Promiscuous PrEP user contracts HIV, scientists baffled

Dutch man acquires HIV, but not due to a drug-resistant strain.
Photo credit:
nbcnews.com

Another case of HIV infection from a man faithfully adhering to a PrEP regimen has come to light, but this case is puzzling experts because it is a non-drug-resistant strain of the disease.

Within the past year, only two cases of PrEP failure have been documented, but these were found to be caused by a drug-resistant strain of the virus which are thought to have bypassed the two effective ingredients in Truvada.    

Researchers are only able to hypothesize how this man became infected. They think it may have something to do with his “remarkably high” amount of sex partners within an eight-month period, all without the use of condoms.

Dr. Elske Hoornenborg, of the Public Health Service Amsterdam presented the findings at the 2017 Conference on Retroviruses and Opportunistic Infections (CROI) in Seattle.

Hoornenborg remained optimistic during her presentation, saying internationally tens-of-thousands of people are using PrEP, adding, “we see that PrEP offers a high degree of protection against HIV. It’s not one-hundred percent. So we’ll have to acknowledge that. It also doesn’t protect against STDs. So we think it’s clever to combine different prevention methods—PrEP being one of them, condoms and other risk-reducing behaviors being other ones.”

The dedicated and unwavering use of PrEP has been shown to be effective by 99-percent.

The 50-year-old Dutch man in question was taking part in a study called AMPrEP and was closely monitored, tested and interviewed throughout the process.

“Upon his enrollment in the study, he tested HIV negative according to a fourth-generation HIV antigen/antibody test and an HIV RNA test,” according to POZ.

The fourth-generation test looks both for HIV antibodies, which typically take a few weeks to develop after infection, and the p24 antigen, which normally appears earlier than antibodies and disappears after a few weeks. An HIV RNA test looks for the virus’s genetic material and is even more sensitive to very early infections.”

Researchers were able to confirm the man had been strictly adhering to the PrEP regimen by counting pills, reading diary entries and taking dried blood tests. Dried blood tests are almost like counting tree rings; they can look back to determine the history and habits of the patient.

He had a negative test result at one, three and six weeks after beginning to take the drug.

According to POZ the man was having sex with men and kept a detailed account of each experience. His alarming rate of sexual partners amounted to 402 over an eight-month period according to reports. 

“He reported a respective 75, 56, 56, 50, 38, 49, 66 and 12 anal sex partners. (The eighth month constituted only 20 days.) During each of these months, he reported having condom-less anal sex on a respective 21, 12, 13, 15, 15, 19, 17 and 3 days. According to his reports, during the days he had condom-less anal sex, the median number of partners he had on those days was 3 during the first month, 4.5 during the second, and 4, 4, 2, 3, 5 and 5 for each following month, respectively.”

“According to computer-assisted questionnaires the man completed, during his first 12-week period on PrEP, he had 90 sexual partners with whom he engaged in condomless anal sex and 100 total condomless anal sex acts. During the second 12-week period, the corresponding figures were 51 and 100, respectively. There were no data on the subsequent 12-week period of his PrEP taking, which was ultimately cut short after he showed signs of HIV infection.

He also contracted rectal gonorrhea twice and rectal chlamydia once.

The man also admitted using crystal meth, cocaine, GHB, mephedrone and ketamine during sex.

After eight months of using PrEP, the patient began showing signs of having been infected with HIV, and a test proved that to be true, but only positive for anti-bodies and not the p24 antigen which would normally be present from a new infection,

 POZ gives details of the results:

“The same day, he tested negative for HIV RNA through an assay that had a detection threshold of a viral load of 50. A Western blot HIV test conducted at that time showed that he had only antibodies to the p160 viral antigen, a result that usually comes up later in the course of an infection, after other HIV-specific antibodies arise.

The researchers even went so far as to conduct a highly sensitive assay known as a nested pol PCR test, which looks for both DNA and RNA of HIV.

“The bottom line is we couldn’t detect virus in any way at that early stage," Hoornenborg said.

Researchers took him off PrEP worried that he would develop a drug resistance.

Three weeks after the test results, the man’s viral load reached 40,000, which prompted the health team to start him on a cocktail of Truvada with Norvir (ritonavir)-boosted Prezista (darunavir) and Tivicay (dolutegravir). Within 30 days his viral load became undetectable.

Further tests showed that his virus did not have drug-resistant mutations to the main drugs in PrEP: tenofovir or emtricitabine.

The question remained: how did this man contract HIV if his particular strain showed no signs of a drug-resistant mutation.

Researchers can only speculate that perhaps the virus remained dormant in a localized area of his body, specifically the rectum was subdued by Truvada.

“Then perhaps a drop in Truvada concentration in the rectum, maybe occurring without a corresponding drop in blood levels, allowed a window for HIV to thrive and establish an infection throughout the body,” reports POZ. “Because there are only two HIV drugs in Truvada as opposed to the three or four needed to successfully treat the virus, PrEP may be unable to thwart such a systemic infection.”

The peculiar opening round of HIV test results may have been a reflection of the immune system responding to that initial, ongoing localized infection. Typically, a standard HIV test would not detect a localized infection; it would find signs of the virus only after it spread throughout the body. One recent study found that, at least among monkeys (that were not on PrEP), HIV spreads out of its initial infection site in the reproductive tract as quickly as within one day.

“PrEP has prevented thousands of infections,” said Robert M. Grant, MD, MPH, a professor at the University of California San Francisco School of Medicine who was the head of the global iPrEx study that first proved PrEP’s efficacy among men who have sex with men in 2010. “The report from Amsterdam is one of only a few people worldwide who have become HIV positive while taking PrEP.  His viral load was undetectable until his PrEP was stopped.”

Read more about this case at POZ.

If you have questions about HIV/AIDS or PrEP  you can contact the San Diego LGBT Center (The Center) by clicking HERE. Or call (619) 692-2077