• Hepatitis B is an infection caused by a virus that attacks the liver.
• Often there are no symptoms or else they are mild and the only way to know if you have it is through testing.
• Testing is important because there are treatments that can keep you healthy.
• Three tests are needed to show if you have an infection, if you have immunity, or if you have no immunity and could be infected in the future.

Hepatitis B infection is caused by the hepatitis B virus that attacks and injures the liver. Infections by hepatitis B can range from being mild to a more severe form which can last for years and can eventually lead to liver cancer.

More than half of people with hepatitis B do not have symptoms which means they do not know they have it and can pass on the infection to other people. However, hepatitis B is preventable and treatable. Testing is the only way to know for sure if you have it. Knowing if you have hepatitis B is important as there are effective drug therapies that can manage the infection and keep you well. A vaccination is available that can prevent you from getting the infection.

Acute and chronic hepatitis B

For most people, the infection is a short-term illness, called acute hepatitis B. Acute hepatitis B lasts less than six months and, in many people, will clear without treatment. However, sometimes, the infection lasts more than six months and is termed chronic. A chronic hepatitis B infection can lead to liver damage, liver failure and liver cancer.

It is important to be tested if you are at risk from hepatitis B infection, if you:

• Are in close contact with anyone who has hepatitis B (especially household and family members), are a man who has sex with other men, are someone who inject drugs, or are a sex worker.
• Are pregnant or are thinking of becoming pregnant as the virus can be passed on to your baby and you may need treatment to prevent this.
• Are a child of a woman who has hepatitis B.
• Are living in an area where hepatitis B is more common especially the Asia Pacific region, Aboriginal and Torres Strait Islander communities, or certain parts of Africa.
• Have hepatitis C or HIV.
• Have chronic liver disease, liver cirrhosis or hepatocellular carcinoma (or someone in your family has any of these).
• Have abnormal liver function tests (LFTs).
• Have acute hepatitis.
• Are about to start cancer treatment or immunosuppressive therapy or are having dialysis treatment.
• Are a healthcare worker who has direct patient care, comes into contact with human tissue or blood, or handles needles or syringes.

Diagnosing hepatis B needs three tests to get a full picture. One looks for an antigen or marker that is found on the surface of the hepatitis B virus. The other two detect antibodies. When you are infected with the hepatitis B virus, as with all infections, your immune system makes antibodies to fight off the virus.

Sometimes a fourth test will be used as well. This looks for a third antibody that usually only increases if you have an acute infection. It can also rise if you have a chronic infection and have a flare up of your symptoms.

HBsAg (Hepatitis B surface antigen)

This is a surface marker on the hepatitis B virus that can be detected in your blood while the hepatitis B virus is active. The level of HBsAg rises about a month after you have been infected, reaches a peak at about three months then declines and becomes undetectable by about six months. It will also briefly rise immediately after vaccination though will quickly become undetectable.

Anti-HBs (Hepatitis B surface antibody)

This is an antibody made by your immune system to fight the virus. It specifically targets the HBsAg marker. If your immune system is able to get rid of the virus, the level of HBsAg falls and the level of anti-HBs rises. This generally shows that you have cleared the virus from your system. It means you are now protected and have immunity from re-infection or that you are building immunity. When you are vaccinated, this is the antibody that your body makes that will protect you from infection.

Anti-HBc (Hepatitis B core antibody)

This is an antibody your immune system makes in response to the virus. The amount in your blood will rise not long after you have been infected, and it remains high indefinitely. It shows that you have had an infection at some time and that you have immunity.

IgM anti-HBc (Hepatitis B core IgM antibodies)

This is an antibody that increases in your blood at about the time your symptoms appear and falls to low levels not long after HBsAg has fallen. IgM anti-HBc antibodies usually only appear if you have an acute infection. It also rises if you have a chronic infection, and you have a flare up.

Sample

Blood

Any preparation?

None

Reading your test report

Your results will generally be presented along with those of your other tests on the same form. You will see separate columns or lines for each of these tests.

If you test negative to all these four tests, it means you do not have hepatitis B. However, it also means you have no immunity and you should ask your doctor about getting vaccinated.

If you test positive and you have an active infection, your doctor will advise you about what to do next. They will notify your state health department as hepatitis B is a notifiable infectious disease. Testing family members and others who are close to you including sexual contacts can be organised. Your doctor may advise vaccination.

Occasionally, the HBsAg and Anti-HBs are negative but the anti-HBc is positive. This combination of results may be due to one of several situations:

• You have had an infection in the past – especially if you come from an area when hepatitis B is common.
• The positive anti-HBc is a false positive – this is more likely to be a false positive if you have a low risk of hepatitis B infection.
• In an infant who has had the Anti-HBc passed from their mother.

Further testing may be required to decide on the stage of the infection and how likely it is to progress. These may include:

• Hepatitis B virus DNA viral load
• Hepatitis Be antigen (HBeAg)
• Liver function tests
• Alpha fetoprotein (AFP) tumour marker test

The choice of tests your doctor makes will be based on your medical history and symptoms. It is important that you tell them everything you think might help.

You play a central role in making sure your test results are accurate. Do everything you can to make sure the information you provide is correct and follow instructions closely.

Talk to your doctor about any medications you are taking. Find out if you need to fast or stop any particular foods, medications or supplements. These may affect your results. Ask:

• Why does this test need to be done?
• Do I need to prepare (such as fast or avoid medications) for the sample collection?
• Will an abnormal result mean I need further tests?
• How could it change the course of my care?
• What will happen next, after the test?

Pathology and diagnostic imaging reports can be added to your My Health Record. You and your healthcare provider can now access your results whenever and wherever needed.

Get further trustworthy health information and advice from healthdirect.