What hepatitis testing should be performed for patients admitted to an acute‑care department, including routine screening and additional tests for suspected acute infection?

Hepatitis Testing in Acute Care Settings

For patients admitted to an acute care department, perform hepatitis B surface antigen (HBsAg), hepatitis B core antibody (anti-HBc), and hepatitis C antibody testing as universal screening, with reflex HCV RNA testing for any reactive HCV antibody results. 1

Universal Screening Approach

Hepatitis B Testing Panel

The 2023 CDC guidelines recommend a three-test panel for all adults ≥18 years at least once in their lifetime 1:

• HBsAg (hepatitis B surface antigen)
• Anti-HBc (hepatitis B core antibody)
• Anti-HBs (hepatitis B surface antibody)

This universal approach is particularly relevant in acute care settings where you encounter diverse patient populations with unknown testing history. Recent inpatient screening data demonstrates this is feasible and effective, identifying 2.9% HBsAg-positive patients and 32.8% with evidence of prior HBV infection 2.

Hepatitis C Testing Sequence

For HCV screening, use a two-step algorithm 3:

1. Initial test: HCV antibody (rapid or laboratory-based assay)
2. Reflex testing: If HCV antibody is reactive, automatically proceed to HCV RNA (NAT) testing on the same blood sample without requiring another draw

Critical point: The standard HCV antibody-to-RNA sequence is NOT designed for diagnosing acute hepatitis C 3. For suspected acute infection, proceed directly to HCV RNA testing or perform both antibody and RNA simultaneously.

When to Suspect Acute Viral Hepatitis

Clinical Triggers for Expanded Testing

If ALT >100 IU/L with clinical hepatitis presentation, add hepatitis E virus (HEV) testing 4. HEV is now recognized as the most common cause of acute viral hepatitis in many settings, with detection rates 31-times higher than HAV and 7-times higher than acute HBV in recent studies 4.

Acute Hepatitis Testing Panel

For patients with jaundice <4 weeks duration and AST/ALT >500 U/L 5:

• HEV: Both IgM ELISA AND RT-PCR (poor inter-test agreement necessitates both) 5
• HAV: IgM antibody (but only if ALT elevated, as most HAV presents with abnormal transaminases) 4
• HBV: HBsAg plus IgM anti-HBc to distinguish acute from chronic infection
• HCV RNA: Direct testing (antibody may be negative in early acute infection)

Important caveat: RT-PCR for HEV is more likely positive earlier in illness (mean 8.6 days vs 11.7 days for negative results), so timing matters 5.

Special Populations Requiring Enhanced Screening

Beyond universal screening, prioritize testing for these high-risk groups 6, 1:

• Persons who inject drugs (current or past)
• Men who have sex with men
• Persons from countries with HBV prevalence ≥2%
• HIV-positive individuals
• Household/sexual contacts of HBsAg-positive persons
• Currently or formerly incarcerated individuals
• History of sexually transmitted infections
• Immunocompromised patients (consider direct HCV RNA testing even if antibody negative) 3

Operational Implementation

Specimen Handling

Best practice: Collect blood in two tubes at initial venipuncture 3:

• Tube 1: HCV antibody testing
• Tube 2: Hold for reflex HCV RNA if antibody reactive

This eliminates the need for patient recall and additional blood draws, which are major contributors to loss-to-follow-up in acute care settings.

For Immunocompromised Patients

Consider direct HCV RNA testing regardless of antibody status, as antibody response may be blunted 3.

Recent Exposure Considerations

If HCV exposure occurred within the past 6 months, antibody testing may be falsely negative. In these cases, perform HCV RNA testing directly or plan follow-up antibody testing 3.

Common Pitfalls to Avoid

1. Don't rely solely on risk factor assessment: Most ED healthcare workers (68%) do not routinely interrogate for hepatitis risk factors when the acute complaint is their priority 7. Automatic screening circumvents this barrier.

2. Don't stop at antibody testing for HCV: A reactive HCV antibody alone cannot distinguish current infection (requiring treatment) from resolved infection. Always reflex to RNA 3.

3. Don't overlook hepatitis E: Traditional algorithms focused on HAV/HBV/HCV miss HEV, which now accounts for 50% of acute hepatitis cases in some settings when combined testing is performed 5, 4.

4. Don't assume normal ALT excludes chronic infection: Most chronic HBV and HCV infections present with normal or minimally elevated transaminases. Universal screening, not symptom-based testing, is the strategy for identifying these patients 1.

Reporting Requirements

Positive HBsAg and HCV RNA results are nationally notifiable conditions requiring mandatory reporting to health departments in most jurisdictions 3. Familiarize yourself with local reporting policies.