In a development that could enhance HIV-prevention research, a new study of heterosexual couples confirms that the risk of transmitting HIV rises with the level of the virus in semen and cervical fluid.
The finding, that more virus translates to higher likelihood of transmission, hasn’t been proven to this extent before, said study lead author Dr. Jared M. Baeten of the University of Washington in Seattle.
“This confirms what we had thought about the biology of HIV,” he said, “and it gives us new information about genital levels of HIV being particularly important, even independent of blood levels.”
For the study, researchers obtained samples of genital fluid from 2,521 heterosexual couples living in seven African countries. Most were married and living together. At the start of the two-year study, one partner in each couple was infected with HIV, the AIDS-causing virus, and none was taking anti-HIV drugs.
Over the course of the study, published April 6 in the journal Science Translational Medicine, 78 partners became infected within the relationship.
This can help researchers better understand “the natural protections that the penis, the vagina and the rectum have that we want to make sure we preserve,” he said. The study “is highlighting what we need to look at going forward,” he added.