In recent years, the FDA published several guidelines on the virus safety of blood donations and/or source plasma, such as the Guideline on HIV and HCV Testing for the Assessment of Blood Donors (February 2018). In September 2018, they published a draft guidance on "Further Testing of Donations that are Reactive on a Licensed Donor Screening Test for Antibodies to Hepatitis C Virus".
The testing of donors for HCV has long been established as an example for a licensed donor screening test for antibodies to hepatitis C virus (anti-HCV). However, the fact that only 75-85% of the HCV infected people develop a chronicle HCV infection even though all patients, chronic or non-chronic, carry antibodies, results in a positive testing of non-chronic persons. Therefore, an additional testing of anti-HCV positive donors is necessary to evaluate their acual infection status.
Modern methods, for example Nucleic Acid Testing (NAT), have made the donor screening less time consuming, more precise and less expensive. Studies like "Distribution of hepatitis C virus in circulating blood components from blood donors", Vox Sanguinis, Published online on March 9, 2012, DOI: 10.1111/j.1423-0410.2012.01598.x , by Caren Chancey, Valerie Winkelman, John B. Foley, Erica Silberstein, Andréa Teixeira-Carvalho, Deborah R. Taylor and Maria Rios have shown the suitability of such methods.
Experience shows that NAT testing will be useful in cases where the infection status needs to be evaluated, especially to pass this information on to the donor and to support current public health initiatives with the aim of identifying actively infected individuals in order to prevent and/or control HCV infection and associated chronic disease, cirrhosis, and hepatocellular carcinoma.
In light of this, the FDA published their draft guidance "providing blood establishments that collect Whole Blood and blood components, including Source Plasma, with recommendations for further testing of donations that are reactive on a licensed donor screening test for antibodies to hepatitis C virus (anti-HCV), as required under 21 CFR 610.40(e)."
Additionally, the document includes recommendations for reporting the implementation of these recommendations. To get more details, please read the draft guidance for industry "Further Testing of Donations that are Reactive on a Licensed Donor Screening Test for Antibodies to Hepatitis C Virus".