title: Seroprevalence of Brucella ovis in rams and associated flock level risk factors in the state of Rio Grande do Sul, Brazil.
abstract: A cross-sectional study based on a planned probabilistic sampling was carried out to estimate animal and flock prevalence of Brucella ovis in rams, as well as to determine risk factors at the flock level. Data regarding the flocks were collected by means of a questionnaire applied on 705 farms in the state of Rio Grande do Sul, Brazil, using one-stage cluster sampling. From the 705 flocks, 20 (2.5%, CI95%: 2.0-3.1%) had at least one positive ram. At the animal level, out of 1800 rams, 52 were positive (2.89%, CI95%: 0.4-5.3%). Statistical analysis identified the following as risk factors: average age of rams in the flocks (PR: 1.99, CI95%: 1.19-3.32); farms larger than 5 km(2) (500 ha) on extension area (PR: 7.46CI95%: 2.03-27.43); and the lack of lambing paddocks (PR: 5.56, CI95%: 1.70-18.11). This study provided relevant information for authorities to elaborate plans for the first Brazilian state based B. ovis disease control and eradication program. To the authors' knowledge, this is the first study that shows the importance of lambing paddocks in order to keep pre-lambing and lambing ewes away from the rest of the flock, the lack of this infrastructure was considered an important risk factor for B. ovis.
authors.affiliation: Laboratory of Veterinary Epidemiology, Faculty of Veterinary, Federal University of Rio Grande do Sul (UFRGS), Av. Bento Gonçalves 9090, CEP, 91540-000 Porto Alegre, RS, Brazil. Electronic address: gustavoetal@gmail.com.
authors.forename: G
authors.initials: G
authors.lastname: Machado
authors.affiliation: Secretary of Agriculture, Livestock and Agribusiness of State of Rio Grande do Sul (SEAPA-RS), Av. Getúlio Vargas 1384, CEP, 95150-900, Porto Alegre, RS, Brazil.
authors.forename: D V
authors.initials: DV
authors.lastname: Santos
authors.affiliation: Secretary of Agriculture, Livestock and Agribusiness of State of Rio Grande do Sul (SEAPA-RS), Av. Getúlio Vargas 1384, CEP, 95150-900, Porto Alegre, RS, Brazil.
authors.forename: I
authors.initials: I
authors.lastname: Kohek
authors.affiliation: Department of Statistics, Mathematical Institute, Federal University of Rio Grande do Sul, Av. Bento Gonçalves 9090, CEP, 91540-000 Porto Alegre, RS, Brazil.
authors.forename: M C
authors.initials: MC
authors.lastname: Stein
authors.affiliation: Laboratory of Veterinary Epidemiology, Faculty of Veterinary, Federal University of Rio Grande do Sul (UFRGS), Av. Bento Gonçalves 9090, CEP, 91540-000 Porto Alegre, RS, Brazil.
authors.forename: H E
authors.initials: HE
authors.lastname: Hein
authors.affiliation: Laboratory of Veterinary Epidemiology, Faculty of Veterinary, Federal University of Rio Grande do Sul (UFRGS), Av. Bento Gonçalves 9090, CEP, 91540-000 Porto Alegre, RS, Brazil.
authors.forename: A S
authors.initials: AS
authors.lastname: Poeta
authors.affiliation: Secretary of Agriculture, Livestock and Agribusiness of State of Rio Grande do Sul (SEAPA-RS), Av. Getúlio Vargas 1384, CEP, 95150-900, Porto Alegre, RS, Brazil.
authors.forename: A C M
authors.initials: AC
authors.lastname: Vidor
authors.affiliation: Laboratory of Veterinary Epidemiology, Faculty of Veterinary, Federal University of Rio Grande do Sul (UFRGS), Av. Bento Gonçalves 9090, CEP, 91540-000 Porto Alegre, RS, Brazil. Electronic address: luis.corbellini@ufrgs.br.
authors.forename: L G
authors.initials: LG
authors.lastname: Corbellini
mesh_terms: D000818:Animals; D001938:Brazil / Q000453:epidemiology; D042061:Brucella ovis / Q000302:isolation & purification*; D002006:Brucellosis / Q000453:epidemiology* / Q000382:microbiology; D003430:Cross-Sectional Studies; D008297:Male; D015995:Prevalence; D012307:Risk Factors; D016036:Seroepidemiologic Studies; D012756:Sheep; D012757:Sheep Diseases / Q000453:epidemiology* / Q000382:microbiology; D034561:Sheep, Domestic
keywords: Epididymitis; Lambing paddocks; Prevalence; Risk factor; Sheep