A second instance of a gay man on pre-exposure prophylaxis (PrEP) contracting HIV was revealed yesterday at the 2016 HIV Research for Prevention conference in Chicago.
Howard Grossman, a well-known HIV doctor in New York City who now practices at the Cleveland Clinic in West Palm Beach, Fla., described the case at the conference. According to Grossman, the man had contracted a very rare, drug-resistant form of HIV. This is the second instance of infection of a gay man who is on PrEP and adhering faithfully to the one-pill a day regimen. In February, another instance was revealed t the 2016 Conference on Retroviruses and Opportunistic Infections in Boston.
Truvada, the pill prescribed for PrEP, contains two antiviral medications — tenofovir and emtricitabine. Apparently both men were infected with a strain of HIV that was resistant to those medications.
In an interview with POZ, Grossman emphasized the overall success rate of PrEP. “PrEP works and is the most successful intervention we have had,” he said. “Failures have been vanishingly rare, and that’s not changing; and tops can get infected.” He added that condoms can further reduce the risk of HIV.
Grossman’s patient, a man in his twenties, was in a relationship with an HIV positive man whose viral load was undetectable. But he also had had sexual relations with two other men five and a half and 11 weeks before testing positive for HIV. Grossman said his patient was the insertive partner and did not wear a condom in either encounter.
Drug resistance testing of the man’s virus found that it had multiple resistance mutations, including those that confer resistance to each of the two drugs in Truvada, tenofovir and emtricitabine. The transmission of such multidrug-resistant strains of the virus are rare, regardless of whether someone is taking Truvada, suggesting that such cases of PrEP failure will remain quite uncommon. In other words, there is very good reason to believe that researchers were correct when they estimated that PrEP is more than 99 percent effective at preventing HIV when taken daily.
The apparent fact that the man contracted HIV from sex in which he was the insertive partner adds to the rarity of his case. Men are far less likely to contract the virus from insertive sex than from receptive sex. (Granted, self reports about sex can be unreliable; so the man may have in fact contracted the virus through receptive sex.)