Equine herpesvirus 1

Taxobox
virus_group = I
familia = "Herpesviridae"
genus = "Varicellovirus"
species = "Equine herpesvirus 1" (EHV-1)

"Equine herpesvirus 1" (EHV-1) is a virus of the family "Herpesviridae" that causes abortion in horses. Initial spread of EHV-1 by a newly introduced horse through direct and indirect contact can lead to abortion and perinatal infection in up to 70 percent of a previously unexposed herd.cite book|author=Fenner, Frank J.; Gibbs, E. Paul J.; Murphy, Frederick A.; Rott, Rudolph; Studdert, Michael J.; White, David O.|title=Veterinary Virology (2nd ed.)|publisher=Academic Press, Inc|year=1993|id=ISBN 0-12-253056-X] Abortion usually occurs in the last four months of gestation, two to four weeks after infection of the mare.cite web|author=Carter, G.R.; Flores, E.F.; Wise, D.J.|year=2006|title=Herpesviridae|work=A Concise Review of Veterinary Virology| url=http://www.ivis.org/advances/Carter/Part2Chap11/chapter.asp?LA=1|accessdate=2006-06-08] Perinatal (around the time of birth) infection can lead to pneumonia and death. Encephalitis can occur in affected animals, leading to ataxia, paralysis, and death. There is a vaccine available, however it’s efficacy is questionable.

Recent molecular epidemiology studies have identified a single nucleotide polymorphism (SNP) which varies between EHV-1 field isolates and shows a highly statistically significant correlation with paralytic compared with non-paralytic disease outbreaks [cite web|url=http://jvi.asm.org/cgi/content/abstract/80/8/4047|author=Nugent J, Birch-Machin I, Smith K, Mumford J, Swann Z, Newton J, Bowden R, Allen G & Davis-Poynter N |title=Analysis of Equid Herpesvirus 1 Strain Variation Reveals a Point Mutation of the DNA Polymerase Strongly Associated with Neuropathogenic versus Nonneuropathogenic Disease Outbreaks|publisher= Journal of Virology|accessdate=2007-02-02] . The SNP corresponds to a single amino acid change in the DNA polymerase enzyme, which is an essential enzyme for replication of viral DNA. This is a significant finding, suggesting that a point mutation in a single virus gene has a major impact upon likely disease severity during an outbreak.

In 2006, an outbreak of EHV-1 among stables in Florida resulted in the institution of various quarantine measures. [cite web|url=http://www.doacs.state.fl.us/ai/Announcements/EquineVirus1StatusReport.shtml|title=Equine Herpes Virus type1 Status Report – Florida|publisher=Florida Department of Agriculture and Consumer Services|accessdate=2007-01-05] The outbreak was determined to have originated with several horses imported from Europe via New York, and then shipped to Florida. [cite web|url=http://www.doacs.state.fl.us/ai/ehv1/outbreak_background.shtml|title=EHV-1, Outbreak Background|publisher=Florida Department of Agriculture and Consumer Services|accessdate=2007-01-05]

References