What is hepatitis C?
Hepatitis C is a virus which can cause damage to the liver. Hepatitis C is mainly transmitted by direct blood to blood contact. Some people infected with hepatitis C will clear the virus from their body, but the majority will have the virus long term. Chronic infection can lead to progressive liver disease, though this usually occurs over a long period. A course of drug treatment for hepatitis C usually takes some months, and cure rates vary according to the strain (genotype) of the virus.
How is hepatitis C transmitted?
Hepatitis C virus is transmitted by transfer of blood, most commonly through drug users sharing needles. It was also transmitted through blood transfusions or blood products prior to screening of donated blood for hepatitis C, which started in New Zealand in July 1992. Non-sterile tattooing or body piercing equipment also poses a risk of hepatitis C transmission. The virus may also be transmitted from mother to child at birth. However, it is much less infectious than hepatitis B and does not spread as readily. The risk of sexual transmission appears to be very low, provided no blood-to-blood contact occurs.
What happens to those infected?
Some people get rid of the virus (approximately 20% in the first year of infection), but in many cases they will become chronically infected. These people have been infected with hepatitis C, and instead of getting rid of the virus, they "carry" it in their liver for many years. They often experience fatigue and other problems such as joint pains and skin irritations. In the long term, they are also at risk from progressive liver damage.
How do I know if I am chronically infected?
Only a blood test can tell you – the Hepatitis Foundation can organise this, or your own doctor can advise you how to get one.
How can I prevent spreading infection to others?
There is no vaccine available for immunisation against hepatitis C virus. To prevent spreading the infection, do not donate blood or share needles. Cover any open cuts and sores, and wipe up blood spills, cleaning the surface with bleach afterwards. Although transmission by conventional male/female sex is uncommon, you are advised to use a condom.
What happens to hepatitis C virus carriers?
Some people with chronic hepatitis C may eliminate the virus from their bodies, but for most (80%), hepatitis C leads to very slow, progressive liver damage. In some, this may eventually lead to liver scarring (cirrhosis) and liver failure, or to liver cancer. The time course can be very long, however, and many hepatitis C carriers will not develop serious complications until 30 to 50 years after infection.
The disease progresses more rapidly in males, those over 40 years, and in those who drink alcohol. It is strongly advised that people with hepatitis C do not drink alcohol, or at least reduce their intake to no more than two units daily.
Vaccination against hepatitis A and hepatitis B
Co-infection with hepatitis B or hepatitis A also has a serious impact on the outcome of chronic hepatitis C infection. People chronically infected with hepatitis C need to be tested for and, if susceptible, vaccinated against hepatitis A and B.
What is a genotype?
There are six main strains or "genotypes" of the hepatitis virus, and subtypes within these. The genotype can influence the level of viral replication, the natural history (course of the disease), and response to drug treatment with pegylated interferon and ribavirin. In New Zealand and Australia, the main genotypes are 1a, 1b and 3a. Genotypes 1 and 4 are the most difficult to treat, with a cure rate of approximately 55-60%. Genotypes 2 and 3 achieve a cure rate of approximately 80%.
Cure means that the hepatitis C virus is no longer detectable through blood tests, six months after treatment is completed. This is called 'sustained virological response' (SVR).
What treatment is available for hepatitis C?
Current treatment for hepatitis C virus is a course of pegylated interferon and ribavirin. Pegylated interferon is available in a pre-filled syringe and administered once a week by subcutaneous (into fat) injection for either 24 or 48 weeks, depending on genotype. Genotypes 1 and 4 are usually for 48 weeks.
Unfortunately, pegylated interferon has a number of drawbacks – it is given by injection and it causes some unpleasant side effects. Most troublesome are muscle aches and lack of energy, though these often improve after the first few doses, and can be lessened by giving the dose at night with aspirin or paracetamol.
It can also make depression worse and affect the number of immune cells in the blood. Both of these side effects need regular review by your doctor. Both pegylated interferon and ribavirin need close monitoring with blood tests. USA recommendations for treatment were published in the journal Hepatology (2002; 36 (5):supplement 1: 1-20).
Original material provided by the Hepatitis Foundation of New Zealand. Reviewed by everybody, March 2011.