The Body: The Complete HIV/AIDS Resource
Follow Us Follow Us on Facebook Follow Us on Twitter Download Our App 
Professionals >> Visit The Body PROThe Body en Espanol
Ask the Experts About

Safe Sex and HIV PreventionSafe Sex and HIV Prevention
Rollover images to visit our other forums!
Recent AnswersAsk a Question
  • Email Email
  • Glossary Glossary

HIV testing of blood donors

Nov 28, 2001

Plese, what do you think about the current strategy of testing HIV antibodies only in blood donors ? Would not be safer to use also HIV antigen testing for screening ? Or some kind of Ag/Ab tests ? Please let me know your view. Thank you.

Response from Mr. Kull

P24 antigen testing is used to screen the nation's blood supply. The p24 antigen test detects the presence of a protein on the surface of HIV (the "p" standing for protein, and "24" standing for its molecular weight). P24 is referred to as an antigen because it provokes the body's immune response, causing it to generate antibodies. Since HIV is present in the body in very high levels before antibodies are produced, the p24 test may be useful in detecting infection when antibody tests cannot. For this reason, p24 tests are useful for screening the blood supply and for diagnosing acute infection. P24 antigen tests probably detect infection about a week earlier than the antibody tests.

When blood is collected from donors by the Red Cross and affiliates, the blood is bar coded and then transported to one of eight national testing laboratories. The blood is then tested for numerous viruses, including HIV-1/HIV-2 and hepatitis antibodies. Any positive or indeterminate result is discarded. Approximately 2% of all donations are destroyed due to positive results, which are for the most part false positives. In 1996, p24 antigen tests were included in the screening method, to increase the safety of the blood supply.

The blood supply in the U.S. is very safe. The Red Cross attempts to notify individuals of possible infection and recommends health care. The risk of receiving an HIV positive blood transfusion is 1 in 676,000.


Reality (female) condom

  • Email Email
  • Glossary Glossary

 Get Email Notifications When This Forum Updates or Subscribe With RSS



This forum is designed for educational purposes only, and experts are not rendering medical, mental health, legal or other professional advice or services. If you have or suspect you may have a medical, mental health, legal or other problem that requires advice, consult your own caregiver, attorney or other qualified professional.

Experts appearing on this page are independent and are solely responsible for editing and fact-checking their material. Neither nor any advertiser is the publisher or speaker of posted visitors' questions or the experts' material.

Review our complete terms of use and copyright notice.

Powered by ExpertViewpoint