Hepatitis B
A vaccine-preventable viral liver infection that can be acute or chronic.
Overview
Hepatitis B virus (HBV) infects the liver; outcome depends on age at infection. Most adults clear acute infection; ~90% of perinatally infected infants develop chronic disease, with long-term risk of cirrhosis and liver cancer. Effective vaccines and antivirals are available.
Symptoms
- • Acute: jaundice, dark urine, fatigue, nausea, right-upper-quadrant discomfort — many infections are silent
- • Chronic: often asymptomatic for decades; may have fatigue or arthralgia
- • Decompensated cirrhosis or HCC in advanced disease
Risk factors
- • Birth to HBV-positive mother (no vaccination)
- • Multiple sexual partners or men who have sex with men
- • Injection drug use, sharing needles
- • Healthcare workers, dialysis patients
- • Origin from high-prevalence regions (East/SE Asia, sub-Saharan Africa)
Causes
- • HBV transmission via blood, sexual contact, perinatal exposure
- • Healthcare and injection drug exposure
🚨 Red flags — seek urgent care
- • Severe jaundice with confusion or bleeding — fulminant hepatitis, emergency
- • Black or bloody stools, vomiting blood
- • Rapidly worsening abdominal swelling
When to seek care
- • Possible exposure (needlestick, unprotected sex with infected partner) — within 24 hours for prophylaxis
- • Persistent fatigue or jaundice
- • Pregnancy with risk factors — screening offered universally in many countries
Diagnosis
- • HBsAg, anti-HBc, anti-HBs serology
- • HBV DNA (viral load) and HBeAg/anti-HBe
- • Liver function tests, FibroScan or biopsy for staging
- • Co-infection screen: HCV, HDV, HIV
Treatment
- • Acute: supportive in most adults; antivirals for severe/fulminant cases
- • Chronic active disease: nucleos(t)ide analogues (tenofovir, entecavir) suppress virus and reduce cirrhosis/HCC risk
- • Pregnancy: tenofovir in third trimester if high viral load to prevent transmission
- • HCC surveillance with 6-monthly ultrasound in cirrhosis or high-risk groups
- • Vaccinate household and sexual contacts; avoid alcohol; vaccinate against hepatitis A
Prevention
- • Universal infant vaccination (highly effective)
- • Post-exposure prophylaxis (HBIG + vaccine) within 24–72 hours
- • Safer sex and injection practices
- • Screen pregnant women and high-risk groups
Complications
- • Cirrhosis
- • Hepatocellular carcinoma (even without cirrhosis)
- • Fulminant hepatic failure
- • Glomerulonephritis, polyarteritis nodosa
Prognosis
More than 95% of immunocompetent adults clear acute HBV. Chronic HBV requires lifelong monitoring; effective antivirals dramatically reduce cirrhosis and HCC risk.
Education & self-care
Hepatitis B is vaccine-preventable and effectively treatable. Screening, vaccination of contacts and adherence to antivirals prevent long-term liver damage.
Frequently asked questions
Is hepatitis B curable?
Functional cure (HBsAg loss) is uncommon. Modern antivirals suppress the virus indefinitely and prevent complications.
Can I have a baby with hepatitis B?
Yes — with antenatal care, antivirals if needed, and infant vaccination plus HBIG at birth, vertical transmission is rare.
Can hepatitis B be cured?
Acute hepatitis B usually resolves on its own. Chronic infection can be controlled lifelong with tenofovir or entecavir, but functional cure (loss of HBsAg) is uncommon — new therapies are in trials.
Is hepatitis B transmitted sexually?
Yes. It spreads through blood, sexual contact and from mother to baby at birth. Vaccination provides over 95% protection and is part of routine childhood immunisation.
Do I need monitoring if I am a carrier?
Yes — usually 6-monthly liver function tests, viral load and alpha-fetoprotein, plus ultrasound for those at risk of liver cancer, even if there are no symptoms.