ABSTRACT
Enzootic bovine leukosis (EBL) is aninfectious and contagious disease caused by bovine leukemia virus (BLV), an oncogenic retrovirus of the family Retroviridae. The present study aimed to evaluate the seroprevalence and respective age influence of BLV in Holstein, Jersey, Brown Swiss and mixed-breed dairy cattle raised in Curitiba and the surrounding area, Paraná, Brazil. A total of 268 samples of bovine serum from five different herds in the counties of São José dos Pinhais, Campina Grande do Sul, Pinhais and Fazenda Rio Grande were tested with immunodiffusion (ID). A total of 151/268 (56.34%) testedseropositive, while 117/268 (43.66%) were considered seronegative. Older animals prsented a significant rise in seropositivity. In conclusion, BLV is widely distributed among dairy cattle of Curitiba and the surrounding area, present in all tested herds, thus requiring adequate application of measures in EBL control and prevention.
KEY WORDS
Infectious diseases; ruminants; immunodiffusion