What labs should be ordered after an accidental needle stick at work?

Laboratory Testing After Accidental Needle Stick at Work

After an accidental needle stick at work, immediate testing should include HBsAg, anti-HCV, and HIV antibody testing for both the source patient (if known) and the exposed healthcare worker. 1

Initial Laboratory Evaluation

Source Patient Testing (if known)

• HBsAg (Hepatitis B surface antigen)
• Anti-HCV (Hepatitis C antibody)
• HIV antibody (consider rapid testing)
• HCV RNA if anti-HCV positive 2

Exposed Healthcare Worker (Baseline Testing)

• HBsAg and anti-HBs (to determine HBV immunity status)
• Anti-HCV and ALT (alanine aminotransferase)
• HIV antibody
• Complete blood count and liver function tests if HIV PEP will be initiated

Follow-up Testing Schedule

Hepatitis B Follow-up

• If HBV vaccination was given, test for anti-HBs 1-2 months after the last vaccine dose 1
• Note: Anti-HBs response cannot be accurately assessed if HBIG (Hepatitis B Immune Globulin) was received in the previous 3-4 months

Hepatitis C Follow-up

• Anti-HCV and ALT at 4-6 months post-exposure 1, 2
• Optional HCV RNA at 4-6 weeks if earlier diagnosis is desired 1, 2
• Confirm repeatedly reactive anti-HCV EIAs with supplemental tests

HIV Follow-up

• HIV antibody testing at baseline, 6 weeks, 3 months, and 6 months post-exposure 1
• More frequent testing if symptoms of acute retroviral syndrome develop
• Additional testing at 2 weeks and ongoing monitoring if on HIV PEP

Special Considerations

Source Unknown or Untested

• Assess risk based on exposure setting and circumstances 1
• For high-risk settings, consider testing as if source were positive
• Do not test discarded needles for virus contamination 1

Monitoring for PEP Side Effects

• If HIV PEP is initiated, laboratory monitoring should include:
  • Baseline and every 2 weeks: CBC, renal and hepatic function tests 1
  • Clinical evaluation for medication side effects

Common Pitfalls to Avoid

1. Delayed reporting - Immediate reporting is essential, especially for HIV exposure where PEP should be started within 24 hours 1

2. Inadequate source testing - Always attempt to test the source patient when possible

3. Incomplete follow-up - Establish a system to ensure exposed workers return for all scheduled follow-up testing 1

4. Inappropriate HCV management - Unlike HBV and HIV, no PEP is currently recommended for HCV exposures 2

5. Neglecting documentation - Maintain thorough records of the exposure, testing results, and follow-up plan

By following this structured laboratory testing approach after a needle stick injury, healthcare facilities can ensure proper monitoring for potential bloodborne pathogen transmission and provide timely intervention if seroconversion occurs.