What is the recommended screening and prevention protocol for Hepatitis B (HBV) as part of Sexually Transmitted Disease (STD) screening?

Hepatitis B Screening and Prevention Protocol for STD Screening

Hepatitis B screening should be offered to all individuals at high risk for infection, including sexually active homosexual and bisexual men, those with multiple sex partners, persons recently diagnosed with another STD, and persons who received treatment in an STD clinic. 1

High-Risk Populations Requiring Screening

Screening for HBV infection should target:

1. Sexually active populations at increased risk:

   • Homosexual and bisexual men
   • Heterosexual individuals with multiple sex partners (>1 partner in preceding 6 months)
   • Persons recently diagnosed with another STD
   • Sex workers
   • Sexual contacts of persons with acute or chronic HBV infection 1

2. Other high-risk groups:

   • Persons born in regions with HBV prevalence ≥2% (Asia, Africa, Pacific Islands, parts of South America) 1, 2
   • Injecting drug users and users of illegal non-injecting drugs
   • Household contacts of persons with chronic HBV infection
   • HIV-positive individuals 1

Screening Protocol

Serologic Testing

The optimal screening approach includes:

• HBsAg (hepatitis B surface antigen) - detects active infection
• Anti-HBs (antibody to hepatitis B surface antigen) - indicates immunity
• Anti-HBc (total antibody to hepatitis B core antigen) - indicates past or current infection 1, 3

For cost-effective screening in STD clinics:

• Use anti-HBc as the preferred serologic test for prevaccination testing, as it detects both resolved and chronic infection 1
• Consider age-based screening strategies - studies show higher prevalence (28%) of past infection in those ≥25 years versus only 7% in younger individuals 1

Practical Implementation

• For adults attending STD clinics, prevaccination testing may be cost-effective due to higher prevalence of HBV infection 1
• To improve compliance, administer the first vaccine dose at the time of testing, then adjust subsequent doses based on test results 1
• Simple targeting criteria of male gender, unemployment status, and birth in medium/high endemic countries can improve screening efficiency 4

Prevention Protocol

Vaccination

For susceptible individuals (HBsAg-negative with no evidence of immunity):

• Vaccination Schedule: Three doses at 0,1-2, and 4-6 months 1
• Alternative Schedule: 0,1,2, and 12 months (approved for one vaccine) 1
• Dosage: 1 mL for adults (IM in deltoid, not buttock); 0.5 or 1 mL for ages 11-19 depending on manufacturer 1
• Efficacy: Protective antibody levels present in ~50% after one dose, 85% after two doses, >90% after three doses 1

Post-Exposure Prophylaxis

For sexual contacts of persons with acute HBV infection:

• Administer HBIG (hepatitis B immune globulin) 0.06 mL/kg IM within 14 days of last exposure 1
• Begin standard three-dose HBV vaccination series at the time of HBIG administration 1
• Early administration is more effective in preventing infection 1

Special Considerations

HIV Co-infection

• HBV infection is more likely to lead to chronic carriage in HIV-infected persons
• HIV infection impairs response to HBV vaccine
• Test HIV-infected vaccinees for anti-HBs 1-2 months after third vaccine dose
• Consider revaccination for non-responders 1

Pregnancy

• Pregnancy is not a contraindication to HBV or HBIG vaccine administration 1
• Routine screening of all pregnant women is recommended as part of comprehensive HBV prevention strategy 1

Common Pitfalls to Avoid

1. Relying on self-reported vaccination status - Verification of immunity through serologic testing is important as many individuals may incorrectly report their vaccination status 4

2. Using only one serologic marker for screening - Using only anti-HBc may misclassify those immune due to vaccination; using only anti-HBs may misclassify carriers 1

3. Delaying post-exposure prophylaxis - HBIG plus vaccination must be administered within 14 days of exposure to be effective 1

4. Administering vaccine in the buttock - This reduces vaccine efficacy; the deltoid is the proper administration site 1

5. Restarting the vaccination series - If doses are missed, the series should not be restarted; simply administer the missing dose as soon as possible 1

By implementing comprehensive screening and prevention protocols for HBV in STD clinics, we can significantly reduce morbidity and mortality associated with chronic HBV infection, which leads to an estimated 5,000 deaths annually in the United States from cirrhosis and hepatocellular carcinoma 1.