title: Equine encephalomyelitis outbreak caused by a genetic lineage 2 West Nile virus in Hungary.
abstract: BACKGROUND
  The spread of lineage 2 West Nile virus (WNV) from sub-Saharan regions to Europe and the unpredictable change in pathogenicity indicate a potential public and veterinary health threat and requires scientific awareness.
  
  
  OBJECTIVE
  To describe the results of clinical and virological investigations of the 1st outbreak of a genetic lineage 2 WNV encephalomyelitis in horses.
  
  
  METHODS
  Seventeen horses with neurologic signs.
  
  
  METHODS
  Information regarding signalment, clinical signs, and outcome was obtained for each animal. Serology was performed in 15 cases, clinicopathological examination in 7 cases, and cerebrospinal fluid was collected from 2 horses. Histopathology was carried out in 4 horses, 2 of which were assessed for the presence of WNV in their nervous system.
  
  
  RESULTS
  WNV neutralizing antibody titers were between 10 and 270 (median, 90) and the results of other serological assays were in agreement with those of the plaque reduction neutralization test. Common signs included ataxia, weakness, asymmetric gait, muscle tremors, hypersensitivity, cranial nerve deficits, and recumbency. Twelve animals survived. Amplicons derived from the infection-positive specimens allowed molecular characterization of the viral strain.
  
  
  CONCLUSIONS
  From our results, we conclude that this outbreak was caused by a lineage 2 WNV strain, even though such strains often are considered nonpathogenic. Neurological signs and survival rates were similar to those reported for lineage 1 virus infections. The disease occurrence was not geographically limited as had been the typical case during European outbreaks; this report describes a substantial northwestern spread of the pathogen.
authors: Large Animal Clinic, Faculty of Veterinary Science, Szent Istvan University, Ullo, Hungary. kutasi.orsolya@aotk.szie.hu
authors: O
authors: O
authors: Kutasi
authors: T
authors: T
authors: Bakonyi
authors: S
authors: S
authors: Lecollinet
authors: I
authors: I
authors: Biksi
authors: E
authors: E
authors: Ferenczi
authors: C
authors: C
authors: Bahuon
authors: S
authors: S
authors: Sardi
authors: S
authors: S
authors: Zientara
authors: O
authors: O
authors: Szenci
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D004196:Disease Outbreaks / Q000662:veterinary*; D005260:Female; D006734:Horse Diseases / Q000097:blood / Q000453:epidemiology / Q000821:virology*; D006736:Horses; D006814:Hungary / Q000453:epidemiology; D007075:Immunoglobulin M / Q000097:blood; D008297:Male; D010802:Phylogeny; D014901:West Nile Fever / Q000097:blood / Q000453:epidemiology / Q000662:veterinary* / Q000821:virology; D014902:West Nile virus / Q000235:genetics* / Q000276:immunology / Q000302:isolation & purification
chemical_list: D000914:Antibodies, Viral; D007075:Immunoglobulin M