Sexual behaviour and incidence of sexually transmitted infections among men who have sex with men (MSM) using daily and event-driven pre-exposure prophylaxis (PrEP): Four-year follow-up of the Amsterdam PrEP (AMPrEP) demonstration project cohort.

BACKGROUND: An increasing number of countries are currently implementing or scaling-up HIV pre-exposure prophylaxis (PrEP) care. With the introduction of PrEP, there was apprehension that condom use would decline and sexually transmitted infections (STIs) would increase. To inform sexual health counselling and STI screening programmes, we aimed to study sexual behaviour and STI incidence among men who have sex with men (MSM) and transgender women who use long-term daily or event-driven PrEP. METHODS AND FINDINGS: The Amsterdam PrEP demonstration project (AMPrEP) was a prospective, closed cohort study, providing oral daily PrEP and event-driven PrEP to MSM and transgender women from 2015 to 2020. Participants could choose their PrEP regimen and could switch at each three-monthly visit. STI testing occurred at and, upon request, in-between 3-monthly study visits. We assessed changes in numbers of sex partners and condomless anal sex (CAS) acts with casual partners over time using negative binomial regression, adjusted for age. We assessed HIV incidence and changes in incidence rates (IRs) of any STI (i.e., chlamydia, gonorrhoea, or infectious syphilis) and individual STIs over time using Poisson regression, adjusted for age and testing frequency. A total of 367 participants (365 MSM) commenced PrEP and were followed for a median 3.9 years (interquartile range [IQR] = 3.4-4.0). Median age was 40 years (IQR = 32-48), 315 participants (85.8%) self-declared ethnicity as white and 280 (76.3%) had a university or university of applied sciences degree. Overall median number of sex partners (past 3 months) was 13 (IQR = 6-26) and decreased per additional year on PrEP (adjusted rate ratio [aRR] = 0.86/year, 95% confidence interval [CI] = 0.83-0.88). Overall median number of CAS acts with casual partners (past 3 months) was 10 (IQR = 3-20.5) and also decreased (aRR = 0.92/year, 95% CI = 0.88-0.97). We diagnosed any STI in 1,092 consultations during 1,258 person years, resulting in an IR of 87/100 person years (95% CI = 82-92). IRs of any STI did not increase over time for daily PrEP or event-driven PrEP users. Two daily PrEP users, and no event-driven PrEP users, were diagnosed with HIV during their first year on PrEP. Study limitations include censoring follow-up due to COVID-19 measures and an underrepresentation of younger, non-white, practically educated, and transgender individuals. CONCLUSIONS: In this prospective cohort with a comparatively long follow-up period of 4 years, we observed very low HIV incidence and decreases in the numbers of casual sex partners and CAS acts over time. Although the STI incidence was high, it did not increase over time. TRIAL REGISTRATION: The study was registered at the Netherlands Trial Register (NL5413) https://www.onderzoekmetmensen.nl/en/trial/22706.

The Best Predictor of Future Behavior May Be the Past: Exploring Behavior Change in Men Who Have Sex with Men Using Pre-exposure Prophylaxis in the Netherlands.

Pre-exposure prophylaxis (PrEP) use prevents HIV transmission, and may lead to changes in sexual behavior. We aimed to explore sexual behavior over time, and identify predictors of behavior change in men who have sex with men (MSM) using PrEP at sexual health centers (SHC) in the Netherlands. We used longitudinal data from the national STI surveillance database (January 2018-June 2021) of HIV-negative MSM who first initiated PrEP in the national PrEP pilot. We modelled behavior change after PrEP initiation, and identified predictors of behavior change using multi-state Markov models. The probability of stopping group sex, chemsex, use of poppers or erection stimulants, and having ≥ 10 partners in the past 6 months among included MSM (n = 4,349, n SHC visits = 21,820) was higher compared to the probability of starting with these behaviors after PrEP initiation. However, MSM who used condoms consistently during anal sex had a high probability of changing to inconsistent condom use (0.8) at the next visit, and inconsistent condom users mostly remained inconsistent (0.8). First visit, visiting the SHC more often (vs. regular), and STI diagnosis were predictors of starting or continuing with most of the behaviors associated with increased risk. Behavior change was less likely among older participants (> 34 compared to ≤ 34 years), and during COVID-19 lockdown and post-lockdown periods compared to pre-COVID-19. Although condom use decreased over time, transitions towards stopping with other behaviors associated with increased likelihood of acquiring an STI after PrEP initiation were common. This may suggest increased sexual empowerment, especially among younger MSM. Predictors of behavior change may help to identify MSM who are likely to start with or continue to engage in these behaviors in the near future and to provide suitable and timely counselling about behavior and PrEP adherence.

One Health in action: Investigation of the first detected local cluster of fatal borna disease virus 1 (BoDV-1) encephalitis, Germany 2022.

BACKGROUND: Zoonotic Borna disease virus 1 (BoDV-1) causes fatal encephalitis in humans and animals. Subsequent to the detection of two paediatric cases in a Bavarian municipality in Germany within three years, we conducted an interdisciplinary One Health investigation. We aimed to explore seroprevalence in a local human population with a risk for BoDV-1 exposure as well as viral presence in environmental samples from local sites and BoDV-1 prevalence within the local small mammal population and its natural reservoir, the bicoloured white-toothed shrew (Crocidura leucodon). METHODS: The municipality's adult residents participated in an anonymised sero-epidemiological study. Potential risk factors and clinical symptoms were assessed by an electronic questionnaire. Small mammals, environmental samples and ticks from the municipality were tested for BoDV-1-RNA. Shrew-derived BoDV-1-sequences together with sequences of the two human cases were phylogenetically analysed. RESULTS: In total, 679 citizens participated (response: 41 %), of whom 38 % reported shrews in their living environment and 19 % direct shrew contact. No anti-BoDV-1 antibodies were detected in human samples. BoDV-1-RNA was also undetectable in 38 environmental samples and 336 ticks. Of 220 collected shrews, twelve of 40 C. leucodon (30%) tested BoDV-1-RNA-positive. BoDV-1-sequences from the previously diagnosed two paediatric patients belonged to two different subclades, that were also present in shrews from the municipality. INTERPRETATION: Our data support the interpretation that human BoDV-1 infections are rare even in endemic areas and primarily manifest as severe encephalitis. Sequence analysis linked both previous paediatric human infections to the local shrew population, but indicated independent infection sources. FUNDING: The project was partly financed by funds of the German Federal Ministry of Education and Research (grant numbers: 01KI2005A, 01KI2005C, 01KI1722A, 01KI1722C, 01KI2002 to MaBe, DR, RGU, DT, BS) as well as by the ReForM-A programme of the University Hospital Regensburg (to MaBa) and by funds of the Bavarian State Ministry of Health, Care and Prevention, project "Zoonotic Bornavirus Focal Point Bavaria - ZooBoFo" (to MaBa, MaBe, BS, MMB, DR, PS, RGU).

Evaluation of mpox contact tracing activities and data collection in EU/EEA countries during the 2022 multicountry outbreak in nonendemic countries.

To control human-to-human mpox transmission during the 2022 outbreak, European Union (EU)/European Economic Area (EEA) countries conducted case investigation and contact tracing (CT). We aimed to provide an overview of CT activities, describe CT data collection practices, and identify related facilitators, barriers, and potential opportunities for improvement. Between April 03, 2023 and May 12, 2023, a survey was distributed to CT stakeholders in 30 EU/EEA countries, asking about mpox CT activities and data collection and requesting to rank enablers, barriers, and improvements for CT on a five-point Likert scale. The 139 respondents from 27 countries indicated having performed case investigations (96%, n = 133), backward CT (88%, n = 122), forward CT (87%, n = 121), and follow-up on contacts' outcomes (77%, n = 107). Sixty percent (n = 80/134) used standardized data collection forms and 73% (n = 91/124) used databases. The highest-rated enablers were clear guidelines (mean = 3.9), quick access to laboratory results (3.6), and sufficient expertise (3.6). Highly rated barriers were inability to contact contacts (3.0) or cases (2.5) and lack of staff (2.4). The most needed improvements were availability of staff (3.5), expertise on affected populations (3.4) and data reporting tools and systems (3.3). To improve CT of mpox and diseases with similar transmission patterns, EU/EEA countries should increase workforce capacity in public and sexual health, offer training on CT operations and communication with affected communities, and use common CT data collection tools and systems.

SARS-CoV-2 vaccination uptake in six ethnic groups living in Amsterdam, the Netherlands: A registry-based study within the HELIUS cohort.

OBJECTIVE: Ethnic minority groups have experienced a disproportionate burden of COVID-19, and should therefore be especially encouraged to receive SARS-CoV-2 vaccination. This study compared first-dose uptake of the primary SARS-CoV-2 vaccination series across six ethnic groups in Amsterdam, the Netherlands in 2021. METHODS: We analyzed data from participants of the population-based HELIUS cohort. We linked their data to the SARS-CoV-2 vaccination registry data of the Public Health Service of Amsterdam. We included registry data from January 6, 2021 (the start of the Dutch vaccination campaign) until September 6, 2021 (a date by which all adults in the Netherlands could have received one or two vaccine doses). SARS-CoV-2 vaccination uptake was defined as having received at least one vaccine dose of the primary vaccination series. We examined the association between ethnicity and vaccination uptake using multivariable logistic regression, while accounting for the age and sex distribution of ethnic groups in Amsterdam. RESULTS: We included 19,006 participants (median age 53 years [interquartile range 41-62], 57% female). SARS-CoV-2 vaccination uptake was highest in the South-Asian Surinamese group (60.3%, 95%CI = 58.2-62.3%), followed by the Dutch (59.6%, 95%CI = 58.0-61.1%), Ghanaian (54.1%, 95%CI = 51.7-56.5%), Turkish (47.7%, 95%CI = 45.9-49.6%), African Surinamese (43.0%, 95%CI = 41.2-44.7%), and Moroccan (35.8%, 95%CI = 34.1-37.5%) groups. After adjusting for age, sex, perceived social support, and presence of relevant comorbidities, participants of African Surinamese, Ghanaian, Turkish and Moroccan origin were significantly less likely to be vaccinated than those of Dutch origin. CONCLUSIONS: Prevention strategies should continue tailoring to specific ethnic groups to encourage vaccination uptake and reduce barriers to vaccination.

Online-Mediated HIV Pre-exposure Prophylaxis Care and Reduced Monitoring Frequency for Men Who Have Sex With Men: Protocol for a Randomized Controlled Noninferiority Trial (EZI-PrEP Study).

BACKGROUND: Daily and event-driven HIV pre-exposure prophylaxis (PrEP) with oral tenofovir-emtricitabine is highly effective to prevent HIV in men who have sex with men (MSM). PrEP care generally consists of in-clinic monitoring every 3 months that includes PrEP dispensing, counseling, and screening for HIV and sexually transmitted infections (STIs). However, the optimal frequency for monitoring remains undetermined. Attending a clinic every 3 months for monitoring may be a barrier for PrEP. Online-mediated PrEP care and reduced frequency of monitoring may lower this barrier. OBJECTIVE: The primary objective of this study is to establish the noninferiority of online PrEP care (vs in-clinic care) and monitoring every 6 months (vs every 3 months). The secondary objectives are to (1) examine differences between PrEP care modalities regarding incidences of STIs, HIV infection, and hepatitis C virus infection; retention in PrEP care; intracellular tenofovir-diphosphate concentration; and satisfaction, usability, and acceptability of PrEP care modalities; and (2) evaluate associations of these study outcomes with sociodemographic, behavioral, and psychological characteristics. METHODS: This study is a 2×2 factorial, 4-arm, open-label, multi-center, randomized, controlled, noninferiority trial. The 4 arms are (1) in-clinic monitoring every 3 months, (2) in-clinic monitoring every 6 months, (3) online monitoring every 3 months, and (4) online monitoring every 6 months. The primary outcome is a condomless anal sex act with a casual partner not covered or insufficiently covered by PrEP (ie, "unprotected act") as a proxy for HIV infection risk. Eligible individuals are MSM, and transgender and gender diverse people aged ≥18 years who are eligible for PrEP care at 1 of 4 participating sexual health centers in the Netherlands. The required sample size is 442 participants, and the planned observation time is 24 months. All study participants will receive access to a smartphone app, which contains a diary. Participants are requested to complete the diary on a daily basis during the first 18 months of participation. Participants will complete questionnaires at baseline and 6, 12, 18, and 24 months. Dried blood spots will be collected at 6 and 12 months for assessment of intracellular tenofovir-diphosphate concentration. Incidence rates of unprotected acts will be compared between the online and in-clinic arms, and between the 6-month and 3-month arms. Noninferiority will be concluded if the upper limit of the 2-sided 97.5% CI of the incidence rate ratio is <1.8. RESULTS: The results of the main analysis are expected in 2024. CONCLUSIONS: This trial will demonstrate whether online PrEP care and monitoring every 6 months is noninferior to standard PrEP care in terms of PrEP adherence. If noninferiority is established, these modalities may lower barriers for initiating and continuing PrEP use and potentially reduce the systemic burden for PrEP providers. TRIAL REGISTRATION: ClinicalTrials.gov NCT05093036; https://tinyurl.com/28b8ndvj. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/51023.

A psychosocial network approach studying biomedical HIV prevention uptake between 2017 and 2019.

Biomedical HIV-prevention strategies (BmPS) among men who have sex with men (MSM), such as pre-exposure prophylaxis (PrEP) and viral load sorting (VLS), are essential but relatively new and their uptake gradual. Using an extension of the causal attitude network approach, we investigated which beliefs are related to uptake of PrEP and VLS at each time-point. We included 632 HIV-negative MSM from the Amsterdam Cohort Studies from four data-waves between 2017 and 2019. We estimated weighted, undirected networks for each time-point, where we included pairwise interactions of PrEP and VLS uptake and related beliefs. PrEP use increased from 10 to 31% (p < 0.001), while VLS was reported by 7-10% at each time-point. Uptake of both BmPS was directly related to the perceived positive impact of the strategy on one's quality of sex life and perceived supportive social norms. Overall network structure differed between time points, specifically in regard to PrEP. At earlier time points, perceptions of efficacy and affordability played an important role for PrEP uptake, while more recently social and health-related concerns became increasingly important.The network structure differed across data-waves, suggesting specific time changes in uptake motives. These findings may be used in communication to increase prevention uptake.

COVID-19 burden differed by city districts and ethnicities during the pre-vaccination era in Amsterdam, the Netherlands.

Background: During the first wave of COVID-19 in Amsterdam, the Netherlands, a disproportional number of COVID-19 hospitalizations occurred in individuals with an ethnic minority background and in individuals living in city districts with a lower socioeconomic status (SES). In this study, we assessed whether these disparities continued throughout the second wave, when SARS-CoV-2 testing was available to anyone with symptoms but prior to the availability of COVID-19 vaccination. Methods: Surveillance data on all notified SARS-CoV-2 cases in Amsterdam between 15 June 2020 and 20 January 2021 were matched to municipal registration data to obtain the migration background of cases. Crude and directly age- and sex-standardized rates (DSR) of confirmed cases, hospitalizations, and deaths per 100,000 population were calculated overall, and by city districts, and migration backgrounds. Rate differences (RD) and rate ratios (RR) were calculated to compare DSR between city districts and migration backgrounds. We used multivariable Poisson regression to assess the association of city districts, migration backgrounds, age, and sex with rates of hospitalization. Results: A total of 53,584 SARS-CoV-2 cases (median age 35 years [IQR = 25-74]) were notified, of whom 1,113 (2.1%) were hospitalized and 297 (0.6%) deceased. DSR of notified infections, hospitalization, and deaths per 100,000 population were higher in lower SES peripheral city districts (South-East/North/New-West) than higher SES central districts (Central/West/South/East), with almost a 2-fold higher hospitalization DSR in peripheral compared to central districts (RR = 1.86, 95%CI = 1.74-1.97). Individuals with a non-European migration background also had a higher COVID-19 burden, particularly with respect to hospitalization rates, with a 4.5-fold higher DSR for individuals with a non-European background compared to ethnic-Dutch (RR 4.51, 95%CI = 4.37-4.65). City districts, migration backgrounds, male gender, and older age were independently associated with COVID-19 hospitalization rates. Discussion: Individuals with a non-European background and individuals living in city districts with lower SES continued to independently have the highest COVID-19 burden in the second wave of COVID-19 in Amsterdam, the Netherlands.

Estimated incubation period distributions of mpox using cases from two international European festivals and outbreaks in a club in Berlin, May to June 2022.

BackgroundSince May 2022, an mpox outbreak affecting primarily men who have sex with men (MSM) has occurred in numerous non-endemic countries worldwide. As MSM frequently reported multiple sexual encounters in this outbreak, reliably determining the time of infection is difficult; consequently, estimation of the incubation period is challenging.AimWe aimed to provide valid and precise estimates of the incubation period distribution of mpox by using cases associated with early outbreak settings where infection likely occurred.MethodsColleagues in European countries were invited to provide information on exposure intervals and date of symptom onset for mpox cases who attended a fetish festival in Antwerp, Belgium, a gay pride festival in Gran Canaria, Spain or a particular club in Berlin, Germany, where early mpox outbreaks occurred. Cases of these outbreaks were pooled; doubly censored models using the log-normal, Weibull and Gamma distributions were fitted to estimate the incubation period distribution.ResultsWe included data on 122 laboratory-confirmed cases from 10 European countries. Depending on the distribution used, the median incubation period ranged between 8 and 9 days, with 5th and 95th percentiles ranging from 2 to 3 and from 20 to 23 days, respectively. The shortest interval that included 50% of incubation periods spanned 8 days (4-11 days).ConclusionCurrent public health management of close contacts should consider that in approximately 5% of cases, the incubation period exceeds the commonly used monitoring period of 21 days.

Trajectories of PrEP use among men who have sex with men: a pooled analysis of two prospective, observational cohort studies.

INTRODUCTION: Daily and event-driven oral pre-exposure prophylaxis (PrEP) reduce the risk of HIV acquisition. PrEP use can vary over time, yet little is known about the trajectories of PrEP use irrespective of the chosen PrEP regimens among men who have sex with men (MSM). METHODS: Using data from a mobile, web-based diary application collected daily from 17 August 2015 until 6 May 2018, we analysed PrEP use and sexual behaviour in two large cohorts, AMPrEP (Amsterdam, the Netherlands) and Be-PrEP-ared (Antwerp, Belgium). In both cohorts, participants could choose between daily and event-driven oral PrEP every 3 months. We used group-based trajectory modelling to identify trajectories of PrEP use over time and their determinants. In addition, we estimated the incidence rate of chlamydia, gonorrhoea and syphilis within these trajectories. RESULTS: We included 516 MSM (n = 322 AMPrEP; n = 194 Be-PrEP-ared), of whom 24% chose event-driven PrEP at PrEP initiation. Participants contributed 225,015 days of follow-up (median = 508 days [IQR = 429-511]). Four distinct PrEP use trajectories were identified: ≤2 tablets per week ("low frequency," 12% of the total population), 4 tablets per week ("variable," 17%), "almost daily" (31%) and "always daily" (41%). Compared to participants with "low frequency" PrEP use, participants with "variable" (odds ratio [OR] = 2.18, 95% confidence interval [CI] = 1.04-4.60) and "almost daily" PrEP use were more often AMPrEP participants (OR = 2.64, 95% CI = 1.27-5.49). "Almost daily" PrEP users were more often employed (OR = 6.76, 95% CI = 2.10-21.75) and were younger compared to participants with "low frequency" PrEP use. In addition, the number of days on which anal sex occurred was lower among participants with "low frequency" PrEP use compared to the other groups (all p<0.001). Compared to "low frequency" PrEP users, the incidence rates of chlamydia and gonorrhoea were higher for participants with "almost daily" and "always daily" PrEP use. CONCLUSIONS: We uncovered four distinct PrEP use trajectories, pointing to different patterns of PrEP use in practice beyond the two-regimen dichotomy. These trajectories were related to sexual behaviour and rates of sexually transmitted infection. Tailoring PrEP care according to different PrEP use patterns could be an important strategy to improve efficient PrEP delivery.

Bacterial sexually transmitted infections are concentrated in subpopulations of men who have sex with men using HIV pre-exposure prophylaxis.

OBJECTIVE: Studies have shown varying trends in incidence of sexually transmitted infections (STIs) among individuals using HIV pre-exposure prophylaxis (PrEP). Characterization of individuals at increased risk for STIs may offer an opportunity for targeted STI screening. DESIGN: Group-based trajectory modeling. METHODS: We screened participants from the AMPrEP demonstration project (2015-2020) for urogenital, anal, and pharyngeal chlamydia and gonorrhea, and syphilis every 3 months and when needed. We identified trajectories of STI incidence within individuals over time and determinants of belonging to a trajectory group. We calculated cumulative proportions of STIs within STI trajectory groups. RESULTS: Three hundred and sixty-six participants with baseline and at least one screening visit during follow-up were included (median follow-up time = 3.7 years [interquartile range, IQR = 3.5-3.7]). We identified three trajectories of STI incidence: participants with a mean of approximately 0.1 STIs per 3 months ('low overall', 52% of the population), participants with a mean 0.4 STI per 3 months ('medium overall', 43%), and participants with high and fluctuating (between 0.3 and 1 STIs per 3 months) STI incidence ('high and fluctuating', 5%). Participants in the 'low overall' trajectory were significantly older, and reported less chemsex and condomless anal sex with casual partners than participants in the other trajectories. Participants in the 'high and fluctuating' and 'medium overall' groups accounted for respectively 23 and 64% of all STIs observed during follow-up. CONCLUSIONS: STI incidence was concentrated in subpopulations of PrEP users who were younger, had more chemsex and condomless anal sex. Screening frequency for STIs could be reduced for subpopulations with low risk for incident STIs.

Determinants of adherence to daily PrEP measured as intracellular tenofovir diphosphate concentrations over 24 months of follow-up among men who have sex with men.

OBJECTIVES: Adherence is key to the effectiveness of oral pre-exposure prophylaxis (PrEP) to prevent HIV. Therefore, we aimed to explore factors associated with adherence to daily PrEP (dPrEP). METHODS: Men who have sex with men (MSM) using dPrEP (emtricitabine/tenofovir disoproxil) within the Amsterdam PrEP demonstration project at the Public Health Service of Amsterdam, provided dried blood spots (DBS) 12 and 24 months after PrEP initiation. From DBS, we determined intracellular tenofovir diphosphate (TFV-DP) concentrations to assess adherence; TFV-DP ≥700 fmol/punch was considered adequate. We assessed associations of sociodemographic, clinical and behavioural characteristics with TFV-DP concentrations using multivariable linear regression. RESULTS: Of 263 participants who attended 12-month or 24-month study visits while on dPrEP, 257 (97.7%) provided DBS at one or both visits (492 DBS in total). Median TFV-DP concentration was 1299 (IQR 1021-1627) fmol/punch (12 months: 1332 (1087-1687); 24 months: 1248 (929-1590]). Higher TFV-DP concentrations were associated with: older age (p=0.0008), condomless anal sex with a casual partner in 6 months preceding PrEP initiation (+166 fmol/punch; 95% CI 36.5 to 296) and using a mobile application providing visualised feedback on PrEP use and sexual behaviour (+146 fmol/punch; 95% CI 28.1 to 263). Lower TFV-DP concentrations were associated with longer duration of PrEP use (24 vs 12 months; -91.5 fmol/punch; 95% CI -155 to -28.1). Time-updated number of sex partners, diagnosed STIs and chemsex were not associated with TFV-DP concentrations. CONCLUSIONS: Overall, TFV-DP concentrations were high among MSM using dPrEP, indicating excellent adherence. Especially older participants, those who reported condomless anal sex with a casual partner prior to PrEP initiation and those who used an app with visualised feedback showed higher levels of adherence. As TFV-DP concentrations had decreased slightly at 2 years of PrEP use when compared with 1 year, we emphasise the importance of adherence counselling to those who continue using PrEP. TRIAL REGISTRATION NUMBER: NL5413.

Knowledge, Attitudes and Behaviors regarding Tick-Borne Encephalitis Vaccination and Prevention of Tick-Borne Diseases among Primary Care Physicians in Bavaria and Baden-Wuerttemberg, Germany, May-September 2022.

In 2020, a record number of tick-borne encephalitis (TBE) cases was reported in major endemic areas in Germany, i.e., the southern federal states of Baden-Wuerttemberg and Bavaria. Most cases were unvaccinated. Other tick-borne diseases (TBDs), including Lyme borreliosis and tularemia, are rising, too. Thus, strategies are needed to increase TBE vaccination uptake in risk areas and promote education on TBD prevention. Primary care physicians are key providers of both vaccinations and TBD education. The TBD-Prevention (TBD-Prev) study aimed to investigate the knowledge, attitudes and behaviors of primary care physicians in Baden-Wuerttemberg and Bavaria with regard to TBE vaccination and prevention of TBDs and to derive strategies for increasing vaccination rates and improving knowledge about TBE and other TBDs in the population and among primary care physicians. We invited all primary care physicians (N = 14,046) in both states to participate by mail. Using standardized, self-administered questionnaires, available both on paper and online, we asked physicians anonymously about their knowledge, attitudes and behaviors with respect to TBE vaccination and TBD prevention and their need for further information/educational materials. A total of 2321 physicians participated between May and September 2022 (response rate 17%), of whom 1222 (53%) worked in Baden-Wuerttemberg and 1067 (46%) in Bavaria. Among the participating physicians, 56% were male, 71% were >50 years and 51% worked in an individual practice. Furthermore, 91% were aware of the German national vaccination guidelines, and 98% perceived their knowledge of the risks and benefits of vaccination as adequate. A total of 97% offer TBE vaccinations, 67% provide vaccination counselling during initial consultations with new patients and 64% actively remind patients about due vaccinations. In addition, 24% expressed a need for further information materials, mainly traditional, analogue media such as flyers (82%) and posters (50%), and named timeliness, quality assurance, easy comprehensibility and independence from the pharmaceutical industry as the most important characteristics of such materials. Almost all participating physicians reported offering TBE vaccinations and feeling well-informed about TBE vaccination and TBDs. However, active offering of vaccinations and education could be further improved, and additional, low-threshold information materials are needed. Based on these results, we will develop and provide various materials on TBE vaccination and TBDs, in particular flyers and posters, for use by physicians during consultations.

SARS-CoV-2 Prevalence on and Incidence after Arrival in Travelers on Direct Flights from Cape Town, South Africa to Munich, Germany Shortly after Occurrence of the Omicron Variant in November/December 2021: Results from the OMTRAIR Study.

The highly transmissible SARS-CoV-2-variant B.1.1.529 (Omicron) first appeared in South Africa in November 2021. In order to study Omicron entry to Germany, its occurrence related to incoming airline travel, symptomatology and compliance with entry regulations and recommendations, we conducted a cross-sectional study, followed by a retrospective cohort study among passengers and crew on 19 direct flights from Cape Town, South Africa, to Munich, Germany, between 26 November and 23 December 2021. Travelers were mandatorily PCR-tested on arrival and invited to complete an online questionnaire. SARS-CoV-2-prevalence on arrival was 3.3% (n = 90/2728), and 93% were Omicron. Of the passengers, 528 (19%) completed the questionnaire. Among participants who tested negative on arrival, self-reported SARS-CoV-2-incidence was 4.3% within 14 days, of whom 74% reported a negative PCR-test ≤ 48 h before boarding, 77% were fully vaccinated, and 90% reported wearing an FFP2/medical mask during flight. We found multiple associations between risk factors and infection on and after arrival, among which having a positive-tested travel partner was the most noteworthy. In conclusion, PCR testing before departure was insufficient to control the introduction of the Omicron variant. Additional measures (e.g., frequent testing, quarantine after arrival or travel ban) should be considered to delay virus introduction in such settings.

Intent to vaccinate against SARS-CoV-2 and its determinants across six ethnic groups living in Amsterdam, the Netherlands: A cross-sectional analysis of the HELIUS study.

BACKGROUND: Ethnic minority groups experience a disproportionately high burden of infections, hospitalizations and mortality due to COVID-19, and therefore should be especially encouraged to receive SARS-CoV-2 vaccination. This study aimed to investigate the intent to vaccinate against SARS-CoV-2, along with its determinants, in six ethnic groups residing in Amsterdam, the Netherlands. METHODS: We analyzed data of participants enrolled in the population-based multi-ethnic HELIUS cohort, aged 24 to 79 years, who were tested for SARS-CoV-2 antibodies and answered questions on vaccination intent from November 23, 2020 to March 31, 2021. During the study period, SARS-CoV-2 vaccination in the Netherlands became available to individuals working in healthcare or > 75 years old. Vaccination intent was measured by two statements on a 7-point Likert scale and categorized into low, medium, and high. Using ordinal logistic regression, we examined the association between ethnicity and lower vaccination intent. We also assessed determinants of lower vaccination intent per ethnic group. RESULTS: A total of 2,068 participants were included (median age 56 years, interquartile range 46-63). High intent to vaccinate was most common in the Dutch ethnic origin group (369/466, 79.2%), followed by the Ghanaian (111/213, 52.1%), South-Asian Surinamese (186/391, 47.6%), Turkish (153/325, 47.1%), African Surinamese (156/362, 43.1%), and Moroccan ethnic groups (92/311, 29.6%). Lower intent to vaccinate was more common in all groups other than the Dutch group (P < 0.001). Being female, believing that COVID-19 is exaggerated in the media, and being < 45 years of age were common determinants of lower SARS-CoV-2 vaccination intent across most ethnic groups. Other identified determinants were specific to certain ethnic groups. CONCLUSIONS: Lower intent to vaccinate against SARS-CoV-2 in the largest ethnic minority groups of Amsterdam is a major public health concern. The ethnic-specific and general determinants of lower vaccination intent observed in this study could help shape vaccination interventions and campaigns.

The impact of COVID-19-related restrictions in 2020 on sexual healthcare use, pre-exposure prophylaxis use, and sexually transmitted infection incidence among men who have sex with men in Amsterdam, the Netherlands.

OBJECTIVES: We studied the effects of restrictions related to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2; coronavirus disease 2019 [COVID-19]) pandemic on the use of sexual healthcare and pre-exposure prophylaxis (PrEP) and on the incidence of sexually transmitted infections (STIs) among men who have sex with men (MSM) in a prospective, open-label PrEP demonstration study (AMPrEP) in Amsterdam, the Netherlands. METHODS: We retrieved data from 2019 to 2020 for participants with one or more study visit in 2019 (n = 305) and from two COVID-19 questionnaires (2020: n = 203; 2021: n = 160). Analyses were stratified for three periods of pandemic-related restrictions (first: 15 March 2020-15 June 2020; second: 16 June 2020-15 September 2020; third: 16 September 2020-31 December 2020 or 1 April 2021 for the COVID-19 questionnaire). Endpoints included returning for care during the pandemic, PrEP use (increased/unchanged vs. deceased/stopped, relative to 2019), and any STI/HIV. We modelled determinants of care and PrEP use via multivariable logistic regression and STI incidence using piecewise Poisson regression, comparing the 2020 and 2019 periods. RESULTS: Of the 305 MSM included in the analysis, 72.8% returned for care during the pandemic, and this was significantly more likely among daily (vs. event-driven) PrEP users (p < 0.001). Increased/unchanged PrEP use ranged from 55.2% to 58.1% across the three pandemic periods and was more likely among those reporting chemsex in the first (p = 0.001) and third (p = 0.020) periods and among those reporting an increased/unchanged number of sex partners during the second period (p = 0.010). STI incidence was significantly lower in 2020 than in 2019 during the first period (incidence rate ratio [IRR] 0.43; 95% confidence interval [CI] 0.28-0.68) and not significantly different during the second (IRR 1.38; 95% CI 0.95-2.00) and third (IRR 1.42; 95% CI 0.86-2.33) periods. No HIV was diagnosed. CONCLUSION: COVID-19-related restrictions coincided with reduced care and PrEP use. Changes in STI incidence suggest delayed diagnoses. Ways to ensure continued access to sexual healthcare during restrictions are needed.

Can we screen less frequently for STI among PrEP users? Assessing the effect of biannual STI screening on timing of diagnosis and transmission risk in the AMPrEP Study.

BACKGROUND: In many countries, HIV pre-exposure prophylaxis (PrEP) users are screened quarterly for STIs. We assessed the consequences of less frequent STI testing. We also assessed determinants of asymptomatic STI and potential for onward transmission. METHODS: Using data from the AMPrEP study, we assessed the proportion of syphilis, and genital, anal, and pharyngeal chlamydia and gonorrhoea diagnoses which would have been delayed with biannual versus quarterly screening. We assessed the potential for onward transmission by examining reported condomless anal sex (CAS) in periods after to-be-omitted visits when screening biannually. We assessed determinants of incident asymptomatic STIs using Poisson regression and calculated individual risk scores on the basis of the coefficients from this model. RESULTS: We included 366 participants. Median follow-up was 47 months (IQR 43-50). 1,183STIs were diagnosed, of which 932(79%) asymptomatic. With biannual screening, 483 asymptomatic STIs (52%) diagnoses would have been delayed at 364 study visits. Of these visits, 129 (35%), 240 (66%) and 265 (73%) were followed by periods of CAS with steady, known casual or unknown casual partners, respectively. Older participants had a lower risk of asymptomatic STI (incidence rate ratio (IRR) 0.86/10-year increase, 95% CI 0.80 to 0.92), while CAS with known (IRR 1.36, 95% CI 1.10 to 1.68) and unknown (IRR 1.86, 95% CI 1.48 to 2.34) casual partners and chemsex (IRR 1.51, 95% CI 1.28 to 1.78) increased the risk. The individual risk scores had limited predictive value (sensitivity=0.70 (95% CI 0.66 to 0.74), specificity=0.50 (95% CI 0.48 to 0.51)). CONCLUSION: Reducing the STI screening frequency to biannually among PrEP users will likely result in delayed diagnoses, potentially driving onward transmission. Although determinants for asymptomatic STIs were identified, predictive power was low.

Factors Associated With Using the COVID-19 Mobile Contact-Tracing App Among Individuals Diagnosed With SARS-CoV-2 in Amsterdam, the Netherlands: Observational Study.

BACKGROUND: Worldwide, efforts are being made to stop the COVID-19 pandemic caused by SARS-CoV-2. Contact tracing and quarantining are key in limiting SARS-CoV-2 transmission. Mathematical models have shown that the time between infection, isolation of cases, and quarantining of contacts are the most important components that determine whether the pandemic can be controlled. Mobile contact-tracing apps could accelerate the tracing and quarantining of contacts, including anonymous contacts. However, real-world observational data on the uptake and determinants of contact-tracing apps are limited. OBJECTIVE: The aim of this paper is to assess the use of a national Dutch contact-tracing app among notified cases diagnosed with SARS-CoV-2 infection and investigate which characteristics are associated with the use of the app. METHODS: Due to privacy regulations, data from the app could not be used. Instead, we used anonymized SARS-CoV-2 routine contact-tracing data collected between October 28, 2020, and February 26, 2021, in the region of Amsterdam, the Netherlands. Complete case logistic regression analysis was performed to identify which factors (age, gender, country of birth, municipality, number of close contacts, and employment in either health care or education) were associated with using the app. Age and number of close contacts were modelled as B-splines due to their nonlinear relationship. RESULTS: Of 29,766 SARS-CoV-2 positive cases, 4824 (16.2%) reported app use. Median age of cases was 41 (IQR 29-55) years, and 46.7% (n=13,898) were male. In multivariable analysis, males (adjusted odds ratio [AOR] 1.11, 95% CI 1.04-1.18) and residents of municipalities surrounding Amsterdam were more likely to use the app (Aalsmeer AOR 1.34, 95% CI 1.13-1.58; Ouder-Amstel AOR 1.96, 95% CI 1.54-2.50), while people born outside the Netherlands, particularly those born in non-Western countries (AOR 0.33, 95% CI 0.30-0.36), were less likely to use the app. Odds of app use increased with age until the age of 58 years and decreased sharply thereafter (P<.001). Odds of app use increased with number of contacts, peaked at 8 contacts, and then decreased (P<.001). Individuals working in day care, home care, and elderly nursing homes were less likely to use the app. CONCLUSIONS: Contact-tracing app use among people with confirmed SARS-CoV-2 infection was low in the region of Amsterdam. This diminishes the potential impact of the app by hampering the ability to warn contacts. Use was particularly low among older people, people born outside the Netherlands, and people with many contacts. Use of the app was also relatively low compared to those from some other European countries, some of which had additional features beyond contact tracing, making them potentially more appealing. For the Dutch contact-tracing app to have an impact, uptake needs to be higher; therefore, investing more into promotional efforts and additional features could be considered.

Ethnic Differences in Coronavirus Disease 2019 Hospitalization and Hospital Outcomes in a Multiethnic Population in the Netherlands.

Background: Evidence from the United States and United Kingdom suggests that ethnic minority populations are at an increased risk for developing severe coronavirus disease 2019 (COVID-19); however, data from other West-European countries are scarce. Methods: We analyzed data from 1439 patients admitted between February 2020 and January 2021 to 4 main hospitals in Amsterdam and Almere, the Netherlands. Differences in the risk for hospitalization were assessed by comparing demographics to the general population. Using a population-based cohort as reference, we determined differences in the association between comorbidities and COVID-19 hospitalization. Outcomes after hospitalization were analyzed using Cox regression. Results: The hospitalization risk was higher in all ethnic minority groups than in those of Dutch origin, with age-adjusted odds ratios ranging from 2.2 (95% confidence interval [CI], 1.7-2.6) in Moroccans to 4.5 (95% CI, 3.2-6.0) in Ghanaians. Hypertension and diabetes were similarly associated with COVID-19 hospitalization. For all other comorbidities, we found differential associations. Intensive care unit admission and mortality during 21-day follow-up after hospitalization was comparable between ethnicities. Conclusions: The risk of COVID-19 hospitalization was higher in all ethnic minority groups compared to the Dutch, but the risk of adverse outcomes after hospitalization was similar. Our results suggest that these inequalities may in part be attributable to comorbidities that can be prevented by targeted public health prevention measures. More work is needed to gain insight into the role of other potential factors such as social determinants of health, which might have contributed to the ethnic inequalities in COVID-19 hospitalization.

Changes in substance use among HIV-negative MSM: A longitudinal analysis, 1995-2019.

BACKGROUND: Research suggests shifting patterns of recreational drug consumption among MSM in recent decades. The present study evaluates population-level mean trajectories of substance use among HIV-negative MSM from 1995 to 2019. METHODS: Using open cohort study data following MSM in the Netherlands (n=1495) since 1995, we applied generalized estimating equations to examine population-averaged estimates of five substances - alcohol, cannabis, ecstasy, cocaine, and poppers - from 1995 to 2019, as well as their use during sexual encounters. RESULTS: Recent alcohol use decreased; predicted probabilities declined from 1995 to 2019 (.96 to .87). During the same period, cocaine and poppers use increased - (.10 to .23 and .37 to .47, respectively) and use during sex also increased (.05 to .16, and .32 to .41, respectively). Ecstasy use increased over time (.23 to .38), although not during sex. No significant changes in cannabis use occurred. CONCLUSIONS: While changes in use of various substances were mixed, increases in cocaine and poppers use during sexual encounters occurred among HIV-negative MSM over time. Efforts to intervene on substance use in connection with sex remain critical for health promotion.