active tuberculosis

Active tuberculosis is what happens when the standoff ends and the bacteria win the upper hand. Instead of sitting quietly contained, they multiply, damage tissue and produce illness — the smouldering coals have flared back into open flame. Unlike latent infection, active TB causes symptoms and, when it is in the lungs, can spread to others.

Typical lung symptoms build slowly over weeks: a persistent cough, sometimes with blood-streaked sputum, plus fever, drenching night sweats, fatigue and steady weight loss. As the disease progresses it can hollow out areas of lung into cavities teeming with bacteria, which is why people with cavitary disease are especially infectious.

Diagnosis combines imaging with direct proof of the bacterium in sputum — by smear microscopy, molecular tests or culture. Treatment is a months-long course of several antibiotics; with full adherence, cure rates are high. Because patients become much less contagious within weeks of starting effective therapy, prompt diagnosis and treatment protect both the individual and the community.