1: What is Hepatitis B?
Hepatitis means inflammation of the liver and it is caused by the Hepatitis B Virus (HBV), a DNA (Double stranded nucleic acid).
Hepatitis B virus was discovered in 1967 by Dr Baruch Blumberg.
HBV infection is the leading cause of chronic liver infection (hepatitis) worldwide.
Persistence of the infection can lead to liver damage (hepatitis) and this can lead to scarring (fibrosis), eventual liver damage (cirrhosis) and liver cancer.
Each year, it is estimated that one million people worldwide die from complications (cirrhosis and liver cancer) caused by Hepatitis B infection.
2: How many types of hepatitis are there and what are the differences?
There are many causes of hepatitis but the three most common causes are viruses (Hepatitis A, B and C) and medications (drug-induced hepatitis).
Certain virus such as Hepatitis A only causes acute hepatitis (meaning there is no chronic infection). In such instance, majority of patients who catch Hepatitis A will have flu-like illness and recover.
However, for a small minority, acute hepatitis can be fulminant (severe) and life-threatening.
Exposure to medications can also lead to acute hepatitis.
Hepatitis B, Hepatitis C and long-term exposure to certain medications can lead to chronic hepatitis, leading to liver damage. Other viruses such as dengue virus can also cause hepatitis.
3: How common is it? How common is it in Brunei Darussalam?
HBV infection is the leading cause of chronic liver infection (hepatitis) worldwide and is particularly common in the Asia Pacific region, where 75 per cent of those infected are residing.
It is estimated that two billion of the world's population have been exposed to the Hepatitis B virus and 350 million are chronically infected.
Brunei Darussalam lies in the zone categorised by the World Health Organization (WHO) as "moderately endemic" with rates of between two per cent and eight per cent. This means that there are between two to eight people who have HBV infection for every 100 person.
Fortunately, with improvement of the healthcare system and standard of living and the introduction of universal vaccination for babies after delivery, the rate is now much lower.
According to research conducted at RIPAS Hospital, the prevalence of HBV among blood donors was 0.31 per cent (31 per 10,000 people) (Brunei International Medical Journal 2011; 7 (6); 321-327. available from www.bimjonline.com) and under 1.5 per cent (150 per 10,000 people) among pregnant women.
4: How can Hepatitis B virus be transmitted?
There are two routes of transmissions. HBV can only be transmitted where there is exposure to bodily fluid (blood but to a lesser extent other bodily fluid like semen or saliva).
The most common is known as the 'Vertical Transmission' or 'Perinatal Transmission', where infection is passed from mother to child.
During delivery, babies are exposed to their mother's blood and if the mother has Hepatitis B infection, transmission to the baby can occur. However, this can be prevented.
During nursing period, the baby may be exposed to the mother's bodily fluid.
The other route of transmission is known as 'Horizontal Transmission', which refers to transmission typically occurring during the adulthood (ie transmission through sexual contact).
Transmission through blood transfusion is now extremely rare.
Transmission through sharing of household items such as razors can occur. However, transmission through casual contacts (handshake and hugging) or sharing of household cooking or eating utensils is extremely rare.
5: Who are at risk of Hepatitis B?
Babies born to mothers who have Hepatitis B infection have the highest risk.
Partners to person known to have Hepatitis B who have not been immunised against HBV are at higher risk too. Healthcare workers who are at risk of needle stick injuries are also at risk. People who abuse drugs and have unsafe sex are also at risk.
6: How does Hepatitis B virus cause liver damage?
Hepatitis B virus typically resides inside the liver cells. There are several phases in the natural history of Hepatitis B infection (immune-tolerant, immuno-clearance, chronic inactive phase and chronic low grade active phase).
Liver damage mainly occurs during the immune-clearance phase during the second to fourth decade of infection.
Liver damage is due to the immune system attacking infected liver cells and this leads to liver inflammation.
This is reflected in blood tests showing abnormal liver tests.
When an episode of liver damage is very severe, it can lead to acute liver failure.
However, in most cases, the liver inflammation is low grade but recurrent resulting in cumulative liver damage.
7: Does it cause cancer?
Yes, HBV can cause liver cancer known in medical term as hepatocellular carcinoma or hepatoma.
Presence of liver damage from chronic Hepatitis B infection increases the risk for liver cancer. Hence the risk is higher for a person with liver cirrhosis.
However, liver cancer can also occur in a person without liver cirrhosis. It is roughly estimated that 20 per cent of liver cancer associated with Hepatitis B infection do not have liver cirrhosis.
8: How can one prevent from getting Hepatitis B?
Since vertical transmission is still the most common route of infection, it is important prevent infection when your baby is born.
Therefore, it is very important for all pregnant women to have antenatal check so that their Hepatitis B status is known.
For those found to be positive, they will be referred to the liver clinic for further check and follow-up.
The obstetrician will usually plan the delivery and ensure vaccinations are given immediately after the delivery.
Additional medication in the form of an antibody may be given to the child.
For adults, the best way to prevent infection is through vaccination. Once the antibody to the Hepatitis B virus is formed, one is protected.
9: What are the signs or symptoms of Hepatitis B?
Depending on the stage of the infection (refer to question number five), a patient with Hepatitis B infection may not experience any symptoms at all.
In fact, this is a very common situation.
In the Liver Clinic of RIPAS Hospital, most patients are referred because they are found to have Hepatitis B infection through screening for medical check, family screening or blood donations.
Even if there is evidence of some liver inflammation of blood test, you may not have symptoms.
If the liver damage is advanced, symptoms such as jaundice, swelling of the tummy, easy bruising, feeling weak and vomiting blood may be present.
However, even when there is advanced liver damage or liver cancer, a patient may only experience very nonspecific symptoms.
Often, the first time a person finds out that they have Hepatitis B infection is when they have a blood test.
Such situation is unfortunately still very common in our local setting when patients are diagnosed with liver cancer or liver cirrhosis.
Therefore, it is very important for patients who are known to have Hepatitis B infection to have regular follow-ups with their clinic.
10: Can Hepatitis B be treated?
Apart from preventing transmissions, there are treatments available for Hepatitis B infection.
Currently available treatment can be in the form of injections or tablets.
Unlike, antibiotics where the treatment is usually given for a week and quite effective when given appropriately, treatment of virus infection including Hepatitis B is not as straight forward.
The success rates of treating Hepatitis B infection are limited and depend on the stage of infection.
That is why not all patients are given treatment. There are newer medications that should become available in several years that can improve the treatment success.
11: What should I do if I have Hepatitis B?
If you know you have Hepatitis B infection, you should be referred for a follow-up.
For younger patients under the age of 40 without evidence of advanced liver disease or significant liver inflammation, they are usually followed up at least once or twice a year with blood tests and ultrasound scan of the liver.
For older patients or those with significant liver inflammations or advanced liver disease, they will be followed up more closely with or without treatment.
If you are uncertain, please schedule an appointment with a doctor at your nearest clinic. (Courtesy of Ministry of Health Public Awareness Campaign)
Compiled by Division of Gastroenterology & Hepatology,
Department of Medicine,
Ministry of Health