摘要：With the aim to evaluate strain RB51 Brucella abortus vaccine under field conditions in goats and ovine communities, located at Perote and Coffer Region in Veracruz, Mexico, where, prevalence rates varies, several vaccination operatives were done between 12 to 15 months, using 3x108 to 3x109 Colony Forming Units (CFU) of such vaccine for each animal. A total of 5,168 goats or ovine females 3 months old and older, were vaccinated. Those animals belonged to 322 herds in different communities. Vaccination was done despite their reproductive condition. Twenty animals were randomly selected in each herd and blood samples collected, before and after 12 to 15 months of vaccination, in order to determine brucellosis seroprevalence. Sample size for each community was estimated by a probabilistic model, with unknown population and 50% known prevalence rate (n = 1-p/pv); where, n corresponds to sample size, p for prevalence rate and v variation coefficient (0.05), blood samples were taken by jugular vein punction using vacuum tubes system. The sera collected were tested by using 3% antigen concentration card test as screening and complement fixation as confirmation test, according with Mexican regulations. During the first sampling tests it was found that seroprevalence rates in the communities were: 0, 0.5, 4.5, 5, 38 and 1.4%. The rates of seroprevalence in the second sampling were: 0, 0, 5.5, 0 and 0%. The rates of serum reactors were reduced 80% from different rates to 0.0%. According with these results, RB51 Brucella abortus strain vaccination provided a successful response at the indicated dosage. It is conclusive that RB51 Brucella abortus strain goat and ovine vaccination at communities from Perote and Coffer Region is useful for brucellosis control.
