification and detection, TaqMan RT-PCR. The results of this new technique were compared with those obtained with virus isolation, IPMA, and IHC. With TaqMan RT-PCR, BVDV was detected in many samples negative by IPMA, IHC, and virus isolation with the exception of 1 sample that was positive by IHC. TaqMan RT-PCR in a closed-tube format offers a rapid, economical, high volume, and sensitive method for BVDV detection without the concerns of amplified cDNA product contamination associated with open-tube gel-based PCR tests.
