EPIDEMIOLOGIC-STUDY OF CHLAMYDIAL INFECTION IN SHEEP FARMS IN MADRID,SPAIN

A cross-sectional study was conducted in a population of sheep in Madr id (Spain) to assess seroprevalence and to identify risk factors for c hlamydial infection. Information from 57 flocks was collected and 512 animals were sampled. The effects on the seroprevalence of several var iables, such as farm management practices, farmer characteristics, ani mal health and veterinary services were evaluated using a random-effec ts logistic regression model. The seroprevalence to Chlamydia spp. was 50.5% (+/- 4.5(95% CI)) using the Complement Fixation Test with a 1.3 2 cut-off titer. Fifty-five herds (96.5%) were positive. Three variabl es were associated with seroprevalence in the final model. Being a dai ry animal was a risk factor (OR = 2.40, P = 0.067), Distance among far ms greater than 500 m acted as protective factor (OR = 0.55, P = 0.02 6). The third variable confirmed the endemic situation of chlamydiosis in the area: seropositive animals belonged to herds in which the obse rved percentage of abortions was greater than 5% (OR = 2.40, P = 0.01 0). (C) 1998 Published by Elsevier Science B.V.