title: Surveillance of equine respiratory viruses in Ontario.
abstract: The objective of this project was to develop and implement an active surveillance program for the early and rapid detection of equine influenza viruses in Ontario. For this purpose, from October 2003 to October 2005, nasopharyngeal swabs and acute and convalescent serum samples were collected from 115 client-owned horses in 23 outbreaks of respiratory disease in Ontario. Sera were paired and tested for antibody to equine influenza 1 (AE1-H7N7), equine influenza 2 (AE2-H3N8), equine herpesvirus 1 and 4 (EHV1 and EHV4), and equine rhinitis A and B (ERAV and ERBV). Overall, the cause-specific morbidity rate of equine influenza virus in the respiratory outbreaks was 56.5% as determined by the single radial hemolysis (SRH) test. The AE2-H3N8 was isolated from 15 horses in 5 outbreaks. A 4-fold increase in antibody levels or the presence of a high titer against ERAV or ERBV was observed in 10 out of 13 outbreaks in which AE2-H3N8 was diagnosed as the primary cause of disease. In conclusion, AE2-H3N8 was found to be an important contributor to equine respiratory viral disease. Equine rhinitis A and B (ERAV and ERBV) represented an important component in the equine respiratory disease of performing horses.
authors.affiliation: Department of Clinical Studies, University of Guelph, Ontario, Canada.
authors.forename: Andrés
authors.initials: A
authors.lastname: Diaz-Mendez
authors.forename: Laurent
authors.initials: L
authors.lastname: Viel
authors.forename: Joanne
authors.initials: J
authors.lastname: Hewson
authors.forename: Paul
authors.initials: P
authors.lastname: Doig
authors.forename: Susy
authors.initials: S
authors.lastname: Carman
authors.forename: Thomas
authors.initials: T
authors.lastname: Chambers
authors.forename: Ashish
authors.initials: A
authors.lastname: Tiwari
authors.forename: Catherine
authors.initials: C
authors.lastname: Dewey
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D016009:Chi-Square Distribution; D004196:Disease Outbreaks / Q000662:veterinary*; D004861:Herpesvirus 1, Equid / Q000235:genetics / Q000302:isolation & purification; D023141:Herpesvirus 4, Equid / Q000235:genetics / Q000302:isolation & purification; D006734:Horse Diseases / Q000453:epidemiology* / Q000821:virology*; D006736:Horses; D053123:Influenza A Virus, H3N8 Subtype / Q000235:genetics / Q000302:isolation & purification; D053126:Influenza A Virus, H7N7 Subtype / Q000235:genetics / Q000302:isolation & purification; D009864:Ontario / Q000453:epidemiology; D010802:Phylogeny; D012367:RNA, Viral / Q000737:chemistry / Q000235:genetics; D012141:Respiratory Tract Infections / Q000453:epidemiology / Q000662:veterinary* / Q000821:virology; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D012229:Rhinovirus / Q000235:genetics / Q000302:isolation & purification; D017422:Sequence Analysis, DNA; D012703:Serotyping / Q000662:veterinary
chemical_list: D000914:Antibodies, Viral; D012367:RNA, Viral