Stuen S, Djuve R, Bergström K: Persistence of granulocytic Ehrlichia infection during wintertime in two sheep flocks in Norway. Acta vet. scand. 2001, 42, 347-353.-Granulocytic Ehrlichia infection in sheep is common in Norway in areas with Ixodes ricinus. In this study, 2 sheep flocks that had been grazing on I. ricinus infested pastures the previous season, were blood sampled after being housed indoors for nearly 6 months during wintertime. Thirty animals from each flock were examined for granu-locytic Ehrlichia infection in the peripheral blood by blood inoculation studies, stained blood smear evaluation, polymerase chain reaction (PCR) analysis and serology (IFA-antibodies). The animals were sampled twice within a three-week period, the first time before and the second time after lambing. Two sheep in one flock were found Ehrlichia positive by both blood smear evaluation and PCR before lambing, and 3 sheep were found positive after lambing; 2 by blood smear examination and 3 by PCR. In the other flock, no sheep was found infected before lambing, but 2 ewes were found positive after lambing by both blood smear evaluation and PCR. In the first flock, 87% of the animals were found seropositive before lambing, and the mean antibody titre (log 10 ± SD) to E. equi was 2.45 ± 0.401. In the second flock, 40% were found seropositive before lambing, and the mean antibody titre was 1.93 ± 0.260. Seroprevalence and mean anti-body titre in these 2 flocks were significantly different (p<0.001). The present study indicates that sheep may be a reservoir host for granulocytic Ehrlichia infection from one grazing season to the next under natural conditions in Norway. antibodies; PCR; blood smear; reservoir host; Ehrlichia phagocytophila; tick-borne fever.

No abstract

During 1996, aborted bovine fetuses from dairy herds in norther Spain were examined by histopathological, immunohistochemical and serological methods for evidence of infection by Neospora caninum. Microscopical brain changes consistent with those of neosporosis were detected in 36 of 81 fetuses and specific antibodies (IFAT titres > or = 1/16) in 32 of 63. Eight fetuses with neurological lesions were seronegative, and eight without lesions were seropositive. In 25 of 34 fetal brains with lesions consistent with published descriptions of neosporosis, immunohistochemical analysis revealed the presence of N caninum antigen. Depending on the diagnostic criteria, the prevalence of neosporosis related to bovine abortion was between 32 and 57 per cent of the fetuses submitted and between 33 and 58 per cent of the herds involved. Data on the geographical, seasonal and fetal age distribution of the infection are given for the fetuses examined and the value of the different diagnostic methods is discussed.

The 'fitness for purpose' of a probabilistic model designed to assess dietary exposure to pesticides was validated. The model had to meet two prerequisites. First, it should provide more realistic estimates of intake than conservative methods. Second, it should not underestimate 'true' intakes. True intakes were estimated using a duplicate diet study. Three approaches were used to check the prerequisites: visual comparison, a statistical test of a high percentile, and a comparison for each infant of the duplicate diet, conservative and model intake values. Compliance with the prerequisites was met for the six pesticides selected, in the three approaches. Model outcome distributions reduced the uncertainty, considered as the difference between conservative and duplicate diet intakes, by 75-98% for high percentiles, depending on the pesticides. A sensitivity analysis of the model based on analysis of variance for selected factors was conducted for three pesticides. The factors included concentration and food consumption input data presentations, values assigned to pesticide-food commodities without analysis, values assigned to samples with results below the limit of reporting, unit-to-unit variability and processing factors. Their significance and relevance were studied. Assigning values to pesticide-food commodities without analysis and processing factors, when available, were the most relevant factors in this study.