Patients with active TB must be isolated until sputum is negative for AFB. 

a. First-line therapy is a four-drug regimen: isoniazid (INH), rifampin, pyrazinamide, and ethambutol or streptomycin. 

b. The initial treatment regimen consists of 2 months of treatment with the four drug regimen. After this initial 2-month phase, a phase of 4 months is recommended using INH and rifampin. 

2. Prophylactic treatment for latent (primary) TB (i.e., positive PPD skin test): consists of 9 months of INH after active TB has been excluded (negative CXR, sputum, or both).