What tests and treatments are recommended for viral hepatitis?

Viral Hepatitis Testing and Treatment

For viral hepatitis diagnosis, HCV-antibody testing with reflex HCV RNA PCR testing is recommended for initial screening, while HBV testing should include HBsAg, anti-HBc, and anti-HBs to determine infection status. 1

Hepatitis B Testing Algorithm

Initial Testing

• HBsAg: Marker of current infection
• Anti-HBc (total): Indicates previous or ongoing infection
• Anti-HBs: Indicates immunity (from vaccination or resolved infection)

Interpretation of HBV Test Results

• Acute HBV infection: Positive HBsAg and IgM anti-HBc 1
• Chronic HBV infection: HBsAg positive for >6 months 1
• Resolved HBV infection: Negative HBsAg, positive anti-HBs and anti-HBc 1
• Vaccine-induced immunity: Negative HBsAg, negative anti-HBc, positive anti-HBs 1
• Isolated anti-HBc positive: May indicate:
  • Window period of acute infection
  • Remote resolved infection with waned anti-HBs
  • Occult HBV infection 1

Additional Testing for Chronic HBV

• HBeAg/anti-HBe: Indicates viral replication status
• HBV DNA: Quantifies viral load
• ALT/AST: Assesses liver inflammation
• Liver fibrosis assessment: Non-invasive markers or biopsy (optional) 1

Hepatitis C Testing Algorithm

Initial Testing

• HCV antibody with reflex HCV RNA PCR: Recommended for initial screening 1

Interpretation of HCV Test Results

• Current HCV infection: Positive HCV antibody and detectable HCV RNA 1, 2
• Resolved HCV infection or false positive: Positive HCV antibody but undetectable HCV RNA 1, 2
• No HCV infection: Negative HCV antibody (unless recent exposure or immunocompromised) 1

Special Testing Scenarios

• Recent exposure (<6 months): Consider direct HCV RNA testing or repeat antibody testing after 6 months 1, 2
• Immunocompromised patients: Consider direct HCV RNA testing due to possible false-negative antibody results 1, 2
• Risk of reinfection: Use HCV RNA testing (antibody will remain positive from prior infection) 1

Pre-Treatment Evaluation for Chronic Viral Hepatitis

For HBV:

1. Complete blood count, liver function tests (AST/ALT, alkaline phosphatase, GGT, bilirubin, albumin), prothrombin time, creatinine 1
2. HBeAg/anti-HBe and HBV DNA quantification 1
3. Tests for coinfections: anti-HCV, anti-HDV (if history of drug use), anti-HIV (high-risk groups) 1
4. Hepatitis A immunity status (IgG anti-HAV) in patients <50 years 1
5. Fibrosis assessment (non-invasive or biopsy) 1
6. HCC screening: ultrasound and serum α-fetoprotein 1

For HCV:

1. HCV genotype testing (if treatment regimen depends on genotype) 1
2. Quantitative HCV RNA (baseline viral load) 1
3. Complete blood count, liver function tests, INR 1
4. Assessment for HBV coinfection (HBsAg, anti-HBc) 3
5. Calculated GFR 1
6. Drug-drug interaction assessment 1

Treatment Monitoring

For HBV:

• Monitor HBV DNA, HBeAg/anti-HBe, ALT/AST during treatment
• Long-term monitoring even after treatment due to risk of reactivation

For HCV:

• Assessment of cure (SVR): HCV RNA testing 12 weeks after completing therapy 1
• Monitor for hypoglycemia in patients taking diabetes medications 1
• Monitor INR in patients taking warfarin 1
• Assess for other causes of liver disease if transaminases remain elevated after achieving SVR 1

Important Precautions

1. HBV reactivation risk: Test all HCV patients for HBV (HBsAg and anti-HBc) before starting direct-acting antiviral therapy 3
2. Drug interactions: Assess potential drug-drug interactions before starting antiviral therapy 1
3. Alcohol abstinence: Advise all patients with viral hepatitis to abstain from alcohol 1
4. Vaccination: Recommend hepatitis A and B vaccination for susceptible individuals with chronic liver disease 4

Follow-up for Treatment Failure

• Patients who fail initial HCV treatment should be evaluated for retreatment by specialists 1
• Patients with ongoing risk factors should receive risk reduction counseling and annual HCV RNA testing 1

By following these comprehensive testing and treatment algorithms, clinicians can effectively diagnose, monitor, and manage viral hepatitis to reduce morbidity and mortality associated with these infections.