RESUMEN
A cross-sectional study was carried out to estimate prevalence of Chlamydophila spp. antibodies and to investigate risk factors associated with chlamydial infection in 552 ewes between March 2011 and January 2012 in the province of Constantine. Anti-Chlamydophila antibodies were detected using an indirect enzyme-linked immunosorbent assay kit in 24.5% of examined sera. Of the herds, 70.4% had at least one seropositive animal. A pretested structured questionnaire was administered in order to collect information on individual animal health and herd management practices. Chi-square analysis and multivariable logistic regression model were used to identify risk factors related to Chlamydophila seropositivity. Univariable analysis revealed 17 variables with p < 0.25 that were offered to the multivariable logistic regression model which in turn identified 12-23 months age group (OR = 5.903, 95% CI (OR) = 1.690; 20.618) and not using disinfectants (OR = 2.099, 95% CI (OR) = 1.314; 8.065) as risk factors for Chlamydophila spp. seropositivity. Moreover, occurrence of stillbirth problem (OR = 3.682, 95% CI (OR) = 1.825; 7.430) and 5-10% mortality rate in young lambs (OR = 2.584, 95% CI (OR) = 1.058; 6.310) were significantly associated with seropositivity to Chlamydophila spp. On the other hand, availability of veterinary service was identified as a protective factor (OR = 0.161, 95% CI (OR) = 0.051; 0.511).