HIV in Blood VS. HIV in Semen
A guide to the difference between HIV in blood versus semen, the PCR semen test, “sperm washing,” and how SPAR developed the most stringent safety standards for semen testing in the world.
HIV in Blood VS. HIV in Semen
Research has shown that HIV blood tests do not reliably predict viral burden in semen, as semen producing organs are a separate compartment of HIV infection. Semen viral burden is different from blood viral burden, even in men on therapy. For this reason, SPAR is structured around semen testing, using only sperm from specimens that test undetectable for HIV for fertility attempts.
Data compiled by BRF scientists from 2000-2006 revealed that 19% of the semen specimens from 262 men entering SPAR were positive for HIV, even though the men had an undetectable burden of viral RNA (HIV particles) in blood. From 2007-2011 18% of semen specimens from 368 men tested positive. The most recent data compiled from 2012-2022, showed that 16% of semen samples from 652 men tested positive, despite more wide spread use of antiviral therapy. All men eventually produced at least two specimens with undetectable virus.
This important finding, that HIV is intermittently present in semen specimens, is what makes testing each specimen so important to preventing transmission.