There are a number of tests used in diagnosing and monitoring infection with the hepatitis C virus.
HEP C Testing infographic
To test for hep C, visit your Doctor, Nurse or Clinic to ask to get tested. You will need to take an Antibody Test, which will show if you've ever been exposed (if you've ever had the hep C virus in your blood).
Produced by Hepatitis NSW
The antibody test
The initial screening test for hepatitis C is a simple blood test. The antibody test does not look for the virus itself but for the antibodies raised against the hepatitis C virus. Antibodies are specific to particular viruses. The antibody test therefore indicates whether the person has, at any time, been infected with the virus. It does not determine whether someone still has the hepatitis C virus since the antibodies will remain in the blood even if the body has cleared the virus. The test also cannot tell how long ago the person was infected or for how long they might have had hepatitis C. Antibody test results are usually clearly positive or negative, but sometimes they come back as indeterminate. In this case, a follow-up test may be required. A repeat test is always performed to confirm positive results. Testing for antibodies can be done at three months.
Polymerase Chain Reaction (PCR) test
This is also a blood test. The term PCR refers to the actual laboratory technique (polymerase chain reaction) that amplifies the viral genetic material to a level that can be detected. The technique is complex and consists of many stages and is therefore fairly expensive. The Medicare rebate is available for the HCV PCR test for people who fulfil certain criteria and also to anyone considering whether to have treatment. In relation to the hepatitis C virus, this technique or related molecular techniques may be used to test for the following three factors:
- The presence or absence of the virus in the blood
- The level of virus present in the blood (viral load)
- The genotype of the virus
The PCR test can be done at three weeks.
Liver function test
This is a blood test that is used to detect abnormal levels of specific enzyme production in the liver. When the liver is attacked by the hepatitis C virus it becomes inflamed and, as a consequence, some liver cells die and release enzymes. These enzymes are often very specific to certain viruses or conditions. One of the signs that infection with the hepatitis C virus is resulting in inflammation of the liver is a raised level of ALT (alanine aminotransferase) in the blood. For people who are hepatitis C positive, ALT is the most commonly monitored enzyme in liver function tests.
This procedure is regarded as the most reliable test currently available to assess the current health of the liver. A liver biopsy used to be a requirement for people considering treatment but this is no longer the case. A biopsy is a minor surgical procedure in which a specialist takes a tiny piece of the liver for laboratory examination. Your specialist may have specific reasons for recommending that you have a liver biopsy. Other non-surgical options for assessing liver damage are currently being researched and may become available in the near future. The decision to have a liver biopsy should not be taken lightly. While it is generally considered a safe procedure, there is always the risk of bleeding or other more serious complications. For this reason, other techniques may be used for assessing liver damage in people with haemophilia or other blood clotting conditions. Nowadays it is generally standard procedure that an ultrasound or CT scan is used to pinpoint an appropriate site for the biopsy.
The Fibroscan is a relatively new piece of equipment that can assess the degree of liver damage or scarring. The Fibroscan has similarities to an ultrasound and it measures the level of liver stiffness, which indicates the level of scarring (damage or fibrosis). The good news is that it is a non-invasive procedure and only takes 10-15 minutes. Although the scan is good at picking up on mild liver damage and cirrhosis, sometimes a liver biopsy can be still required to assess the level of liver damage and progression.
Further information on the fibroscan can be found here.
For testing guidelines see the National Hepatitis C testing policy policy.