Discuss the global burden of DR-TB under various parameters and historical trend.

Understand 'air exchanges per hour' as a crucial metric for adequate ventilation in settings where TB patients are present.

Discuss how poor or waning immune response increases risk of TB infection and disease. Mention common conditions with poor host immunity.

Discuss how poor ventilation and inadequate air circulation increases risk of TB. Discuss what constitutes adequate ventilation.

Explain what all can be a source of TB infection and how the type of source may affect the infectiousness / risk of transmission of disease.