Hepatitis+B

=Hepatitis B=

What it is
Hepatitis B is a virus that can cause acute (short term) or chronic (long term) infection of the liver. 9 out of 10 children infected as babies remain persistently infected for many years (known as ‘hepatitis B carriers’) and can pass the virus on to others. As many as 1 in 4 hepatitis B carriers may develop and suffer from cirrhosis of the liver, liver cancer, liver failure and death. Young children who contract the hepatitis B virus may have only mild or no symptoms at all so it is hard to diagnose. The hepatitis B virus is found in infected body fluids including; blood, saliva, vaginal secretions, breast milk and semen. Babies of mothers with the hepatitis B virus are at a very high risk of becoming infected with the disease during delivery.

Hepatitis B virus can be spread by: • breastfeeding; • child-to-child – through open sores or wounds; • infected mother to newborn – at or around the time of birth. It can also be spread through sharing injecting equipment, needle-stick injury and contaminated instruments (such as those used for body piercing) or sexual contact.
 * Risk Factors**

Symptoms
//Symptoms resulting from acute hepatitis B infection among adults are common, with jaundice occurring approximately 12 weeks after initial infection.// The symptoms of acute hepatitis B include: - loss of appetite; - nausea and vomiting; - tiredness; - abdominal pain; - muscle and joint pain; and - jaundice (yellowish eyes and skin, dark urine and pale-coloured faeces/poo).
 * Acute hepatitis B**

Many people with acute hepatitis B have no symptoms and never realise they had the infection. A very small percentage of people with acute hepatitis B become very sick in a short period of time. This happens if there is massive damage to the liver and it stops working. This is called ‘fulminant hepatitis’.

//Most people with chronic hepatitis B do not have any symptoms of infection which means they may feel healthy and not be aware they are infected. However, other people may experience symptoms which are similar to those experienced with other forms of viral hepatitis//. These can include: - tiredness, depression and irritability; - pain in the liver (upper, right side of abdomen); - nausea and vomiting; - loss of appetite; and - joint aches and pains.
 * Chronic hepatitis B**

People with chronic hepatitis B have a significantly increased risk of developing liver cancer.

How to Treat
//Vertical transmission occurs in up to 90% of pregnancies where the mother is HBeAg-positive (indicating virus is replicating - patient is much more infectious) and 10% where she is HBsAg-positive (virus surface antigen - indicates patient is currently infected) and HBeAg-negative (indicating virus is not replicating). Hepatitis B vaccine and hepatitis B immunoglobulin given to the baby at birth reduce vertical transmission by 90%//
 * Vaccination**

Pre-term babies do not respond as well to hepatitis B-containing vaccines as term babies. Thus, for babies born at <32 weeks' gestation or <2000g: - give vaccine at 0, 2, 4 and 6 months and either: a) measure anti-HBs at 7 months of age, give booster at 12 months of age if antibody titre <10 mIU/mL b) give a booster at 12 months without measuring antibody titre

People who have immunity and normal LFTs do not need treatment. People who are chronically infected but do not have any liver damage also do not need treatment but need close monitoring with regular (6 monthly) liver function tests. However, if a person has liver damage they should consider having treatment for hepatitis B. The decision on when to start treatment is complex and should be made in consultation with a gastroenterologist with an interest in hepatitis B.
 * Treatment**

The Australian Government through the Pharmaceutical Benefits Scheme (PBS) funds several different medications to treat chronic hepatitis B. They are: __Pegylated Interferon (Pegasys®)__ Is given by injection once a week, usually for 6 months to a year. The drug has many potential side effects, such as flu symptoms and depression, but can control the virus in a third of patients without need for long term medication.

__Lamivudine (Zeffix®) (nRTI)__ Is a tablet taken once a day for at least a year or longer. There are almost no side effects, however a significant concern is the possible development of hepatitis B virus mutations and antiviral drug resistance after long term use.

__Adefovir (Hepsera®) (ntRTI)__ Is a tablet taken once a day for a year or longer. In Australia, Adefovir is only funded for people who have developed a hepatitis B virus mutation after taking Lamivudine. There are almost no side effects except for the possibility of developing virus mutations and antiviral drug resistance.

__Entecavir (Baraclude®) (nRTI)__ Is a tablet taken once a day for up to a year, with almost no side effects except for the possibility of developing virus mutations and antiviral drug resistance. Entecavir is the most potent oral antiviral drug available for treatment of chronic hepatitis B. It was approved for use in Australia in December 2006 and has replaced lamivudine as first line tablet therapy.

Additional Resources
[|Hepatitis Australia - Hepatitis B] [|SA Health - Hepatitis B]