Donated blood may NOT be used for allogeneic transfusion when HCV testing shows what?

The reasoning behind the choice that indicates donated blood may not be used for allogeneic transfusion when the EIA initial testing is reactive, and one duplicate repeat result is reactive, hinges on the established protocols for blood safety and the interpretation of serological testing.

When a donated blood sample tests reactive in an initial enzyme immunoassay (EIA), it signifies a potential exposure to the Hepatitis C virus (HCV). However, in blood banking practices, further confirmatory testing is necessary to ascertain the true infection status. If one duplicate repeat test is also reactive, it raises substantial concern regarding the possibility of active infection with HCV. In this scenario, the presence of two reactive tests implies a stronger likelihood that the individual is indeed infected with HCV, as opposed to reactive tests from non-pathogenic causes (which may occur).

Regulatory guidelines dictate that blood with confirmed reactivity on two separate tests (the initial and at least one duplicate) cannot be used for allogeneic transfusions due to the risk of transmitting HCV to recipients. Therefore, the presence of reactive results in both the initial and one duplicate test signals a critical need to discard that blood product to ensure patient safety. This aligns with the strict standards within transfusion medicine