ABSTRACT
Background: A prospective demonstration project in Amsterdam (AMPrEP) provided pre-exposure prophylaxis (PrEP) to people vulnerable to HIV in 2015- 2020. Data on long-term trends in sexual behavior and incidence of STIs during PrEP use are needed to inform future PrEP programs. Therefore, we assessed sexual behavior and incidence rates of STIs among MSM and transgender women on PrEP over four years. Method(s): AMPrEP participants chose between oral PrEP daily (dPrEP) or event-driven (edPrEP) at baseline and could switch regimens at each 3-monthly study visit. They were tested for STIs at these visits and if necessary in between. Follow-up began at PrEP initiation and continued until 48 months of follow-up or was censored at March 15, 2020 (start COVID-19), whichever occurred first. We assessed changes over time in incidence rates (IR) of chlamydia, gonorrhea, and infectious syphilis using Poisson regression. We estimated the IR of Hepatitis C (HCV) diagnoses per consecutive year. We described the number of HIV diagnoses, and sexual behavior (i.e. number of sex partners, condomless anal sex acts with casual partners [CAS]). Result(s): A total of 367 (365 MSM) started PrEP and contributed 1249 person-years of observation. IRs of any STI was 87[95%CI 82-93]/100PY. There was no change in the IR of any STI and infectious syphilis over time on PrEP. We observed a slight decrease in incident chlamydia and gonorrhea in daily PrEP users (Table). Two incident HIV cases were diagnosed in the first year of follow-up. IRs for HCV were 1.5[0.6-3.6], 2.5[1.3-5.0], 0.7[0.2-2.7], and 0.4[0.1- 2.8]/100PY, per consecutive year on PrEP. Median number of sex partners per 3-month period decreased from 16[IQR 8-34] and 12[6-25] (dPrEP and edPrEP, respectively) at baseline, 15[7-30] and 8[3-16] at 24 months, and 12[6-26] and 5[2-12] at 48 months. Median number of CAS acts with casual partners were respectively 7[3-15] and 4[1-9] at baseline, 14[5-25] and 4[1-12] at 24 months, and 12[4-25] and 4[1-9] at 48 months. Conclusion(s): Over the first 4 years of PrEP use overall STI incidence was high and stable. Chlamydia and gonorrhea incidence declined slightly in daily users. Numbers of sex partners seemed to decrease in both dPrEP and edPrEP users. Number of CAS acts with casual partners appeared to increase first, and then stabilized. Notably, this did not result in increased incidence of STIs. Regular testing and treatment of STIs remain a priority among PrEP users. Biomedical prevention of STIs can be examined in this context.
ABSTRACT
Background: This study explores the effects of COVID-19 restrictions on sexual healthcare use, pre-exposure prophylaxis (PrEP) use, and sexually transmitted infection (STI) incidence among men who have sex with men (MSM) participating in a PrEP demonstration project in Amsterdam, the Netherlands (AMPrEP). Methods: We retrieved data from 2019-2020 for AMPrEP participants with ≥1 study visit in 2019 (n=305), and two questionnaires on COVID-19 measures and sexual behaviour in 2020 and 2021 (n=203;n=160). Analyses were stratified for three periods of COVID-19 restrictions (first: 15/3/2020-15/6/2020;second: 16/6/2020-15/9/2020;third: 16/9/2020-31/12/2020 or 1/4/2021 for COVID-19 questionnaire data). Evaluated endpoints included proportion returning for sexual healthcare during COVID-19, change in PrEP use (increased/unchanged vs. deceased/stopped;relative to 2019), and incidence of any STI (chlamydia, gonorrhoea, or syphilis;diagnosed at clinic/study visit) or HIV. We modelled determinants of care and PrEP use via multivariable logistic regression, and STI incidence using piecewise Poisson regression;comparing 2020 periods to those in 2019. Results: Of the 305 included in the analysis, 72.8% (n=222) of participants returned for care during COVID-19, among which 147, 190, and 148 visits took place during the first, second, and third period of COVID-19 restrictions, respectively. Daily (versus event-driven) PrEP use was significantly associated with returning for care across periods (p<0.001). Increased/unchanged PrEP use was reported by 55.2% (n=112), 58.1% (n=93), and 55.6% (n=89) during the first, second, and third periods, respectively. Increased/unchanged PrEP use was more likely among those reporting chemsex in the first (p=0.001) and third (p=0.020) periods, and those reporting increased/unchanged number of sex partners relative to 2019 during the second period (p=0.010). STI incidence was significantly lower in 2020 than 2019 during the first (IRR=0.43, 95%CI=0.28-0.68), yet seemed higher during the second (IRR=1.38, 95%CI=0.95-2.00) and third periods (IRR=1.42, 95%CI=0.86-2.33), albeit non-significantly (figure 1). No new HIV infections were diagnosed. Conclusion: COVID-19 restrictions coincided with reduced care and PrEP use. The significantly lower STI incidence during the first period of COVID-19 restrictions and subsequent increase suggests a delayed diagnosis effect. We need ways to ensure continued access to sexual healthcare during restrictions.