Persistence of Granulocytic EhrlichiaInfection During Wintertime in Two Sheep Flocks in Norway

Autor: Stuen, S, Djuve, R, Bergström, K
Zdroj: Acta Veterinaria Scandinavica; September 2001, Vol. 42 Issue: 3
Abstrakt: Granulocytic Ehrlichiainfection in sheep is common in Norway in areas with Ixodes ricinus. In this study, 2 sheep flocks that had been grazing on I. ricinusinfested 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 granulocytic Ehrlichiainfection in the peripheral blood by blood inoculation studies, stained blood smear evaluation, polymerase chain reaction (PCR) analysis and serology (IFAantibodies). 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 Ehrlichiapositive 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. equiwas 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 antibody titre in these 2 flocks were significantly different (p < 0.001). The present study indicates that sheep may be a reservoir host for granulocytic Ehrlichiainfection from one grazing season to the next under natural conditions in Norway.
Databáze: Supplemental Index