What are the recommendations for Hepatitis B (HBV) lab testing after exposure to sexually transmitted diseases (STDs)?

Hepatitis B Lab Testing Recommendations After STD Exposure

For individuals exposed to sexually transmitted diseases (STDs), hepatitis B testing should include HBsAg (hepatitis B surface antigen) testing, with follow-up testing for anti-HBs (antibody to hepatitis B surface antigen) 1-2 months after completing vaccination if indicated. 1

Initial Assessment After STD Exposure

• Evaluate the risk of HBV infection based on the type of exposure (sexual contact) and the source's HBV status 1
• Test known sources for HBsAg to determine their infection status 1
• Assess the exposed person's immune status for HBV infection by reviewing history of hepatitis B vaccination and previous vaccine response 1

Laboratory Testing Protocol

• For initial evaluation after STD exposure:

  • Collect serum sample for immediate evaluation for hepatitis B (HBsAg) 1
  • Test exposed person for anti-HBs if previously vaccinated to confirm immunity 1

• For follow-up testing after STD exposure:

  • If hepatitis B vaccine is administered, perform follow-up anti-HBs testing 1-2 months after the last dose of vaccine 1
  • Note that anti-HBs response to vaccine cannot be accurately assessed if HBIG (Hepatitis B Immune Globulin) was received in the previous 3-4 months 1

Post-Exposure Prophylaxis Recommendations

• For sexual exposure to a person with acute hepatitis B, administer a single dose of HBIG (0.06 mL/kg) within 14 days of the last sexual contact 2
• Begin the hepatitis B vaccine series concurrently with HBIG administration 2
• The vaccine should be administered at a different site than the HBIG but can be given at the same time 2
• Follow-up doses of vaccine should be administered 1-2 and 4-6 months after the first dose 1

Special Considerations

• Sexual transmission accounts for the majority of HBV infections in industrialized countries, making testing particularly important after STD exposure 3
• The most common risk factors for heterosexual transmission include having multiple sex partners (more than one partner in six months) or a recent history of an STD 1
• Persons with a history of multiple sex partners or treatment for STDs appear to have an increased risk for HBV infection 1
• Studies have found a significant association between HBV infection and current or past STIs, with prevalence ratios ranging from 1.15 to 6.76 depending on the specific HBV marker and STI 4

Common Pitfalls to Avoid

• Delaying testing and prophylaxis beyond 14 days after exposure significantly reduces effectiveness 2
• Failing to complete the full vaccination series (completion rates are often low, with a median of only 30%) 5
• Not testing for anti-HBs after vaccination in immunocompromised individuals, such as those with HIV 1
• Overlooking the need for hepatitis B testing in STD evaluations despite recommendations 6

Remember that hepatitis B is unique among STDs in that a safe, effective vaccine is available, making prevention particularly important in the management of potential exposures 7.