What are the treatment recommendations for a 50-year-old traveling nurse with a new positive Quantiferon Gold (Interferon-Gamma Release Assay) test, no symptoms, and a negative chest x-ray?

Management of New Positive QuantiFERON Gold in a 50-Year-Old Traveling Nurse

This traveling nurse should be offered treatment for latent tuberculosis infection (LTBI) with 9 months of daily isoniazid or 3 months of weekly rifapentine plus isoniazid, after confirming no active TB disease. 1

Immediate Next Steps

Confirm Absence of Active TB Disease

• Obtain detailed history focusing on: TB symptoms (cough, fever, night sweats, weight loss, hemoptysis), known TB exposures, HIV risk factors, immunosuppressive conditions, and BCG vaccination history 1
• The chest x-ray is already negative, which is appropriate baseline evaluation 1
• HIV testing is strongly recommended because HIV infection increases both TB disease risk and urgency of LTBI treatment 1
• If any symptoms suggestive of active TB are present, obtain sputum samples for acid-fast bacilli smear and mycobacterial culture before initiating LTBI treatment 1

Assess for Treatment Candidacy

• Screen for contraindications to LTBI treatment: active hepatitis, end-stage liver disease, history of severe liver injury, or excessive alcohol consumption 1
• If liver disease risk factors exist, obtain baseline liver function tests (aminotransferases) 1
• Healthcare workers with positive QuantiFERON Gold results should be considered for LTBI treatment regardless of age 1

Treatment Recommendations

Preferred Regimens

The preferred treatment is 9 months of daily isoniazid 1. Alternative options include:

• 3 months of once-weekly rifapentine plus isoniazid (3RPT/INH), which has shown 80% treatment initiation and 40% completion rates in clinical studies 2
• 4 months of daily rifampin 1

Regimen to Avoid

Do NOT use the 2-month rifampin plus pyrazinamide regimen due to severe liver injury and death risk; this should typically not be offered for LTBI treatment 1

Important Considerations for Healthcare Workers

Serial Testing Context

• As a traveling nurse, this individual likely undergoes serial TB screening 1
• QuantiFERON Gold can be used for both initial and serial testing of healthcare workers, replacing the tuberculin skin test in all circumstances 1
• No need to confirm positive QuantiFERON Gold with tuberculin skin test before initiating treatment; a positive result should prompt the same interventions as a positive TST 1

Occupational Risk Assessment

• Healthcare workers are at increased risk for TB infection due to occupational exposure 3
• Document specific exposure history: recent contact with TB patients, work in high-risk settings (emergency departments, respiratory wards, homeless shelters) 1
• If recent exposure occurred (within 8-10 weeks), consider that this could represent recent infection requiring more urgent treatment 1

Treatment Monitoring

Baseline Assessment

• Before starting treatment: complete medical history, physical examination, chest radiograph (already done), and HIV testing 1
• Baseline liver function tests if risk factors present: history of liver disease, alcohol use, concurrent hepatotoxic medications 1

During Treatment

• Monthly clinical monitoring for symptoms of hepatotoxicity (nausea, vomiting, abdominal pain, jaundice, dark urine) 1
• Baseline and follow-up aminotransferase monitoring recommended if liver disease risk factors exist 1
• For the 3RPT/INH regimen: monitor for hypersensitivity reactions (occurred in 4% of patients in clinical trials) 2

Common Pitfalls to Avoid

Do Not Repeat Testing

• Do not follow a positive QuantiFERON Gold with a tuberculin skin test - this is unnecessary and may cause confusion 1
• QuantiFERON Gold typically remains positive after LTBI treatment completion (87.5% still positive at 3 months, 84.6% at 15 months), so it should not be used to monitor treatment response 4

Treatment Completion

• Treatment completion rates are higher with QuantiFERON Gold-based screening (40%) compared to TST-based screening (30%) in clinical studies 5
• Directly observed therapy may improve completion rates, particularly for the once-weekly rifapentine regimen 1, 2

Special Consideration for Traveling Nurses

• Ensure continuity of care given the transient nature of travel nursing assignments 1
• Document treatment clearly in medical records to prevent unnecessary repeat treatment if future QuantiFERON Gold tests remain positive 1
• Annual QuantiFERON Gold testing should continue if the nurse remains in high-risk healthcare settings, though the test will likely remain positive 1