Primary care providers in San Francisco did not order HIV testing for nearly one-quarter of patients starting pre-exposure prophylaxis, or PrEP, according to recent findings published in Open Forum Infectious Diseases.
Susan Buchbinder, MD, director of Bridge HIV, San Francisco Department of Public Health, and colleagues also reported that many providers failed to comply with CDC recommendations to test PrEP users for HIV every 3 months and sexually transmitted infections (STIs) at least every 6 months. The researchers warned that such “suboptimal” laboratory monitoring could increase the risk for HIV drug resistance, as well as HIV and STI transmission.
In previous studies, HIV drug resistance has been found in less than 0.5% of patients who seroconverted while on PrEP, according to the researchers. Although rare, resistance developed primarily during unrecognized acute infection.
“HIV testing prior to initiating PrEP is therefore critical to avoid resistance, as well as forward HIV transmission with a potentially resistant, unrecognized virus,” Buchbinder and colleagues wrote. “Furthermore, if PrEP adherence is poor and breakthrough HIV infection occurs, PrEP continuation without monitoring also leads to resistance.”
The researchers examined data from 15 primary care clinics in the San Francisco Health Network to investigate adherence to HIV and STI testing recommendations. They also assessed factors associated with adherence, including a panel management program, which the researchers described as a population-based care approach that focuses on the health of all patients assigned to a clinic rather than only patients seen during care visits. During the study, two clinics implemented a panel management program, which included active PrEP registries and follow-up reminders.
Between January 2013 and July 2017, Buchbinder and colleagues identified 405 patients who were prescribed PrEP through the clinics (median duration, 11.3 months). Among them, approximately two-thirds were men who have sex with men, 13% were transgender women having sex with men, 15% were in a discordant relationship, 5% were high-risk heterosexual patients and 1% were people who inject drugs. Over the course of the study, one patient who discontinued PrEP and one using PrEP intermittently developed HIV. In addition, 19% of patients were diagnosed with an STI.
Before PrEP initiation, only 77% of patients were tested for HIV and 81% were tested for bacterial STIs, including gonorrhea, chlamydia and syphilis. Among patients who were screened, only 74% completed HIV testing and 79% completed STI testing before starting PrEP.
Following PrEP initiation, only 68% of patients were tested for HIV at quarterly intervals and 67% were tested for STIs every 6 months.
In an adjusted analysis, providers were less likely to order HIV testing for older patients and were more likely to order testing when caring for two or more PrEP users or working at a clinic with panel management.
“Although we discovered suboptimal HIV and STI testing in a primary care population, our data suggest the promise of panel management, which could address disparities in PrEP testing,” the researchers concluded. “Future research into innovative population management strategies could help minimize PrEP’s potential risks and maximize its preventive impact.”