Tuberculosis (TB) is transmitted through the air from one person to another. When a person with active TB disease in the lungs or throat coughs, sneezes, speaks, sings, or laughs, they release tiny airborne droplets containing TB bacteria. People nearby may breathe in these droplets and become infected. This transmission usually requires close and prolonged contact with the person who has active TB. TB is not spread by shaking hands, sharing food or drink, touching bed linens or toilet seats, sharing toothbrushes, or kissing.
The bacteria can remain airborne and infective for several hours, especially in poorly ventilated indoor areas. Only people with active TB disease (not latent infection) are contagious and can spread TB to others.
Key facts about TB transmission:
- Airborne transmission via droplets from coughs, sneezes, speech, or singing.
- Close, frequent, or prolonged contact with an infectious person increases risk.
- Poor ventilation and crowded environments raise transmission likelihood.
- People with latent TB infection do not spread TB.
- TB is not spread by casual physical contact or shared objects.
This airborne mode of transmission makes TB particularly a concern in crowded or poorly ventilated settings and among individuals with weakened immune systems.