Silicosis
Who TPT should be offered to TPT should be deferred or not offered if the individual Management of TPT for people with silicosis People with confirmed silicosis have a significant risk for developing TB disease and require initial TPT regardless of significant exposure. After new TB exposure, TB evaluation is again required along with a decision to offer TPT or TB treatment (see Section 4 - Adult
TPT should be deferred or not offered if the individual
Management of TPT for people with silicosis
People with confirmed silicosis have a significant risk for developing TB disease and require initial TPT regardless of significant exposure.
After new TB exposure, TB evaluation is again required along with a decision to offer TPT or TB treatment (see Section 4 - Adult, Adolescent and Older Child Contacts).
Who TPT should be offered to
TPT should be offered to all people with confirmed silicosis regardless of whether they have a known significant exposure (regardless of prior TB treatment or TPT unrelated to silicosis).
People with silicosis who have completed TB treatment and have bacteriological proof of cure should be screened for TB symptoms and assessed for TPT eligibility if they have not previously received TPT or if they are re-exposed. If bacteriological cure is not demonstrated after completion of treatment, reassess the patient for TPT eligibility three months after completion of TB treatment.
People with silicosis who have completed a TPT regimen are eligible for subsequent TPT (again) if they experience a significant exposure (see Section 4 - Adult, Adolescent and Older Child Contacts).
TPT should be deferred or not offered if the individual:
- is diagnosed with TB disease
- has active liver disease (acute or chronic)
- has symptoms and signs of severe peripheral neuropathy (could consider rifampicin only regimen)
- has a history of adverse reactions to any of the drugs used for TPT
- uses alcohol excessively (and is unwilling or unable to scale down), defined as:
- for men: Five or more standard drinks on any day or 15 or more per week
- for women: Four or more standard drinks on any day or eight or more per week
For individuals with abnormal baseline liver function test results, sound clinical judgement is required to ensure that the benefit of TB preventive treatment outweighs the risks, and they should be tested routinely at subsequent visits.
Management of TPT for people with silicosis
If TPT is declined (despite counselling) re-counsel regarding TB symptoms and offer TPT again at the next opportunity. For symptoms suggestive of TB, re-evaluate for TB disease and offer either TB treatment or TPT again, if TB disease has been excluded.
Evaluation for TB disease amongst silicosis
Evaluation for TB disease includes symptom screening, physical examination, and diagnostic testing, regardless of symptoms. TB can either be bacteriologically confirmed or clinically diagnosed. Amongst people with silicosis a minimum of symptom screening and a sputum test are required prior to initiating either TB treatment or TPT.
People with silicosis will present with similar symptoms and signs of TB. Therefore, it is imperative that all adults presenting with TB symptoms should always be asked about history of working in the mines and silicosis.
Symptom screening for TB disease amongst adults with silicosis:
- current cough
- weight loss
- fever
- night sweats
- haemoptysis
Testing for latent tuberculosis infection (LTBI) amongst adults with silicosis
Where available, tuberculin skin test (TST) or interferon gamma release assay (IGRA) may be useful to distinguish silicosis from TB disease.
TPT regimens for adults with silicosis
There are currently three potential regimens for this group: 3HP, 3RH or 12H. In general, the short course 3HP regimen should be prioritised where possible. Patients should also receive pyridoxine (vitamin B6) 25mg for the duration of their TPT.
Recommended weekly dosages for the 3HP regimen for adults with silicosis
| Body weight (kg) | Rifapentine | Isoniazid | Duration |
| 150mg tablets (weekly) | 300 mg tablets (weekly) | ||
| 25-29.9 | 4 | 2 | 3 months |
| 30 – 49.9 | 6 | 3 | 3 months |
| >50 | 6 | 3 | 3 months |
Recommended daily dosages for 12H for adults with silicosis
| Drug | Isoniazid (H)* |
| Dose | 5mg/kg |
| Maximum Dose/day | 300mg |
| Duration | 12 months |
| Interval | Daily |
* If 300mg tablets are not available, use 100mg
Recommended daily dosages for 3RH for adults with silicosis – see Section 4 - Adult, Adolescent and Older Child Contacts).
National Guidelines on the Treatment of Tuberculosis Infection, February 2023
Silicosis