Low incidence of HIV infection and decreasing incidence of sexually transmitted infections among PrEP users in 2020 in Germany
Authors: Schmidt Daniel , Kollan Christian , Bartmeyer Barbara , Bremer Viviane , Schikowski Tim , Friebe Martin , Schellberg Sven , Scholten Stefan , Bickel Markus , Hanhoff Nikola , Rüsenberg Robin , Schewe Knud ,   The NEPOS study group, Knechten Heribert , Panstruga Petra , Baumgarten Axel , Reisenweber Bianca , Hillenbrand Heribert , Zucker Kai , Köppe Siegfried , Da Silva Ribeiro Marc , Krznaric Ivanka , Pitan Denis , Lieb Christian , Yasin Hussen , Ochlast Ingo , Shnurenko Irina , Rausch Michael , Krasov Svetlana , Schellberg Sven , Stueber Peter , Schranz Dietmar , Rittweger Michael , Schulbin Hubert , Smiley Adam , Ummard-Berger Kevin , Berger Andreas , Lenz Johannes , Boesecke Chistoph , Oberschlep Martha , Koch Susann , Monsees Mareen , Heuchel Thomas , Richter Manuela , Bellmunt-Zschäpe Andreas , Hahn Jutta , Jenke Andreas , Pursche Stefan , Mauss Stefan , Berger Florian , Bickel Marcus , Rößler Monja , Haberl Anette , Schott Peter , Khaykin Pavel , Bracone Michaela , Usadel Susanne , Mattmüller Tina , Friese Georg , Kratz Ulrike , Hertling Sandra , Berzow Dirk , Schewe Knud , Rickassel Constantin , Heiken Hans , Rieke Ansgar , Becker Petra , Römer Katja , Scholten Stefan , Roder Andreas , Wyen Christoph , Lammersmann Kerstin , Ruck Ines , Schappert Burkhard , Kastenbauer Ulrich , Pauli Ramona , Mikazans Oskar , Schabaz Farhad , Spinner Christoph , Gladis Stefanie , Christensen Stefan , Offermann Sabine , Baumann Robert , Schübel Niels , Lüssenheide Anja , Audebert Franz , Sepsy Elisabeta , Gospodinov Beatrice , Bulut Aynur , Beck Patrick , Weida Jennifer , Härter Georg , Schütz Petra , Seidel Thomas , Mauruschat Sabine , Rößler Steve 
Published: September 2022

Abstract
Introduction
Objectives of this study, as part of a nation-wide HIV pre-exposure prophylaxis (PrEP) evaluation project, were to determine the incidence of infections with HIV, chlamydia, gonorrhea, syphilis, hepatitis A/B/C in persons using PrEP, and to describe the health care funded PrEP use in Germany. Additionally, factors associated with chlamydia/gonorrhea and syphilis infections were assessed.

Methods
Anonymous data of PrEP users were collected at 47 HIV-specialty centers from 09/2019–12/2020. Incidence rates were calculated per 100 person years (py). Using longitudinal mixed models, we analyzed risk factors associated with sexually transmitted infections (STIs).

Results
4620 PrEP users were included: 99.2% male, median age 38 years (IQR 32–45), 98.6% men who have sex with men (MSM). The median duration of PrEP exposure was 451 days (IQR 357–488), totaling 5132 py. Four HIV infections were diagnosed, incidence rate 0,078/100py (95% CI 0.029–0.208). For two, suboptimal adherence was reported and in the third case, suboptimal adherence and resistance to emtricitabine were observed. One infection was likely acquired before PrEP start. Incidence rates were 21.6/100py for chlamydia, 23.7/100py for gonorrhea, 10.1/100py for syphilis and 55.4/100py for any STI and decreased significantly during the observation period. 65.5% of syphilis, 55.6% of chlamydia and 50.1% of gonorrhea cases were detected by screening of asymptomatic individuals. In a multivariable analysis among MSM younger age, PrEP start before health insurance coverage and daily PrEP were associated with greater risk for chlamydia/gonorrhea. Symptom triggered testing and a history of STI were associated with a higher risk for chlamydia/gonorrhea and syphilis. A significantly lower risk for chlamydia/gonorrhea and syphilis was found for observations during the COVID-19 pandemic period.

Conclusions
We found that HIV-PrEP is almost exclusively used by MSM in Germany. A very low incidence of HIV infection and decreasing incidence rates of STIs were found in this cohort of PrEP users. The results were influenced by the SARS-CoV-2 pandemic. Rollout of PrEP covered by health insurance should be continued to prevent HIV infections. Increased PrEP availability to people at risk of HIV infection through the elimination of barriers requires further attention. Investigation and monitoring with a longer follow-up would be of value.