title: Persistence of serum antibodies to Sarcocystis neurona in horses moved from North America to India.
abstract: BACKGROUND
  The study reported here was undertaken to assess the presence of antibodies to Sarcocystis neurona in the serum of horses of North American origin that had been relocated for 1 year or more to India (ie, outside of the known endemic areas for S. neurona).
  
  
  OBJECTIVE
  The presence or absence of such antibodies should provide information concerning the persistence of such antibodies, or support the presence of chronic infection, or both.
  
  
  METHODS
  A total of 228 Thoroughbred horses were sampled in India, of which 86 were of North American origin that had been in India between 1 and 13 years, 124 were Indian-born horses that had never been out of India, 8 were of Irish origin, 8 were of English origin, and 2 were originally from France.
  
  
  METHODS
  Sera were tested using established western blot analysis.
  
  
  RESULTS
  Of the Indian-born horses, 0.8% were test positive, and of the North American horses, 42% were test positive. All of the English and Irish horses were test negative, and the 2 French horses were test positive.
  
  
  CONCLUSIONS
  These data indicate that antibodies against S. neurona can be detected for many years after horses have been removed from an endemic area and that this may be attributable to long half-life of the antibodies or to chronic infection and ongoing antibody production, or both.
authors.affiliation: Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Canada. cmbrown@uoguelph.ca
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Brown
authors.forename: Jennifer K
authors.initials: JK
authors.lastname: Morrow
authors.forename: Carla L
authors.initials: CL
authors.lastname: Carleton
authors.forename: Balachandran
authors.initials: B
authors.lastname: Ramanathan
authors.forename: Ravinder
authors.initials: R
authors.lastname: Reddy
authors.forename: Vijay
authors.initials: V
authors.lastname: Vaidya
authors.forename: Salem M
authors.initials: SM
authors.lastname: Karthikeyan
authors.forename: Ali A
authors.initials: AA
authors.lastname: Zulfikar
authors.forename: Vasant S
authors.initials: VS
authors.lastname: Kannadkar
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood*; D005060:Europe / Q000453:epidemiology; D006734:Horse Diseases / Q000453:epidemiology*; D006736:Horses; D007194:India / Q000453:epidemiology; D009656:North America / Q000453:epidemiology; D012522:Sarcocystis / Q000276:immunology*; D012523:Sarcocystosis / Q000453:epidemiology / Q000662:veterinary*; D013997:Time Factors; D014186:Transportation
chemical_list: D000913:Antibodies, Protozoan