Immunological concepts in tuberculosis diagnostics for non-human primates: a review

Area of Science:

• Veterinary Medicine
• Primate Health
• Infectious Diseases

Background:

• Tuberculosis (TB) diagnosis in non-human primates (NHPs) is critical due to diverse disease presentations mirroring human TB.
• Clinical suspicion guides diagnostic strategies in primate colonies, integrating clinical assessments with screening and microbiological methods.

Purpose of the Study:

• To review diagnostic modalities for tuberculosis in non-human primates.
• To discuss the advantages and disadvantages of various pathogen identification and immunologic host response techniques.

Main Methods:

• Categorization of diagnostic modalities into pathogen identification and immunologic host response techniques.
• Evaluation of classic tuberculin skin tests, interferon-gamma release assays (IGRAs), lymphocyte proliferation assays, and antibody detection.
• Discussion of surrogate sample collection (gastric aspirate, stool, respiratory samples) for microbiologic identification.

Main Results:

• The tuberculin skin test has limited sensitivity and specificity; IGRAs offer similar accuracy but use different mechanisms.
• Acid-fast smear and culture are crucial for pathogen identification, offering optimal sensitivity and specificity.
• Pathogen identification confirms TB, but negative results do not exclude the diagnosis; necropsy may be required.

Conclusions:

• Interpretation of immunologic screening tools requires caution and correlation with clinical suspicion.
• Definitive diagnosis may necessitate pathological review at necropsy if pathogen detection is negative.
• Weighing risks and benefits is essential when considering euthanasia for diagnostic purposes in primate colonies.