Cases of HIV, while infrequent, have been reported during tenofovir disoproxil fumarate/emtricitabine use as pre-exposure prophylaxis (PrEP). We describe the incidence of HIV and patterns of PrEP use within the Veterans Health Administration (VHA).
We conducted a retrospective cohort study among persons initiating PrEP in the VHA between July 2012 and April 2016 using national VHA data. We defined time on PrEP and time at risk of HIV exposure as the total time from the first PrEP fill to exhaustion of supply of the final PrEP prescription. We identified incident cases of HIV infection after PrEP initiation based on laboratory data. Medication adherence measures and days without pills were calculated using pharmacy fill data. We used a chart review to determine patient-reported PrEP use around the time of diagnosis.
We identified 825 unique patients initiating PrEP; they were 97% men and 67% white, with a mean age of 41 years. Six HIV infections were observed during the study period, yielding an HIV incidence of 0.8 (Poisson exact 95% confidence interval: 0.3 to 1.8) cases per 100 person-years. Two cases occurred during active PrEP use by self-report and perfect adherence based on fill data. Both were infected with viruses containing the M184V mutation. Four additional cases were diagnosed after self-reported discontinuation.
HIV infection was rare in a nationwide cohort of PrEP users. Although most of the infections occurred during inconsistent PrEP use, infections during periods of high measured adherence were also observed. These findings highlight the importance of PrEP persistence during periods of risk.
aGeriatric Research Education and Clinical Center, Louis Stokes Cleveland VA Medical Center, Cleveland, OH;
bDivision of Infectious Diseases, Department of Medicine, Case Western School of Medicine, Cleveland, OH;
cUniversity Hospitals Cleveland Medical Center, Cleveland, OH;
dVA Puget Sound Health Care System, Seattle, WA;
eDivision of General Internal Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, WA;
fVA Portland Health Care System, Portland, OR;
gDivision of Infectious Diseases, Oregon Health and Sciences University, Portland, OR;
hCenter for Access and Delivery Research and Evaluation (CADRE), Iowa City, IA; and
iDepartment of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA.
Correspondence to: Puja Van Epps, MD, Louis Stokes Cleveland VA Medical Center, 10701 East Boulevard, Cleveland, OH 44106 (e-mail: firstname.lastname@example.org).
Presented at the Conference on Retroviruses and Opportunistic Infections; March 4–7, 2019; Seattle, WA.
P.V.E and B.M.W. receive support from the VA Geriatric Research Education and Clinical Center. M.M.M. and L.A.B. receive support from the VA Office of HIV, Hepatitis and Related Pathogens. M.E.O. receives support from VA Center for Access and Delivery Research and Evaluation. The remaining author has no conflicts of interest to disclose.
Received April 19, 2019
Accepted September 09, 2019