Tuberculosis (TB)

BCG Vaccination

BCG vaccine is NOT part of the routine immunisation schedule in the UK, but is selectively offered to those at higher risk of TB exposure.

Mantoux -ve is the main requirement for ALL people before offering BCG vaccination:
  • +ve Mantoux test (induration ≥5 mm) are NOT given BCG as they are sensitised and vaccination is unnecessary

Main indications for BCG vaccine:
 
Category Specific Group
Neonates / children
  • Living in UK areas with TB incidence ≥40/100,000
  • With a parent / grandparent born in a country with TB incidence ≥40/100,000
Specific situations:
  • HIV +ve mother
  • Immunosuppressed mother
  • Family history of TB in the last 5 years
Close contact
  • <16y/o, and
  • Unvaccinated (no prior BCG), and
  • Household or equivalent close contact with a patient with sputum smear positive pulmonary / laryngeal TB
Occupational risk Unvaccinated <35 y/o healthcare workers are typically offered vaccination during occupational health screening

Healthcare workers that:
  • Direct contact with TB patients or potentially infectious materials
  • Works in high-risk settings (e.g. TB clinics, infectious disease wards, pulmonary units, microbiology, pathology department, autopsy room)
  • Involved in care of high TB risk populations (e.g. prisoners, homeless people, asylum seekers, refugees, drug / alcohol misuse)

Latent TB Guidelines

1st line: Mantoux test (tuberculin skin testing) (+ve test defined by induration ≥5mm regardless of BCG history)
  • +ve Mantoux test → assess for active TB (see below)
 
  • If no signs of active TB
    • Offer treatment for latent TB
    • However if more evidnece of infection is needed to decide on treatment (e.g. requiring enhanced case management, or adverse events from treatment) → offer interferon gamma release assay 

If testing in immunocompromised patients: offer Mantoux test and interferon-gamma release assay

Offer the following testing before starting treatment for latent TB:
  • HIV
  • Hepatitis B and C

NICE recommends either of the following regimens depending on clinical circumstances:
 
Drugs Duation Indication
Rifampicin + isoniazid (+ pyridoxine) 3 months Shorter duration is preferred in <35 y/o if hepatotoxicity is a concern
Isonidazid (+ pyridgoooxine) 6 months To avoid rifampicin which is a potent liver enzyme inducer

Can be problematic in those with HIV and post-transplant due to the medications they need to take
 

Active TB Guidelines

1st line test: chest X-ray

If X-ray appearance suggest TB → perform microbiology sample testing (definitive testing):
  • Obtain 3 deep cough sputum respiratory samples (preferable 1 early morning sample)
    • If patient unable to produce sputum → induce sputum or bronchoscopy and lavage
 
  • Send for microscopy, culture and histology
  • Ideally, before starting treatment (otherwise within 7 days of starting treatment)

Request NAATNucleic acid amplification tests for M. tuberculosis complex if:
  • HIV +ve patient, or
  • Rapid information about species would affect management, or
  • Large contact-tracing initiative 

1st line: NAATNucleic acid amplification tests for M. tuberculosis complex (M. tuberculosis, M. bovis, M. africanum)

Imaging: CXR, CT Thorax

Microbiology: culture

NAAT
Acid fast bacilli 

If TB is a possibility, microbiology staff should consider carrying out TB culture on samples (see recommendations 1.3.2.2 and 1.3.2.3), even if it is not requested

If there are clinical signs and symptoms consistent with a diagnosis of TB, start treatment without waiting for culture results.

References

Author: Adams Lau
Reviewer:
Last edited: 02/08/25