title: A review of infection of wildlife hosts with Mycobacterium bovis and the diagnostic difficulties of the 'no visible lesion' presentation.
abstract: The pathology, frequency and diagnostic implications of 'no visible lesion' (NVL) tuberculosis (Tb), i.e. infection with Mycobacterium bovis in the absence of macroscopic lesions, are described in a wide taxonomic range of wildlife hosts. Information collected and evaluated on the definition and occurrence of NVL Tb, histopathological characteristics, post-mortem techniques to detect minimal lesions, and diagnostic difficulties revealed most Tb-infected individuals with NVL had minute tuberculous lesions, which were difficult to see by eye. Acid-fast organisms (AFO) were sometimes detected in the lesions. Ideally, mycobacterial culture of pools of lymph nodes and/or oropharyngeal tonsils is necessary for the accurate diagnosis of Tb in the absence of macroscopic lesions. At a very minimum, the diagnostic methods applied for studying the prevalence of Tb in the population should be clearly described, to allow comparison between studies.
authors.affiliation: National Veterinary Institute (SVA) and Department of Biomedical Sciences and Veterinary Public Health, University of Agricultural Sciences (SLU), SE-75189 Uppsala, Sweden. dolores.gavier-widen@sva.se
authors.forename: D
authors.initials: D
authors.lastname: Gavier-Widén
authors.forename: M M
authors.initials: MM
authors.lastname: Cooke
authors.forename: J
authors.initials: J
authors.lastname: Gallagher
authors.forename: M A
authors.initials: MA
authors.lastname: Chambers
authors.forename: C
authors.initials: C
authors.lastname: Gortázar
mesh_terms: D000234:Adenoids / Q000382:microbiology / Q000473:pathology; D000818:Animals; D000835:Animals, Wild / Q000382:microbiology*; D001344:Autopsy / Q000662:veterinary; D003937:Diagnosis, Differential; D004199:Disease Vectors; D008198:Lymph Nodes / Q000382:microbiology / Q000473:pathology; D009163:Mycobacterium bovis / Q000302:isolation & purification; D014066:Palatine Tonsil / Q000382:microbiology / Q000473:pathology; D016133:Polymerase Chain Reaction / Q000662:veterinary; D014376:Tuberculosis / Q000175:diagnosis / Q000453:epidemiology / Q000635:transmission / Q000662:veterinary*