Table 5. Definitions of tuberculosis cases and treatment outcomes
A. Definitions of tuberculosis cases
Case of tuberculosis
A patient in whom tuberculosis has been confirmed by bacteriology or diagnosed by a clinician.
A patient with positive culture for the Mycobacterium tuberculosis complex. In countries where culture is not routinely available, a patient with two sputum smears positive for acid-fast bacilli (AFB+) is also considered a definite case.
A patient with tuberculosis disease involving the lung parenchyma.
Smear-positive pulmonary case
A patient with at least two initial sputum smear examinations (direct smear microscopy) AFB+; or one sputum examination AFB+ and radiographic abnormalities consistent with active pulmonary tuberculosis as determined by a clinician; or one sputum specimen AFB+ and culture positive for M. tuberculosis.
Smear-negative pulmonary case
A patient with pulmonary tuberculosis not meeting the above criteria for smear-positive disease. Diagnostic criteria should include: at least three sputum smear examinations negative for AFB; and radiographic abnormalities consistent with active pulmonary tuberculosis; and no response to a course of broad-spectrum antibiotics; and a decision by a clinician to treat with a full course of antituberculosis chemotherapy; or positive culture but negative AFB sputum examinations.
A patient with tuberculosis of organs other than the lungs (e.g. pleura, lymph nodes, abdomen, genitourinary tract, skin, joints and bones, meninges). Diagnosis should be based on one culture-positive specimen, or histological or strong clinical evidence consistent with active extrapulmonary disease, followed by a decision by a clinician to treat with a full course of antituberculosis chemotherapy. A patient in whom both pulmonary and extrapulmonary tuberculosis has been diagnosed should be classified as a pulmonary case.
A patient who has never had treatment for tuberculosis or who has taken antituberculosis drugs for less than one month.
A patient previously declared cured but with a new episode of bacteriologically positive (sputum smear or culture) tuberculosis.
A patient previously treated for tuberculosis, undergoing treatment for a new episode, usually of bacteriologically-positive tuberculosis.