Hepatitis B — Chronic

📋 Key Information Summary

📋

Diagnosis: Chronic hepatitis B (CHB) defined by persistence of HBsAg for ≥6 months; approximately 230,000 people living with CHB in Australia, with significant under-diagnosis particularly among Aboriginal and Torres Strait Islander peoples and culturally diverse communities.
Serology interpretation is critical: HBsAg indicates active infection; anti-HBs indicates immunity; anti-HBc IgM suggests acute hepatitis; anti-HBc IgG indicates past or current exposure; isolated anti-HBc may reflect resolved infection with waned anti-HBs, occult HBV, or false positive — always check HBV DNA.
HBeAg/anti-HBe and HBV DNA guide replication status and treatment decisions; HBsAg quantification assists with phase confirmation and predicts HBsAg loss.
Four phases of chronic infection: Immune-tolerant (HBeAg+, high DNA, normal ALT), immune-active HBeAg-positive (high DNA, elevated ALT), inactive carrier (HBeAg−, anti-HBe+, low DNA, normal ALT), and HBeAg-negative chronic hepatitis (precore/BCP mutant, fluctuating ALT).
Treatment indicated when: ALT persistently elevated with HBV DNA >20,000 IU/mL (HBeAg+) or >2,000 IU/mL (HBeAg−), significant fibrosis (≥F2) on transient elastography or biopsy, or any cirrhosis with detectable HBV DNA.
First-line oral antivirals: Entecavir 0.5 mg daily or tenofovir; tenofovir alafenamide (TAF) 25 mg preferred over tenofovir disoproxil (TDF) in patients with renal impairment or osteoporosis risk.
Pegylated interferon alfa-2a offers a finite treatment course (48 weeks) in selected patients (young, high ALT, low DNA, genotype A or B) but has significant side-effect profile.
HCC surveillance mandatory: 6-monthly abdominal ultrasound ± AFP for all patients with cirrhosis, family history of HCC, Africans aged >20 years, Asian males >40 years, and Asian females >50 years.
Reactivation risk: B-cell depleting agents (rituximab — highest risk), anthracycline-based chemotherapy, anti-TNF therapy, and moderate-to-high dose corticosteroids can precipitate HBV reactivation; prophylactic antiviral therapy (entecavir or tenofovir) is essential regardless of HBsAg status or isolated anti-HBc.
Aboriginal and Torres Strait Islander peoples have higher prevalence, earlier acquisition (often perinatal/childhood), and higher HCC rates — enhanced screening, culturally safe care, and government-funded antiviral access are essential.
All antivirals are PBS-listed in Australia; entecavir and tenofovir are General Benefit; treatment is generally long-term with periodic reassessment for finite therapy cessation in selected patients.

Serology Interpretation

Interpretation of hepatitis B serological markers is foundational to diagnosis, phase classification, treatment decisions, and assessment of immunity. A systematic approach combining HBsAg, anti-HBs, anti-HBc (IgM and IgG), HBeAg, anti-HBe, HBV DNA, and HBsAg quantification provides the complete clinical picture.

Core Serological Markers

Marker	Significance	Clinical Interpretation
HBsAg	Surface antigen — indicates active infection	Present in both acute and chronic hepatitis B. Persistence ≥6 months defines chronic infection. Quantitative HBsAg (qHBsAg) aids phase prediction and monitoring.
Anti-HBs	Protective antibody — indicates immunity	≥10 mIU/mL = protective level post-vaccination or resolved infection. Levels may wane over time; memory immunity generally persists despite serological loss.
Anti-HBc IgM	Marker of acute or recent infection	Present in acute hepatitis B (typically high titre). Low-level positive may occur during HBeAg-negative chronic hepatitis flare — correlation with clinical context essential.
Anti-HBc IgG	Marker of past or current HBV exposure	Persists lifelong. Present in resolved infection, chronic infection, and occult HBV. Does not distinguish between active and resolved — must interpret with HBsAg.
HBeAg	Marker of active viral replication	Positive in immune-tolerant and immune-active phases. Seroconversion to anti-HBe marks transition to inactive carrier in most patients.
Anti-HBe	Antibody to e antigen	Usually indicates reduced replication. However, HBeAg-negative chronic hepatitis (precore/BCP mutants) presents with anti-HBe positivity and ongoing disease activity.

Viral Markers and Quantitative Assays

Test	Role	Key Thresholds
HBV DNA (viral load)	Quantifies replication activity; critical for phase classification and treatment indication	HBeAg+ chronic: treat if >20,000 IU/mL. HBeAg− chronic: treat if >2,000 IU/mL. Inactive carrier: typically <2,000 IU/mL. Undetectable = good treatment response.
HBsAg quantification (qHBsAg)	Aids phase confirmation; predicts probability of HBsAg loss; guides treatment cessation decisions	qHBsAg <100 IU/mL associated with higher rates of HBsAg loss. >1,000 IU/mL suggests active immune-active phase in HBeAg− patients.

Interpreting Common Serological Patterns

Pattern	Interpretation	Action
HBsAg+, HBeAg+, anti-HBc IgG+, high DNA	Chronic HBV — likely immune-tolerant or immune-active phase	Check ALT, HBV DNA level, assess fibrosis; classify phase
HBsAg−, anti-HBs+, anti-HBc IgG+	Resolved (past) infection with immunity	No treatment; document for transplant/immunosuppression screening
HBsAg−, anti-HBs−, anti-HBc IgG+	Isolated anti-HBc	Check HBV DNA — may represent occult HBV infection, resolved infection with waned anti-HBs, or false positive. If HBV DNA undetectable: vaccinate if immunosuppression anticipated; monitor if high-risk immunosuppression planned.
HBsAg−, anti-HBs+, anti-HBc−	Vaccine-induced immunity (never infected)	No further action required
HBsAg−, anti-HBs−, anti-HBc−	Susceptible — no evidence of infection or immunity	Offer vaccination per Australian National Immunisation Program

⚠️

Isolated anti-HBc — do not ignore: In patients with isolated anti-HBc (HBsAg−, anti-HBs−, anti-HBc+), always check HBV DNA before immunosuppressive therapy. Occult HBV infection may reactivate dangerously. This pattern is more common in Aboriginal and Torres Strait Islander peoples, migrants from highly endemic regions, and people with HIV or HCV co-infection.

Laboratory Availability in Australia

MBS Available

HBsAg, anti-HBs, anti-HBc (total and IgM), HBeAg, anti-HBe

Available through all major Australian pathology providers (Sonic, Healius, Clinical Labs). Bulk-billed under Medicare.

MBS Available

HBV DNA quantitative (viral load)

MBS item available; performed by PCR-based assays. Lower limit of detection typically 20 IU/mL. Order with Medicare rebate for patients with confirmed HBsAg positivity.

MBS Available

HBsAg quantification (qHBsAg)

Available at specialist request through reference laboratories. Increasingly used in clinical practice for phase confirmation and treatment cessation planning.

MBS Available

Transient elastography (FibroScan®)

MBS-rebated when performed in appropriate clinical setting; used for non-invasive fibrosis assessment to guide treatment decisions.

Phases of Chronic Infection

Chronic hepatitis B (CHB) evolves through recognisable immunological phases. Accurate phase classification — combining HBeAg status, HBV DNA level, ALT, and hepatic fibrosis assessment — directly determines whether antiviral treatment is indicated. Not all patients progress sequentially through every phase, and phases may overlap or change with host immune status.

ℹ️

Updated terminology: Current international guidelines (AASLD 2018, EASL 2017, APASL 2015) use the terms below. The older "immune-tolerant" label is retained for familiarity but recognition that some patients in this phase may have subclinical hepatic inflammation is evolving.

Phase 1 — Immune-Tolerant (HBeAg-Positive Chronic Infection)

Phase 1

Immune-Tolerant

Serology: HBeAg positive, anti-HBe negative
HBV DNA: Very high (typically >10⁷ IU/mL)
ALT: Persistently normal
Fibrosis: Minimal to none (F0–F1)
HBsAg: High levels (>10,000 IU/mL)

Treatment: Generally NOT indicated — monitor every 6–12 months. Recent data suggest some patients may harbour histological inflammation; consider liver biopsy or elastography if age >30–40 years or duration >20 years.

Phase 2 — Immune-Active, HBeAg-Positive (HBeAg-Positive Chronic Hepatitis)

Phase 2

Immune-Active (HBeAg+)

Serology: HBeAg positive, anti-HBe negative
HBV DNA: High (typically 10⁵–10⁷ IU/mL, often >20,000)
ALT: Elevated (fluctuating or persistently raised)
Fibrosis: Progressive — may be F1–F4
HBsAg: >1,000 IU/mL

Treatment: INDICATED — this is the primary treatment window. Spontaneous HBeAg seroconversion possible but treatment reduces fibrosis progression and HCC risk.

Phase 3 — Inactive Carrier (HBeAg-Negative Chronic Infection)

Phase 3

Inactive Carrier

Serology: HBeAg negative, anti-HBe positive
HBV DNA: Low or undetectable (<2,000 IU/mL)
ALT: Persistently normal
Fibrosis: Stable or regressing
HBsAg: Variable, often <1,000 IU/mL

Treatment: NOT indicated. Monitor ALT every 3–6 months for first 1–2 years to confirm stability, then annually. HBsAg loss occurs at ~1% per year. HBsAg <100 IU/mL = favourable prognosis.

Phase 4 — HBeAg-Negative Chronic Hepatitis (Precore/BCP Variant)

Phase 4

HBeAg-Negative Chronic Hepatitis

Serology: HBeAg negative, anti-HBe positive
HBV DNA: Detectable, fluctuating (typically 10³–10⁷ IU/mL, often >2,000)
ALT: Fluctuating — may be intermittently normal (flares and remissions)
Fibrosis: Progressive — often advanced at presentation
Mechanism: Precore (G1896A) or basal core promoter (BCP) mutations prevent HBeAg synthesis

Treatment: INDICATED — more common in Australia than HBeAg-positive chronic hepatitis; characterised by relapsing course with risk of cirrhosis and HCC.

Phase 5 — Resolved Hepatitis B (HBsAg Loss)

Phase 5

Resolved HBV

Serology: HBsAg negative, anti-HBs positive (or negative with anti-HBc+), anti-HBc IgG positive
HBV DNA: Undetectable (occult HBV: cccDNA persists in hepatocytes)
ALT: Normal

Treatment: Not required. Reactivation risk with immunosuppression — see HCC Surveillance & Reactivation section. Screen prior to chemotherapy/immunosuppression.

Phase Assessment Algorithm

1

Confirm HBsAg positive ≥6 months

Establish chronic infection. If HBsAg positive <6 months — suspect acute hepatitis B.

2

Check HBeAg and anti-HBe

HBeAg+ = phases 1 or 2. HBeAg−/anti-HBe+ = phases 3 or 4.

3

Measure HBV DNA and ALT

Elevated ALT + high DNA = active hepatitis (phase 2 or 4). Normal ALT + low DNA = inactive carrier (phase 3). Normal ALT + very high DNA = immune-tolerant (phase 1).

4

Assess fibrosis

Transient elastography (FibroScan®) preferred. Liver biopsy if non-invasive tests discordant or inconclusive. Fibrosis stage ≥F2 or cirrhosis = treatment indicated regardless of ALT/DNA thresholds.

5

Reassess over time

Phases are dynamic. Recheck ALT/DNA every 6 months. Patients may transition between phases — repeated flares in HBeAg− patients distinguish them from stable inactive carriers.

⚠️

Do not rely on a single ALT measurement: ALT may be intermittently normal in HBeAg-negative chronic hepatitis (phase 4). Serial monitoring over 12 months with HBV DNA is essential to distinguish inactive carrier from HBeAg-negative chronic hepatitis before deciding against treatment.

Treatment Indications & Agents

Antiviral therapy for chronic hepatitis B aims to suppress HBV replication, reduce hepatic inflammation and fibrosis progression, prevent cirrhosis decompensation, and reduce hepatocellular carcinoma (HCC) risk. Treatment is usually long-term; finite therapy is possible in selected patients after prolonged consolidation.

Treatment Indications

✅

Treat with antiviral therapy if ANY of the following are present:

HBeAg-positive chronic hepatitis: ALT > ULN and HBV DNA >20,000 IU/mL
HBeAg-negative chronic hepatitis: ALT > ULN and HBV DNA >2,000 IU/mL
Significant fibrosis (≥F2 on transient elastography or liver biopsy), regardless of ALT
Cirrhosis (compensated or decompensated) with any detectable HBV DNA
Family history of HCC or hepatocellular carcinoma
Extrahepatic manifestations (polyarteritis nodosa, glomerulonephritis)
Prior to or during immunosuppressive therapy (reactivation prophylaxis)
Pregnancy: if HBV DNA >200,000 IU/mL — antenatal tenofovir from 28–32 weeks to reduce perinatal transmission

First-Line Oral Antiviral Agents

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Entecavir

Baraclude® · Generic · Nucleoside analogue

Adult dose 0.5 mg PO once daily, on an empty stomach (≥2 hours after food)

Lamivudine-refractory dose 1.0 mg PO once daily

Paediatric dose ≥2 years, ≥10 kg: weight-based dosing (0.015 mg/kg up to 0.5 mg daily)

Renal adjustment Required — reduce dose if CrCl <50 mL/min; consult product information

Key side effects Headache, fatigue, lactic acidosis (rare); generally well tolerated

Resistance Very low barrier to resistance in treatment-naïve patients (~1.2% at 5 years); higher in lamivudine-exposed

PBS status ✔ PBS General Benefit

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Tenofovir Alafenamide (TAF)

Vemlidy® · Nucleotide analogue (prodrug)

Adult dose 25 mg PO once daily, with food

Renal adjustment Not recommended if CrCl <15 mL/min (no haemodialysis data). Preferred over TDF in CKD stage 3+.

Advantages Lower renal toxicity and less bone mineral density loss compared to TDF; preferred in elderly, CKD, osteoporosis risk

Key side effects Nausea, headache; improved renal and bone safety profile vs TDF

PBS status ✔ PBS General Benefit

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Tenofovir Disoproxil Fumarate (TDF)

Viread® · Generic · Nucleotide analogue

Adult dose 300 mg PO once daily, with or without food

Renal adjustment Required — extend dosing interval if CrCl <50 mL/min; monitor renal function and bone density

Key concerns Proximal renal tubular dysfunction, reduced bone mineral density — monitor eGFR, phosphate, urine protein/creatinine ratio annually

Resistance No documented resistance in treatment-naïve patients at 8+ years

PBS status ✔ PBS General Benefit

⚠️

TAF vs TDF selection: Tenofovir alafenamide (TAF) is preferred over tenofovir disoproxil (TDF) in patients with or at risk of renal impairment (eGFR <60 mL/min), osteoporosis, or bone fractures. Both are PBS-listed. In patients with normal renal function and no bone risk, either agent is appropriate. Do NOT co-prescribe TAF with boosted protease inhibitors (e.g., ritonavir-boosted darunavir in HIV co-infection) due to increased tenofovir exposure.

Finite-Duration Therapy — Pegylated Interferon Alfa-2a

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Pegylated Interferon Alfa-2a

Pegasys® · Immunomodulator

Adult dose 180 micrograms SC once weekly for 48 weeks

Best candidates Young patients, high ALT (>2–5× ULN), low HBV DNA (<2 × 10⁸ IU/mL), genotype A or B, HBeAg-positive, no cirrhosis

Advantages Finite duration; higher HBsAg loss rates (~3–7%); no resistance

Key side effects Flu-like symptoms, cytopenias, depression, thyroid dysfunction, autoimmune exacerbation — contraindicated in decompensated cirrhosis, autoimmune disease, significant psychiatric illness

PBS status ✔ PBS General Benefit

Agents No Longer Recommended as First-Line

Agent	Issue	Current Role
Lamivudine	High resistance rate (~70% at 5 years)	Not recommended for chronic HBV monotherapy; only in combination for HIV co-infection
Adefovir	Weak potency, nephrotoxicity, high resistance	Obsoleted by tenofovir; not recommended
Telbivudine	Moderate resistance, limited availability in Australia	Not PBS-listed for HBV in Australia; not recommended

Treatment Cessation Considerations

Most patients require long-term (often indefinite) oral antiviral therapy. However, finite therapy may be considered in carefully selected patients:

HBeAg-positive patients: After HBeAg seroconversion (HBeAg−, anti-HBe+) with undetectable HBV DNA for ≥12 months of consolidation therapy — consider cessation with close monitoring. Risk of relapse ~50%.
HBeAg-negative patients: Cessation may be considered if HBsAg loss achieved (functional cure) or HBsAg <100 IU/mL with undetectable HBV DNA for ≥3 years — but relapse rates remain high (~50–60%).
Cirrhosis: Do NOT stop treatment — indefinite therapy required due to high risk of hepatic decompensation upon relapse.
Post-cessation monitoring: ALT and HBV DNA every 3 months for ≥12 months; retreat promptly if ALT flare or HBV DNA rebound detected.

🚨

Never stop antivirals abruptly in cirrhosis: Sudden cessation of entecavir or tenofovir in patients with cirrhosis (even compensated) can precipitate severe hepatitis flares with hepatic decompensation and death. Indefinite treatment is mandatory in all cirrhotic patients.

Special Treatment Considerations

🫘 Renal Impairment

Entecavir: reduce dose if CrCl <50 mL/min

Dose reduction per product information: CrCl 30–49 = 0.25 mg daily; CrCl 10–29 = 0.15 mg daily; haemodialysis/CAPD = 0.05 mg daily

TAF preferred over TDF

TAF has significantly lower impact on renal tubular function and eGFR decline compared to TDF

TDF: extend dosing interval if CrCl <50 mL/min

Monitor renal function, serum phosphate, urine protein/creatinine ratio every 6 months on TDF

🫁 Hepatic Impairment

Entecavir and tenofovir: no dose adjustment required

Both are hepatically safe. Decompensated cirrhosis requires urgent hepatology referral and lifelong antiviral therapy — transplant assessment if Child-Pugh ≥B

🤰 Pregnancy

Tenofovir (TDF) is the preferred agent in pregnancy

Antenatal tenofovir from 28–32 weeks gestation if HBV DNA >200,000 IU/mL reduces perinatal transmission from ~15% to <2% when combined with HBV vaccination + HBIg at birth. Breastfeeding is safe on antivirals.

HCC Surveillance & Reactivation Prevention

Hepatocellular carcinoma (HCC) is the most serious long-term complication of chronic hepatitis B, even in the absence of cirrhosis. Concurrently, HBV reactivation during immunosuppressive therapy represents an acute, potentially fatal complication that is entirely preventable with appropriate prophylaxis.

HCC Surveillance Programme

⚠️

HCC can develop without cirrhosis in chronic hepatitis B: Unlike other chronic liver diseases, HBV-related HCC may arise in non-cirrhotic livers — particularly in patients with high-level viraemia, ongoing necroinflammation, or specific risk demographics. Surveillance criteria are therefore broader than for other aetiologies.

Who Requires HCC Surveillance?

Risk Group	Surveillance Criteria
All patients with cirrhosis (any aetiology including HBV)	6-monthly ultrasound ± AFP — regardless of antiviral therapy or viral suppression
Family history of HCC (first-degree relative)	6-monthly ultrasound ± AFP from age 20 or from diagnosis, whichever is later
African-born patients	6-monthly ultrasound ± AFP from age 20 (higher incidence at younger age)
Asian-born males	6-monthly ultrasound ± AFP from age 40
Asian-born females	6-monthly ultrasound ± AFP from age 50
Aboriginal and Torres Strait Islander peoples	Lower threshold for surveillance; consider from age 40 or earlier if additional risk factors (co-infection, alcohol, diabetes)

Surveillance Modality

Abdominal ultrasound: Primary surveillance tool — MBS-rebated. Sensitivity ~60–80% for early-stage HCC. Perform every 6 months (not annually).
Alpha-fetoprotein (AFP): Adjunct to ultrasound; alone has insufficient sensitivity (~60%) and specificity. Recommended combined with ultrasound.
Multiphasic CT or MRI: Not routine surveillance; reserved for diagnostic workup of lesions detected on ultrasound (LI-RADS classification).

Australian Pathway — Abnormal Surveillance Result

1

Ultrasound detects nodule <1 cm

Repeat ultrasound at 3 months. If stable, return to 6-monthly surveillance. If growing → CT/MRI.

2

Nodule 1–2 cm

Multiphasic CT or gadoxetic acid-enhanced MRI. If typical HCC pattern (arterial hyperenhancement + washout) → treat as HCC. If indeterminate → biopsy or second modality.

3

Nodule >2 cm

Multiphasic CT or MRI. Typical features = diagnostic of HCC without biopsy. Refer to multidisciplinary hepatobiliary team.

4

AFP >400 ng/mL with liver mass

Diagnostic of HCC in cirrhotic liver — refer urgently for staging and multidisciplinary management.

HBV Reactivation During Immunosuppressive Therapy

🚨

HBV reactivation is a medical emergency: Mortality rates of 5–30% when reactivation occurs during B-cell depleting therapy. ALL patients must be screened for HBsAg, anti-HBc, and anti-HBs before starting any immunosuppressive regimen — this is a National Safety and Quality Health Service (NSQHS) standard.

Risk Stratification for Reactivation

Low Risk

<1% reactivation rate

• Low-dose corticosteroids (<10 mg prednisolone/day or <2 weeks)
• Methotrexate
• Azathioprine/6-MP
• Small molecule TKIs (e.g., imatinib)
• Anti-TNF agents (in HBsAg−/anti-HBc+ patients)

Monitoring: ALT + HBV DNA every 3 months during therapy. Treat if reactivation occurs.

Moderate Risk

1–10% reactivation rate

• Anthracycline-based chemotherapy (e.g., R-CHOP without rituximab)
• Anti-TNF agents (in HBsAg+ patients)
• Moderate-dose corticosteroids (≥10 mg/day prednisolone ≥4 weeks)
• Tyrosine kinase inhibitors
• Other targeted therapies

Prophylaxis: Antiviral therapy (entecavir or tenofovir) starting before immunosuppression and continuing ≥12 months after cessation (≥6 months after anti-TNF).

High Risk

>10% reactivation rate

• Rituximab (anti-CD20) — HIGHEST RISK
• Ofatumumab, obinutuzumab (anti-CD20)
• Brentuximab vedotin
• Alemtuzumab (anti-CD52)
• High-dose corticosteroids (≥20 mg/day ≥4 weeks)
• Haematopoietic stem cell transplant

Mandatory prophylaxis: Entecavir or tenofovir — start ≥2 weeks before and continue ≥12–18 months after last dose. Applies to BOTH HBsAg+ and isolated anti-HBc+ patients.

Prophylactic Antiviral Agents for Reactivation Prevention

🛡️

Entecavir (prophylactic)

Preferred for reactivation prophylaxis

Dose 0.5 mg PO once daily — start ≥2 weeks before immunosuppression

Duration Continue ≥12–18 months after last dose of immunosuppressive agent (≥18 months post-rituximab)

PBS status ✔ PBS General Benefit

🛡️

Tenofovir (TDF or TAF) (prophylactic)

Alternative prophylactic agent

TDF dose 300 mg PO once daily

TAF dose 25 mg PO once daily (preferred if renal/bone concerns)

Duration Same as entecavir — ≥12–18 months post-immunosuppression

PBS status ✔ PBS General Benefit

⚠️

Isolated anti-HBc patients are NOT immune to reactivation: Patients who are HBsAg−/anti-HBs−/anti-HBc+ (isolated anti-HBc) harbour occult HBV in ~10–50% of cases depending on endemicity. High-risk immunosuppression (especially rituximab) can trigger reactivation with fulminant hepatitis. Prophylactic antivirals are recommended for high-risk regimens in this group — check HBV DNA before starting therapy.

Co-Infection Considerations

Co-Infection	Key Management Point
HBV + HIV	Use tenofovir (TDF or TAF) + lamivudine or emtricitabine as part of antiretroviral regimen to cover both. Do not use entecavir as sole HBV-active agent in HIV co-infection (risk of HIV resistance). Coordinate with HIV specialist.
HBV + HCV	Direct-acting antiviral (DAA) therapy for HCV can trigger HBV reactivation. Screen HBV serology before DAAs. If HBsAg+ → start prophylactic entecavir/tenofovir before DAA and continue 12 weeks post-DAA. If isolated anti-HBc → monitor ALT and HBV DNA during/after DAA.
HBV + HDV	HDV co-infection (present in ~5% of HBsAg+ patients globally) causes the most aggressive form of chronic viral hepatitis. Screen all HBsAg+ patients with anti-HDV. Pegylated interferon is the only effective treatment for HDV (48+ weeks). Bulevirtide (Hepcludex®) approved in Europe but not yet PBS-listed in Australia.

Aboriginal and Torres Strait Islander Health

Aboriginal and Torres Strait Islander Health Considerations

Prevalence

CHB prevalence in Aboriginal and Torres Strait Islander peoples is approximately 3–6 times higher than the non-Indigenous Australian population. The estimated prevalence of HBsAg positivity is ~1.8% compared to ~0.3% in the general population. The Northern Territory, Queensland, and Western Australia carry the greatest burden.

Age of acquisition

HBV transmission in Aboriginal and Torres Strait Islander communities often occurs in early childhood (horizontal transmission) rather than perinatally, differing from patterns in Asia-Pacific migrant populations. This leads to a distinct epidemiological pattern with potential for earlier immune clearance but also higher rates of chronic infection acquired in the first 5 years of life.

HCC burden

HCC incidence is 3–6 times higher in Aboriginal and Torres Strait Islander peoples compared to non-Indigenous Australians, with younger age at presentation. Contributing factors include higher HBV prevalence, later diagnosis, lower treatment uptake, higher rates of co-morbid metabolic syndrome, and greater alcohol-related liver disease.

Screening gap

An estimated 30–40% of Aboriginal and Torres Strait Islander people with CHB remain undiagnosed. The Australian National Hepatitis B Strategy prioritises closing this gap through opt-out testing in primary care, antenatal screening, and community-based programmes.

Culturally safe care

Engagement with Aboriginal Community Controlled Health Organisations (ACCHOs) is essential. Care should be delivered in culturally safe environments with Aboriginal Health Workers and Practitioners involved in patient education, monitoring, and follow-up. Flexible appointment systems and family-centred care improve retention.

Remote access

Specialist hepatology services are limited in remote and very remote communities. Telehealth has expanded access significantly. Medication delivery, pathology collection, and ultrasound access require coordination through Royal Flying Doctor Service, Aboriginal Health Services, and state/territory viral hepatitis programmes. Ensure antiviral medications are available through remote area pharmacies.

Treatment access

Entecavir and tenofovir are PBS General Benefit — no co-payment barrier for patients with Medicare. However, out-of-pocket costs for specialist consultations, elastography, and travel may impede access. Patient-assisted travel schemes (PATS) and state-funded viral hepatitis programmes can offset these costs.

Vaccination

Universal infant hepatitis B vaccination (birth dose + 3-dose schedule) has been part of the National Immunisation Programme since 2000. Coverage in Aboriginal and Torres Strait Islander infants is now >95%. Catch-up vaccination remains important for unvaccinated adolescents and adults born before 2000, particularly in high-prevalence communities.

ℹ️

Government programmes: The Australian Government's National Hepatitis B Strategy (2023–2030) targets a 90% diagnosis rate, 80% treatment rate among those eligible, and virtual elimination of hepatitis B as a public health threat by 2030. State and territory health departments fund community-based HBV testing and linkage-to-care programmes specifically targeting Aboriginal and Torres Strait Islander communities.

Monitoring

Ongoing monitoring of patients with chronic hepatitis B serves dual purposes: assessing response to antiviral therapy and detecting disease progression, fibrosis evolution, or HCC development. Monitoring schedules vary by phase and treatment status.

Monitoring Schedule

Clinical Scenario	Tests	Frequency
On oral antiviral therapy	ALT, HBV DNA, eGFR, phosphate (if on TDF)	Every 3–6 months; HBV DNA at 24 and 48 weeks to confirm virological response, then every 6 months
Inactive carrier (confirmed)	ALT, HBsAg quantitative (if available)	ALT every 6 months for first 2 years, then annually. HBsAg quantitative annually if accessible.
Immune-tolerant phase	ALT, HBV DNA, HBeAg	Every 6 months; consider fibrosis assessment if age >30 or duration >20 years
Treatment-naïve — phase unclear	ALT, HBV DNA, HBeAg/anti-HBe, fibrosis assessment	Every 3–6 months until phase classification confirmed
Post-treatment cessation	ALT, HBV DNA	Every 3 months for ≥12 months; retreat promptly if ALT flare or DNA rebound
On TDF long-term	eGFR, serum phosphate, urine protein/creatinine ratio, bone density (DEXA if risk factors)	Annually; more frequently if eGFR declining or risk factors present

Defining Treatment Response

Virological response: HBV DNA undetectable (<20 IU/mL) — primary goal of oral antiviral therapy
Biochemical response: ALT normalisation — expected within 3–6 months of effective viral suppression
Serological response: HBeAg seroconversion (HBeAg+/anti-HBe− → HBeAg−/anti-HBe+) or HBsAg loss/seroconversion — long-term goals
Histological response: Fibrosis regression on serial elastography or biopsy — encouraging evidence with long-term viral suppression

Treatment Failure and Resistance

With entecavir or tenofovir as first-line agents, virological breakthrough (confirmed rise in HBV DNA >1 log₁₀ above nadir on therapy) is uncommon in treatment-naïve patients. If virological breakthrough occurs:

First confirm adherence — non-adherence is the most common cause of apparent treatment failure
If adherent: check for resistance (genotypic testing available through reference laboratories)
Entecavir resistance: switch to tenofovir (TDF or TAF)
Tenofovir resistance: extremely rare — reassess adherence; consider specialist referral
Refer to hepatologist/gastroenterologist for complex resistance management

📚 References

1. World Health Organization. Guidelines for the prevention, care and treatment of persons with chronic hepatitis B infection. Geneva: WHO; 2015 (updated March 2024).
2. European Association for the Study of the Liver. EASL 2017 Clinical Practice Guidelines on the management of hepatitis B virus infection. J Hepatol. 2017;67(2):370–398.
3. Terrault NA, Lok ASF, McMahon BJ, et al. Update on prevention, diagnosis, and treatment of chronic hepatitis B: AASLD 2018 hepatitis B guidance. Hepatology. 2018;67(4):1560–1599.
4. Sarin SK, Kumar M, Lau GK, et al. Asian-Pacific clinical practice guidelines on the management of hepatitis B: a 2015 update. Hepatol Int. 2016;10(1):1–98.
5. Australian Institute of Health and Welfare. Chronic hepatitis B infection in Australia. Cat. no. PHE 260. Canberra: AIHW; 2023.
6. The Kirby Institute. HIV, viral hepatitis and sexually transmissible infections in Australia: Annual surveillance report 2023. Sydney: UNSW; 2023.
7. Australian Government Department of Health and Aged Care. National Hepatitis B Strategy 2023–2030. Canberra: Commonwealth of Australia; 2023.
8. Reddy KR, Beavers KL, Hammond SP, et al. American Gastroenterological Association Institute guideline on the prevention and treatment of hepatitis B virus reactivation during immunosuppressive drug therapy. Gastroenterology. 2015;148(1):215–219.
9. Revill PA, Chisari FV, Block JM, et al. A global scientific strategy to cure hepatitis B. Lancet Gastroenterol Hepatol. 2019;4(7):545–558.
10. Visvanathan K, Dusheiko G, Giles M, et al. Managing HBV in pregnancy. Prevention, prophylaxis, treatment and follow-up: position paper produced by Australian, UK and New Zealand key opinion leaders. Gut. 2016;65(2):340–350.
11. National Health and Medical Research Council. Australian Immunisation Handbook. Canberra: Australian Government Department of Health; 2022 (updated online).