Patient with Mycobacterium tuberculosis complex identified from a clinical specimen, either by conventional culture or by a newer method recommended by WHO such as line probe assay or Xpert MTB/RIF; or A case in whom a health worker (clinician or other medical practitioner) has diagnosed TB and has decided to treat the patient with a full course of TB treatment; or In countries that lack the laboratory capacity to routinely identify Mycobacterium tuberculosis complex, a pulmonary patient with one or more initial sputum smear examinations positive for acid-fast bacilli (AFB) is also considered a case of TB, provided that there is a functional external quality assurance (EQA) system with blind rechecking

Particular episode of clinical TB disease. Refers only to the disease, not to the person with the disease. According to local laws and regulation, TB cases and suspect TB cases must be reported to the local or state health department

In settings with appropriate quality assurance procedures, it is defined as someone with one positive smear – that is, at least 1 acid-fast bacillus in at least 100 microscopic fields

Positive histological examination (extrapulmonary TB) OR TB case without bacteriological or WHO-approved rapid diagnostic test results, put on a full course of TB treatment by a qualified physician or health worker

Definite case of TB or one in which a health worker (clinician or other medical practitioner) has diagnosed TB and has decided to treat the patient with a full course of TB treatment. Note: Any person given treatment for TB should be recorded as a case. Incomplete “trial” TB treatment should not be given as a method for diagnosis