Background In 1997 the German Red Cross (GRC) blood donor services introduced mini-pool nucleic acid testing (NAT) for human immunodeficiency virus (HIV)-1, hepatitis C virus (HCV) and hepatitis B virus (HBV) to increase blood safety. With the new cobas s 201/cobas TaqScreen MPX, a fully automated extraction method and a multiplex amplification system specifically adapted to the needs of blood donation services is available.
Methods The cobas s 201 system was evaluated at the GRC BTS locations Hagen, Springe and Frankfurt. In phase A, the analytical sensitivity for the detection of HBV, HCV and HIV-1 was investigated and in phase B, at least 60 000 samples at each test site were screened in parallel with the MPX test on s 201 system and the existing routine mini-pool NAT system to compare the diagnostic specificity and the diagnostic sensitivity.
Results Comparable analytical sensitivities in a range of 1·6–3·6 IU/ml, 4·9–10·9 IU/ml and 14·7–26·6 IU/ml for HBV, HCV HIV, respectively, for the MPX test on s 201 system (95% probability based on probit analysis) were determined at all test sites. The diagnostic sensitivity was 99·8% and the diagnostic specificity was 99·85%.
Conclusions The MPX test on s 201 system is a fully automated NAT system suitable for routine blood donor screening. The analytical sensitivity as well as the diagnostic sensitivity fulfilled all requirements of the Paul Ehrlich Institute for blood donor screening in mini-pools up to 96 donations per pool. A major benefit of the automated NAT system is the reduced personnel time and the extensive complete barcode-controlled process documentation.