Comparison of TB in humans versus rhesus and cynomolgus macaquesa

ParameterHumansRhesus macaquesCynomolgus macaques
Clinical manifestations
    Rate of disease progressionbAcute ≪ latent (10% vs 90%)Acute ≫ latent (90% vs 10%)Acute > latent (60% vs 40%)
    Presence of active/chronic infection symptom
        Bloody sputum+++
        Increased body temp+++
        Wt loss+++
    Presence of latent infection symptoms
        No clinical signs+++
        Activated by coinfection (HIV or SIV)+++
Clinical tests
    Skin tests
        Old tuberculin test+++
    Blood tests
        ELISA, ELISpot+++
        Quantiferon-TB Gold+++
        CBC, ESR, CRP, LT+++
    Imaging (chest X-Ray, MRI, PET/CT)+++
    Fluid sampling (BAL, gastric aspirate)+++
    Caseous granulomas+++
    Fibrous capsule+/−+/−+/−
    Pulmonary cavities+++
    Disseminated lesions+/−+/−+/−
  • a The majority of macaques, particularly the rhesus species, develop acute or active TB after artificial infection, whereas 90% of infected humans have latent TB. Chronic infection is defined as persistent signs of active disease, radiographic involvement, or culture positivity. Although the PPD and old tuberculin skin tests are used in both humans and macaques, these diagnostic exams are less reliable in macaques than in humans (69). Also, macaques exhibit a more random than apical distribution of pulmonary cavities. Abbreviations: BAL, bronchoalveolar lavage; CBC, complete blood count; CRP, C-reactive protein; LT, lymphocyte transformation; rBCG, recombinant bacillus Calmette-Guérin, +, positive for the indicated finding or functional modality; −, absent finding or unused modality; +/−, a variable finding.

  • b Acute disease lasts weeks to months, and latent disease lasts months to years. Percentages (in parentheses) indicate the global percentage of the species infected with M. tuberculosis.