title: Infectious risk factors for individual postweaning multisystemic wasting syndrome (PMWS) development in pigs from affected farms in Spain and Denmark.
abstract: Two prospective longitudinal studies in 13 postweaning multisystemic wasting syndrome (PMWS)-affected farms from Spain (n=3) and Denmark (n=10) were performed. Blood samples from pigs were longitudinally collected from 1st week until the occurrence of the PMWS outbreak. Wasted and healthy age-matched pigs were euthanized, necropsied and histopathologically characterised. PMWS diagnosis was confirmed by means of lymphoid lesions and detection of porcine circovirus type 2 (PCV2) in these tissues by in situ hybridization or immunohistochemistry. Serological analyses were performed in longitudinally collected serum samples to detect antibodies against, PCV2, porcine reproductive and respiratory syndrome virus (PRRSV), porcine parvovirus (PPV), swine influenza virus (SIV) and Lawsonia intracellularis (law), Mycoplasma hyopneumoniae, Aujeszky's disease virus (ADV) and Salmonella spp. A Cox proportional hazards model was used to investigate the simultaneous effects of seroconversion and maternal immunity against the studied pathogens. Results showed that high levels of maternal immunity against PCV2 had a protecting effect in farms from both countries. Moreover, for the Danish dataset, seroconversion against law had an overall protecting effect, but for animals with very low levels of maternal antibody levels against this pathogen, the effect appeared neutral or aggravating. Otherwise, for the Spanish dataset, maternal immunity against PPV and PRRSV gave protective and aggravating effects, respectively. In conclusion, the present study reflects the complex interaction among different pathogens and their effects in order to trigger PMWS in PCV2 infected pigs.
authors.affiliation: Departament de Sanitat i Anatomia Animals, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain. llorenc.grau@uab.cat
authors.forename: Llorenç
authors.initials: L
authors.lastname: Grau-Roma
authors.forename: Anders
authors.initials: A
authors.lastname: Stockmarr
authors.forename: Charlotte S
authors.initials: CS
authors.lastname: Kristensen
authors.forename: Claes
authors.initials: C
authors.lastname: Enøe
authors.forename: Sergio
authors.initials: S
authors.lastname: López-Soria
authors.forename: Miquel
authors.initials: M
authors.lastname: Nofrarías
authors.forename: Vivi
authors.initials: V
authors.lastname: Bille-Hansen
authors.forename: Charlotte K
authors.initials: CK
authors.lastname: Hjulsager
authors.forename: Marina
authors.initials: M
authors.lastname: Sibila
authors.forename: Sven E
authors.initials: SE
authors.lastname: Jorsal
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Fraile
authors.forename: Poul
authors.initials: P
authors.lastname: Baekbo
authors.forename: Hakan
authors.initials: H
authors.lastname: Vigre
authors.forename: Joaquim
authors.initials: J
authors.lastname: Segalés
authors.forename: Lars E
authors.initials: LE
authors.lastname: Larsen
mesh_terms: D000818:Animals; D003718:Denmark / Q000453:epidemiology; D005260:Female; D007112:Immunity, Maternally-Acquired; D053570:Porcine Postweaning Multisystemic Wasting Syndrome / Q000453:epidemiology / Q000382:microbiology*; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013030:Spain / Q000453:epidemiology; D013552:Swine