title: Transmission paths of Neospora caninum in a dairy herd of crossbred cattle in the northeast of Brazil.
abstract: The aim of this study was to determine the transmission paths of Neospora caninum in a dairy herd of crossbred cattle. Two hundred and ninety animals were grouped according to the year of their birth to verify the distribution of infection according to age. The blood of 196 cattle was collected thrice, with an average interval of 210 days, to evaluate the existence of horizontal transmission in the herd. To evaluate vertical transmission, the blood of 64 calves was collected prior to ingestion of colostrum and from their mothers at parturition. Moreover, 63 family trees were built. The presence of anti-N. caninum antibodies was detected using an indirect fluorescent antibody test. The chi-square test (χ(2)) with Yates' correction or Fisher's exact test was used to evaluate the relation between the serology and age groups and between the serostatus of cows and their progeny in different calvings. A higher seropositivity (p=0.035) was found in animals born in 2008 compared to those born in 1997-2007. The serological status of only 13 animals presented changes, of which six (3.1%) became seropositive, indicating a low proportion of horizontal transmission. All seropositive cows gave birth to seropositive calves, resulting in 100% vertical transmission. Sixty-three family trees were constructed. In 29 (46%) of these families, there were animals seropositive for N. caninum. Congenital infection in relation to the number of births was estimated from the relation of Mother+ and Daughter+, without significant differences (p=0.84) between the number of births and the transmission of the parasite from infected cows to their progeny. The low proportion of horizontal transmission combined with the high proportion of vertical transmission allowed us to conclude that transplacental transmission is the principal route of N. caninum infection in the herd.
authors.affiliation: Departamento de Ciências Agrárias e Ambientais, Universidade Estadual de Santa Cruz (UESC), Campus Soane Nazaré de Andrade Rodovia Ilhéus Itabuna, Km 16, Salobrinho, Ilhéus 45662-000, BA, Brazil.
authors.forename: Vanessa Carvalho Sampaio
authors.initials: VC
authors.lastname: de Magalhães
authors.affiliation: Faculdade de Ciências Sociais e Aplicadas (FACISA), Rodovia BR 101, 1130 Km 808, Santo Antônio Monte, Itamaraju 45836-000, BA, Brazil.
authors.forename: Uillians Volkart
authors.initials: UV
authors.lastname: de Oliveira
authors.affiliation: Departamento de Ciências Agrárias e Ambientais, Universidade Estadual de Santa Cruz (UESC), Campus Soane Nazaré de Andrade Rodovia Ilhéus Itabuna, Km 16, Salobrinho, Ilhéus 45662-000, BA, Brazil.
authors.forename: Sonia Carmen Lopo
authors.initials: SC
authors.lastname: Costa
authors.affiliation: Departamento de Ciências Agrárias e Ambientais, Universidade Estadual de Santa Cruz (UESC), Campus Soane Nazaré de Andrade Rodovia Ilhéus Itabuna, Km 16, Salobrinho, Ilhéus 45662-000, BA, Brazil.
authors.forename: Ivanildo dos Anjos
authors.initials: Idos A
authors.lastname: Santos
authors.affiliation: Departamento de Parasitologia Animal, IV, UFRRJ BR-465 Km 7 Seropédica, Rio de Janeiro, RJ, Brazil.
authors.forename: Maria Julia Salim
authors.initials: MJ
authors.lastname: Pereira
authors.affiliation: Departamento de Ciências Agrárias e Ambientais, Universidade Estadual de Santa Cruz (UESC), Campus Soane Nazaré de Andrade Rodovia Ilhéus Itabuna, Km 16, Salobrinho, Ilhéus 45662-000, BA, Brazil. Electronic address: munhoz@uesc.br.
authors.forename: Alexandre Dias
authors.initials: AD
authors.lastname: Munhoz
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D001938:Brazil; D002417:Cattle; D002418:Cattle Diseases / Q000635:transmission*; D003048:Coccidiosis / Q000635:transmission / Q000662:veterinary*; D004285:Dogs; D005260:Female; D018445:Infectious Disease Transmission, Vertical / Q000662:veterinary*; D008297:Male; D018688:Neospora / Q000502:physiology*; D011247:Pregnancy
chemical_list: D000913:Antibodies, Protozoan
keywords: Horizontal transmission; Longitudinal study; Neosporosis; Vertical transmission