Mass vaccination as a complementary tool in the control of a severe outbreak of bovine brucellosis due to Brucella abortus in Extremadura, Spain.

We report the evolution of an outbreak of bovine brucellosis (Brucella abortus) in the region of Extremadura (Spain) involving more than 1000 herds and nearly 40,000 animals. S19 vaccination of young cattle combined with a test and slaughter strategy did not result in a rapid decrease in herd prevalence and animal incidence; these parameters showed a constant decreasing trend only when a combination of restriction of cattle movements, increased test frequency, S19 vaccination and mass RB51 vaccination (with yearly revaccinations) were applied to all susceptible populations. These measures were applied for 5 years; abortions following RB51 vaccination of pregnant cows were limited to the first inoculation and the involvement of the vaccine strain could only be demonstrated in 78 out of 897 abortions. Our results demonstrate the usefulness - and lack of significant side effects - of RB51 mass vaccination as a complementary tool to control bovine brucellosis outbreaks in areas where the disease cannot be contained using more conservative approaches.

Heavy metal (Cd, Pb, Zn) and metalloid (As) content in raptor species from Galicia (NW Spain).

As top consumers in food chains, birds of prey forage over large geographical areas and so might be expected to accumulate environmental contaminants which are distributed in the environment. These wild animals can offer opportunities to detect and assess the toxicological effects of different inorganic elements on terrestrial ecosystems. In this study, different raptor species, both diurnal and nocturnal, were investigated for heavy metal (Pb, Cd and Zn) and As concentrations in liver samples, with the aim of furnishing indirect information concerning contamination of their habitats. Dead animals were obtained with the special collaboration of the Wildlife Rehabilitation Centres from Galicia (NW Spain). After sample wet digestion, metal analysis was performed by inductively coupled plasma-mass spectrometry (ICP-MS). Hepatic concentrations of Zn and As, respectively, situated on the interval 147-298 and 1.21-6.88 ppm (dry weight, dw), could be considered as indicative of low and background amounts of both elements, with no ecotoxicological concern. Nevertheless, with respect to Pb, some diurnal raptors showed hepatic concentrations above the considered threshold value (6 ppm dw) for sublethal or lethal toxicity, the species with the highest hepatic level corresponding to a common buzzard (>18 ppm, dw). Similarly, nocturnal raptors exceeded the threshold value for Cd (3 ppm dw), with a maximum corresponding to an individual barn owl (39 ppm, dw). In both cases, although concentrations could not be directly related to lethal effect, they might constitute a serious environmental factor affecting the survival of the considered populations.