PITTSBURGH, Penn., June 25--Current testing practices, which typically measure the viral load or the amount of freely circulating genetic material of HIV-1 in the blood, may not accurately detect the amount of virus in semen, say researchers from the University of Pittsburgh Graduate School of Public Health (GSPH).
In a report presented on June 30 at the 12th World AIDS Conference, Pitt researcher, Phalguni Gupta, Ph.D., emphasized that testing viral load levels in semen as well as targeting treatments to sites of seminal virus production may offer physicians a better way to monitor viral activity in HIV-infected patients and also stem transmission of HIV-1.
"To accurately assess how easily and how much HIV can be transmitted during risky sexual contact with HIV-infected individuals, we can't rely on blood tests. Instead, we need to test viral load levels in semen," said Dr. Gupta, who is a professor of infectious diseases and microbiology at Pitt's GSPH.
"Most of the HIV-infected men in our study had very high levels of virus present in their semen at certain time points and then at other times had a lower amount. This indicates that some men may be more likely to transmit the virus during risky sexual behaviors at certain times."
Dr. Gupta and his colleagues are the first to report HIV in semen can fluctuate greatly in some HIV-infected men and does not correspond to viral levels in blood. A previous study by the Pitt group found differences between the types of HIV found in the blood and semen of some HIV-infected men.
"These results, taken together with our new findings, indicate that
virus found in the semen originates from a separate site, different from that of
virus that circulates throughout the body." remarked Dr. Gupta. "If we locate
the site where seminal virus is produced, we may be able to target treatments to
this site and suppress replication of viral strains which may be different than
Contact: Amy Kemp
University of Pittsburgh Medical Center