Serumprevalence of antibodies against Anaplasma marginale were studied by the indirect Enzyme-Linked Immunosorbent Assay (ELISA). Sera samples from 223 bovines of eight municipalities in the "Médio Paraíba" mesorregion, in the state of Rio de Janeiro state, were analysed. The prevalence showed 98.21% of positives, of which were: 36.32% with a titre of 1:500, 43.50% of 1:1000, 12.56% of 1:2000, 3.59% of 1:4000, 1.79% of 1:8000, 0.45% of 1:16000, and 1.79% were negative. The evaluation was done within three age groups: 1 to 3 years (n = 53), 3 to 6 years (n = 71) and > 6 years (n = 99), of which 96.23%, 100% and 97.98% were positive, respectively. Regarding to the breed, 100% of beef cattle (n = 38) and 97.84% of dairy cattle (n = 185), were positive. According to the sex, 98.91% of the females (n = 183) and 95.00% of the males (n = 40), were positive. There were no significant differences (P > 0.05) between the prevalence of age groups, breeding types and sexes. There were significant differences (P < 0.0001) among the serumprevalence in the municipalities. The region was characterized as an enzootically stable area to A. marginale.
Anaplasma marginale; seroprevalence; bovine anaplasmosis; "Médio Paraíba" mesoregion
