Anew way of occurrence and serodiagnosis for Infectious Bovine Rhinotrchitis in Iranian cattle herds

Infectious Bovine Rhinotrachitis (IBR) caused by Bovine Herpes Virus-1 (BoHV-1) was first, observed in one of the Tehran Industrial cattle breeders, with importation of cattle in 1965. Later, the isolation of bovine herpes virus approved the existence of the disease in the most of the provinces of the Iran. Presence of antibodies against BoHV-1 was evaluated in young bovines of north, south and central provinces of Iran. Bovines with age 1 to 4 years old, non-vaccinated and without clinical symptoms were included in the study. 558 serum samples were collected equivalent to 10% of the population in each farm. The sera were tested by ELISA and micro serum neutralization (MSN) in monolayers of MDBK cells using BoHV- 1 reference strain. The results of ELISA showed that 56% (314/558) were positive and 44% (244/558) were negative for BoHV-1 specific antibody. Whoever MSN assay showed that 48% (269/558) were negative and 52% (289/558) were positive. These positive sera demonstrated that 54% had serum neutralization titer between 4-16, 35% on 32 to 64 and 11% on 64. Results suggest that the virus is actively circulating and transmitting in young herds and is a constant source of infection in the herd