Infectious DiseasePending review
Tuberculosis
Chronic granulomatous infection with Mycobacterium tuberculosis, contained by cell-mediated immunity into a latent state in most people, but able to reactivate into active, transmissible disease when that containment fails.
In a nutshell
Inhaled M. tuberculosis survives inside macrophages and is walled off into a granuloma rather than cleared, so most infection becomes latent, not active. Reactivation occurs when cell-mediated immune surveillance weakens, letting the granuloma rupture and disease disseminate to the lung apex or elsewhere.
Classic presentation
A chronic productive cough lasting over three weeks with haemoptysis, night sweats, weight loss and low-grade fever, often with apical changes on chest X-ray.
Key points
- Most TB infection is contained as latent disease within a granuloma; only a minority progresses to active disease.
Educational content pending clinical review. Not medical advice.