Pulmonary tuberculosis

Centers for Disease Control and Prevention: 2009 case definition of TB[58]Centers for Disease Control and Prevention. Tuberculosis (TB) (Mycobacterium tuberculosis) 2009 case definition. 2009 [internet publication]. https://ndc.services.cdc.gov/case-definitions/tuberculosis-2009

Clinical criteria

A case that meets all the following criteria:

• A positive tuberculin skin test or positive interferon gamma release assay for Mycobacterium tuberculosis

• Other signs and symptoms compatible with TB (e.g., abnormal chest radiograph, abnormal chest computerized tomography scan or other chest imaging study, or clinical evidence of current TB disease)

• Treatment with two or more antituberculosis medications

• A completed diagnostic evaluation.

Laboratory criteria for diagnosis:

• Isolation of M tuberculosis from a clinical specimen, OR

• Demonstration of M tuberculosis complex from a clinical specimen by nucleic acid amplification test, OR

• Demonstration of acid-fast bacilli in a clinical specimen when a culture has not been or cannot be obtained or is falsely negative or contaminated.

Confirmed case:

A case that meets the clinical case definition or is laboratory confirmed.

World Health Organization: case definition of TB[59]World Health Organization. Definitions and reporting framework for tuberculosis - 2013 revision (updated December 2014 and January 2020). Jan 2020 [internet publication]. https://apps.who.int/iris/handle/10665/79199

Clinically diagnosed TB:

• A case which does not fulfill the criteria for bacteriologic confirmation, but has been diagnosed with active TB by a clinician or other medical practitioner, and a full course of TB treatment is given

• This definition includes cases diagnosed on the basis of x-ray abnormalities or suggestive histology, and extrapulmonary cases without laboratory confirmation

• Clinically diagnosed cases subsequently found to be bacteriologically positive (before or after starting treatment) should be reclassified as bacteriologically confirmed.

Bacteriologically confirmed TB:

• Biological specimen is positive by smear microscopy, culture, or World Health Organization-approved rapid diagnostics (e.g., Xpert MTB/RIF).

Bacteriologically confirmed or clinically diagnosed cases of TB are also classified according to:

• Anatomical site of disease

• History of previous treatment

• Drug resistance

• HIV status.