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EQUINE INFLUENZA, CANINES - USA (FLORIDA) ***************************************** |
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A ProMED-mail post <http://www.promedmail.org> ProMED-mail, a program of the International Society for Infectious Diseases <http://www.isid.org> Date: 1 Jun 2004 From: ProMED-mail <[email protected]> Source: DVM Magazine [edited] <http://www.dvmnewsmagazine.com/dvm/article/articleDetail.jsp?id=99227> UF researchers link equine influenza virus to canine susceptibility ------------------------------------------------ For the 1st time, University of Florida (UF) veterinary researchers believe they have documented cases of equine influenza virus jumping the species barrier into dogs. The virus is the likely cause of a respiratory disease outbreak that killed 8 racing Greyhounds from kennels in Jacksonville. Although the outbreak has been isolated and quashed, any time a virus jumps species it is considered an important epidemiological event, the university reports. Although researchers stress the findings involve only these particular Jacksonville dogs, they will investigate possible connections to similar disease outbreaks that have affected racing dogs in Florida and elsewhere in recent years. Cynda Crawford, DVM, Ph.D., a UF veterinary immunologist, explains, "I want to stress that our team's findings are preliminary and confined to the dogs affected by an outbreak at one Florida track, an outbreak that occurred 3 months ago and was contained through a voluntary statewide quarantine, which is no longer in effect." UF's research team also worked with Cornell University's College of Veterinary Medicine in Ithaca, N.Y., and the Centers for Disease Control and Prevention (CDC). Ed Dubovi, director of virology section at Cornell's Animal Health Diagnostic Lab isolated the virus. CDC was brought in to assess the public health threat and monitor the outbreak. "The virus found in the canine samples is probably representative of the strain that is circulating now in horses in Florida and elsewhere in the United States," says Ruben Donis, Ph.D. with CDC. On the basis of genetic sequencing, Donis and colleagues at the Influenza Branch conclude the virus found in canine samples resembled a strain of equine influenza virus that appeared in horses in Wisconsin during 2003. The researchers also found that the dogs developed antibodies specific for the influenza virus. "This implies that the virus replicated enough within the dogs for their immune system to recognize it and form antibodies," Crawford says. Equine influenza is a disease of horses and is present in North America, Europe and parts of Asia. Horses typically develop a fever and a dry, hacking cough. In the early stages of the disease, horses are reluctant to eat or drink for several days, but usually recover in 2-3 weeks. Crawford adds that she is unsure how the Jacksonville Greyhounds could have been exposed to equine influenza virus, and that is one of many questions they intend to pursue through further epidemiological studies. When Crawford learned about the January outbreak, she visited the Jacksonville track to find 24 dogs affected with symptoms including cough, fever and other more serious symptoms. Out of the total, 8 dogs died and 16 recovered. Crawford reports she collected blood and nasal fluid samples from 35 dogs, and 5 of the dogs that died underwent postmortem examinations. The team also alerted dog owners not to experiment with prevention products approved for other species because of the potential for adverse reactions, including death. [Details of the story provided by Sarah Carey, University of Florida.] -- ProMED-mail <[email protected]> [Equine influenza virus 1 (H7N7) was isolated in Europe in 1956 and subsequently in the USA. Then a second equine influenza virus (H3N8) was isolated in 1963 in the USA and subsequently elsewhere in the world. Equine influenza virus 2 (H3N8) has been responsible for the majority of recent outbreaks and sequencing studies indicate that equine influenza virus 2 virus has undergone only slight genetic drift since first isolation. No influenza virus has been designated as specific to canines so far. In 1989 a severe outbreak of influenza A virus infection in horses in northeastern China was caused by a virus withe the same antigenicity as the prevalent equine influenza virus. However, it appeared to be a reassortant as its other genes were of avian origin. It will be important to establish whether the virus recovered from the affected greyhounds is an equine virus that has simply jumped species, or whether it is a reassortant virus that has acquired genes from another source. This information will be important in accessing the potential of this canine virus for transmission to humans. - Mod.CP] [see also: Undiagnosed illness, canine - USA (FL)(02) 20040730.2081 Undiagnosed illness, canine - USA (FL) 20040701.1753] .........................tg/pg/cp/lm *##########################################################* ProMED-mail makes every effort to verify the reports that are posted, but the accuracy and completeness of the information, and of any statements or opinions based thereon, are not guaranteed. The reader assumes all risks in using information posted or archived by ProMED-mail. ISID and its associated service providers shall not be held responsible for errors or omissions or held liable for any damages incurred as a result of use or reliance upon posted or archived material. ************************************************************ Visit ProMED-mail's web site at <http://www.promedmail.org>. 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