title: Influenza viruses in adult dogs raised in rural and urban areas in the state of São Paulo, Brazil.
abstract: In 1970, searching for the interspecies transmission of influenza viruses led to the first study on influenza viruses in domestic animals. Birds and mammals, including human beings, are their natural hosts; however, other animals may also play a role in the virus epidemiology. The objective was to investigate the incidence of influenza viruses in adult dogs raised in rural (9, 19.56%) and urban (37, 80.43%) areas in the state of São Paulo, Brazil. Dog serum samples were examined for antibodies to influenza viruses by the hemagglutination inhibition (HI) test using the corresponding antigens from the circulating viruses in Brazil. Dogs from rural areas presented antibodies to influenza A H3N2, and influenza A H7N7 and H3N8. In rural areas, dog sera displayed mean titers as 94.37, 227.88, 168.14, 189.62 HIU/25 µL for subtypes H1N1, H3N2, H7N7, H3N8, respectively. About 84% and 92% of dogs from urban areas exhibited antibodies to human influenza A H1N1 and H3N2, respectively, with statistical difference at p < 0.05 between the mean titers of antibodies to H1N1 and H3N2. About 92% and 100% were positive for H7N7 and H3N8, respectively. In dogs from urban areas, the mean titers of antibodies against influenza A H1N1, H3N2, H7N7 and H3N8, were 213.96, 179.42, 231.76, 231.35 HIU/25 µL respectively. The difference among them was not statistically significant at p > 0.05. In conclusion, these dogs were positive for both human and equine influenza viruses. The present study suggests the first evidence that influenza viruses circulate among dogs in Brazil.
authors.affiliation: Laboratório de Virologia, Divisão de Desenvolvimento Científico, Instituto Butantan, São Paulo, SP, Brazil. dapmancini@butantan.gov.br
authors.forename: Dalva Assunção Portari
authors.initials: DA
authors.lastname: Mancini
authors.forename: Rita Maria Zucatelli
authors.initials: RM
authors.lastname: Mendonça
authors.forename: Aparecida Santo Pietro
authors.initials: AS
authors.lastname: Pereira
authors.forename: Adélia Hiroko Nagamori
authors.initials: AH
authors.lastname: Kawamoto
authors.forename: Camila Infantosi
authors.initials: CI
authors.lastname: Vannucchi
authors.forename: José Ricardo
authors.initials: JR
authors.lastname: Pinto
authors.forename: Enio
authors.initials: E
authors.lastname: Mori
authors.forename: Jorge
authors.initials: J
authors.lastname: Mancini Filho
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D001938:Brazil; D004283:Dog Diseases / Q000175:diagnosis / Q000821:virology*; D004285:Dogs; D004797:Enzyme-Linked Immunosorbent Assay; D006385:Hemagglutination Inhibition Tests; D015994:Incidence; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology; D053122:Influenza A Virus, H3N2 Subtype / Q000276:immunology; D053123:Influenza A Virus, H3N8 Subtype / Q000276:immunology; D053126:Influenza A Virus, H7N7 Subtype / Q000276:immunology; D009975:Orthomyxoviridae / Q000145:classification / Q000276:immunology*; D009976:Orthomyxoviridae Infections / Q000175:diagnosis / Q000662:veterinary*; D012424:Rural Population; D014505:Urban Population
chemical_list: D000914:Antibodies, Viral