Changes

==Distribution==

==Distribution==

BLV is globally distributed, but prevalence widely varies. The UK is currently free of infection.

BLV is globally distributed, but prevalence widely varies. The UK is currently free of infection evidenced by governement funded bulk milk antibody surveillance and investigations of tumours found in live or dead animals.

While 89% dairy operations in the USA showed seropositive results and 43.5% of all USA dairy cattle were seropositive <ref> USDA/APHIS/Veterinary Services, (1997). High prevalence of BLV in US dairy herds. Fort Collins, CO, USA: USDA: APHIS:VS Centers For Epidemiology and Animal Health.</ref>, seroprevalence in the EU rarely exceeds 0.5-1.5%. <ref>Lorenz, R. J., Straub, O. C. (1987) The epidemiology of enzootic bovine leukosis. In: Burny A, Mammerick, M, eds. Enzootic bovine leukosis and bovine leukemia virus. Boston, USA: Martinus Nijhoff Publishing, 51-68</ref>

While 89% dairy operations in the USA showed seropositive results and 43.5% of all USA dairy cattle were seropositive <ref> USDA/APHIS/Veterinary Services, (1997). High prevalence of BLV in US dairy herds. Fort Collins, CO, USA: USDA: APHIS:VS Centers For Epidemiology and Animal Health.</ref>, seroprevalence in the EU rarely exceeds 0.5-1.5%. <ref>Lorenz, R. J., Straub, O. C. (1987) The epidemiology of enzootic bovine leukosis. In: Burny A, Mammerick, M, eds. Enzootic bovine leukosis and bovine leukemia virus. Boston, USA: Martinus Nijhoff Publishing, 51-68</ref>