Initial Serologic Testing for Hepatitis B Infection
The correct answer is C: Hepatitis B surface antigen (HBsAg), hepatitis B core antibody (anti-HBc), and hepatitis B surface antibody (anti-HBs) should be included as initial serologic testing for hepatitis B infection. This three-test panel represents the standard baseline serologic assessment recommended by major guidelines 1.
Rationale for the Three-Test Panel
The CDC and multiple professional societies consistently recommend this specific combination for initial screening 2, 1:
- HBsAg identifies current active infection (either acute or chronic) and is the hallmark marker of HBV infection 2, 3
- Anti-HBs indicates immunity from either vaccination or past cleared infection 2, 1, 4
- Total anti-HBc distinguishes natural infection from vaccine-induced immunity and persists for life after exposure 2, 1
Why Other Options Are Incorrect
Option A is incorrect because it includes HBV DNA and hepatitis B e-antigen (HBeAg), which are not part of initial screening but rather used for disease monitoring and treatment decisions in patients already known to have chronic infection 4, 5.
Option B is incorrect because while it includes HBeAg, this marker is used to assess viral replication status in known chronic infections, not for initial diagnosis 2, 4.
Option D is incorrect because it omits anti-HBc and anti-HBs, which are essential for determining immune status and distinguishing between different phases of infection 2, 1.
Clinical Application of the Three-Test Panel
This testing strategy allows complete interpretation of hepatitis B status 2, 1, 4:
- All three negative: Patient is susceptible and needs vaccination 2, 1
- HBsAg positive: Active infection present; requires HBV DNA and additional workup 1, 4
- Anti-HBs positive only: Vaccine-induced immunity 4
- Anti-HBs and anti-HBc positive, HBsAg negative: Past infection with recovery 4
- Isolated anti-HBc positive: Requires careful interpretation; may represent remote infection with waning anti-HBs, occult hepatitis B, or false positive 2, 1
Special Populations Requiring This Testing
The CDC recommends universal screening for all adults aged 18 years and older using this three-test strategy 1. Specific high-priority groups include 2:
- Persons born in countries with HBV prevalence ≥2% 2
- Household, sexual, or needle-sharing contacts of HBsAg-positive persons 2
- Hemodialysis patients before admission to dialysis units 2
- Persons needing immunosuppressive therapy 2, 6
- HIV-positive persons 2
- Persons who inject drugs 2
Common Pitfall to Avoid
Do not order HBeAg or HBV DNA as part of initial screening—these are second-line tests reserved for patients with confirmed HBsAg positivity to assess disease activity and guide treatment decisions 4, 5. Ordering these tests prematurely increases costs without providing diagnostic value for initial screening 1.