Expanding daily oral antiretroviral pre-exposure prophylaxis (PrEP) to persons at high risk for HIV may accelerate the reductions in new HIV diagnoses in the United States, according to a study published in Clinical Infectious Diseases.

To reduce the number of new HIV infections in the United States, there have been efforts to bring delivery of antiretroviral prevention to scale. As a result, the overall annual incidence of HIV in the United States has been decreasing slowly overall since 2008; however, among some populations, the incidence has remained stable or has been increasing. Moreover, several years of decline, HIV incidence has been stable from 2013 to 2016. Efforts to reduce new infections have focused on expanding sustained antiretroviral therapy (ART) to people living with HIV and expanding daily oral antiretroviral PrEP with coformulated tenofovir disoproxil fumarate and emtricitabine to persons without HIV who are at high risk of acquiring an HIV infection.

The United States Food and Drug Administration approved PrEP in 2012 and since then the estimated number of people in the United States who were prescribed PrEP has increased from 8768 in 2012 to 100,282 in 2017. In addition, ART delivery to all individuals with HIV has increased as well as efforts to retain people with HIV in care and to support high medication adherence to achieve viral suppression levels associated with no sexual transmission to others. Although previous studies have demonstrated that HIV diagnosis reductions associated with increased ART, PrEP, or combination of both, other studies have shown only minimal change. However, mathematical models have indicated that increasing HIV testing and coverage of ART and PrEP (alone or in combination) can result in substantial decreases in HIV incidence in specific groups. Therefore, this study assessed whether there is an association between uptake of PrEP and decreases in HIV diagnoses.

To estimate viral suppression and annual percentage change in diagnosis rate (EAPC), data from the US National HIV Surveillance System from 2012 to 2016 for 33 jurisdictions was used. PrEP uptake estimates were made using data from the national pharmacy database. Poisson regression with random effects for state and year was used to estimate the association between PrEP coverage and EAPC, with and without accounting for changes in viral suppression: within jurisdictional quintiles grouped by PrEP coverage changes, regressing EAPC on time, and among all jurisdictions.

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Results showed that across the 10 states that showed the greatest increases in PrEP coverage, the EAPC decreased 4.0% between 2012 and 2016. Across all states and the District of Columbia, the EAPC decreased by an average of 1.1% in any given year when PrEP coverage increased to 1 per 100 persons with indications. When controlling for viral suppression, the EAPC decreased an average of 1.3%. When controlling for viral suppression in the 33 areas with ³3 years of viral suppression data, the state-specific HIV diagnosis rate decreased by 1.3% for a given year, for a PrEP coverage of 1 per 100, and by 6.6% for an increase in PrEP coverage of 5 per 100. When PrEP coverage was accounted for, viral suppression had no effect on the HIV diagnosis rate.

Overall, the study authors concluded that, “We found statistically significant associations between jurisdictional increases in PrEP coverage and decreases in EAPC independent of changes in VS, which supports bringing PrEP use to scale in the US to accelerate reductions in HIV infections.”

Reference

Smith DK, Sullivan PS, Cadwell B, et al. Evidence of an association of increases in pre-exposure prophylaxis coverage with decreases in human immunodeficiency virus diagnosis rates in the United States, 2012-2016 [published online February 25, 2020]. Clin Infect Dis. doi:10.1093/cid/ciz1229