The numbers of PrEP, pre-exposure prophylaxis for HIV infection, in Italy. Target population, implementation limits, risk compensation. The access program ItaPrEP compared to Prevenir Study.

Globally, 37.9 million of people are living with HIV; 1.7 million of them, became newly infected, in 2018. Moreover, eight million people living with HIV did not know to be infected, at end of 20181. Several HIV prevention methods are available, including male and female barrier methods, voluntary medical male circumcision, prevention of mother-to-child HIV transmission and harm reduction strategies, such as provision of sterile injecting equipment and opiate substitution therapy for people who inject drugs. All these have contributed to levelling the rate of new infections in some countries; elsewhere, however, the momentum of the epidemic remains strong. Additional safe and effective approaches to HIV prevention are urgently needed. In recent years, a promising new approach has emerged in the use of antiretroviral drugs for HIV prevention. Pre-exposure prophylaxis (PrEP) is the use of drugs to prevent HIV infection in people who have not yet been exposed to HIV virus. PrEP is a prevention strategy for people who are HIV negative but who also have higher-than-average risk of contracting HIV including sexually active adults at increased risk of HIV, people who engage in injection drug use, and serodiscordant sexually active couples. Nowadays, there is no doubt about the efficacy of PrEP in the reduction of the spreading if HIV infection. Several factors, however, can contribute to non-adherence to the PrEP therapy and several studies underline that some groups appear to have more difficulty taking PrEP. This dissertation shows the ongoing results of the ItaPrEP study, in terms of key factors contributing to explaining non-adherence. From January 2018 to March 2020, 456 people have been enrolled to participate in ItaPrEP access program, whose main goal is the assessment of the feasibility of a National PrEP Administration Program in Italy, defined as the active follow-up maintenance of >80% of participants for a total duration of the 1-year study. Determining the rate of PrEP adherence and discontinuation is a secondary goal of the study. The ongoing results of ItaPrEP are compared with the ANRS PREVENIR study, an ongoing prospective cohort study, enrolling individuals at high risk for HIV infection on PrEP in Paris area, which started in May 2017, for which 3,000 among people at risk of HIV infection are monitored across the “Ile de France”. The primary objective of Prevenir study is to show at 3 years more than 15% reduction in new HIV diagnoses among MSM in the Paris Region in comparison with the number provided by the National Surveillance network in 2016, while one of the Secondary Objectives is PrEP adherence and coverage of sex events (self-report, dried blood spots). In the 2020 (when this study ends), it will be known whether a comprehensive prevention strategy, based on regular testing, immediate treatment of people who have discovered their HIV status, and the use of the PrEP and TPE for HIV-negative people, results in a significant decrease in the number of new HIV infections among those most at risk of HIV infection. The thesis is organized as follows:
❖ A brief review of all most important studies and clinical trials, that demonstrated the efficacy of PrEP.
❖ An overview of the PrEP implementation projects in progress in the world, with the specific examples of Australia, France, and UK.
❖ A description of the compensation risks, and limits to PrEP implementation including adherence, costs, STI, barrier methods use, PrEP online and adverse effects.
❖ The ItaPrEP Italian observational prospective protocol and its objective s materials,
❖ methods and comparison and results. of ItaPrEP's results and Prevenir results focusing on adherence, PrEP discontinuation, STI, possible implementation strategies.
❖ Conclusion.