Interlaboratory study to evaluate the performance of laboratories involved in West Nile virus RNA screening of blood and blood components by nucleic acid amplification testing in Italy

An Italian interlaboratory study was run in 2010 to assess the performance of Blood Transfusion Services in detecting the genome of West Nile virus (WNV) in plasma. Each laboratory received a panel of samples containing four samples negative for WNV and six positive samples with a nominal viral concentration close to or below the 95% detection limit of two commercially available nucleic acid amplification tests (NAT) for WNV, the PROCLEIX® WNV kit and the Cobas® TaqScreen West Nile Virus kit. Ten laboratories took part in the study. All correctly identified the positive samples with a viral concentration above the 95% detection limit. No pre- or post-analytical errors were observed. The interlaboratory study run in 2010 allowed participants to assess the performance of the NAT methods applied in their seasonal routine screening of blood donations.