The introduction of a NAT method of screening blood donors in Italy : a report of the first two years’ experience and a re-evaluation of residual risk

The use of NAT technology to screen blood donors in Italy became obligatory in July 2002, but the methodology had been introduced in a trial form the previous year. In the same period an EIA test to detect HCVcoreAg had also been introduced. This EIA narrows the window of immunologically silent HCV infection to a similar extent to that of the NAT methodology. The experimental phase of introducing NAT technology in screening blood in Italy lasted 18 months, but the test became obligatory in July 2002. There was an initial reorganisation of biological validation of units of blood and, despite the tests being concentrated in a smaller number of structures, the feared difficulties in releasing blood components did not occur. Furthermore, the NAT was added to the previously used tests without replacing any of them and a variety of organisational models were set up in the different Regions. The "Italian Group for the Study of Transfusion-Transmissible Diseases" of SIMTI has collected the epidemiological data relating to the two years from 219 Transfusion Services in Italy: overall, data were collected on tests for HCV markers in 2,756,739 units of blood components, of which 1,906,659 were examined with NAT techniques, and on 888,506 units examined for HIV RNA. The incidence of cases that were positive only by NAT, and negative for the respective antibodies, was 3.1/106 for HCV RNA and 1.1/106 for HIV RNA. The introduction of NAT technology allows 10 units potentially infectious for HCV or HIV to be identified in one year and reduces the residual risk of transmitting HCV and HIV via transfusion to 0.5 and 1.1 units per million, respectively.