Testing for viral infection in donors using NAT

A colleague reports that blood establishments in Denmark do not currently apply NAT to detect viral infections due to very low risk of transmission. The inquiring colleague wonders if this might change due to a transmission of HIV during the window period when an infected donor tested negative in a licensed HIV EIA test. The inquiring colleague is therefore trying to collect facts about licensed NAT kits for HIV or for a combination of HIV/HCV/HBV.

1. An American colleague comments that tests in use in the US may not apply to Denmark. For example, a large multi-state blood collection agency uses the licensed Gen-Probe test distributed by Chiron (now Novartis). They test in pools of 16. The American colleague adds "The Ultrio test (HIV/HCV/HBV) has been licensed in the US on both the semi-automated and automated platforms, but due to limited efficacy in the US with the use of sensitive HBsAg testing (PRISM) and anti-HBc testing, there would be limited to no efficacy for adding HBV in the US, and the costs would be very high. In order to have HBV yield, smaller pool sizes or individual unit testing is required, and there still is the question about yield and clinical efficacy." Having said that, she adds "although Ultrio has been FDA licensed, the HBV screening claim is still unlicensed; the test is licensed for screening of HIV and HCV but only detection of HBV, not a screening claim. The clinical trials never demonstrated any HBV yield due to small size. Currently, a few sites are assisting GP/Chiron in getting the HBV claim for this test. The current Roche system (AmpliScreen using Amplicor) is used in pools of 24; however, this will soon be replaced by the MPx system using RT PCR and the s201 platform using pools of 6. All the Roche systems separately extract RNA/DNA for the 3 viruses, so you can run all 3 viruses or only 2." She believes that once the s201 is licensed by FDA, sites will run all 3.

2. Another American colleague reports that in his experience, there are only two licensed manufactures of NAT assays, Roche and Chiron/Gen-Probe/Novartis. If the colleague from Denmark needs a European contact, there is a testing service run by the German Red Cross.

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Ira A. Shulman, MD
CBBS e-Network Forum Editor & Moderator

W. Tait Stevens, MD
CBBS e-Network Forum Assistant Editor & Moderator