The initial tests we use to screen blood are highly sensitive to guarantee the safety of Canada’s blood supply. Our tests are designed to detect donations with even the smallest levels of infection. This ultra-sensitive means of testing can sometimes create a reaction with proteins in the blood and produce a "reactive" (i.e., positive) result. We then check the result using a more specific test with a different standard of sensitivity. If that test does not produce the same positive result, we consider the first result to have been a "false reactive" or "false positive."
In the past, a false reactive result meant that a donor was indefinitely deferred from giving blood. Since then, mnay countries has approved a re-entry program for some false positive results to allow eligible donors to be re-tested after a six-month waiting period.
If you have received a false reactive result in the past and would like to set up an appointment to be re-tested.
