<s>[INST] Is TB always infectious?  [/INST] Microbiologically confirmed pulmonary TB patients (people with lung TB) are infectious. However, these patients don’t remain infectious, if at least 2 weeks of Anti TB medicines are taken. It is important to complete the entire duration of medication. In comparison, if it's a case of TB affecting other organs (other than the lung), then they are not infectious.
Wearing a mask potentially cuts transmission of the disease/infection, therefore person who has cough for any duration (even if not yet tested) is encouraged to wear a mask. Source: Government of India. Link: https://tbcindia.gov.in/index4.php?lang=1&level=0&linkid=382&lid=2753. Field: Lung Disease. Disease: Tuberculosis </s>