TUBERCULOSIS

bacillus Mycobacterium tuberculosis

 

Tuberculosis is a contagious bacterial disease caused by the bacillus Mycobacterium tuberculosis. With 8 million new cases each year, tuberculosis is the second leading cause of death from infectious diseases throughout the world, after acquired immune deficiency syndrome (AIDS).

Symptoms against tuberculosis

  • Following infection, usually through the airborne route, the bacteria grow within the pulmonary alveoli and macrophages. When bacterial multiplication can no longer be contained by the immune system (in five to 10% of patients), the active disease develops.
  • The most common form of active tuberculosis is the pulmonary form. Symptoms include chronic cough, moderate fever, nighttime sweats, fatigue, decreased appetite and weight loss.
  • Miliary (diffuse impairment of lungs, spleen, liver, and bone marrow) and meningeal tuberculosis are the most severe forms of the disease.
  • Treatment relies on the administration of anti-tuberculosis drugs for many months.

Epidemiology and vaccination against tuberculosis

  • Approximately one third of the people on the planet are infected by the bacillus but the infection remains latent. Among them, only five to 10% will go on to develop an active form of the disease. (27)
  • A tuberculosis vaccine is administered in many countries by the intradermal route, at birth, during infancy or before school entry.
  • The tuberculosis vaccine does not prevent reactivation of the latent forms and has no impact on the transmission of the disease, but it is of great value in the prevention of the most severe forms of the disease (e.g., childhood meningeal tuberculosis).

References:

27 - BCG vaccine. WHO position paper. WER 2004, 79:25-40: