Diagnosis

DIAGNOSIS

Specimens to be collected

  • Specimens for direct microscopy from live animals include scrapings /pinch biopsies from the rectum. Faeces may be submitted for culture.
  • In case of dead animals, tissues from affected region of the intestines and from regional lymphnodes are useful for histopathology.

Diagnosis by

  • Microscopical examination by staining the faecal smears with acid-fast stain.
  • Bacteriological examination
    • Materials decontaminated with 0.3% benzalkonium chloride and concentrated by centrifugation and subsequently cultured in Herrold's egg yolk medium and are incubated at 370C for up to 16 weeks.
  • Based on PM lesions
  • Serological tests
    • Complement fixation test can be used. But CFT is laborious and relatively insensitive.
    • Agar gel precipitation test has been used for confirming clinical infection. ELISA, using serum absorbed with M.phlei may detect subclinically infected animals.
  • Johnin test
    • Intra dermal Johnin test
      • Inoculate Johnin PPD into the skin of the neck region.
      • The delayed hypersensitivity reaction is measured after 48 hours.
      • Peak response usually develops a month or so after infection.
    • Intra venous Johnin test
      • The intravenous Johnin test reaction is measured by increase in body temperature following intra venous Johnin PPD injection.
  • DNA probes, which are highly sensitive, are being used to detect organisms in faeces.
Last modified: Monday, 4 June 2012, 5:05 AM