Before blood is issued to hospitals for use in transfusion, it is tested for:
In addition to screening out individuals whose health or high risk activities may put recipients at risk, stringent laboratory tests for infectious diseases are conducted on each unit of blood or plasma.
No matter how many times a donor may have donated, each unit of blood or plasma collected is tested to detect agents that might cause diseases including AIDS, hepatitis, syphilis and West Nile Virus. If the blood or plasma tests positive for any disease marker, it is destroyed and the donor is notified of the abnormal test results.*
False Reactive or False Positive Results