title: Serological dynamics and risk factors of Besnoitia besnoiti infection in breeding bulls from an endemically infected purebred beef herd.
abstract: Bovine besnoitiosis has been deemed a re-emerging disease in Western Europe and considered endemic in Spain, Portugal, France and in some areas of Northern Italy. This report refers to an infection outbreak in a purebred beef herd from Northern Italy involving a large number of bulls. In October 2013, 544 animals were serologically tested with an in-house ELISA followed by a confirmatory Western blot to evaluate Besnoitia besnoiti seroprevalence. A year later, 461 animals were then serologically re-tested together with imported animals (n = 268). Overall, 812 animals were involved in the study. Histology and immunohistochemistry were performed on skin biopsies of suspected animals and several tissue samples from a slaughtered bull. In the first sampling, 100 animals were seropositive (18.4%); in the second sampling, prevalence increased up to 36.5%, with incidence calculated at 39.6%. The risk factor analysis revealed that the infection was associated with age (OR = 1.007) and sex, with males presenting a greater risk (OR = 2.006). In fact, prevalence values in bulls increased from 29.6 to 56.7%, with an incidence of infection of 53.3%. Moreover, mating with a seropositive bull enhanced infection risk for a seronegative cow (OR = 1.678). Clinical signs typical of bovine besnoitiosis were found in seven seropositive animals, with confirmation of B. besnoiti through histology and immunohistochemistry. The study outcomes confirm that bovine besnoitiosis is a disease with serious economic impact on beef cattle breeding, particularly on bulls in service. Good management practises such as clinical monitoring and serological testing of imported animals should be implemented to control its occurrence.
authors.affiliation: Department of Veterinary Medicine, Università degli Studi di Milano, Via Celoria 10, 20133, Milan, Italy. alessia.gazzonis@unimi.it.
authors.forename: Alessia Libera
authors.identifier: http://orcid.org/0000-0003-4293-0719
authors.initials: AL
authors.lastname: Gazzonis
authors.affiliation: SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain.
authors.forename: Gema
authors.initials: G
authors.lastname: Alvarez Garcia
authors.affiliation: Department of Veterinary Medicine, Università degli Studi di Milano, Via Celoria 10, 20133, Milan, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Maggioni
authors.affiliation: Department of Veterinary Medicine, Università degli Studi di Milano, Via Celoria 10, 20133, Milan, Italy.
authors.forename: Sergio Aurelio
authors.initials: SA
authors.lastname: Zanzani
authors.affiliation: Department of Veterinary Medicine, University of Perugia, Via S. Costanzo 4, 06126, Perugia, Italy.
authors.forename: Emanuela
authors.initials: E
authors.lastname: Olivieri
authors.affiliation: Department of Veterinary Medicine, Università degli Studi di Milano, Via Celoria 10, 20133, Milan, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Compiani
authors.affiliation: Department of Veterinary Medicine, Università degli Studi di Milano, Via Celoria 10, 20133, Milan, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Sironi
authors.affiliation: SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain.
authors.forename: Luis Miguel
authors.initials: LM
authors.lastname: Ortega Mora
authors.affiliation: Department of Veterinary Medicine, Università degli Studi di Milano, Via Celoria 10, 20133, Milan, Italy.
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Manfredi
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology / Q000469:parasitology*; D003048:Coccidiosis / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*; D004196:Disease Outbreaks; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005260:Female; D007558:Italy / Q000453:epidemiology; D008297:Male; D012307:Risk Factors; D021745:Sarcocystidae / Q000145:classification*; D016036:Seroepidemiologic Studies; D012698:Serologic Tests; D013030:Spain / Q000453:epidemiology
keywords: Beef cattle; Besnoitia besnoiti; Bulls; Immunohistochemistry; Risk factors; Western blot