Hepatitis B is a viral infection that causes inflammation of the liver. It is caused by the hepatitis B virus (HBV), which attacks the liver cells cauing either acute (short term) or chronic (long term) hepatitis.
Acute hepatitis produces obvious symptoms from which people fully recover, while chronic hepatitis symptoms are more subtle and treatment is focused on preventing long term liver damage and transmission of the disease.
A vaccine has been used to good effect in New Zealand since the 1980s, greatly reducing the incidence of the disease.
Approximately 60% of people infected with hepatitis B do not go on to develop an illness as the body successfully fights off the virus. These people are then immune to the virus and cannot contract hepatitis B again.
When illness does occur, it is either acute (short-term) or chronic (long-term). Acute hepatitis B (affecting approximately 20% of people infected) is usually a mild illness from which people fully recover. The chronic form of hepatitis B (affecting approximately 20% of people infected) is more serious and can lead to complications such as liver cirrhosis (scarring of the liver), liver failure and liver cancer.
New Zealand has a low overall prevalence of chronic hepatitis B (0.9% of the population) but a higher prevalence among Maori, Pacific Island and Asian ethnic groups.
is another form of viral hepatitis that is more likely to eventually lead to serious liver complication.
The hepatitis B virus is spread from person to person in blood or body fluids. The virus is highly infectious and modes of transmission include:
- Infected blood or other body fluids getting into cuts and scratches
- Sexual contact
- Sharing personal items such as toothbrushes and razors
- Sharing of needles by intravenous drug users
- Tattooing, acupuncture and ear piercing if equipment is not sterilised
- From a mother to her unborn baby (the highest risk of transmission is during birth).
Hepatitis B has also been known to spread through blood transfusions. However, all blood donated in New Zealand has been screened for hepatitis since 1992.
Acute Hepatitis B symptoms
Approximately one in five adults (and a smaller proportion of children) infected with the hepatitis B virus will develop the full-blown illness, then go on to make a full recovery. This is known as acute hepatitis B. While acute hepatitis B is usually a mild illness, the range and severity of symptoms experienced differs between individuals and depends on factors such as their age and general health. Symptoms include:
- Jaundice (yellowish skin and eyes)
- Weight loss
- Decreased appetite
- Nausea and vomiting
- Bad breath and bitter taste in the mouth
- Dark brown urine
- Pale coloured bowel motions
- Pain in the right side of the abdomen, just below the ribs.
Acute hepatitis B has a long incubation period (the time from infection to when the illness occurs), being on average two to three months. The most infectious period is from several weeks before symptoms appear until several weeks or months later.
Most people who have a mild illness will recover completely within four to eight weeks, though in cases where the condition was more severe, recovery can take several months. In rare cases acute hepatitis B can cause serious liver damage and in very rare cases it can be fatal. After infection with, and recovery from, acute hepatitis B, the person is immune and is not able to pass the virus on to others.
Chronic Hepatitis B symptoms
Approximately one in five people infected with the hepatitis B virus will develop chronic hepatitis B and become carriers of the virus. The majority of people who are carriers of hepatitis B contracted the virus as babies or young children. It is unusual for adults to become chronic carriers.
Chronic hepatitis B sufferers do not get ill at the time of infection with the hepatitis B virus and most will probably never suffer any negative effects. However up to 25% of hepatitis B carriers go on to develop liver damage later in life. Over many years this damage to the liver may cause cirrhosis, a serious liver disease, which creates a further risk of liver cancer. Even though they may not become unwell, and may not even know they have had the virus, chronic carriers can pass the virus on to other people. It is estimated that there are currently up to 100 000 chronic hepatitis B sufferers in New Zealand.
A diagnosis of hepatitis B is confirmed by blood tests. The detection of the hepatitis B virus or antibodies to the virus in blood tests indicates hepatitis B infection. During the early stages of acute hepatitis B blood tests may show a significant change in liver function.
If the hepatitis B virus is present in the blood for longer than six months, but the person has not developed the acute illness, chronic hepatitis B is diagnosed.
Acute hepatitis B treatment
While there is no cure for acute hepatitis B, treatment for it can be given within 24 hours to one week of exposure to the virus. Injections of hepatitis B-specific immune globulin (a concentrated blood protein) can be given to help the body to develop antibodies that fight the hepatitis B virus. While this may not stop the disease developing altogether, it does enhance the body's ability to fight the virus.
If symptoms develop, an important part of treatment is rest. A nutritious diet and maintaining an adequate fluid intake is also recommended. Avoiding alcohol and medications is important, as these are metabolised by the liver.
Chronic hepatitis B treatment
The aim of treatment in patients with hepatitis B is to prevent progression to cirrhosis, liver failure and liver cancer; and also to prevent transmission of the disease to others. Chronic hepatitis B sufferers should maintain a healthy diet and avoid alcohol and unnecessary medications.
Regular blood tests to monitor the functioning of the liver will be recommended. Biopsies of the liver may also be recommended to monitor the seriousness of any liver damage over time.
The serious liver complications of chronic hepatitis B can be prevented if the disease is detected and treated in its early stages. Chronic hepatitis B is treated with antiviral medication that reducing the viral load on the body, and allowing the immune system to keep infection in check.
Medications available to help treat those with chronic hepatitis B include:
Interferon alpha-2b (Intron A) and Pegylated interferon alpha-2a (Pegasys)
These medications are synthetic versions of one of the body's natural immune proteins, interferon. They work by assisting the body's immune system to block reproduction of the hepatitis B virus. They are given as a course of weekly injections over a pierod of up to one year. Side effects can be troublesome and include flu-like symptoms such as muscle aches, fatigue and a feeling of being generally unwell.
Lamivudine (Zeffix, Zetlam)
Lamivudine works by stopping the hepatitis B virus from replicating. It is given once daily in either tablet or solution form over several months or even years. It has fewer side effects than Interferon but, over time, the hepatitis B virus can develop resistance to the medication.
This medication is used when hepatitis B carriers with serious liver disease have become resistant to lamivudine. It is taken orally as a table once daily and usually needs to be taken long term.
This is the most powerful of the anti-viral medications available for treatment of chronic hepatits B but is not usually used in patients who have failed treatment with lamivudine. It is taken once daily orally as a tablet or solution.
While these medications can be effective, they are only successful in a moderate proportion of cases and their use is limited by side effects and the development of drug resistance by the hepatitis B virus.
Liver transplantation may be a treatment option for some patients with liver cancer or liver failure. Hepatits B-specific immune globulin and antiviral medication is usually used before and after the transplant procedure to prevent recurrence of the hepatitis B virus.
Vaccination and other prevention measures
Vaccination is a safe and effective way of preventing the spread of hepatitis B. Since 1985 the hepatitis B vaccine has been part of the national immunisation schedule, and in 1988 New Zealand was one of the first countries to introduce universal infant hepatitis B immunisation. the vaccine is given to babies at six weeks, three months and five months. Babies born to mothers with hepatitis B will also be given an extra dose of the vaccine at birth.
In adolescents, two doses of the vaccine are recommended, with the second dose four to six months after the first. In adults, three doses of the vaccine are recommended, with the initial dose followed by doses one month and six months later. These doses can be given more closely together if more rapid protection is required.
Hepatitis B immunisation is recommended and publicly funded for the following groups:
- All infants and children up to their 16th birthday
- Household and sexual contacts of known carriers.
Hepatitis B immunisation is recommended, but not publicly funded for the following adults:
- Those at risk because of their occupation eg: nurses, doctors, dentists
- Household contacts and sexual partners of people with known hepatitis B
- People with multiple sexual partners
- People undergoing testing or treatment for a sexually-transmitted infection
- Adults with chronic liver disease prior to liver transplantation
- Adults with hepatitis C
- Those with haemophlilia and other recipients of blood products
- Prison inmates
- Those undergoing renal dialysis
- Homosexual men
- Intravenous drug users
- Commercial sex workers.
Measures that can help prevent the spread of the hepatitis B virus include:
- Teaching children not to touch the blood or wounds of others
- Covering cuts, scratches and grazes
- Not sharing personal items such as razors and toothbrushes
- Avoiding intravenous drug use
- Practising safe sex, including the use of condoms.
Further support and information
The Hepatitis Foundation can offer support and information on hepatitis B.
The Hepatitis Foundation of New Zealand
PO Box 647
Freephone: 0800 33 20 10
Ph: (07) 307 1259
Fax: (07) 3071266
For information about hepatitis B vaccination, consult a doctor or contact the:
Immunisation Advisory Centre
Freephone: 0800 466 863
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Last Reviewed - 26 June 2013