Hepatitis B is a viral infection that causes inflammation of the liver. Most babies or children who are infected with hepatitis B are unable to clear the virus from their liver where it remains life-long. It can cause significant damage.
Approximately 15%–25% of people who are infected with hepatitis B go on to develop chronic liver disease.
Chronic liver disease includes cirrhosis, liver failure, or liver cancer. In cirrhosis, the liver is small and hard and if untreated, may lose function, leading to bleeding from the gut and liver failure.
The hepatitis B virus enters the body and infects the liver where it remains life-long. The immune system then attacks the infected liver cells causing damage. The liver tries to heal by scarring. Over many years, this scarring becomes worse and eventually leads to cirrhosis. In cirrhosis, the liver is small and hard and if untreated, may lose function, leading to bleeding from the gut and liver failure.
The risk for chronic infection varies according to the age at infection and is greatest among young children. 25%–50% of infected children aged 1–5 years will remain chronically infected. By contrast, approximately 95% of adults recover completely from hepatitis B and do not become chronically infected.
There are several blood tests available to identify whether you are currently infected or have developed an immunity to hepatitis B. Testing should be offered to household and sexual contacts of people who already have hepatitis B.
Regular surveillance of hepatitis B is vital in preventing liver cancer (hepatocellular carcinoma (HCC))
The treatments for hepatitis B aim to prevent the virus being active and multiplying in the liver.
In New Zealand there are a number of drugs used to treat chronic hepatitis B:
- Pegylated interferon (Pegasys) boosts the body’s immune system and changes the virus’ ability to multiply. It is a synthetic version of a protein our bodies naturally produce (interferon). Pegylated interferon is injected under the skin once a week for up to 48 weeks.
- Entecavir is an oral antiviral drug used in adults who have active virus and liver damage. Entecavir is funded as a first-line therapy for patients with chronic hepatitis B. Almost all patients achieve viral suppression (undetectable) and biochemical response (ALT below the upper limit of normal). Entecavir resistance is rare at less than one per cent after six years.
- Tenofovir is an antiviral drug. It is an oral tablet taken once a day. Tenofovir has replaced Adefovir in New Zealand as the first-line therapy for Lamivudine resistant hepatitis B infection. This is the preferred treatment during pregnancy and breastfeeding. No resistance to Tenofovir has been observed after five years of therapy.
Chronic hepatitis B is not curable and lifelong treatment is usually required. Long-term treatment is well tolerated and will prolong survival.
Hepatitis B and cirrhosis
Chronic hepatitis can cause cirrhosis of the liver.
Cirrhosis is a result of advanced scarring of the liver which results from persistent injury to the liver usually from a chronic viral infection (especially chronic hepatitis B and chronic hepatitis C but also from alcohol or too much fat).
This scarring is a slow process and it takes between 20 and 40 years from the onset of the liver disease until the development of cirrhosis.
This scar tissue reduces the blood flow through the liver, causing increase in pressure in the veins which may cause bleeding in the gullet and stomach. Symptoms of cirrhosis may include a loss of appetite, extreme tiredness, nausea, abdominal swelling, and the inability to tolerate fatty foods.
Cirrhosis can also lead to liver failure or liver cancer. Unlike liver failure, liver cancer does not cause any symptoms or signs until it is very large and at this stage it is not curable.
The time of the onset of liver cancer until it causes symptoms is usually 2-3 years.
For this reason, every person with cirrhosis should have regular screening with an ultrasound and blood test so that if they do develop a liver cancer, it can be detected when still small and curable.
Reduce alcohol intake
Regular and heavy alcohol intake will increase liver damage and increase your risk of cirrhosis and dying from a complication of hepatitis B. Anyone diagnosed with chronic hepatitis B is recommended to keep alcohol intake to a minimum in order to reduce the risk of developing hepatitis-related complications. Reducing your alcohol intake is the single most important lifestyle change you can make. Patients with cirrhosis are advised not to drink alcohol at all.
Reduce cannabis use
Heavy cannabis use is associated with increased liver scarring. If you can reduce or stop cannabis use, you will slow the progression of liver damage.
Reduce the risk of fatty liver disease
Fatty liver is a condition where excess fat builds up inside the cells within the liver. Fatty liver may speed up the progression of scarring in people with chronic hepatitis B. Maintaining a healthy lifestyle will prevent this.
Avoid fatty liver by:
- staying within a healthy weight range
- avoiding foods and beverages containing a lot of fats and/or sugars;
- exercising daily
- maintaining a healthy, well-balanced diet
- maintaining control of diabetes, if you have it
- watch out for diabetes, try to maintain a healthy weight and keep physically active to reduce your risk of developing it.