How reliable are the tests?
In combination, the search and confirmation tests have a very high accuracy. In all circumstances of a common infection with the hepatitis C virus, both tests can provide a reliable diagnosis. Only rare concomitant circumstances or factors can influence the accuracy of the test.
These include immunosuppression, for example. In rheumatics, HIV patients or patients on dialysis, for example, the addiction test can be negative. This is because in these cases the body does not respond reliably to the infection by producing antibodies.
The infection can occur even if no antibodies against the pathogen are detected. If antibody production takes an unusually long time and significantly exceeds the normal period of about 7 weeks, the test may also be false negative. A further weakness of the screening test is that antibodies can be found in both acute and chronic or cured and more recent diseases. It is therefore not possible to differentiate between the different stages of the disease. In order to compensate for all these uncertainties, the confirmatory test is carried out, which allows both the virus itself to be detected without an immune response, and the stage of the disease and the amount of virus in the body to be determined.
How fast are the results there?
The screening test has a high diagnostic gap.This means that the incubation period of the virus is long and the disease is usually not detectable via antibodies up to 7 weeks after infection. In some cases, antibody formation may start a few weeks later or even a few weeks earlier. A negative test result after 7 weeks must therefore be repeated if suspicion exists.
The exact duration of the screening test until the results are available can vary greatly. Although the test itself is performed quickly, the samples often have to be sent to special laboratories, which take different lengths of time for the test. In case of acute suspicion of a disease, the confirmatory test, the determination of HCV-RNA can be performed before.
The RNA can be detected after about 1-2 weeks and can therefore provide important early information. Modern rapid tests, on the other hand, provide the results in a very short time. Although the tests have not yet become clinically established, they deliver their relatively reliable results within 20 minutes. Similar to the confirmatory test, they can be performed after about 1-2 weeks.
