Hepatitis C seldom manifests with symptoms especially in the early stages. However, these individuals are capable of spreading the infection. This makes diagnosing the disease early vital.
Blood tests are available to check for this infection. Blood tests for screening for hepatitis C may be undertaken in the sexual health clinic, GUM (genitourinary medicine) clinic or drug treatment service as well.
Screening for Hepatitis C on a regular basis is important for some persons at high risk. These individuals are:-
This test, simply put, detects if the person has ever been exposed to the hepatitis C virus.
When the body is exposed to an infective organism, it raises antibodies against it. Some antibodies acquired after an infection may last for years or may lie dormant until the person is infected again.
This is the principle behind most viral infections like chicken pox which usually do not recur after the person has developed antibodies against it.
The antibody test for hepatitis C detects presence of such proteins produced by the immune system to fight the virus. However, development of these antibodies against the infection may take some time – usually some months. Thus the test will not show a positive reaction for some months after infection.
If the antibody test is negative but the person still has symptoms, the test may be advised to be repeated again. If the test is positive it indicates infection. However, an earlier infection that has already been cleared by the blood will also show a positive result.
In addition positive anti-HCV IgM levels are found in 50-93% of patients with acute hepatitis C and in 50-70% of patients with chronic hepatitis C. Therefore, anti-HCV IgM cannot be used as a reliable marker of acute HCV infection. To confirm a current infection the PCR test is recommended.
The PCR test or the Polymerase Chain Reaction test is applied to detect the presence of the reproducing and multiplying virus hepatitis C in the body.
A positive test is reported as detectable and indicates the infection has progressed to a chronic (long-term) stage.
This test usually takes around two weeks to process. Genotyping and quantitative hepatitis C RNA tests are performed before treatment of patients.
Those with possible long term infection with hepatitis C are also prescribed other tests including:-