Hepatitis B is an uncommon infection in Australia due to most Australians being vaccinated. Even in those who do develop Hepatitis B most people (more than 95% of adults) will naturally cure the virus on their own unless it is acquired as child. A small minority will develop chronic Hepatitis B which can be treated but which can not yet be cured. Most people who develop chronic Hepatitis B first catch it as a baby or as a child under the age of 5.
How do you get Hepatitis B?
The most common way to acquire Hepatitis B in Australia is through sexual contact or sharing needles in people who inject drugs into their veins. Men who have sex with men (MSM) and indigenous Australians are at the highest risk. Outside of Australia, in particular in South East Asia, this STI is much more common and is usually acquired during pregnancy from a mother who has chronic Hepatitis B. This infection can be transmitted between children but how this happens isn’t really understood. It might be through saliva or breaks in the skin. This sort of transmission doesn’t appear to happen in adults.
How is Hepatitis B diagnosed?
This STI can be difficult to diagnose because most people (about 70%) will either have no symptoms or have symptoms so mild that they don’t worry about them. The diagnosis might first be suspected by abnormalities in a blood tests for liver function and is then confirmed with further blood tests that specifically test for Hepatitis B. It can take up to two months before the blood test will show evidence of the infection although it is usually positive after one month.
Who should be tested for Hepatitis B?
Testing should be carried out in the following populations assuming they have not been vaccinated as children.
- Aboriginal and Torres Strait Islanders
- Men who have sex with men
- People with multiple sexual partners
- People who are in prison or who have ever been in prison
- Pregnant women
- People with unexplained abnormalities in blood tests for liver function
- People with symptoms of a new hepatitis infection
- People who were born in a country where a lot of people have Hepatitis B
- The children of women who have chronic Hepatitis B
What happens when you get Hepatitis B?
In more than 95% of adults the infection will resolve on its own and these patients will be considered cured. In 70% of cases the symptoms they first develop will be mild and not last very long. In the remainder there will be symptoms of acute hepatitis including fatigue, poor appetite, vomiting or feeling like vomiting, pain in the abdomen and around the liver, and jaundice (where the skin turns a yellow colour). This illness is usually prolonged and may last a few months. It’s more common to develop these symptoms the infection occurs in older adults and much less common to develop symptoms in babies and children.
How is Hepatitis B treated?
In most cases no specific treatment is needed because the illness will usually resolve on its own. In adults who develop acute hepatitis that is particularly severe or in adults who have a weakened immune system then it may be necessary to treat with antiviral medications. In those with chronic Hepatitis B the decision to start treatment will depend on what phase the infection is in. Chronic infection moves through different phases over time and some of these phases are associated with liver damage, scarring and liver cancer. Treatment is initiated to prevent or minimise the impact of these complications.
What follow up is needed?
Patients who develop acute Hepatitis B need follow up to make sure they clear the virus naturally on their own (which will be the case in more than 95% of adults). In those who develop chronic Hepatitis B, follow up is lifelong with blood tests every 6-12 months to monitor the phase of the infection and to check for evidence of liver damage.
In those adults who develop acute Hepatitis B, sexual contacts from the last 6 months should be notified, tested and vaccinated if this hasn’t already been performed. Household members and regular sexual partners of people who develop this STI should also be vaccinated if they haven’t been already.