Prevalence of bovine herpesvirus 1 (BHV-1) infection in Hungarian cattle herds

Hungarian cattle herds were surveyed for bovine herpesvirus 1 (BHV-1) infec tion by ELISA of milk and serum samples. In 1993, 75% of the large cattle h erds (consisting of more than 50 cattle) and all small herds (small-scale p roducers' stocks), while in 1997 90% of the small herds were included in th e survey. In the case of large herds, 79.3% of the herds and 64.1% of the s amples tested were found to be positive. Of the small herds, 13.5% and 15.7 % tested positive in 1993 and 1997, respectively. The majority of large her ds were Holstein-Friesian dairy stocks. Small herds with an infection rare markedly exceeding the average were found in those counties where the small herds had been in close contact with the large-scale farms, or where new h erds were established by using animals of uncontrolled infectious bovine rh inotracheitis (IBR) status originating from large farms. Attention is calle d to the importance of maintaining the IBR-free status of small herds that constitute one-third of the Hungarian cattle population.