This lack of sensitivity could have been influenced by either insufficient viral protein in the samples or the presence of antigen-antibody complexes that would prevent a positive reaction from developing within the test. was 56.5% as determined by the sole radial hemolysis (SRH) test. The AE2-H3N8 was isolated from 15 horses in 5 outbreaks. A 4-collapse 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) displayed an important component in LAMA4 antibody the equine respiratory disease of carrying out horses. Rsum Lobjectif du prsent projet tait de dvelopper et mettre en place un programme de monitoring active pour la dtection hative et rapide des disease de linfluenza quin en Ontario. cette fin, durant la priode allant de octobre 2003 octobre 2005, des couvillons naso-pharyngs et des chantillons de srum prlevs en phase aigu? et de convalescence ont t pris chez 115 chevaux de clients lors de 23 pisodes de VU0152100 maladies respiratoires en Ontario. Les srums ont t pairs et checks pour la prsence danticorps contre linfluenza quin de type 1 (AE1-H7N7), linfluenza quin de type 2 (AE2-H3N8), les herps disease quins de type 1 et 4 (EHV1 et EHV4), VU0152100 et les disease de la rhinite quine A et B (ERAV et ERBV). De manire globale, le taux de morbidit spcifique associ au disease de linfluenza quin dans les pousses de cas de maladies respiratoires tait VU0152100 de 56,5 % tel que dtermin par lpreuve dhmolyse radiale simple (SRH). Le disease AE2-H3N8 a t isol de 15 chevaux dans 5 pisodes. Une augmentation dun facteur de 4 des titres danticorps ou la prsence dun titre danticorps lev envers ERAV ou ERBV a t observe dans 10 des 13 pisodes lors desquels le disease AE2-H3N8 a t identifi comme la cause premire de la maladie. En summary, le disease AE2-H3N8 a t identifi comme tant un contributeur important des maladies respiratoires quines. Les disease de la rhinite quine A et B (ERAV et ERBV) pourrait galement reprsent une composante importante des maladies respiratoires quines chez les chevaux de overall performance. (Traduit par Docteur Serge Messier) Intro Equine influenza A disease is considered probably one of the most common viruses affecting the respiratory tract of young horses worldwide (1,2). The equine influenza A disease was first isolated in 1956 during an equine respiratory outbreak in Eastern Europe and was characterized as AE1-H7N7 (3). The AE1-H7N7 subtype has not been isolated since 1979. In 1963, the AE2-H3N8 subtype was recognized during an outbreak of equine influenza in Miami, Florida, USA (4). The AE2-H3N8 disease soon spread throughout America and Europe and has been the cause of many respiratory outbreaks in the last 25 y (5C7). In 1986, the AE2-H3N8 disease was introduced into a na?ve equine population in South Africa and subsequently had a negative effect on the racing industry (8). More recently, this disease has been launched into Australia (9) with major consequences inside a vulnerable human population. Since 1990, variations in the VU0152100 viral ribonucleic acid (RNA) and antigenic epitopes have been identified (10). At that time, 2 varied lineages were identified: the Western and the American lineages (11). The influenza disease affects specifically the respiratory tract, diminishing the overall performance potential of the animal and raising the risk of secondary bacterial complications (7,12). As a result, this viral respiratory illness is a danger to the equine human population due to the loss of teaching days and the high risk of severe epidemics (7). Influenza disease infection has traditionally been diagnosed through disease isolation and/or serology [hemagglutinin inhibition (HI)]. However, the solitary radial hemolysis (SRH) test has been introduced as a technique with more accurate quantitative titers for determining safety in vaccinated horses (13). The SRH test is based on the passive hemolysis of virus-sensitized sheep erythrocytes from the anti-hemagglutinin antibodies in the test serum. The hemolysis observed has been shown to be directly proportional to the amount of strain-specific antibody in the serum becoming tested (11). An increase of 25 mm2 or a doubling of the hemolysis area is considered to be a significant increase. An international monitoring system for equine influenza has been established in an attempt to increase the recognition of outbreaks and recognize fresh strains influencing the world horse human population. Canada has not actively been part of this system. This project was therefore founded to develop and implement an active surveillance VU0152100 system for the early and rapid detection of equine influenza viruses in Ontario. Materials and methods Study design The study was designed for.