Isolation and characterization of BoHV-1 from seropositive cows after inducing artificial stress in West Bengal, India.

Infectious Bovine Rhinotracheitis (BoHV-1) is the most important emerging disease of cattle in India. With an aim to reactivate BoHV-1 from latently infected sero-positive cattle for molecular characteristics of the isolates prevalent in tropical and sub-tropical countries like India and further epidemiological investigations on IBR infections this study had been conducted. Artificial stress with dexamethasone at the dose rate of 0.1 mg kg(-1) body weight for 5 consecutive days was induced in BoHV-1 sero-positive cows. Then isolation from nasal swabs was attempted in Madin Darby Bovine Kidney (MDBK) cell line to find out the prevalent strain in India. The virus was isolated from all the three cows. All the three isolates were typed as BoHV-1.2 (Strain India 4, India 5 and India 6). The reactivation obtained in this study with dexamethasone suggests the usefulness of BoHV-1 cow latency model for epidemiological investigations on BoHV-1 infections in tropical and sub-tropical countries like India, Pakistan etc.