Detection of hepatitis C virus and parvovirus B19 in human plasma pools by nucleic-acid amplification techniques - Trends in results of EDQM proficiency testing studies from 2004 to 2018.

The European Directorate for the Quality of Medicines & HealthCare (EDQM) has run proficiency testing schemes on the detection of viral contaminants in human plasma pools by nucleic-acid amplification techniques since 1999 for hepatitis C virus and since 2004 for parvovirus B19. A retrospective analysis was performed to assess their impact and identify trends and progress in the results obtained by participating laboratories over a 15-year span, from 2004 to 2018. The results demonstrate that overall performance improved over that time, especially among the regular participants. Participation in these proficiency testing schemes is therefore recommended for all interested control laboratories. This analysis also shows that hepatitis C virus detection now seems well established compared to that of parvovirus B19, which still appears more challenging.

The use of nucleic acid amplification techniques to increase the viral safety of blood.

Despite recent significant improvements in the viral safety of blood and blood products there remains a small risk of contamination mainly due to the existence of a window period before the appearance of antibodies. Nucleic acid amplification technologies (NAT) permit a direct detection of the viral genome itself with an extreme sensitivity and specificity, without depending anymore on the delayed appearance of antibodies. These technologies can be applied to detect most blood-borne viruses. However, the usefulness and strategies will largely depend on different features specific to the type of the virus, such as pathogenicity, prevalence of the infection, viral load during preseroconversion, doubling time of the virus and infectious dose. Many studies have already been conducted in different parts of the world, and the results proving the feasibility of the NAT screening are more than encouraging. However, some problems still remain to be solved in theroutine application of these technologies.