Transmitted Drug Resistance: The Other Side to the PrEP Failure Case We're Not Talking About

Much of the media coverage thus far about the person who HIV seroconverted while on (and adherent) to PrEP has focused on the side of the story that's been documented -- the target case's own story of consistent adherence to Truvada, exposure to HIV and resulting seroconversion. But what about the other side of the story, of the person who unwittingly transmitted multi-drug resistant HIV?

"It's not uncommon for people to acquire a drug resistant strain of HIV from a partner, but transmission of multi-drug resistant HIV is very rare," said Hyman Scott, M.D., from the University of California San Francisco, who explained that this is what makes this case so compelling -- and a major concern.

In the U.S., it is estimated that almost 20%, or 1 in 5, newly-diagnosed men who have sex with men (MSM) have transmitted drug resistance to one or more classes of HIV drugs. A large surveillance project by the Centers for Disease Control and Prevention (CDC) found that about 10% of HIV-positive MSM who had not yet taken antiretrovirals were resistant to a non-nucleoside reverse transcriptase inhibitor (NNRTI), 7% to a nucleoside reverse transcriptase inhibitor (NRTI), and 6% to a protease inhibitor.

But the surveillance study found that transmission of multi-drug resistant virus is rare. Less than 1% (0.4%) of people had drug resistant mutations to all three classes of HIV drugs, while just over 2% had resistance to 2 classes of drugs and 16% were resistant to only one.

This excerpt was cross-posted with the permission of BETAblog.org. Read the full article.