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Table 1 Definitions of TB for the DarDar Study

From: Basis for treatment of tuberculosis among HIV-infected patients in Tanzania: the role of chest x-ray and sputum culture

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. an 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.
  1. AFB, acid fast bacillus; CFU, colony forming units; MTB, Mycobacterium tuberculosis; TB, tuberculosis.
  2. * a positive AFB smear is defined as ≥ 2 acid-fast organisms per 100 oil immersion field