title: Porcine circovirus type 2 (PCV-2) coinfections in US field cases of postweaning multisystemic wasting syndrome (PMWS).
abstract: The prevalence of different pathogens detected in combination with porcine circovirus type 2 (PCV-2) was studied retrospectively in field cases of postweaning multisystemic wasting syndrome (PMWS) diagnosed at the Iowa State University Veterinary Diagnostic Laboratory, Ames, Iowa, between January 2000, and September 2001. The presence of PCV-2 antigen in lymphoid tissues and/or lung, demonstrated by immunohistochemistry, together with moderate to severe lymphoid depletion and/or granulomatous lymphadenitis, was used as the criteria for the diagnosis of PMWS. A total of 484 cases fulfilled these criteria. Most of the cases (294/369) of PMWS occurred in pigs between the ages of 8 and 18 weeks, with a peak at 10 weeks of age. Porcine reproductive and respiratory syndrome virus was detected in 51.9% of the cases, Mycoplasma hyopneumoniae in 35.5%, bacterial septicemia in 14.0%, bacterial pneumonia in 7.6%, swine influenza virus in 5.4%, and PCV-2 alone in 1.9%. In cases with bacterial septicemia the most frequently isolated pathogen was Streptococcus suis. In cases with bacterial pneumonia, Pasteurella multocida was the most prevalent.
authors.affiliation: Veterinary Diagnostic Laboratory, College of Veterinary Medicine, Iowa State University, Ames 50011, USA.
authors.forename: F J
authors.initials: FJ
authors.lastname: Pallarés
authors.forename: P G
authors.initials: PG
authors.lastname: Halbur
authors.forename: T
authors.initials: T
authors.lastname: Opriessnig
authors.forename: S D
authors.initials: SD
authors.lastname: Sorden
authors.forename: D
authors.initials: D
authors.lastname: Villar
authors.forename: B H
authors.initials: BH
authors.lastname: Janke
authors.forename: M J
authors.initials: MJ
authors.lastname: Yaeger
authors.forename: D J
authors.initials: DJ
authors.lastname: Larson
authors.forename: K J
authors.initials: KJ
authors.lastname: Schwartz
authors.forename: K J
authors.initials: KJ
authors.lastname: Yoon
authors.forename: L J
authors.initials: LJ
authors.lastname: Hoffman
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000956:Antigens, Viral / Q000032:analysis; D018173:Circoviridae Infections / Q000150:complications / Q000662:veterinary*; D017925:Circovirus / Q000302:isolation & purification / Q000472:pathogenicity*; D015897:Comorbidity; D009175:Mycoplasma Infections / Q000150:complications / Q000662:veterinary; D010326:Pasteurella Infections / Q000150:complications / Q000662:veterinary; D016979:Pasteurella multocida / Q000472:pathogenicity; D019318:Porcine Reproductive and Respiratory Syndrome / Q000473:pathology; D012189:Retrospective Studies; D018805:Sepsis / Q000150:complications / Q000662:veterinary; D013552:Swine; D013553:Swine Diseases / Q000473:pathology / Q000821:virology*; D019282:Wasting Syndrome / Q000662:veterinary* / Q000821:virology; D014886:Weaning
chemical_list: D000956:Antigens, Viral