Table 1 Current tuberculosis classification for U.S. immigration applicants

No TB classification

No evidence of TB infection or disease

A

Smear or culture^a positive pulmonary TB. Typically requires treatment prior to U.S. entry.

B1-Pulmonary

1. Suspected active pulmonary TB based on clinical findings but with negative sputum smears and cultures^a

2. History of pulmonary TB, treatment complete

B1-Extrapulmonary

Extrapulmonary TB

B2

TST ≥ 10 mm or positive IGRA but otherwise negative TB evaluation (LTBI)

B3

Recent close contact with a known active TB case and TST/IGRA negative