What is hepatitis C?
Hepatitis C is a liver disease caused by the hepatitis C virus (HCV), which is found in the blood of persons who have this disease. HCV is spread by contact with the blood of an infected person.
Vaccine for the prevention of HCV infection is not available.
What blood tests are available to check for hepatitis C?
There are several blood tests that can be done to determine if you have been infected with HCV. Your doctor may order just one or a combination of these tests. The following are the types of tests your doctor may order and the purpose for each:
a) Anti-HCV (antibody to HCV)
- EIA (enzyme immunoassay) or CIA (enhanced chemiluminescence immunoassay) Test is usually done first. If positive, it should be confirmed
- RIBA (recombinant immunoblot assay) A supplemental test used to confirm a positive EIA test
Anti-HCV does not tell whether the infection is new (acute), chronic (long-term) or is no longer present.
b) Qualitative tests to detect presence or absence of virus (HCV RNA)
c) Quantitative tests to detect amount (titer) of virus (HCV RNA)
A single positive PCR test indicates infection with HCV. A single negative test does not prove that a person is not infected. Virus may be present in the blood and just not found by PCR. Also, a person infected in the past who has recovered may have a negative test. When hepatitis C is suspected and PCR is negative, PCR should be repeated.
Can you have a "false positive" anti-HCV test result?
Yes. A false positive test means the test looks as if it is positive, but it is really negative. This happens more often in persons who have a low risk for the disease for which they are being tested. For example, false positive anti-HCV tests happen more often in persons such as blood donors who are at low risk for hepatitis C. Therefore, it is important to confirm a positive anti-HCV test with a supplemental test as most false positive anti-HCV tests are reported as negative on supplemental testing. Click here for more information on Guidelines for Laboratory Testing and Result Reporting of Antibody to Hepatitis C Virus.
Can you have a "false negative" anti-HCV test result?
Yes. Persons with early infection may not as yet have developed antibody levels high enough that the test can measure. In addition, some persons may lack the (immune) response necessary for the test to work well. In these persons, research-based tests such as PCR may be considered.
How long after exposure to HCV does it take to test positive for anti-HCV?
Anti-HCV can be found in 7 out of 10 persons when symptoms begin and in about 9 out of 10 persons within 3 months after symptoms begin. However, it is important to note that many persons who have hepatitis C have no symptoms.
How long after exposure to HCV does it take to test positive with PCR?
It is possible to find HCV within 1 to 2 weeks after being infected with the virus.
What is the next step if you have a confirmed positive anti-HCV test?
Measure the level of ALT ( alanine aminotransferase, a liver enzyme) in the blood. An elevated ALT indicates inflammation of the liver and you should be checked further for chronic (long-term) liver disease and possible treatment. The evaluation should be done by a healthcare professional familiar with chronic hepatitis C.
Can you have a normal liver enzyme (ALT) level and still have chronic hepatitis C?
Yes. It is common for persons with chronic hepatitis C to have a liver enzyme level that goes up and down, with periodic returns to normal or near normal. Some persons have a liver enzyme level that is normal for over a year but they still have chronic liver disease. If the liver enzyme level is normal, persons should have their enzyme level re-checked several times over a 6 to 12 month period. If the liver enzyme level remains normal, your doctor may check it less frequently, such as once a year.
Can I donate blood if I have had any type of viral hepatitis?
If you had any type of viral hepatitis since aged 11 years, you are not eligible to donate blood. In addition, if you ever tested positive for hepatitis B or hepatitis C, at any age, you are not eligible to donate, even if you were never sick or jaundiced from the infection.
Who should get tested for hepatitis C?
• persons who ever injected illegal drugs, including those who injected once or a few times many years ago
• persons who were treated for clotting problems with a blood product made before 1987 when more advanced methods for manufacturing the products were developed
• persons who were notified that they received blood from a donor who later tested positive for hepatitis C
• persons who received a blood transfusion or solid organ transplant before July 1992 when better testing of blood donors became available
• long-term hemodialysis patients
• persons who have signs or symptoms of liver disease (e.g., abnormal liver enzyme tests)
• healthcare workers after exposures (e.g., needle sticks or splashes to the eye ) to HCV-positive blood on the job
• children born to HCV-positive women