title: Lymphocyte blastogenesis, complement fixation, and fecal culture as diagnostic tests for paratuberculosis in North American wild ruminants and domestic sheep.
abstract: The efficacy of the lymphocyte blastogenesis and complement-fixation tests and fecal culture for detection of Mycobacterium paratuberculosis infection was assessed in bighorn sheep (Ovis canadensis), elk (Cervus elaphus nelsoni), mule deer (Odocoileus hemionus), white-tailed deer (O virginianus), bighorn X mouflon (O musimon) hybrid sheep, and domestic sheep. Spontaneously infected bighorns were tested at the time of capture; experimentally infected animals were tested monthly for 12 months or periodically for 36 months. Lymphocyte blastogenesis tests were conducted with peripheral blood mononuclear cells and protein antigens of M avium, M bovis, and M paratuberculosis. Best diagnostic results were obtained when M avium purified-protein derivative was used as antigen and 20% bovine fetal serum was incorporated in the culture medium; a positive test was defined as a stimulation index greater than or equal to 3.5. Test sensitivity and specificity, respectively, were 82% and 94% in hybrid sheep and were 72% and 100% in domestic sheep. Sensitivity and specificity, respectively, were 39% and 94% in elk and 53% and 92% in deer. When infection was determined in spontaneously infected bighorns by culture of M paratuberculosis and/or the presence of acid-fast bacilli in characteristic microscopic lesions, sensitivity was 75% and specificity was 87%. Fecal cultures and the complement-fixation tests seldom correctly identified infected animals.
mesh_terms: D000818:Animals; D000835:Animals, Wild; D003168:Complement Fixation Tests / Q000662:veterinary*; D003670:Deer; D005243:Feces / Q000382:microbiology*; D008213:Lymphocyte Activation; D009161:Mycobacterium / Q000302:isolation & purification*; D009656:North America; D010283:Paratuberculosis / Q000175:diagnosis*; D012756:Sheep; D012757:Sheep Diseases / Q000175:diagnosis* / Q000382:microbiology