Tuberculosis Epidemiology

A 32-year-old male construction worker from rural Maharashtra presents with a 3-week history of productive cough with blood-tinged sputum, low-grade fever in the evenings, and night sweats drenching his clothes. He lives in a crowded 1-room tenement with 6 family members. His 8-year-old daughter was treated for tuberculosis 6 months ago. On examination, he is cachectic with crackles in the right upper lobe. Sputum smear microscopy shows acid-fast bacilli (2+ on Ziehl-Neelsen staining). What is the epidemiological classification of this case in the context of TB control programs?

All of the following are recognized risk factors for tuberculosis transmission and disease progression in the Indian population EXCEPT:

A 28-year-old female healthcare worker in Mumbai is found to have a positive tuberculin skin test (TST: 15 mm induration) during routine screening. She is asymptomatic with normal chest X-ray. Which investigation is most appropriate to determine if she has latent TB infection (LTBI) versus active TB disease?

A 32-year-old male construction worker from Delhi presents with a 3-week history of productive cough, fever, and night sweats. He is a known contact of a smear-positive tuberculosis patient. Chest X-ray shows an apical infiltrate with cavitation. Which investigation is the gold standard for confirming active pulmonary tuberculosis in this patient?

Among patients with tuberculosis in India, which is the most common site of extrapulmonary tuberculosis?