Systematic Veterinary Virology

LABORATORY DIAGNOSIS

• Microscopical identification of inclusion bodies: Distemper inclusion bodies” are actual clumps of virus that are visible under the microscrope within infected cells. Post-mortem inclusion bodies are readily visible in the urinary bladder tissues. In the living animals the inclusion bodies are readily visible in WBCs and conjunctival membranes. The inclusion bodies, which red stained (eosinophilic) oval structures are also found in the epithelial cells of the salivary glands, central nervous system, adrenal glands, bile duct, urinary tract, lymph nodes spleen and skin.
• Immunocytolgy
• To enhance the visibilty of inclusion bodies,  “immunocytology” is used. In this technique, antibodies against distemper virus are tagged with fluorescent markers. The antibodies bind to virus if it is present effectively dying the inclusion body with glow-in-the-dark fluorescent color. 
• The presence of inclusion bodies confirms distemper infection. The lack of dectectable inclusion bodies does not rule out distemper infection as inclusion bodies ultimately become coated with the host’s own antibodies, which in turn block the fluorescent-tagged antibodies used in the test.
• Isolation and identification: The virus are identified by AGPT, Antigen capture ELISA and PCR techniques.