• The Review Course in Family Medicine

The Canadian Tuberculosis Standards: 8th Edition

Here are the highlights:


  • The overall incidence of tuberculosis (TB) remains low, but foreign-born individuals and Canadian Indigenous people are disproportionately affected.

  •  Screening for high-risk individuals must include chest radiography.

  •  Confirm diagnosis with acid-fast bacilli (AFB) microbiology or nucleic acid amplification tests (NAATs). We do NOT recommend monitoring response to treatment or determine contagiousness with NAAT.

  • Tuberculin skin test (TST) and interferon gamma release assays (IGRA) are not sufficient for diagnosis, but they have special uses. - IGRA is preferred in pediatrics and those who have received the BCG vaccine - TST is preferred for serial testing or when assessing risk of new infection - Combining both increases sensitivity in high-risk individuals

*Up to 30% of children may have negative TST or IGRA so clinical context is important.

Treatment

  • Avoid monotherapy! Minimum 3 drugs are recommended in the intensive phase (first 2 months), ideally Isoniazid, Rifampin, Pyrazinamide and Ethambutol.

  • When treating children, daily therapy is strongly recommended.

  • Ethambutol is now routinely used in initial empiric therapy in infants and children.

  • Drug-resistant TB (DR-TB) is uncommon and is mainly mono-resistance to Isoniazid or Pyrazinamide.

  • Use phenotypic drug susceptibility testing (DST) and rapid molecular tests to guide therapy. - For mono-isoniazid resistance, late generation fluoroquinolones (levofloxacin) are preferred. - For multi drug resistant TB (MDR-TB), initial regimens should include Levofloxacin AND Bedaquiline AND Linezolid AND Clofazimine AND Cycloserine.

  •  Monitor for recurrence in for 1-2 years post-therapy.


Preventive Treatment

  • The recommended first-line TB preventive treatment (TPT) can be: - once weekly Rifapentine and Isoniazid for 3 months (3HP) - Daily Rifampin for 4 months (4R)- preferred in children under 2 years


Extra-Pulmonary Tuberculosis

  • Extend therapy for 12 months for extra-pulmonary TB.

  • *NEW: For TB meningitis, use high dose Rifampin (>15 mg/kg/day PO/IV) during intensive phase.

  • *NEW: For pleural TB, routine corticosteroid or therapeutic thoracentesis is not recommended. However, corticosteroids can be considered for TB pericarditis in HIV-negative patients.


Special Populations

  • All foreign-born persons immigrating to Canada undergo screening including chest radiography and are subsequently treated if found with active TB. They must be followed for reactivation based on provincial/territorial guidelines.

  • Baseline TST is recommended for all healthcare workers, but periodic testing is NO LONGER routinely recommended.

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