Assessing the drivers of syphilis among men who have sex with men in Switzerland reveals a key impact of screening frequency: A modelling study.

Over the last decade, syphilis diagnoses among men-who-have-sex-with-men (MSM) have strongly increased in Europe. Understanding the drivers of the ongoing epidemic may aid to curb transmissions. In order to identify the drivers of syphilis transmission in MSM in Switzerland between 2006 and 2017 as well as the effect of potential interventions, we set up an epidemiological model stratified by syphilis stage, HIV-diagnosis, and behavioral factors to account for syphilis infectiousness and risk for transmission. In the main model, we used 'reported non-steady partners' (nsP) as the main proxy for sexual risk. We parameterized the model using data from the Swiss HIV Cohort Study, Swiss Voluntary Counselling and Testing center, cross-sectional surveys among the Swiss MSM population, and published syphilis notifications from the Federal Office of Public Health. The main model reproduced the increase in syphilis diagnoses from 168 cases in 2006 to 418 cases in 2017. It estimated that between 2006 and 2017, MSM with HIV diagnosis had 45.9 times the median syphilis incidence of MSM without HIV diagnosis. Defining risk as condomless anal intercourse with nsP decreased model accuracy (sum of squared weighted residuals, 378.8 vs. 148.3). Counterfactual scenarios suggested that increasing screening of MSM without HIV diagnosis and with nsP from once every two years to twice per year may reduce syphilis incidence (at most 12.8% reduction by 2017). Whereas, increasing screening among MSM with HIV diagnosis and with nsP from once per year to twice per year may substantially reduce syphilis incidence over time (at least 63.5% reduction by 2017). The model suggests that reporting nsP regardless of condom use is suitable for risk stratification when modelling syphilis transmission. More frequent screening of MSM with HIV diagnosis, particularly those with nsP may aid to curb syphilis transmission.

Pediatric Tuberculosis Disease during Years of High Refugee Arrivals: A 6-Year National Prospective Surveillance Study.

BACKGROUND: In Europe, surveillance and monitoring of pediatric tuberculosis (TB) remains important, particularly in the light of migration in recent years. The aim of the study was to evaluate incidence rates of childhood TB and detailed diagnostic pathways and treatment. METHODS: Data were collected through the Swiss Pediatric Surveillance Unit (SPSU) from December 2013 to November 2019. Monthly -notifications are obtained from the 33 pediatric hospitals in the SPSU, and a detailed questionnaire was sent out upon notification. Inclusion criteria were children and adolescents aged up to 15 years with culture- or molecular-confirmed TB disease or for whom a treatment with ≥3 antimycobacterial drugs had been initiated. Data were compared with age-matched notification data from the Swiss Federal Office of Public Health (FOPH). RESULTS: Of the 172 cases notified to SPSU, a detailed questionnaire was returned for 161 (93%) children, of which 139 met the inclusion criteria. Reasons for exclusion were age >15 years, double reporting, and not fulfilling the criteria for TB disease. During the same time period, 172 pediatric TB cases were reported to the FOPH, resulting in an incidence of 2.1 per 100,000, ranging from 1.4 to 2.8 per year, without a clear trend over time. In the 64 (46.0%) foreign-born children, incidence rates were higher and peaked in 2016, with 13.7 per 100,000 (p = 0.018). The median interval between arrival in Switzerland and TB diagnosis was 5 (IQR 1-21) months, and 80% were diagnosed within 24 months of arrival. In 58% of the cases, TB disease was confirmed by culture or molecular assays. Age >10 years, presence of fever, or weight loss were independent factors associated with confirmed TB. CONCLUSION: The annual pediatric TB incidence rate only varied among foreign-born children and was highest in 2016 when refugee influx peaked in Europe. Importantly, most foreign-born children with TB were diagnosed within 2 years after arrival in Switzerland. Thus, the early period after arrival in Switzerland is associated with a higher risk of TB disease in children, and this should be considered for screening guidance in refugees.

Changes in the prevalence of self-reported sexually transmitted bacterial infections from 2010 and 2017 in two large European samples of men having sex with men-is it time to re-evaluate STI-screening as a control strategy?

BACKGROUND/OBJECTIVES: Many European countries reported increased numbers of syphilis, gonorrhoea and chlamydia diagnoses among men who have sex with men (MSM) in recent years. Behaviour changes and increased testing are thought to drive these increases. METHODS: In 2010 and 2017, two large online surveys for MSM in Europe (EMIS-2010, EMIS-2017) collected self-reported data on STI diagnoses in the previous 12 months, diagnostic procedures, STI symptoms when testing, number of sexual partners, and sexual behaviours such as condom use during the last intercourse with a non-steady partner in 46 European countries. Multivariate regression models were used to analyse factors associated with diagnoses of syphilis, gonorrhoea/chlamydia, and respective diagnoses classified as symptomatic and asymptomatic. If applicable, they included country-level screening rates. RESULTS: Questions on STI diagnoses and sexual behaviours were answered by 156,018 (2010) and 125,837 (2017) participants. Between 2010 and 2017, overall diagnoses with gonorrhoea/chlamydia and syphilis increased by 76% and 83% across countries. Increases were more pronounced for asymptomatic compared to symptomatic infections. The proportion of respondents screened and the frequency of screening grew considerably. Condomless anal intercourse with the last non-steady partner rose by 62%; self-reported partner numbers grew. Increased syphilis diagnoses were largely explained by behavioural changes (including more frequent screening). Gonorrhoea/chlamydia increases were mainly explained by more screening and a change in testing performance. A country variable representing the proportion of men screened for asymptomatic infection was positively associated with reporting symptomatic gonorrhoea/chlamydia, but not syphilis. DISCUSSION/CONCLUSION: The positive association of country-level screening rates with the proportion of symptomatic infections with gonorrhoea/chlamydia may indicate a paradoxical effect of screening on incidence of symptomatic infections. Treatment of asymptomatic men might render them more susceptible to new infections, while spontaneous clearance may result in reduced susceptibility. Before expanding screening programmes, evidence of the effects of screening and treatment is warranted.

Clusters of Sexual Behavior in Human Immunodeficiency Virus-positive Men Who Have Sex With Men Reveal Highly Dissimilar Time Trends.

BACKGROUND: Separately addressing specific groups of people who share patterns of behavioral change might increase the impact of behavioral interventions to prevent transmission of sexually transmitted infections. We propose a method based on machine learning to assist the identification of such groups among men who have sex with men (MSM). METHODS: By means of unsupervised learning, we inferred "behavioral clusters" based on the recognition of similarities and differences in longitudinal patterns of condomless anal intercourse with nonsteady partners (nsCAI) in the HIV Cohort Study over the last 18 years. We then used supervised learning to investigate whether sociodemographic variables could predict cluster membership. RESULTS: We identified 4 behavioral clusters. The largest behavioral cluster (cluster 1) contained 53% of the study population and displayed the most stable behavior. Cluster 3 (17% of the study population) displayed consistently increasing nsCAI. Sociodemographic variables were predictive for both of these clusters. The other 2 clusters displayed more drastic changes: nsCAI frequency in cluster 2 (20% of the study population) was initially similar to that in cluster 3 but accelerated in 2010. Cluster 4 (10% of the study population) had significantly lower estimates of nsCAI than all other clusters until 2017, when it increased drastically, reaching 85% by the end of the study period. CONCLUSIONS: We identified highly dissimilar behavioral patterns across behavioral clusters, including drastic, atypical changes. The patterns suggest that the overall increase in the frequency of nsCAI is largely attributable to 2 clusters, accounting for a third of the population.

Lack of HIV testing and dissatisfaction with HIV testing and counselling among men having sex with men in Hungary.

Background: Using data from a large internet-based survey of European men having sex with men (MSM), we assessed factors associated with HIV testing and reasons for dissatisfaction with HIV testing and counselling among Hungarian MSM. Methods: A total of 2052 Hungarian MSM provided evaluable data for the European MSM Internet Survey (EMIS) in 2010. χ2 tests and Poisson regression with a robust variance estimator were used to assess factors associated with HIV testing and dissatisfaction with HIV testing and counselling. Results: A total of 42.1% of MSM reported never being testing for HIV. Over one-half of men (54.1%) who reported condomless anal intercourse (CAI) in the prior 12 months with a person of unknown or sero-discordant HIV status reported no lifetime HIV testing. The factor most strongly associated with dissatisfaction with HIV testing and counselling was test site with increased dissatisfaction with inpatient hospital settings vs. community-based organizations. Both lack of HIV testing and dissatisfaction with testing were independently associated with MSM who reported that no one, or only a few people, knew they were attracted to men. Conclusions: Lack of HIV testing was strongly associated with CAI. MSM reported that community-based organizations better supported confidentiality and were more respectful during HIV testing.

Determinants of never having tested for HIV among MSM in the Netherlands.

OBJECTIVES: Men who have sex with men (MSM) who are unaware of their HIV infection are more likely to infect others, and unable to receive treatment. Therefore, we aimed to identify the proportion and characteristics of Dutch MSM who never tested for HIV. METHODS: In 2010, the European MSM Internet Survey (EMIS) recruited 174,209 men from 38 countries through an anonymous online questionnaire in 25 languages. We analysed data from participants living in the Netherlands (N=3787). The outcome we investigated was having never (lifetime) been tested for HIV. RESULTS: A total of 770 MSM (20.4%) had never been tested for HIV. In multivariate regression analyses, not being from Amsterdam (adjusted OR, aOR 1.54, CI 1.17 to 2.03), with low education (aOR 1.28, CI 1.04 to 1.57) and low knowledge on HIV-testing (aOR 2.23, CI 1.37 to 3.64) were significantly associated with never having tested. Lower sexual risk (including having fewer sexual partners (aOR 2.19, CI 1.57 to 3.04) and no anal intercourse (aOR 5.99, CI 3.04 to 11.77)), and less social engagement (including being less out (aOR 1.93, CI 1.55 to 2.40)) were also associated with having never been tested. Additionally, 36.1% of MSM who never tested for HIV reported high-risk sexual behaviour that may have put them at HIV risk. CONCLUSIONS: MSM make their own risk assessments that inform their choices about HIV-testing. Nevertheless, MSM who were never tested may have been at risk for HIV, and remain important to target for HIV interventions.

Prevalence of hepatitis C in a Swiss sample of men who have sex with men: whom to screen for HCV infection?

BACKGROUND: While the numbers of hepatitis-C-virus (HCV) infections among men who have sex with men (MSM) who are co-infected with the human immunodeficiency virus (HIV) are on the rise, with vast evidence for sexual transmission of HCV in this population, concerns have also been raised regarding sexual HCV-transmission among MSM without HIV infection. Therefore, the aim of this study was to estimate the prevalence of hepatitis C among MSM without HIV diagnosis in Zurich (Switzerland). METHODS: Participants were recruited from a gay health centre and various locations such as dark rooms, saunas and cruising areas in Zurich. Participants self-completed a questionnaire assessing known and suspected risk factors for HCV-infection, and provided a blood sample for detection of past (antibodies) and present (core antigen, RNA) infections with HCV. RESULTS: In total, 840 MSM aged 17-79 (median: 33 years) underwent HCV-testing and completed the questionnaire, among whom 19 reported living with HIV. Overall, seven tested positive for HCV-antibodies, and two were also positive for HCV core antigen and HCV-RNA-these two were immigrants, one from a country where HCV is endemic. None of the seven were aware of their infection. The seroprevalence of hepatitis C among the 821 non-HIV-diagnosed MSM was 0.37% (95%-CI: 0.12-1.69%), and one man harboured replicating virus (0.12%; 0.02-0.69%), resulting in a number needed to test of 821 to detect one active infection. Significant univariable associations of lifetime HCV-infection were found with known HIV-diagnosis (OR=72.7), being tattooed (OR=10.4), non-injection use of cocaine/amphetamines (OR=8.8), and non-Swiss origin (OR=8.5). For MSM without HIV-diagnosis, the only variable marginally associated with positive HCV-serostatus was being tattooed (OR=8.3). No significant associations were observed with reported injection drug use, unprotected anal intercourse, sexual practices that may lead to mucosal trauma, or proxy measures for group sex and lesion-prone STIs. CONCLUSIONS: Our findings suggest that in Switzerland, hepatitis C among MSM without diagnosed HIV is not more prevalent than in the general population. We found no evidence of elevated rates of sexual transmission of HCV among MSM without HIV-infection. Therefore, we currently see no reason for promoting HCV-testing among all MSM in Switzerland.