What is the recommended prophylaxis for healthcare workers exposed to Tuberculosis (TB)?

Prophylaxis for Healthcare Workers Exposed to Tuberculosis

Healthcare workers exposed to tuberculosis should receive latent TB infection (LTBI) screening and, if positive, should be evaluated for preventive therapy with isoniazid or other appropriate regimens based on their risk factors.

Exposure Assessment and Initial Management

When a healthcare worker (HCW) is exposed to tuberculosis, the following steps should be taken:

1. Immediate post-exposure screening:

   • Perform a Mantoux tuberculin skin test (TST) as soon as possible after exposure unless the HCW has documented negative TST within the previous 3 months 1
   • Document baseline status to determine if conversion occurs later

2. Follow-up testing:

   • If initial TST is negative, repeat the test 12 weeks after the exposure ended 1
   • Consider the test positive if:
     • ≥5 mm induration in exposed persons 1
     • Any symptoms suggestive of TB develop regardless of TST results

Prophylaxis Decision Algorithm

For HCWs with Positive TST or Conversion:

1. Rule out active TB first:

   • Clinical evaluation including symptom assessment
   • Chest radiograph (not needed routinely after initial assessment unless symptoms develop) 1
   • If symptoms present: collect sputum specimens for AFB smear, culture, and drug susceptibility testing

2. If active TB ruled out, evaluate for preventive therapy based on:

   • HIV status (strongly encourage HIV testing if status unknown) 1
   • Other immunocompromising conditions
   • Recent conversion (within past 2 years)
   • Previous completion of preventive therapy

3. Standard preventive therapy regimens:

   • Isoniazid for appropriate duration according to published guidelines 1
   • Alternative regimens based on drug resistance patterns or contraindications

Work Restrictions and Return to Work

For HCWs with Active TB:

• Exclude from workplace until:
  • Adequate treatment is instituted
  • Cough is resolved
  • Sputum is free of bacilli on three consecutive smears collected on different days 1
  • Continue monitoring while on therapy to ensure maintenance of effective drug therapy 1

For HCWs with Latent TB Infection:

• No work restrictions necessary for HCWs receiving preventive treatment 1
• HCWs who cannot take or do not complete preventive therapy:
  • Should be evaluated for possible reassignment based on risk assessment 1
  • Should be counseled about risk of developing active TB
  • Should be instructed to seek prompt evaluation if TB symptoms develop 1
  • No mandatory work restrictions if otherwise healthy 1

Special Considerations

For Immunocompromised HCWs:

• More frequent monitoring for TB symptoms may be considered 1
• In settings with high risk of drug-resistant TB transmission:
  • Immunocompromised HCWs should be fully informed about increased risks 1
  • Consider work reassignment to lower-risk areas if requested by employee 1

BCG Vaccination:

BCG vaccination is generally not recommended for HCWs in the United States, except in very specific circumstances where:

• High percentage of TB patients have multi-drug resistant TB (resistant to both isoniazid and rifampin)
• Transmission of such drug-resistant strains to HCWs is likely
• Comprehensive TB infection control precautions have been unsuccessful 1

Implementation Pitfalls and Caveats

1. Knowledge gaps among HCWs: Despite generally good knowledge about TB transmission and prevention, specific knowledge about proper specimen collection may be lacking 2

2. Patient contact tracing challenges: Following TB exposure incidents, patient notification and follow-up can be challenging, with studies showing up to 72% of patients may be lost to follow-up 3

3. Administrative controls: Administrative infection control measures (early identification, isolation) are often the most poorly implemented yet most critical first-line defenses 2, 4

4. Respiratory protection: Ensure appropriate N95 respirators are available and properly used by HCWs when caring for patients with suspected or confirmed TB 2

5. Comprehensive approach needed: Guidelines alone are insufficient; implementation requires leadership commitment, proper training, and worker participation in decision-making 4