BVDV induced gastro-neuropathy outbreak in a feedlot calves around Tehran [Iran]

An outbreak of a lethal disease was reported in 4-6-month-old Holstein calves in a feedlot around Tehran. The signs of central nervous system and gastrointestinal system [GI] involvement were observed in the diseased animals. Necropsy samples of GI, liver, kidney, spleen and lung from 3 died animals were prepared for histopathological examination. Blood and formalin-fixed ear notch samples of 6 calves were submitted for RT-PCR, antigen-capture ELISA [ACE] and immunohistochemistry [IHC] for the detection of BVDV. The results of ACE on buffy coats were negative but RT-PCR of all 6 cases and IHC of 4 cases were positive for BVDV infection. Based on the clinical signs and pathological findings in the GI system and brain, we strongly suggest that the BVDV may represent a gastro-neuropathogen strain. To the best of our knowledge, this is the first outbreak of gastro-neuropathogenic BVDV infection in Iran, which may be acquired postnatally

Comparison of ear notch immunofluorescent, buffy coat antigen-capture ELISA and RT-PCR for detection of calves suspected to actuely infected with bovine pesti virus

Twelve calves of 4-10 months old with clinical signs suspected to bovine viral diarrhea virus [BVDV] infection were selected for this study. Histopathologic sections were performed on formalin fixed paraffin-embded ear notch biopsies, mounted on poly-L-lysine coated slides and stained for BVDV by Anti-BVDV monoclonal antibody labelled with fluorescein isothiocyanate. Stained sections were examined by fluorescent microscopy for detection of green fluorescent evidence within the cytoplasm of keratinocytes, other dermal cells and chondrocytes. Detection of BVDVantigen in buffy coat cells was performed by using a commercially available antigen-capture ELISAkit, and RT- PCR, using a universal primers set, specific for all pestiviruses. Based on 11 positive cases detected by RT-PCR, immunofluorescent staining and antigen-capture ELISAcould detect 8 cases [72.72%] and one case [9%] respectively. Results of this study suggest immunofluorescent test on ear notch biopsies has a relatively high sensitivity, and can be used as a reliable and feasible method for detection of calves with acute infection with BVDV