Internal Medicine

Hepatitis C test

introduction

The hepatitis C virus causes dangerous liver inflammation, which is mostly chronic and progressive. In Germany, around 0.3% of the population is infected with hepatitis C.

Thanks to early diagnoses, good results are now possible with modern treatment options. In this way, the disease can be cured in a large number of cases before it becomes chronic. So-called "search tests" and "confirmation tests" have proven effective in diagnostics.

If possible, diagnostic tests should always be very sensitive and at the same time very specific. This means that the tests are highly likely to be positive if the disease is present, but reliably deliver negative results even if the disease is not present.

What types of hepatitis C tests are there?

In the diagnosis of hepatitis C, two tests are mainly used clinically, a search test and a confirmatory test.

The screening test is also called the anti-HCV antibody test. Here, the body is looking for antibodies against the hepatitis C virus. About 7-8 weeks after infection, the body forms antibodies against the virus, which can be detected with a very high degree of certainty in this test procedure. The search test is suitable as an initial test if an infection is suspected.
If the test is positive, however, this does not necessarily mean a disease. Even if the disease is not present, the test can be positive in some cases.
A confirmation test must then be carried out. The so-called "HCV-RNA" is determined in this case. This in turn has a high specificity, which means that it is almost never positive if there is no disease. In this test, the direct genetic material of the hepatitis virus is determined, which not only confirms the infection, but also the genotype and the amount of virus in the body. The genotype plays a role especially in therapy planning, as the drugs act differently on different genotypes.
Nowadays, rapid tests are also being developed to simplify the diagnosis of hepatitis C virus infection. These offer the possibility of recognizing the infection from venous blood, finger blood or saliva. New studies show that the rapid tests already have high diagnostic success rates. However, they have not yet established themselves in everyday clinical practice.

Learn more about the disease and its effects below: Hepatitis C

Rapid test

In the diagnosis of the hepatitis C virus, rapid tests are currently being developed with which the first suspected diagnoses in everyday clinical practice are possible before the lengthy laboratory procedures. There are already similar rapid tests that are used clinically in HIV diagnostics. The advantage of the rapid tests lies in the duration of 20 minutes per test procedure.

Obtaining the sample material is also an advantage, since it can be obtained not only by intravenous blood sampling, but also by a drop of blood from the fingertip or by saliva.

Read more on the subject at: Rapid hepatitis C test

How reliable are the tests?

When combined, the search and confirmation tests have a very high level of accuracy. In all circumstances of a usual infection with the hepatitis C virus, both tests can make a reliable diagnosis.

Only rare accompanying circumstances or factors can influence the test accuracy. This includes, for example, immunosuppression. In rheumatics, HIV patients or patients requiring dialysis, 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 be present even if no antibodies against the pathogen are recognized.

If antibody production takes an unusually long time and significantly exceeds the normal period of around 7 weeks, the screening test can also be false negative. Another weakness of the screening test is that antibodies can be found in both acute and chronic illnesses or illnesses that have healed and been in the past. It is therefore not possible to differentiate between the various stages of the disease.

To compensate for all these uncertainties, the confirmatory test is carried out, in which both the virus itself can be detected without an immune response, as well as the stage of the disease and the amount of virus in the body.

How quickly are the results there?

The addiction test has a large diagnostic gap. This means that the virus has a long incubation period and the disease is usually not detectable by antibodies up to 7 weeks after infection. In some cases, the formation of antibodies can even start a few weeks later or a few weeks earlier. A negative test result after 7 weeks must therefore be repeated if there is a suspicion.

The exact duration of the search test until the results are available can vary widely. The test itself can be carried out quickly, but the samples often have to be sent to special laboratories that take different lengths of time for the examination.

If there is an acute suspicion of an illness, the confirmatory test and the determination of the HCV-RNA can be carried out beforehand. The RNA can be detected after about 1-2 weeks and can therefore provide important early information.

Modern rapid tests, on the other hand, deliver the results in a very short time. The tests have not yet become clinically established, but deliver their relatively reliable results within 20 minutes. Similar to the confirmation test, they can be carried out after about 1-2 weeks.

Cost of testing

The cost of the different hepatitis C tests can vary with the different laboratories. Simple rapid tests can be purchased in pharmacies for less than € 10. However, there are many different ones, the respective test security of which can vary.

In the case of acute suspicion, the diagnosis should be carried out clinically using the established search and confirmation tests. Depending on the required performance, these can cost around € 100 for a single test procedure. The antibody screening tests are significantly cheaper than the tests for HCV RNA. Most expensive are the tests for the subsequent therapy decision to determine the amount and genotype of the hepatitis C virus.

Who bears the costs?

If there is justified medical suspicion, the costs are covered by the health insurance company. If the suspected diagnosis of hepatitis C is made by a doctor, the diagnostic tests must be carried out in order to receive confirmation as soon as possible and to initiate therapy with a prospect of a cure.

However, the laboratory procedures are not paid for by the health insurance company if there is no medical indication. For prophylaxis and screening you have to pay for the tests yourself. In most cases, the quick tests are also not accepted. These can be purchased in pharmacies at your own expense.

Where can you get tested for hepatitis C?

Search and confirmation tests for hepatitis C diagnostics can be carried out by almost all doctors, especially in hospitals. For this purpose, blood serum must be taken from the vein, which is then examined for antibodies and RNA in the hospital's own or private laboratories.

Rapid tests can also be done at home. This often only requires a drop of blood from the fingertip or a little saliva.

Is that also possible during pregnancy?

The hepatitis C diagnosis can also be carried out during pregnancy. Only the dangers and possible therapies differ.
Transmission to the child is very unlikely during pregnancy. However, direct blood contact increases the likelihood. Breastfeeding is also usually not a problem and can be continued despite the mother's HCV infection.

The therapy options for HCV infection during pregnancy are severely limited. Conventional drugs are harmful to the unborn child and newer therapeutic agents cannot yet be recommended or used. After birth, the hepatitis C RNA should also be determined in the newborn as soon as possible in order to be able to treat a potential early infection effectively.