Department Head authorisation required
Mycobacterial culture should also be requested
The use of nucleic acid amplification tests (NAAT) for screening specimens from patients with suspected TB should be limited to:
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Respiratory smear-positive specimens where the result is likely to influence clinical (treatment) and/or public health (isolation, contact investigation) decisions;
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Respiratory smear-negative specimens from a patient with a high probability of TB, when prompt management and public health decisions are required; and
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Selected non-respiratory specimens (e.g. meningeal, some tissue biopsies) where a prompt management decision is necessary (recognised that such tests have not been validated or approved).
The use of NAAT is considered inappropriate in the following instances:
When a patient is respiratory smear-negative and has a low probability of TB;
When a patient is respiratory smear-positive and has a very high probability of TB;
Paucibacillary non-respiratory specimens (e.g. pleural fluid, ascitic fluid).