How much do you know about hepatitis B and what if you’re a silent ‘carrier’ of the virus?

SINGAPORE — Hepatitis B affects about one in 25 people in Singapore, but more than half of the population here do not know that viral hepatitis can cause liver failure.

More than half are also unaware that the infection can be spread through unprotected sex, a doctor who has done research on the disease told TODAY. 

In Singapore, hepatitis B is the most common cause of long-term, chronic viral hepatitis, a term used to describe inflammation of the liver.

Despite being able to cause serious life-threatening health problems, awareness of viral hepatitis remains low, especially among younger people aged 25 and below. Many mistakenly believe that hepatitis B is transmitted by eating contaminated raw seafood, for instance.

Professor Tan Chee Kiat, senior consultant with the department of gastroenterology and hepatology at Singapore General Hospital (SGH), said that Singapore and the Asia region are particularly vulnerable to the infection and liver disease because hepatitis B is endemic in the region. This means the virus circulates and causes infections regularly.

Prof Tan is the co-author of the Asia Pacific Liver Index Study, which was commissioned by biopharmaceutical company Gilead Sciences across 11 countries and territories in Asia in 2020, including Singapore.

He said that hepatitis is often dubbed a “silent killer”.

“People with viral hepatitis often experience no obvious symptoms until the infection causes serious health implications. This may cause many people to fall victim to the disease.”

Ahead of World Hepatitis Day on July 28, experts shed light on the most common cause of viral hepatitis here, how it spreads and what asymptomatic carriers can do to protect themselves and others.

WHY IS VIRAL HEPATITIS SERIOUS?

There are five main hepatitis viruses: Types A, B, C, D and E.

Hepatitis A and hepatitis E are usually short-term infections. Hepatitis A, for instance, is spread through contaminated food and is usually passed out of the body after some months without long-lasting health problems.

Hepatitis B and C can become chronic, lead to liver damage and are associated with liver cancer.

In 2015, there was a hepatitis C outbreak in SGH that affected 25 patients, of whom eight died — with the disease likely contributing to the deaths of seven. Disciplinary action was later taken against Ministry of Health officials and SGH staff members for not doing enough and failing to recognise how serious was the situation and the lapses in infection controls.

It is hepatitis B, though, that is the most common cause of chronic viral hepatitis.

A recent study here showed that more than half of 3,000 liver cancer cases in three major public hospitals in Singapore were due to hepatitis B infection, Prof Tan said. 

This liver infection can also lead to permanent scarring and hardening of the liver, liver failure and long-term inflammation.

Hepatitis D, which occurs only in people with hepatitis B infection, is also associated with liver cancer.

LIVER TRANSPLANTS NEEDED IN SOME CASES

Some of the most severe cases that Prof Tan has seen involve younger adults.

“They have a flare-up of their hepatitis B disease, which is so bad that they need urgent life-saving liver transplantation,” he said.

There are also some patients who develop liver cancer.

“The majority of these patients either do not bother to follow up with their doctors even though they are aware that they have hepatitis B or were not aware that they have hepatitis B until the serious complication (such as liver cirrhosis and liver cancer) occurred,” he added.

HOW IT IS SPREAD

Associate Professor George Goh, chairperson of the National Foundation of Digestive Diseases, said that in Singapore, the hepatitis B virus is most commonly spread from an infected mother to a child during birth.

However, this mode of transmission will become less common over time. This is due to the increasing prevalence of vaccination as well as routine vaccination against hepatitis B of all newborns, Prof Tan explained.

Assoc Prof Goh, who is also a senior consultant at SGH’s department of gastroentrology and hepatology, said that people in Singapore with the infection are largely those who missed the nationwide childhood immunisation, which started in 1987.

Hepatitis B vaccination is included in the Singapore National Childhood Immunisation Schedule, where all children should receive three doses at appropriate intervals.

Hepatitis B can be transmitted through body secretions such as blood and semen, similar to that of the human immunodeficiency virus, Prof Tan said.

A person can get the virus through unprotected sex with an infected person or blood transfusions.

Prof Tan said that another route of transmission is via contaminated needles or sharp instruments used during acupuncture, tattooing, ear piercing and manicures, for example.

“While hepatitis B is prevalent in the Asia region, people can protect themselves against the virus during overseas travel by being vaccinated (against hepatitis B) and taking precautionary measures such as using condoms, and not sharing needles for piercings, tattoos and injecting drugs,” he added.

“The mode of hepatitis B transmission is the same regardless of where one travels or where one is. It is not the travel itself that transmits hepatitis B, but rather the individual’s behaviour when overseas.”

AN INFECTED PERSON MAY HAVE NO SYMPTOMS

Viral hepatitis B can develop as an acute infection or become a chronic condition. 

Assoc Prof Goh explained: “When first infected, it is considered an acute or new infection. If the person is not able to get rid of the virus beyond six months, he or she is considered to have chronic hepatitis B infection.”

The age in which the person is exposed to the virus matters.

“The younger the person when he or she is first infected, the greater the risk of developing chronic hepatitis B infection,” Assoc Prof Goh said, adding that more than 90 per cent of infants infected would develop chronic hepatitis B.

By contrast, only 5 to 10 per cent of adults would develop chronic hepatitis B, with the majority of adults recovering from the acute infection.

For those with symptoms, there may be jaundice, or yellowing of the skin and whites of the eyeballs. They may also have dark tea-coloured urine, nausea, loss of appetite and vomiting, prolonged tiredness, fever and abdominal pain.

Assoc Prof Goh said that most people with chronic hepatitis B are asymptomatic or have no symptoms. They are known as “carriers” and can go about their daily activities without any problems.

The down side is, this makes the virus difficult to detect.

“It may also give a false sense of security that everything is fine,” he added.

“Patients with hepatitis B, even those without any symptoms, may be at risk of serious medical complications (such as liver damage).”

Assoc Prof Goh said that a routine blood test would be the hepatitis B surface antigen test.

If positive, it would signify hepatitis B infection. If this is persistent over more than six months, it would be considered chronic hepatitis B.

VACCINATION AVAILABLE FOR ADULTS

The hepatitis B vaccination is also included in Singapore’s National Adult Immunisation Schedule, whereby individuals aged 18 years or older who have not been vaccinated before or lack evidence of past infection or immunity should receive it. The vaccine has to be taken in three doses.

“The vaccine is safe and extremely effective if individuals complete all three doses at appropriate intervals,” Assoc Prof Goh said.

However, the thing to note is that the hepatitis B vaccine is effective only for people who have not been infected with the hepatitis B virus, he pointed out.

This means that the vaccine is not recommended for hepatitis B carriers. 

“Instead, it is recommended that people who have been infected visit their medical professionals to learn more about the best treatments for controlling the virus and precautionary measures to take to protect their loved ones and people around them.”

PRECAUTIONS TO AVOID SPREAD

To avoid transmitting it to other people, Prof Tan from SGH advised the following precautionary measures for hepatitis B carriers:

• Avoid donating blood, blood products, organs and sperm
• Avoid sharing toothbrush, shaving equipment
• Household contacts and sexual partners of carriers should be screened and immunised against hepatitis B if they are not vaccinated
• Female carriers who are pregnant should have her child vaccinated at birth

Assoc Prof Goh said that all pregnant mothers are tested during pregnancy to identify those with chronic hepatitis B, who are at risk of transmitting the virus to their baby.

Pregnant mothers who know they have hepatitis B should inform their doctor of their status. Their doctor will assess whether treatment is warranted during the pregnancy to reduce the risk of transmission to their baby.

Infants born to mothers with hepatitis B are also recommended to receive hepatitis B vaccination and hepatitis B immunoglobulin (containing antibodies against the hepatitis B virus) at birth, Assoc Prof Goh added.

For those who are considering getting their vaccine shots, he said that there is limited information for now on administering Covid-19 vaccines at the same time as other non-Covid-19 vaccines.

“As recommended by the Ministry of Health, a minimum interval of 14 days is encouraged before or after any other vaccines, but is not strictly necessary,” he added.

IS THERE A CURE?

Although vaccination can prevent hepatitis B, there is no cure for it, Prof Tan said.

The doctors said that once diagnosed, there should be regular active monitoring. This is done via blood tests and liver scans to determine if treatment is necessary.

Assoc Prof Goh said that typically, it would be a half-yearly blood test and a liver ultrasound done every six months to one year, but this would depend on the individual patient and subject to the attending doctor’s discretion.

Prof Tan said: “Treatment can help control the virus, delay or possibly reverse liver damage and reduce the risk of other complications such as liver failure and liver cancer.” 

In the Singapore Liver Index Study published last year, a substantial proportion (70 per cent) of people diagnosed with liver disease are not on treatment, saying that cost was a factor or they preferred Traditional Chinese Medicine over Western medicine.

Prof Tan said that based on Western literature, there is no Traditional Chinese Medicine known to be effective in treating hepatitis B.

WHAT ABOUT THE RECENT ACUTE HEPATITIS AFFECTING CHILDREN?

As of July 8, 35 countries have reported 1,010 probable cases of severe acute hepatitis of an “unknown” origin in children aged 16 or younger, including 22 deaths, the World Health Organization said earlier this month.

Since the outbreak was first reported in the United Kingdom in early April, similar cases have been reported in Europe and Asia. However, the health authorities around the world are still investigating the cause of the liver inflammation. 

Laboratory testing excluded the hepatitis A to E viruses in these children. Health officials have said that the adenovirus (a common virus affecting children) is the most frequently detected pathogen among the cases.

Assoc Prof Goh said that some of the symptoms reported are similar to that of the hepatitis viruses A, B and C — such as abdominal pain, diarrhoea and vomiting — but most of the children did not have a fever.

In Singapore, three cases of acute hepatitis of an “indeterminate” cause have been reported. The Ministry of Health (MOH) announced the first domestic case, a 10-month-old infant, on April 30.

A three-year-old and eight-year-old were also identified to have developed the illness in October and November last year respectively, after MOH conducted a look-back investigation.

In a May 31 statement released by MOH, it was stated that hepatitis in young children is “not uncommon” and it is not unusual for the cause of some hepatitis cases in children to remain unknown.

Although the cause of hepatitis in all three children here has not been identified, it may not mean that these cases are linked to the global outbreak, MOH added.