TB Case definition
Paradoxical tuberculosis-associated IRIS (immune reconstitution inflammatory syndrome)
Recurrent, new, or worsening symptoms or signs of tuberculosis following initiation of antiretroviral therapy (ART) in people living with HIV, diagnosed with tuberculosis, and started on anti-tuberculosis treatment before ART. These signs or symptoms typically occur within the first few weeks and up to 3 months after ART is initiated.
Possible tuberculous meningitis (TBM)
Clinical entry criteria consistent with tuberculous meningitis plus exclusion of alternative diagnoses.
Extrapulmonary tuberculosis (EPTB)
Any bacteriologically confirmed or clinically diagnosed case of tuberculosis involving organs other than the lungs (e.g. pleura, peripheral lymph nodes, abdomen, genitourinary tract, skin, joints and bones, meninges).
Incipient tuberculosis
Individuals with M. tuberculosis infection in whom progression to tuberculosis has started and who have no symptoms, no radiographic abnormalities suggestive of tuberculosis, and negative microbiological investigations.
Disseminated tuberculosis
Simultaneous involvement of at least two non-contiguous organ sites of the body resulting from the hematogenous spread of M. tuberculosis.
Clinically diagnosed tuberculosis (case definition)
Tuberculosis in a person who does not fulfil the criteria for bacteriological confirmation and has been diagnosed with tuberculosis by a medical practitioner who has decided to initiate anti-tuberculosis treatment.
Bacteriologically confirmed tuberculosis (case definition)
Tuberculosis occurring in a patient from whom a biological specimen tests positive by smear microscopy, culture or WHO-recommended rapid diagnostic. Also known as laboratory or microbiologically confirmed tuberculosis case.
Active tuberculosis
Symptomatic disease that occurs in someone infected with M. tuberculosis or other mycobacteria from M. tuberculosis complex. This term is broadly used but is outdated. The preferred term is ‘tuberculosis’.
Unconfirmed tuberculosis (for intrathoracic tuberculosis in children)
Pediatric tuberculosis in which bacteriological confirmation is not obtained and at least 2 of the following conditions are present: Symptoms/signs suggestive of tuberculosis (as defined); Chest radiograph consistent with tuberculosis; Close tuberculosis exposure or immunologic evidence of M. tuberculosis infection; Positive response to tuberculosis treatment (requires documented positive clinical response on tuberculosis treatment—no time duration specified) – With M. tuberculosis infection; Immunological evidence of M. tuberculosis infection(TST and/or IGRA positive) – Without M. tuberculosis infection; No immunological evidence of M. tuberculosis infection. This term was developed for diagnostic research purposes.
Unlikely tuberculosis (for intrathoracic tuberculosis in children)
Condition in which a person does not have M. tuberculosis bacteriological confirmation and the criteria for “unconfirmed tuberculosis” is not met – With M. tuberculosis infection; Immunological evidence of M. tuberculosis infection (TST and/or IGRA positive) – Without M. tuberculosis infection; No immunological evidence of M. tuberculosis infection. This term was developed for diagnostic research purposes.
