Definite TB | 1. One or more sputum cultures positive for Mycobacterium tuberculosis (MTB) with ≥ 10 colony forming units (CFU); or, |
 | 2. Two or more sputum cultures with 1–9 CFU of MTB (indeterminate MTB culture); or, |
 | 3. Two or more positive sputum smears for acid fast bacilli (AFB); or, |
 | 4. One or more cultures for MTB from the blood or other sterile body site. |
Probable TB | 1. Positive chest x-ray plus either |
 |    a. one positive sputum AFB smear, or, |
 |    b. one indeterminate MTB culture result; or, |
 | 2. Clinical symptoms/signs plus either |
 |    a. one positive sputum AFB smear, or, |
 |    b. one indeterminate MTB culture result; or, |
 | 3. Clinical symptoms/signs and a positive x-ray plus a response to anti-TB therapy; or, |
 | 4. One positive sputum AFB smear from a sterile site plus clinical symptoms/signs of tuberculosis; or, |
 | 5. Caseous necrosis on a tissue biopsy. |
Latent TB | 1. Tuberculin skin test ≥ 5 mm |
 | 2. No definite or probable TB. |