Quick answer. Hepatitis B (HBV) is a viral liver infection that has long been a significant health concern in Singapore, where roughly 3 to 4 percent of the population are chronic carriers – higher among older and Asian-born residents. It spreads through blood and body fluids, most importantly from mother to child at birth, and also through unprotected sex and shared needles. Many carriers feel completely well for decades, yet chronic HBV can silently cause cirrhosis and liver cancer. Singapore has given the HepB vaccine to all newborns since 1987. Chronic HBV cannot always be cured, but daily antiviral tablets control the virus well and lower cancer risk. Carriers need lifelong 6-monthly monitoring.
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Hepatitis B is an infection of the liver caused by the hepatitis B virus (HBV). It is one of the most common chronic infections worldwide and has historically had high relevance in Singapore, particularly among older residents and those born in the region before universal vaccination began. Many people carry the virus for life without knowing, because it often causes no symptoms until significant liver damage has occurred.
This guide explains how hepatitis B spreads in the Singapore context, why chronic infection raises the risk of cirrhosis and liver cancer, the national childhood vaccination programme, who should be screened, and how modern antiviral treatment and regular monitoring protect carriers. It is general information and not a substitute for advice from your doctor or a gastroenterologist.
At a glance
| Aspect | Key points | What it means for you |
|---|---|---|
| How it spreads | Mother-to-child at birth, blood, unprotected sex, shared needles/sharp instruments | Not spread by sharing food, hugging or casual contact |
| Chronic carriers in SG | Roughly 3 to 4 percent of residents; higher in older/Asian-born groups | Many carriers feel well but still need monitoring |
| Main risks if chronic | Cirrhosis (liver scarring) and liver cancer over years to decades | Risk is much higher than in non-carriers – screening matters |
| Vaccination | Free for all SG newborns since 1987; 3-dose course for unprotected adults | Highly effective at preventing infection |
| Treatment | Daily oral antivirals control (not always cure) the virus | Lowers liver damage and cancer risk; often long-term |
| Monitoring | Blood tests and liver ultrasound, usually every 6 months | Detects problems and liver cancer early |
Why hepatitis B matters in Singapore
Singapore is considered an area of intermediate hepatitis B prevalence. Before vaccination, an estimated 5 to 6 percent of the population were chronic carriers; this has fallen to around 3.6 percent of adults in more recent surveys, and to well under 1 percent among children and young adults thanks to the national vaccination programme. Carrier rates remain higher among older Singaporeans and people born overseas in higher-prevalence regions.
Hepatitis B is important because chronic infection is the leading cause of liver cirrhosis and liver cancer in Singapore. In local series, chronic hepatitis B underlies roughly two-thirds of cirrhosis cases. The risk of liver cancer is estimated to be far higher in carriers than in non-carriers, which is why identifying and monitoring carriers is a public-health priority.
How hepatitis B spreads
HBV is transmitted through blood and body fluids. Recognised routes in Singapore include:
- Mother-to-child at birth (vertical transmission) – historically the most important route locally; infection acquired as a baby is the most likely to become lifelong.
- Blood and body fluids – sharing needles, unsterile tattooing or piercing, and sharing razors or toothbrushes that may carry blood.
- Unprotected sex with an infected partner.
Hepatitis B is not spread by sharing food or utensils, hugging, holding hands, coughing or sneezing. Babies born to carrier mothers in Singapore are protected with hepatitis B immunoglobulin plus vaccination at birth, which greatly reduces transmission.
Why it is often silent
Acute hepatitis B may cause tiredness, poor appetite, nausea, abdominal discomfort, dark urine or yellowing of the eyes and skin (jaundice) – but many people, especially those infected as babies, have no symptoms at all. Chronic carriers typically feel completely well for years or decades even while inflammation slowly scars the liver.
Because symptoms often appear only once cirrhosis or liver cancer is advanced, you cannot rely on how you feel. The only reliable way to know your status is a blood test. This is why screening of at-risk groups is so important.
The national vaccination programme and screening
Singapore introduced hepatitis B vaccination for babies of carrier mothers in 1985 and extended it to all newborns from 1 September 1987, as part of the National Childhood Immunisation Schedule. The vaccine is given as a course of doses and is highly effective at preventing infection for life.
Adults who were never vaccinated and are not immune can receive a 3-dose course. Screening with a blood test (for HBsAg and antibodies) is recommended for:
- People born before universal vaccination, or born overseas in higher-prevalence regions
- Household members and sexual partners of carriers
- Pregnant women (routinely tested in Singapore)
- People who inject drugs, are on dialysis, or are immunosuppressed
Screening costs vary by clinic and some tests are eligible for subsidies at public healthcare institutions – check with your provider.
Treatment and lifelong monitoring
Chronic hepatitis B cannot always be cured, but it can usually be very well controlled. Daily oral antiviral tablets (such as those in the nucleos(t)ide analogue class) suppress the virus, reduce liver inflammation and lower the risk of cirrhosis and liver cancer. Not every carrier needs medication immediately – the decision depends on viral levels, liver enzymes and the degree of liver damage, so specialist assessment is important.
All chronic carriers, whether or not they are on treatment, need regular monitoring – typically blood tests and a liver ultrasound around every 6 months – to track the virus and screen for liver cancer at an early, treatable stage. Avoiding excess alcohol, maintaining a healthy weight, and not stopping antivirals without medical advice are all important.
When to see a doctor
Get tested or see a doctor if you have never been screened and fall into an at-risk group, or if a family member is a carrier. If you are a known carrier, keep your 6-monthly monitoring appointments even when you feel well.
Seek urgent medical attention if you develop yellowing of the eyes or skin (jaundice), persistent vomiting, severe abdominal pain or swelling, confusion or drowsiness, or you vomit blood or pass black tarry stools – these can signal serious liver complications and need emergency care.
Related guides
- Best Gastroenterology Clinics in Singapore — our editorial shortlist
- gastroenterology clinics directory
- Hepatitis C
- Liver cirrhosis
- Liver cancer screening
Sources
- HealthHub – Hepatitis B
- Communicable Diseases Agency (CDA) – Hepatitis B
- SingHealth – Hepatitis B: Conditions & Treatments
- NUHS – Hepatitis B
Related conditions & guides
Related conditions and guides you may find useful:
See also: our directory of hepatologists (liver specialists) in Singapore.
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