title: Prevalence of antibodies against influenza virus in non-vaccinated equines from the Brazilian Pantanal.
abstract: The prevalence of antibodies against Equine Influenza Virus (EIV) was determined in 529 equines living on ranches in the municipality of Poconé, Pantanal area of Brazil, by means of the hemagglutination inhibition test, using subtype H3N8 as antigen. The distribution and possible association among positive animal and ranches were evaluated by the chi-square test, spatial autoregressive and multiple linear regression models. The prevalence of antibodies against EIV was estimated at 45.2% (95% CI 30.2 - 61.1%) with titers ranging from 20 to 1,280 HAU. Seropositive equines were found on 92.0% of the surveyed ranches. Equine from non-flooded ranches (66.5%) and negativity in equine infectious anemia virus (EIAV) (61.7%) were associated with antibodies against EIV. No spatial correlation was found among the ranches, but the ones located in non-flooded areas were associated with antibodies against EIV. A negative correlation was found between the prevalence of antibodies against EIV and the presence of EIAV positive animals on the ranches. The high prevalence of antibodies against EIV detected in this study suggests that the virus is circulating among the animals, and this statistical analysis indicates that the movement and aggregation of animals are factors associated to the transmission of the virus in the region.
authors.affiliation: Programa de Pós-graduação em Ciências Veterinárias, Universidade Federal de Mato Grosso, Cuiabá, MT, Brazil.
authors.forename: Lucas
authors.initials: L
authors.lastname: Gaíva e Silva
authors.affiliation: Programa de Pós-graduação em Ciências Veterinárias, Universidade Federal de Mato Grosso, Cuiabá, MT, Brazil.
authors.forename: Alice Mamede Costa Marques
authors.initials: AM
authors.lastname: Borges
authors.affiliation: Laboratório de Raiva e Encefalites Virais, Instituto Biológico, São Paulo, SP, Brazil.
authors.forename: Eliana Monteforte Cassaro
authors.initials: EM
authors.lastname: Villalobos
authors.affiliation: Laboratório de Raiva e Encefalites Virais, Instituto Biológico, São Paulo, SP, Brazil.
authors.forename: Maria do Carmo Custodio Souza Hunold
authors.initials: Mdo C
authors.lastname: Lara
authors.affiliation: Laboratório de Raiva e Encefalites Virais, Instituto Biológico, São Paulo, SP, Brazil.
authors.forename: Elenice Maria Siquetin
authors.initials: EM
authors.lastname: Cunha
authors.affiliation: Departamento de Estatística, Universidade Federal de Mato Grosso, Cuiabá, MT, Brazil.
authors.forename: Anderson Castro Soares
authors.initials: AC
authors.lastname: de Oliveira
authors.affiliation: Programa de Pós-graduação em Ciências Veterinárias, Universidade Federal de Mato Grosso, Cuiabá, MT, Brazil.
authors.forename: Isis Assis
authors.initials: IA
authors.lastname: Braga
authors.affiliation: Programa de Pós-graduação em Ciências Veterinárias, Universidade Federal de Mato Grosso, Cuiabá, MT, Brazil.
authors.forename: Daniel Moura
authors.initials: DM
authors.lastname: Aguiar
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D001938:Brazil / Q000453:epidemiology; D005260:Female; D006385:Hemagglutination Inhibition Tests / Q000662:veterinary; D006734:Horse Diseases / Q000175:diagnosis / Q000453:epidemiology*; D006736:Horses; D053123:Influenza A Virus, H3N8 Subtype / Q000276:immunology*; D008297:Male; D009976:Orthomyxoviridae Infections / Q000175:diagnosis / Q000453:epidemiology / Q000662:veterinary*; D011159:Population Surveillance; D015995:Prevalence
chemical_list: D000914:Antibodies, Viral