Tuberculosis A040

Current RMA Instruments:

Changes from previous instruments:

ICD Coding:

• ICD-10-AM Codes: A15, A16, A17, A18, A19

Brief description:

Tuberculosis (TB) is a bacterial infection with one of the Mycobacterium tuberculosis group of organisms (includes M. tuberculosis, M. africanum, M. canettii, M. caprae, M. microti, M. orygis, M. pinnipedi and M. bovis)

The infection primarily affects the lungs but it can also affect other parts of the body. It can also be active or quiescent. If it is quiescent, it is referred to as ‘latent TB,’ with the bacteria being present in the body but not causing active infection. The individual does not have symptoms and is not contagious. Latent TB can become active if the person becomes immunosuppressed. 

Confirming the diagnosis:

To confirm the diagnosis of active pulmonary TB infection there needs to be positive respiratory specimen results (identifying mycobacterium tuberculosis). Often there is also supportive evidence that can be via chest X-ray imaging.  Latent infection is established by a positive interferon gamma release assay (blood test) specific for tuberculosis. 

A positive Mantoux skin test can be considered insufficient due to the possibility of false positive readings from: 

• past immunisation depending on the level
• other Mycobacterium such as M. avium, M. intracellulare, M. kansasii, M. marinum or M. ulcerans which are specifically excluded from this SOP.

The relevant medical specialist is an infectious diseases physician or respiratory physician.

Additional diagnoses covered by these SOPs

• Latent tuberculosis (TB)
• Primary TB
• Pulmonary TB
• Extrapulmonary TB
• Reactivated TB
• Infection with Mycobacterium (M.) tuberculosis, M. africanum, M. canettii, M. bovis, M. caprae, M. microti, M. orygis, or M. pinnipedi.

Conditions not covered by these SOPs   

• Infections by atypical mycobacterium such as M. avium, M. intracellulare, M. kansasii, M. marinum or M. ulcerans #

# non-SOP condition

Clinical onset

This SOP is complicated as it covers both symptomatic (active) and asymptomatic (latent) tuberculosis infection.

Once ‘active’ tuberculosis as a diagnosis is established via clinical assessment and testing, the clinical date of onset will be when the symptoms and signs of the infection first presented. E.g. Pulmonary TB cases will often involve a persistent cough lasting weeks, reports of coughing up blood (haemoptysis), episodes of chest pain, fever, loss of appetite, and fatigue. 

For the ‘latent’ tuberculosis, the condition is asymptomatic and hence does not really have a clinical onset apart from the date of first confirmed positive test. If there is a typical lung focus of past infection, then the latent tuberculosis clinical onset could be taken back to the date of the first positive chest imaging. Extrapulmonary TB cases will present differently depending on the location affected (e.g. lymph nodes, brain, kidneys etc). 

Clinical worsening

The natural history of tuberculosis is complicated and depends upon the individual host response. As such it is recommended that an opinion from an infectious disease physician be sought, to provide an opinion on whether a clinical worsening is out of keeping with the natural history of the underlying pathology.

Active TB should always be treated with antibiotics for at least 6- 9 months. Latent TB may also benefit from antibiotic treatment but patients may also choose to only be monitored as the antibiotics and medications may result in side effects.