title: Faecal shedding detected earlier than immune responses in goats naturally infected with Mycobacterium avium subsp. paratuberculosis.
abstract: Paratuberculosis was diagnosed in a goat herd that participated in a sanitation program against Mycobacterium avium subsp. paratuberculosis. The aim of this study was to characterise the development of gamma interferon (IFN-γ) and antibody responses as well as the occurrence of faecal shedding. Faecal culture appeared surprisingly sensitive as about 18% and 40% of the goats were positive at 9 and 15-17 months of age, respectively, and shedding was often seen prior to peripheral immune responses. Peripheral IFN-γ responses were not related to protection as clinical and high shedding goats often had high responses. An IFN-γ response usually preceded a humoral response. However, positive antibody titers could sometimes be seen simultaneously with, and even prior to, IFN-γ responses. In conclusion, faecal culture appeared as sensitive as IFN-γ testing. Furthermore, the antibody ELISA and the IFN-γ assay may perform equally well in an infected herd if surveillance is conducted annually.
authors.affiliation: Department of Animal Health, National Veterinary Institute, P.O. Box 750 Sentrum, 0106 Oslo, Norway. Electronic address: kari.lybeck@vetinst.no.
authors.forename: Kari R
authors.initials: KR
authors.lastname: Lybeck
authors.affiliation: Department of Food Safety and Infection Biology, Norwegian School of Veterinary Science, P.O. Box 8146, Dep., N-0033 Oslo, Norway.
authors.forename: Anne K
authors.initials: AK
authors.lastname: Storset
authors.affiliation: Department of Animal Health, National Veterinary Institute, P.O. Box 750 Sentrum, 0106 Oslo, Norway.
authors.forename: Berit
authors.initials: B
authors.lastname: Djønne
authors.affiliation: Department of Animal Health, National Veterinary Institute, P.O. Box 750 Sentrum, 0106 Oslo, Norway.
authors.forename: Mette
authors.initials: M
authors.lastname: Valheim
authors.affiliation: Department of Animal Health, National Veterinary Institute, P.O. Box 750 Sentrum, 0106 Oslo, Norway.
authors.forename: Ingrid
authors.initials: I
authors.lastname: Olsen
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D057138:Bacterial Shedding; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005243:Feces / Q000382:microbiology*; D015511:Goat Diseases / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology; D006041:Goats; D007371:Interferon-gamma / Q000097:blood; D016927:Mycobacterium avium subsp. paratuberculosis / Q000276:immunology / Q000302:isolation & purification*; D010283:Paratuberculosis / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology; D015203:Reproducibility of Results
chemical_list: D000907:Antibodies, Bacterial; D007371:Interferon-gamma