San Francisco Man Contracts HIV Despite Regular Adherence To PrEP

San Francisco Man Contracts HIV Despite Regular Adherence To PrEP

A 21-year-old Latinx man in San Francisco, California, has contracted HIV despite adhering to a daily PrEP regime.

According to, he is the first known HIV seroconversion with verified adherence to PrEP in the United States,

Medical experts were informed of the news at the annual IDWeek conference, run by the Infectious Diseases Society of America, this past weekend in San Francisco.

Reports show the man began PrEP through a city health clinic in San Francisco in late 2016. At the time, he was confirmed to be HIV negative.

Repeat testing during return visits at the three, six and ten month marks showed he had been consistent in taking the medication and he remained HIV negative. By analyzing samples of his hair, doctors were able to confirm he had adhered to the PrEP regime on a regular basis for the previous six months.

In early 2018, during a followup visit, he tested negative through a rapid test, but a more comprehensive RNA test came back positive. Further testing showed he was indeed HIV positive.

He was immediately placed on HIV medications and his viral load was suppressed where it has remained since treatment began.

Health care experts were able to identify that the man had acquired a particularly resistant strain of HIV usually identified with those who have begun treatment with HIV medications but stopped.

Researchers were able to determine that the man’s primary male partner had been diagnosed with HIV, used medications for a period of time but had stopped. His viral load was found to be very high and matched the 21-year-old’s strain. He has since returned to treatment.

This marks the sixth reported case of HIV infection while using PrEP.

Four cases, two in 2016 in New York and Toronto, and two in 2017 in North Carolina and Australia, are believed to be due to exposure to high viral loads of resistant strains of HIV.

Medical experts believe the fifth previous case, in Amsterdam, was the result of a gay man having “unusually high number” of sexual partners – an average of 56 partners a month – which may have repeatedly exposed him to HIV, according to

Even in light of this new report, health care professionals insist PrEP (currently being taken on a regular basis by over 350,000 people around the world) is extremely effective in combating HIV infection.

“We know PrEP is greater than 99% effective,” Robert Grant, M.D. of the University of California San Francisco told

“There are some cases where HIV will break through. We only have a handful of cases now, and next year, we’ll probably have a handful more. Fortunately, these cases are caught early, treated, and suppressed quickly. The person goes from taking one pill a day to one pill a day. The biggest difference is stigma.”

(h/t: TheBodyPro)