One of the chief sources of infection with the hepatitis C virus (HCV) lies in contaminated blood banks, which is why all the blood banks in Europe or the USA are routinely tested for the virus. However, the poorer countries cannot afford this. The new procedure could change this. “In Brazil, a standard hepatitis C test costs over 100 dollars a sample – for us, in contrast, the cost lies at just under 19 dollars”, declares Dr. Jan Felix Drexler. If poorer countries would test their blood banks, “this would be a significant breakthrough for containing the disease”, Drexler stresses.
The procedure of the test functions, in principle, in the same way as most of the commercial tests hitherto available: all these procedures recognise genotype sequences in the blood, which originate from the HCV. However, the problem is that various types of pathogen exist, whose genotypes are sometimes very different. A good blood test ought to raise the alarm equally well for each of these types.
The genotypes of diverse pathogens are to a great extent identical. Geneticists speak here of conserved regions, and all commercial tests have been “specialised” with respect to one of these points. The new procedure, in contrast, reacts when it detects sequences from a different conserved region which has not so far been used for HCV diagnosis. Working on the basis of just under 600 blood samples from five different countries, researchers were able to demonstrate how well this functions. “We are, at least, just as sensitive as the two best standard procedures”, emphasises Christian Drosten, a virologist from Bonn University.
The procedure will not only detect the presence of an infection. Doctors can also determine the total concentration of the viruses in the blood. Hence, this blood test can also be used for monitoring therapeutic success.
In one Brazilian laboratory the blood test has been given trials on 127 patients – with success. In a publication, the researchers reveal the details of their methods. “For anyone wishing to use this test we can also supply the control reagents”, Drexler declares.
MEDICA.de; Source: Rheinische Friedrich-Wilhelms-Universität Bonn