What is the approach for a patient living with a spouse with recent active Tuberculosis (TB) not yet on treatment?

Management of Patient Living with Spouse with Active TB Not Yet on Treatment

This patient should immediately receive treatment for latent tuberculosis infection (LTBI) regardless of tuberculin skin test (TST) or interferon-gamma release assay (IGRA) results, after active TB disease has been excluded. 1, 2

Immediate Actions Required

1. Rule Out Active TB Disease First

• Obtain a chest radiograph (posterior-anterior view) to exclude active pulmonary TB before starting LTBI treatment 1, 2
• Assess for TB symptoms: persistent cough (≥3 weeks), weight loss, night sweats, bloody sputum, fever, or anorexia 1
• If chest radiograph shows abnormalities suggestive of TB or if symptoms are present, obtain three consecutive sputum samples on different days for acid-fast bacilli (AFB) smear and culture 1
• Do not start single-drug LTBI treatment until active TB is definitively excluded 1

2. Initiate LTBI Testing (But Treatment Should Not Wait for Results)

• Administer TST (5-TU purified protein derivative by Mantoux method) or IGRA as soon as possible 1, 2
• A TST reaction ≥5 mm induration is considered positive in household contacts of active TB cases 1, 2
• Critical point: Close contacts of infectious TB patients should receive LTBI treatment regardless of TST/IGRA results, age, or prior treatment history 1, 2

LTBI Treatment Regimens

Recommended Options (Choose One):

• 9 months of daily isoniazid (5 mg/kg, maximum 300 mg daily) - most widely used regimen 1
• 6 months of daily isoniazid (alternative to 9-month regimen) 1
• 3-4 months of daily isoniazid plus rifampin (isoniazid 5 mg/kg max 300 mg + rifampin 10 mg/kg max 600 mg) 1
• 4 months of daily rifampin alone (10 mg/kg, maximum 600 mg) 1
• 12 weeks of once-weekly rifapentine plus isoniazid (under direct observation) 1

Special Considerations for Regimen Selection:

• If the spouse's TB is isoniazid-resistant, avoid isoniazid-containing regimens; consult public health authorities 1
• If the spouse's TB is rifampin-resistant, avoid rifamycin-containing regimens 1
• For HIV-infected patients on protease inhibitors or NNRTIs, rifampin is contraindicated; use 9-month isoniazid or consider rifabutin substitution 1

Monitoring During Treatment

Baseline Assessment:

• Obtain baseline liver function tests (AST/ALT, bilirubin) if patient has: history of liver disease, HIV infection, pregnancy/postpartum status (within 3 months of delivery), regular alcohol use, or concurrent hepatotoxic medications 1
• Complete blood count and platelets if using rifampin-containing regimens 1
• HIV testing should be offered if status unknown 1

During Treatment:

• Monthly clinical monitoring for all patients to assess adherence and adverse effects 1, 2
• Educate patient about hepatitis symptoms: nausea, vomiting, abdominal pain, dark urine, jaundice 1
• Repeat liver function tests if symptoms develop or if baseline tests were abnormal 1
• Add pyridoxine (vitamin B6, 25-50 mg daily) to prevent peripheral neuropathy when using isoniazid 1

Adherence Strategies:

• Directly observed preventive therapy (DOPT) should be used for twice-weekly regimens and considered for all regimens when operationally feasible 1, 2
• Provide patient education in their primary language about LTBI, treatment importance, and expected duration 1
• Establish flexible clinic hours and minimize waiting times to improve completion rates 1

Critical Pitfalls to Avoid

• Never delay LTBI treatment while waiting for TST/IGRA results in household contacts of active TB cases 1, 2
• Do not use single-drug therapy if active TB cannot be definitively excluded; use multidrug therapy pending culture results 1
• Avoid the 2-month rifampin-pyrazinamide regimen due to unacceptably high rates of severe and fatal hepatotoxicity 1, 3
• Do not rely on anergy testing to guide LTBI treatment decisions, as it is no longer recommended 1

Coordination with Public Health

• Report the exposure to local public health authorities immediately 2
• Public health will conduct contact investigation of the spouse's case and identify other potentially exposed individuals 2
• Ensure the spouse with active TB is started on appropriate multidrug treatment as soon as possible to reduce ongoing transmission risk 1