Table 1 Case definitions.

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.