Seroprevalence of Anaplasma marginale in cattle in the 'Norte Fluminense' mesoregion

摘要

.- Souza J.C.P., Soares C.O., Massard C.L., Scofield A. & Fonseca A.H. 2000. [Seroprevalence of Anaplasma marginale in cattle in the "Norte Fluminense" mesoregion.] Soropreval?ancia de Anaplasma marginale em bovinos na mesorregi?￡o Norte Fluminense. Pesquisa Veterin??ria Brasileira 20(3):97-101. Depto Parasitologia Animal, Univ. Fed. Rural do Rio de Janeiro, Km 47, Serop??dica, RJ 23890-000, Brazil. Serumprevalence of antibodies against Anaplasma marginale was evaluated by the indirect Enzyme-Linked Immunosorbent Assay (ELISA). Sera samples from 532 bovines from nine municipalities in the "Norte Fluminense" mesoregion, Rio de Janeiro state, were analysed. The results showed that 485 (91.16%) were positive, of which 55.45% had a titre of 1:500, 22.18% of 1:1000, 6.77% of 1:2000, 3.01% of 1:4000, 1.50% of 1:8000, 0.94% of 1:16000, 0.75% of 1:32000, 0.56% of 1:64000, and 8.84% were negative. The prevalence analysis was done within three age groups: 1 to 3 years (n= 110), 3 to 6 years (n= 241) and 6 years (n= 181), of which 91.82%, 92.95% and 88.95% were positive, respectively. According to the breed, 91.22% of beef cattle (n= 444) and 90.91% of dairy cattle (n= 88), were positive. Regarding the sex, 91.35% of the females (n= 497) and 88.57% of the males (n= 35), were positive. There were no significant differences between the age groups, breeding types and the sexes (P 0.05); and between the prevalence in the municipalities (P 0.000). The seroprevalence showed that the region has to be considered enzootically stable, and the infection by A. marginale in this area is high and homogeneous. INDEX