Mycobacterium tuberculosis

Mycobacterium tuberculosis


Airborne Precautions (N95)


General Information

Acid fast bacillus

  • Highest global mortality of any infectious disease.
  • Pulmonary TB is exceedingly infectious by the airborne route.
  • Latent disease believed to affect >20% of world population (latent TB is non-infectious).
  • Prevalence higher in developing nations, and highly associated with HIV infection.
  • Diagnosis of active TB: sputum acid fast stain and culture, sputum PCR.
  • Diagnosis of latent TB: interferon-gamma release assay.


  • Cavitating pneumonia
  • Upper lobe pneumonia
  • Occasionally miliary


  • Lymph node disease
  • CNS infection
  • Osteomyelitis (Potts)
  • Peritoneal
  • Others

Infectious Diseases consultation required for suspected active TB.

Airborne precautions for pulmonary TB urgently, on suspicion of diagnosis.

Release isolation after three negative sputum smears.

Caseating granulomas on pathology.

MDR includes rifampin and isoniazid resistance.