title: Coxiella burnetii seropositivity and associated risk factors in goats in Ontario, Canada.
abstract: Coxiella burnetii is a zoonotic bacterium, and infection in goats with this bacterium can result in abortion, stillbirth or birth of non-viable kids. A cross-sectional study was conducted to identify the seroprevalence and risk factors for C. burnetii exposure in Ontario goats. Sera were collected between August 2010 and February 2012, and tested for C. burnetii specific antibodies using an enzyme-linked immunosorbent assay (IDEXX). Overall, 63.2% (48/76, 95% CI=51.9-73.4) of farms had one or more seropositive goats. A higher farm-level seroprevalence of 78.6% (33/42) was found on dairy goat farms, compared to 44.1% (15/34) on meat goat farms (p<0.01). At the overall individual-animal level, 32.5% (714/2195, 95% CI=30.6-34.5) of goats were seropositive. Similarly, a higher individual-level seroprevalence was identified for dairy goats (43.7%, 633/1447) compared to meat goats (10.8%, 81/748) (p<0.001). A mixed multivariable logistic model that controlled for farm-level clustering identified risk factors associated with seropositivity (p<0.05). Increases in the female herd size (logarithmic scale) were associated with increased odds of seropositivity, while increases in male herd size had a negative association with seropositivity. If other sheep or goat farms were located in a 5-km radius, goats had 5.6 times (95% CI=1.01-30.8) times the odds of seropositivity compared to those that were not. Relative to goats from farms where all kidding pen hygiene was practiced (adding bedding, removing birth materials and disinfection after kidding), goats from farms which only added bedding and removed birth materials had a higher odds of seropositivity (OR=19.3, 95% CI=1.1-330.4), as did goats from farms which practiced none of these measures (OR=161.0, 95% CI=2.4-10822.2). An interaction term revealed kidding outdoors when there were no swine on farm had a protective effect on seropositivity compared to kidding indoors, or kidding outdoors with swine on the farm. These results can inform strategies to mitigate exposure to C. burnetii in Ontario.
authors.affiliation: Department of Population Medicine, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G2W1, Canada. Electronic address: smeadows@uoguelph.ca.
authors.forename: S
authors.initials: S
authors.lastname: Meadows
authors.affiliation: Department of Population Medicine, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G2W1, Canada.
authors.forename: A
authors.initials: A
authors.lastname: Jones-Bitton
authors.affiliation: Department of Population Medicine, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G2W1, Canada.
authors.forename: S
authors.initials: S
authors.lastname: McEwen
authors.affiliation: Veterinary Science and Policy, Ontario Ministry of Agriculture, Food and Rural Affairs, 6484 Wellington Rd 7, Unit 10, Elora, Ontario N0B 1S0, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Jansen
authors.affiliation: Department of Population Medicine, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G2W1, Canada.
authors.forename: P
authors.initials: P
authors.lastname: Menzies
mesh_terms: D000822:Animal Husbandry; D000818:Animals; D016997:Coxiella burnetii / Q000502:physiology*; D003430:Cross-Sectional Studies; D003710:Demography; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005260:Female; D015511:Goat Diseases / Q000453:epidemiology* / Q000382:microbiology; D006041:Goats; D016015:Logistic Models; D008297:Male; D009864:Ontario / Q000453:epidemiology; D015995:Prevalence; D011778:Q Fever / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D012307:Risk Factors; D016036:Seroepidemiologic Studies
keywords: Coxiella burnetii; Coxiellosis; Goat; Ontario; Risk factors; Seroprevalence