title: Clinical problems due to encephalomyocarditis virus infections in two pig herds.
abstract: BACKGROUND
  Infections with encephalomyocarditis virus may cause myocarditis and sudden death in young pigs and reproduction disorders in sows. The presence of encephalomyocarditis virus infected rodents is considered a major risk factor for transmission of the virus to pigs. There is currently no effective treatment. Tightening up biosecurity, applying effective rodent control and reducing stress are the main control measures.
  
  
  METHODS
  Two farrow-to-finish herds suffering from problems with sudden death are presented. In herd A, suckling piglets from 3 to 12 days old were dying acutely whereas in herd B, piglets at the end of the nursery period (8-10 weeks) were showing identical problems. A presumptive diagnosis of encephalomyocarditis virus infection was made because typical lesions were observed in some of the affected pigs. These lesions were not always present in pigs dying acutely or in some cases the lesions were very subtle. Therefore other causes had to be ruled out based upon clinical history, clinical signs and diagnostic tests. A conclusive diagnosis was finally established by showing encephalomyocarditis virus in heart tissue using conventional gel-based polymerase chain reaction tests. The real-time PCR test that gave initially negative result was further optimized to avoid false negative results.
  
  
  CONCLUSIONS
  Typical lesions are not always present in piglets infected with encephalomyocarditis virus, indicating the importance of examining multiple animals. Problems in suckling piglets may occur in affected herds without reproductive problems in sows. Transmission routes of EMCV in swine are not fully understood. A stand-empty period following thorough cleaning and disinfection is recommended for controlling EMC virus infections.
authors.affiliation: Department of Reproduction, Obstetrics and Herd Health, Ghent University, Ghent, Belgium.
authors.forename: Klaas
authors.initials: K
authors.lastname: Vansteenkiste
authors.affiliation: Department of Reproduction, Obstetrics and Herd Health, Ghent University, Ghent, Belgium.
authors.forename: Tommy
authors.initials: T
authors.lastname: Van Limbergen
authors.affiliation: Department of Reproduction, Obstetrics and Herd Health, Ghent University, Ghent, Belgium.
authors.forename: Ruben
authors.initials: R
authors.lastname: Decaluwé
authors.affiliation: Veterinary and Agrochemical Research Centre, Machelen, Belgium.
authors.forename: Marylène
authors.initials: M
authors.lastname: Tignon
authors.affiliation: Veterinary and Agrochemical Research Centre, Machelen, Belgium.
authors.forename: Brigitte
authors.initials: B
authors.lastname: Cay
authors.affiliation: Department of Reproduction, Obstetrics and Herd Health, Ghent University, Ghent, Belgium.
authors.forename: Dominiek
authors.initials: D
authors.lastname: Maes
keywords: Case report; EMCV; Encephalomyocarditis virus; Suckling and nursery pigs; Sudden death