Frequent testing of highly sexually active gay men is required to control syphilis

The impact of HIV preexposure prophylaxis on bacterial sexually transmitted infection occurrence in MSM: a systematic review and meta-analysis

OBJECTIVE

To evaluate the effect of preexposure prophylaxis (PrEP) initiation on bacterial sexually transmitted infection (STI) occurrence (overall; chlamydia; gonorrhea; syphilis), in MSM.

DESIGN

Systematic review and meta-analysis.

METHODS

Systematic searches were performed in PubMed, Embase, and Scopus without language restrictions until 1 February 2023. We sought studies reporting data for the estimation of incidence rate ratios (IRR), prevalence ratios or cumulative incidence ratios (the latter in equal time periods before and after PrEP initiation) regarding bacterial STI occurrence. Separate analyses were performed overall for any STI, syphilis, chlamydia and gonorrhea (overall; rectal; urethral; pharyngeal for the two latter conditions); ratios greater than unity denoted increase in STI occurrence after PrEP initiation.

RESULTS

Twenty-three eligible studies with 11 776 participants (age range: 18-71 years) with a median follow-up of 12 months were included. Overall, PrEP initiation was associated with a significant increase in the occurrence of any STI (pooled effect size: 1.15, 95% confidence interval (CI): 1.04-1.26), any gonorrhea (pooled effect size: 1.17, 95% CI: 1.02-1.34), any chlamydia (pooled effect size: 1.31, 95% CI: 1.09-1.58) and rectal chlamydia (pooled effect size: 1.31, 95% CI: 1.05-1.64), whereas a borderline increase was found in urethral chlamydia (pooled effect size: 1.25, 95% CI: 0.99-1.60, P  = 0.064). Changes in pharyngeal chlamydia and site-specific gonorrhea occurrence did not reach statistical significance. Syphilis showed virtually no change after PrEP initiation (pooled effect size: 0.99, 95% CI: 0.72-1.37).

CONCLUSION

These results highlight the need for more comprehensive, accessible STI testing to tackle bacterial STI infections in PrEP users.

Interventions aimed at increasing syphilis screening among non-pregnant individuals in healthcare settings: a systematic review and meta-analysis

Syphilis remains a pressing public health concern with potential severe morbidity if left untreated. To improve syphilis screening, targeted interventions are crucial, especially in at-risk populations. This systematic review synthesises studies that compare syphilis screening in the presence and absence of an intervention. A systematic search of four databases was conducted (Medline, Embase, Cinahl and Scopus). The primary outcomes evaluated included syphilis screening, re-screening and detection rates. Findings were synthesised narratively. Where multiple studies were clinically heterogenous, a pooled odds ratio was calculated. Twenty-four studies were included. A variety of interventions showed promise including clinician alerts, which increased syphilis screening rate (OR range, 1.25-1.45) and patient SMS reminders that mostly improved re-screening/re-attendance rates (OR range, 0.93-4.4). Coupling syphilis serology with routine HIV monitoring increased the proportion of HIV-positive individuals undergoing both tests. However, pooling three studies with this intervention using the outcome of syphilis detection rate yielded inconclusive results (pooled OR 1.722 [95% CI 0.721-2.723], I 2 =24.8%, P =0.264). The introduction of hospital-based packaged testing for screening high-risk individuals is unique given hospitals are not typical locations for public health initiatives. Nurse-led clinics and clinician incentives were successful strategies. Including syphilis screening with other existing programs has potential to increase screening rates (OR range, 1.06-2.08), but requires further investigation. Technology-driven interventions produced cost-effective, feasible and positive outcomes. Challenges were evident in achieving guideline-recommended screening frequencies for men who have sex with men, indicating the need for multifaceted approaches. Wider application of these interventions may improve syphilis screening and detection rates.

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.

Examining the impacts of a syphilis awareness campaign among gay, bisexual, and other men who have sex with men (gbMSM) in British Columbia, Canada

OBJECTIVES

Syphilis rates have increased in BC and disproportionately affect gay, bisexual, and other men who have sex with men (gbMSM). A social marketing campaign (Syphistory) ran from January to September 2017 with the primary goal of increasing syphilis knowledge and a secondary goal of increasing syphilis screening among gbMSM in BC.

METHODS

We used pre- and post-campaign surveys to assess changes in syphilis knowledge from a convenience sample of clients attending STI clinics using one-sided t-tests. We used online Piwik metrics to examine the campaign reach, and provincial testing data to examine trends in syphilis screening. We used data from the Engage Study to examine factors associated with campaign awareness and associations with syphilis testing.

RESULTS

Of the 2155 visitors to the Syphistory website with known geography, 79.4% were from BC. Moreover, STI clinic participants who saw the campaign demonstrated a greater knowledge of syphilis (9.7/12, 80.8%) than those who did not see the campaign (mean 8.9/12, 74%) (p < 0.001). Provincial syphilis testing rates were 8764 and 9749 in the 12 months before and after the campaign; however, we did not find an overall trend in testing before versus after the campaign (p = 0.147). Among Engage participants, 12.7% reported seeing the campaign and we found an association between campaign exposure and recent syphilis testing (aOR = 2.73; 95% CI = 1.51, 4.93).

CONCLUSION

gbMSM who saw the campaign were more likely to report being tested for syphilis in the previous 6 months. STI clinic attendees who reported seeing the campaign also had higher syphilis knowledge compared to those who did not.

Persistently Elevated Risk of Syphilis Among Human Immunodeficiency Virus-Positive Men Receiving Care in a Status-Neutral Setting: A Retrospective Analysis

BACKGROUND

Over the past decade, the incidence of primary and secondary syphilis has increased dramatically in the United States and Western Europe. Men living with human immunodeficiency virus (HIV) and those at risk of HIV infection experience disproportionately high rates of early syphilis (ES). We compared the odds of ES among HIV-positive and HIV-negative men participating in a status-neutral comprehensive HIV prevention and treatment program (CHP).

METHODS

We conducted a retrospective analysis of men aged 18 to 65 years with ≥ 1 CHP visit and ≥2 rapid plasma reagin (RPR) tests performed between January 1, 2018, and December 31, 2021. Early syphilis was defined as newly reactive RPR with a minimum titer of ≥1:4 or a ≥ 4-fold increase in the RPR titer. Multiple logistic regression analyses were performed to determine predictors of ES.

RESULTS

A total of 2490 men met the inclusion criteria, of whom 1426 (57.3%) were HIV-positive and 1064 (42.7%) were HIV-negative. Of the 393 men with ES, 284 (72.3%) were HIV-positive and 109 (27.7%) were HIV-negative. Human immunodeficiency virus-positive men had higher adjusted odds of ES (adjusted odds ratio, 2.86; 95% confidence interval, 2.45-3.27) than HIV-negative men did. Chlamydia or gonorrhea infection did not differ according to HIV status (adjusted odds ratio, 0.93; 95% confidence interval, 0.82-1.04).

CONCLUSIONS

In our status-neutral care setting, HIV-positive status was associated with significantly higher odds of ES, but not chlamydia or gonorrhea. Our findings emphasize the vulnerability of HIV-positive men to syphilis in an era of effective HIV biomedical prevention.

Incidence and Risk Factors for Early Syphilis Among Men Who Have Sex With Men in Australia, 2013-2019: A Retrospective Cohort Study

Background

We aimed to examine the incidence of syphilis in men who have sex with men (MSM) and identify subgroups of MSM at a higher risk of syphilis infection.

Methods

We conducted a retrospective cohort study of MSM attending a sexual health clinic in Australia, during 2013-2019, who had at least 2 syphilis serological tests during the study period. The incidence of syphilis was expressed as per 100 person-years. A cox regression analysis was conducted to identify risk factors for syphilis.

Results

A total of 24 391 individual MSM (75 086 consultations) were included. A total of 1404 new syphilis cases were diagnosed with an incidence of 3.7/100 person-years (95% confidence interval, 3.5-3.9). Syphilis incidence was higher in MSM with human immunodeficiency virus ([HIV] 9.3/100 person-years) than in MSM taking HIV pre-exposure prophylaxis (PrEP) (6.9/100 person-years) or HIV-negative MSM not taking PrEP (2.2/100 person-years). Risk factors associated with high incidence of syphilis included the following: MSM with HIV (adjusted hazard ratio [aHR] 2.7), MSM taking HIV PrEP (aHR 2.1), past history of syphilis infection (aHR 2.4), injecting drug use (aHR 2.7), condomless anal sex (aHR 1.7), >4 sexual partners in the last 12 months (aHR 1.2), and concurrent sexually transmitted infection (chlamydia and gonorrhoea) (aHR 1.6).

Conclusions

The incidence of syphilis remains high among MSM, particularly in subgroups with associated risk factors for syphilis infections. These data highlight the need for biomedical and behavioral interventions to be targeted to subgroups of MSM at the highest risk of syphilis infection.

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.

Preferences of men who have sex with men for performing anal self-examination for the detection of anal syphilis in Australia: A discrete choice experiment

BACKGROUND

Regular anal self-examination could potentially reduce syphilis transmission by detecting anal syphilis earlier among men who have sex with men (MSM). This study aimed to examine the preferences of MSM on performing anal self-examination to detect anal syphilis.

METHODS

An online survey with a discrete choice experiment (DCE) was distributed to MSM attending a sexual health clinic and through social media in Australia between June and November 2020. The DCE examined the preferred attributes of anal self-examination that would encourage MSM to perform anal self-examination. Data were analysed using a random parameters logit (RPL) model.

FINDINGS

The median age of 557 MSM who completed the survey was 35 (inter quartile range, 27-45). The choice to perform anal self-examination was most influenced by two attributes: the accuracy of anal self-examination to diagnose anal syphilis, and the frequency of anal self-examination, followed by the type of instruction materials to perform anal self-examination, waiting time for medical review, and type of support received if abnormalities were found. Using the most preferred attributes, 98% of people would conduct anal self-examination compared with 35% when the least preferred anal self-examination attributes were offered.

INTERPRETATION

If anal self-examination were recommended for anal syphilis screening, it will be important to consider preferences of MSM: men were more likely to undertake anal self-examination if the frequency was once a month and there was higher accuracy of detecting anal syphilis.

FUNDING

Australian National Health And Medical Research Council.

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.

Syphilis, one of the most common sexually transmitted infections, remains a major public health problem. Over the last decade, a rising number of diagnoses especially in men-who-have-sex-with-men (MSM) was observed in Western Europe and Northern America. In Switzerland, the number of syphilis diagnoses in MSM tripled between 2006 and 2017. In this study, we used a mathematical model to assess the drivers of this increase among MSM in Switzerland. Our model could reproduce the increase in syphilis diagnoses in both MSM with and without HIV diagnosis between 2006 and 2017. Based on this model we found that MSM with HIV diagnosis have an over 45 times higher syphilis incidence than MSM without HIV diagnosis. Furthermore, we found that reported sex with non-steady partners is a useful proxy of behavioral risk. Considering counterfactual scenarios, we showed that increasing the screening frequency for syphilis among MSM with HIV diagnosis and with non-steady partners from once a year to twice per year can reduce syphilis incidence by 63.5% to 99.2%.

Sexually Transmitted Infections Treatment Guidelines, 2021

These guidelines for the treatment of persons who have or are at risk for sexually transmitted infections (STIs) were updated by CDC after consultation with professionals knowledgeable in the field of STIs who met in Atlanta, Georgia, June 11-14, 2019. The information in this report updates the 2015 guidelines. These guidelines discuss 1) updated recommendations for treatment of Neisseria gonorrhoeae, Chlamydia trachomatis, and Trichomonas vaginalis; 2) addition of metronidazole to the recommended treatment regimen for pelvic inflammatory disease; 3) alternative treatment options for bacterial vaginosis; 4) management of Mycoplasma genitalium; 5) human papillomavirus vaccine recommendations and counseling messages; 6) expanded risk factors for syphilis testing among pregnant women; 7) one-time testing for hepatitis C infection; 8) evaluation of men who have sex with men after sexual assault; and 9) two-step testing for serologic diagnosis of genital herpes simplex virus. Physicians and other health care providers can use these guidelines to assist in prevention and treatment of STIs.

Routinised Syphilis Screening among Men Living with HIV: A stepped wedge cluster randomised controlled trial

BACKGROUND

Frequent syphilis screening may increase early detection and decrease transmission. We implemented an opt-out clinic-based intervention pairing syphilis tests with routine HIV viral load testing. The primary objective was to determine the degree to which this intervention increased the detection of early syphilis.

METHODS

The Enhanced Syphilis Screening among HIV-positive Men (ESSAHM) Trial was a stepped wedge cluster-randomised controlled trial involving four urban HIV clinics in Ontario, Canada, from 2015 to 2017. Population: HIV-positive adult males. Intervention (I): standing orders for syphilis serological testing with viral loads. Control (C): usual practice. Outcome: early syphilis diagnosis. We obtained test results via linkage with the centralized provincial laboratory and defined cases using a standardized clinical worksheet and medical chart review. We employed a generalized linear mixed model with a logit link to estimate odds ratios (OR) and 95% confidence intervals (CI) of the intervention.

FINDINGS

3,895 men were followed over 7,471 person-years (PY). The mean number of syphilis tests increased from 0.53 to 2.02 tests per person per year. There were 217 new diagnoses of syphilis (C: 81; I: 136), for which 147 (68%) were cases of early syphilis (C:61 (75%); I:86 (63%)). The annualized proportion with newly-detected early syphilis increased from 0.009 to 0.032 with implementation of the intervention; the corresponding time-adjusted OR was 1.25 (CI 0.71, 2.20).

INTERPRETATION

The implementation of standing orders for syphilis testing with HIV viral loads was feasible and increased testing yet produced less-than-expected increases in case detection compared to past uncontrolled pre-post trials.

Exploring How Epidemic Context Influences Syphilis Screening Impact: A Mathematical Modeling Study

Transmission modeling suggests that screening guidelines focused on men who have sex with men are likely insufficient for syphilis control in contexts with substantial infection burden in heterosexual populations.

Supplemental digital content is available in the text.

The current syphilis epidemic in the United States is concentrated in gay, bisexual, and other men who have sex with men (MSM), but substantial heterosexual transmission is reported in some parts of the country. Using the US states of Louisiana and Massachusetts as case studies, we investigated how epidemic context influences the impact of population screening approaches for syphilis control.

Uptake and Impact of Short Message Service Reminders via Sexually Transmitted Infection Partner Services on Human Immunodeficiency Virus/Sexually Transmitted Infection Testing Frequency Among Men Who Have Sex With Men

BACKGROUND

Sexually transmitted infection (STI) partner services (PS) allow provision of human immunodeficiency virus (HIV)/STI prevention interventions to high-risk individuals, including testing reminders via short message service (SMS).

METHODS

In King County, Washington, PS attempt to reach all men who have sex with men (MSM) with early syphilis and those with gonorrhea or chlamydia as resources allow. Since 2013, PS offered quarterly SMS testing reminders. We evaluated correlates of reminder uptake and the association between reminder uptake and postinterview asymptomatic STI diagnosis using Poisson regression, and the association between preinterview SMS reminder use and intertest interval among HIV-negative MSM using median regression.

RESULTS

During July 1, 2013 to January 17, 2018, 8236 MSM were reported with 1 or more STI diagnoses and 5237 received PS interviews. Of these, 4087 (78%) were offered SMS reminders; 545 (13%) accepted, 265 (7%) were already receiving SMS, 3277 (80%) refused. Of 2602 patients who refused and were asked about other reminders, 37% used none, 16% received reminders from medical providers, 20% tested at routine physicals, and 26% used other reminders. SMS reminder use before and after PS interview was associated with negative HIV status, younger age, and diagnosis with gonorrhea or chlamydia (vs. syphilis) (P < 0.05 for all). Preinterview intertest interval was longer among MSM testing at physicals (9.6 months) than those using no reminder (5.6), SMS reminders (4.7, P < 0.05 vs. physicals), and non-SMS reminders (3.6, P < 0.001 vs. SMS). Reminder uptake was not associated with postinterview STI diagnosis.

CONCLUSIONS

Offering SMS reminders through STI PS is feasible. Uptake was low, but higher among young MSM not on preexposure prophylaxis. The SMS reminders may increase testing frequency.

Quarterly screening optimizes detection of sexually transmitted infections when prescribing HIV preexposure prophylaxis

OBJECTIVE

The optimal screening frequency of sexually transmitted infections (STIs) for MSM and transgender women (TGW) on HIV pre-exposure prophylaxis (PrEP) is unclear, with present guidelines recommending screening every 3-6 months. We aimed to determine the number of STIs for which treatment would have been delayed without quarterly screening.

DESIGN

The US PrEP Demonstration Project was a prospective, open-label cohort study that evaluated PrEP delivery in STI clinics in San Francisco and Miami, and a community health center in Washington, DC. In all, 557 HIV-uninfected MSM and TGW were offered up to 48 weeks of PrEP and screened quarterly for STIs.

METHODS

The proportion of gonorrhea, chlamydia, and syphilis infections for which treatment would have been delayed had screening been conducted every 6 versus every 3 months was determined by taking the number of asymptomatic STIs at weeks 12 and 36 divided by the total number of infections during the study follow-up period for each STI.

RESULTS

Among the participants, 50.9% had an STI during follow-up. If screening had been conducted only semiannually or based on symptoms, identification of 34.3% of gonorrhea, 40.0% of chlamydia, and 20.4% of syphilis infections would have been delayed by up to 3 months. The vast majority of participants (89.2%) with asymptomatic STIs reported condomless anal sex and had a mean of 8.1 partners between quarterly visits.

CONCLUSIONS

Quarterly STI screening among MSM on PrEP could prevent a substantial number of partners from being exposed to asymptomatic STIs, and decrease transmission.

Incidence of syphilis among HIV-infected men in Singapore, 2006-2017: temporal trends and associated risk factors

OBJECTIVE

There have been recent reports globally on substantial increase in syphilis diagnoses particularly among high-risk men. The aim of this study was to assess temporal trends of incident syphilis and associated risk factors among HIV-infected men in Singapore.

METHODS

We conducted retrospective cohort analysis using the clinical database maintained by the Clinical HIV Programme at the National Centre for Infectious Diseases, Singapore. HIV-infected men with a negative syphilis result at baseline who had undergone at least one subsequent test in 2006-2017 were included. Factors associated with incident syphilis were investigated using Cox proportional hazards regression analyses.

RESULTS

A total of 1069 HIV-infected men were tested for syphilis at least once following their negative baseline test during the 12-year period, and they contributed 4284 person-years of follow-up (PYFU). There were 266 cases of incident syphilis, giving an overall incidence of 6.21 per 100 PYFU (95% CI 5.49-7.00). The incidence of syphilis per 100 PYFU increased from 1.21 (95% CI 0.33 to 3.10) in 2010 to 26.04 (95% CI 19.97 to 33.40) in 2017. In the multivariable model, risk factors for syphilis seroconversion were: age 15-24 years at HIV diagnosis (adjusted HR (aHR) 1.64, 95% CI 1.05 to 2.56) versus ≥45 years, being Chinese (aHR 1.82, 95% CI 1.01 to 3.29) versus Indian and other minority ethnic groups, men having sex with men (MSM) (aHR 3.29, 95% CI 2.22 to 4.87) versus heterosexuals, and HIV diagnosis in later periods of 2009-2011 (aHR 1.96, 95% CI 1.41 to 2.74), 2012-2014 (aHR 3.96, 95% CI 2.68 to 5.83) and 2015-2017 (aHR 7.94, 95% CI 4.52 to 13.95) versus 2006-2008.

CONCLUSION

The annual incidence rate of syphilis in HIV-infected men was on the rise, and it was consistently higher among MSM than in heterosexual men. The findings supported regular screening for syphilis and enhanced behavioural interventions in Singapore.

Increasing Syphilis Detection Among Patients Assigned Male at Birth Screened at a Boston Community Health Center Specializing in Sexual and Gender Minority Health, 2005-2015

BACKGROUND

United States syphilis rates have increased to levels last seen in the 1990s. We examined syphilis epidemiology of patients attending a Boston community health center specializing in sexual and gender minority health.

METHODS

We performed a retrospective cohort study of all patients assigned male at birth screened with rapid plasma reagin from 2005 through 2015. We developed an algorithm to identify new infections and used repeat cross-sectional analysis to assess temporal trends in syphilis diagnoses. We also performed longitudinal analysis to calculate syphilis incidence using a Cox proportional hazards model that accounts for multiple infections over time.

RESULTS

Eighteen thousand two hundred eighty-two patients had a total of 57,080 rapid plasma reagins, 1170 (2.0%) tests met criteria for syphilis. Adjusted syphilis diagnoses increased from 1.2% to 1.9%, recurrent syphilis diagnoses increased from 0.04% to 0.3% during the study period. Black and Hispanic/Latinx patients, patients aged 35 to 44 years, gay/bisexual patients, cisgender men, and human immunodeficiency virus (HIV)-infected patients and those who became HIV-infected during the study period were more likely to test positive for syphilitic infection in repeat cross-sectional analysis. Among 6199 patients screened more than 1 time over 21,745 person-years, there were 661 new syphilis cases (3.0% annual incidence; 95% confidence interval [CI], 2.8% to 3.2%). Compared with those aged 14 to 24 years, patients 45 years or older were less likely to experience syphilis. New HIV infection was associated with increased risk of incident syphilis (adjusted hazard ratio, 2.87; 95% CI, 1.61-5.13). Virally suppressed HIV-infected patients were less likely to experience incident syphilis (adjusted hazard ratio, 0.69; 95% CI, 0.55-0.87).

CONCLUSIONS

The high incidence of syphilis among patients assigned male at birth disproportionately affected young patients, black and Hispanic/Latinx patients, gay/bisexual patients, cisgender men, and those with new or chronic HIV infection. Syphilitic reinfection rates increased over time.

A cohort study comparing rate of repeat testing for sexually transmitted and blood-borne infections between clients of an internet-based testing programme and of sexually transmitted infection clinics in Vancouver, Canada

OBJECTIVES

Internet-based sexually transmitted and blood-borne infection (STBBI) testing services reduce testing barriers through bypassing face-to-face clinical encounters, potentially enabling clients at ongoing sexual risk to test more frequently. To our knowledge, this hypothesis has not been previously tested. We compared the frequency of repeat testing between Vancouver-based clients of GetCheckedOnline (GCO)-an internet-based STBBI testing service in British Columbia, Canada-and clients of three sexually transmitted infection (STI) clinics in Vancouver for 29 months after GCO launched.

METHODS

An administrative data cohort (n=19 497) was assembled using GCO, clinical and laboratory databases. We included all individuals who tested for HIV, gonorrhoea/chlamydia, syphilis or hepatitis C at three STI clinics or using GCO, between September 2014 and February 2017. The rate of repeat testing (>30 days after first episode) was compared between clients who used GCO at least once and those who tested only in STI clinics. Poisson regression was used to generate relative rate (RR) for repeat testing, with adjustment for age, gender/sexual orientation, risk factors (eg, history of STI diagnosis) and rate of testing before GCO launched.

RESULTS

1093 GCO clients were identified, of whom 434 (40%) had repeat test episodes; 8200/18 404 (45%) of clinic clients tested more than once. During the 29-month analysis period, GCO clients repeat tested 1.87 times per person-year, whereas clinic clients repeat tested 1.53 times per person-year, resulting in a crude RR of 1.22 (95% CI: 1.14 to 1.31). Adjustment for covariates increased the RR to 1.26 (95% CI: 1.15 to 1.37).

CONCLUSIONS

In this cohort, individuals using internet-based STBBI testing had a rate of repeat testing 22% greater than clinic-based clients. This effect was increased after adjusting for characteristics associated with higher test frequency. The online interface of GCO may facilitate more frequent testing and may therefore contribute to earlier STBBI diagnosis.

Optimizing Coverage vs Frequency for Sexually Transmitted Infection Screening of Men Who Have Sex With Men

Background

The incidence of bacterial sexually transmitted infections (STIs) in men who have sex with men (MSM) has increased substantially despite availability of effective antibiotics. The US Centers for Disease Control and Prevention (CDC) recommends annual screening for all sexually active (SA) MSM and more frequent screening for high-risk (HR) MSM. The population-level benefits of improved coverage vs increased frequency of STI screening among SA vs HR MSM are unknown.

Methods

We used a network transmission model of gonorrhea (NG) and chlamydia (CT) among MSM to simulate the implementation of STI screening across different scenarios, starting with the CDC guidelines at current coverage levels. Counterfactual model scenarios varied screening coverage and frequency for SA MSM and HR MSM (MSM with multiple recent partners). We estimated infections averted and the number needed to screen to prevent 1 new infection.

Results

Compared with current recommendations, increasing the frequency of screening to biannually for all SA MSM and adding some HR screening could avert 72% of NG and 78% of CT infections over 10 years. Biannual screening of 30% of HR MSM at empirical coverage levels for annual SA screening could avert 76% of NG and 84% of CT infections. Other scenarios, including higher coverage among SA MSM and increasing frequency for HR MSM, averted fewer infections but did so at a lower number needed to screen.

Conclusions

The optimal screening scenarios in this model to reduce STI incidence among MSM included more frequent screening for all sexually active MSM and higher coverage of screening for HR men with multiple partners.

Resurgence of Syphilis in the United States: An Assessment of Contributing Factors

In the last decade, there has been a marked resurgence of syphilis in the United States despite the availability of effective treatments and previously reliable prevention strategies. The majority of cases are among the population of men who have sex with men (MSM); however, there has also been a recent increase among premenopausal women, coinciding with a concerning rise of congenital cases. The resurgence of syphilis can be largely attributed to changing social and behavioral factors, especially among young MSM. The biological association of syphilis with human immunodeficiency virus (HIV) transmission and acquisition is particularly alarming because of the increased individual and healthcare burden. In addition, some individual actions and public health efforts that are meant to reduce the risk of acquiring HIV may actually lead to risk compensation that facilitates the transmission of syphilis. Untreated syphilis is associated with detrimental health outcomes; therefore, both effective prevention strategies and treatment of this systemic disease have important short-term and long-term public health implications. This article offers a review of social and behavioral factors contributing to the current resurgence and recommendations for reducing syphilis incidence through medical and public health prevention strategies.

The development of an online risk calculator for the prediction of future syphilis among a high-risk cohort of men who have sex with men and transgender women in Lima, Peru

Background Syphilis incidence worldwide has rebounded since 2000, particularly among men who have sex with men (MSM). A predictive model for syphilis infection may inform prevention counselling and use of chemoprophylaxis.

METHODS

Data from a longitudinal cohort study of MSM and transgender women meeting high-risk criteria for syphilis who were followed quarterly for 2 years were analysed. Incidence was defined as a four-fold increase in rapid plasma reagin (RPR) titres or new RPR reactivity if two prior titres were non-reactive. Generalised estimating equations were used to calculate rate ratios (RR) and develop a predictive model for 70% of the dataset, which was then validated in the remaining 30%. An online risk calculator for the prediction of future syphilis was also developed.

RESULTS

Among 361 participants, 22.0% were transgender women and 34.6% were HIV-infected at baseline. Syphilis incidence was 19.9 cases per 100-person years (95% confidence interval (CI) 16.3-24.3). HIV infection (RR 2.22; 95% CI 1.54-3.21) and history of syphilis infection (RR 2.23; 95% 1.62-3.64) were significantly associated with incident infection. The final predictive model for syphilis incidence in the next 3 months included HIV infection, history of syphilis, number of male sex partners and sex role for anal sex in the past 3 months, and had an area under the curve of 69%. The online syphilis risk calculator based on those results is available at: www.syphrisk.net.

CONCLUSIONS

Using data from a longitudinal cohort study among a population at high risk for syphilis infection in Peru, we developed a predictive model and online risk calculator for future syphilis infection. The predictive model for future syphilis developed in this study has a moderate predictive accuracy and may serve as the foundation for future studies.

What could re-infection tell us about R0? A modeling case-study of syphilis transmission

Many infectious diseases can lead to re-infection. We examined the relationship between the prevalence of repeat infection and the basic reproductive number (R₀). First we solved a generic, deterministic compartmental model of re-infection to derive an analytic solution for the relationship. We then numerically solved a disease-specific model of syphilis transmission that explicitly tracked re-infection. We derived a generic expression that reflects a non-linear and monotonically increasing relationship between proportion re-infection and R₀ and which is attenuated by entry/exit rates and recovery (i.e. treatment). Numerical simulations from the syphilis model aligned with the analytic relationship. Re-infection proportions could be used to understand how far regions are from epidemic control, and should be included as a routine indicator in infectious disease surveillance.

Missed Opportunities for Human Immunodeficiency Virus and Syphilis Testing Among Men Who Have Sex With Men in China: A Cross-Sectional Study

BACKGROUND

Men who have sex with men (MSM) are at high risk of human immunodeficiency virus (HIV)/syphilis. To inform strategies for dual testing, we describe patterns of HIV/syphilis testing, and examine factors associated with never testing for HIV/syphilis in China.

METHODS

An online survey (2016) was completed by MSM from 8 cities: men born biologically male, 16 years or older, and had sex with another man at least once during their lifetime. Demographic, sexual behavioral, and HIV/syphilis testing data were collected. Multivariable multinomial logistic regression identified characteristics associated with men who never tested for HIV/syphilis compared with men who ever tested for both infections.

RESULTS

Overall, 2105 men participated. Among them, 35.1% (738/2105) never tested for HIV/syphilis, and in those ever tested for HIV, only half (54.0%, 709/1312) had tested for syphilis. Relative to men who had ever tested for both infections, those with increased probability of never testing for HIV/syphilis include non-gay sexual identity (prevalence odds ratio [POR] 1.86; 95% confidence interval [CI], 1.45-2.37), not disclosed their sexuality/sexual history with men other than their regular partner (POR, 2.22; 95% CI, 1.75-2.78]) or with health professionals (POR, 11.11; 95% CI, 7.69-14.29), no condomless sex with casual partners in the last 3 months (POR, 1.89; 95% CI, 1.37-2.56), no community engagement in sexual health (POR, 15.16; 95% CI, 9.40-24.45), and mainly met partners offline (POR, 1.49; 95% CI, 1.16-1.92).

CONCLUSIONS

There are significant gaps in lifetime testing for HIV/syphilis among Chinese MSM. Strategies to target never testers and integrate syphilis testing within HIV testing services are urgently needed. Future opportunities include point-of-care dual test kits, and testing in China's expanding primary healthcare system.

Identifying high risk subgroups of MSM: a latent class analysis using two samples

Background

Latent class analyses (LCA) are increasingly being used to target specialized HIV interventions, but generalizability of emergent population structures across settings has yet to be considered. We compare LCA performed on two online samples of HIV negative Chinese men who have sex with men (MSM) to detect more generalizable latent class structures and to assess the extent to which sampling considerations impact the validity of LCA results.

Methods

LCAs were performed on an 1) nationwide online survey which involved no in-person contact with study staff and a 2) sentinel surveillance survey in which participants underwent HIV and syphilis testing in the city of Guangzhou, both conducted in 2014. Models for each sample were informed by risk factors for HIV acquisition in MSM that were common to both datasets.

Results

An LCA of the Guangzhou sentinel surveillance data indicated the presence of two relatively similar classes, differing only by the greater tendency of one to report group sex. In contrast an LCA of the nationwide survey identified three classes, two of which shared many of the same features as those identified in the Guangzhou survey, including the fact that they were mainly distinguished by group sex behaviors. The final latent class in the nationwide survey was composed of members with notably few risk behaviors.

Conclusions

Comparisons of the latent class structures of each sample lead us to conclude that the nationwide online sample captured a larger, possibly more representative group of Chinese MSM comprised of a larger, higher risk group and a small yet distinct lower group with few reported behaviors. The absence of a lower risk group in the Guangzhou sentinel surveillance dataset suggests that MSM recruited into studies involving free HIV/STI testing may oversample MSM with higher risk behaviors and therefore greater risk perception. Lastly, two types of higher risk MSM were emergent across both samples distinguished largely by their recent group sex behaviors. Higher odds not only of self-reported HIV infection but also of closeted tendencies and gender fluid identities in this highest risk group suggest that interacting factors drive individual and structural facets of HIV risk.

Investigation of Early Syphilis Trends Among Men Who Have Sex With Men to Identify Gaps in Screening and Case-Finding in Baltimore City, Maryland

BACKGROUND

Syphilis incidence is increasing across the United States among men who have sex with men (MSM). Early latent (EL) versus primary and secondary (P&S) syphilis may be an indicator of delayed diagnosis and increased opportunity for transmission. To inform syphilis control strategies and identify potential gaps in case finding, we described recent syphilis trends among MSM and compared characteristics of syphilis cases by diagnosis stage.

METHODS

We used public health surveillance data on P&S and EL syphilis diagnoses reported to the Baltimore City Health Department between 2009 and 2015. Differences across diagnosis stage were assessed using Cochran-Armitage and χ tests.

RESULTS

Between 2009 and 2015, Baltimore City Health Department received 2436 reports of P&S and EL diagnoses. The majority (61%) of reports were among MSM, among whom 86% were black and 67% were human immunodeficiency virus (HIV)-infected. During this period, P&S and EL syphilis increased by 85% and 245%, respectively (P < 0.0001). MSM with EL versus P&S syphilis were similarly likely to be Black, more likely to be older (P < 0.05), HIV coinfected (P < 0.001), and diagnosed in private health care settings (P < 0.0001), but less likely to report multiple (P < 0.001) and anonymous sex partners (P < 0.001).

CONCLUSIONS

In Baltimore City, syphilis diagnoses, particularly EL diagnoses, are increasing rapidly and are concentrated among Black HIV-infected MSM. Significant gaps in identifying MSM with P&S syphilis may exist, specifically among HIV-infected MSM, and those diagnosed in private health care settings. Strategies to address these gaps may include local guidelines and provider education to screen MSM more frequently than CDC currently recommends and regardless of HIV status or risk.

Neurosyphilis Presenting with Anxiety: A Case Report

The number of cases of late and late latent syphilis in the United States is on the rise. This diagnosis is often forgotten when an elderly patient is being worked up for altered mental status. Rarely does a 70-year-old male with neurosyphilis present simply with anxiety. Due to the decreased severity of the presentation, this patient was sent home from the emergency department multiple times until the anxiety progressed to psychosis. He was finally admitted with delirium, suicidal ideation, and paranoia. A routine Treponema pallidum antibody test returned positive and a further workup of confirmatory lab work, a thorough neurological exam, and magnetic resonance imaging (MRI) revealed a chronic syphilis infection. This case study explores signs in the history and physical examination that should quickly prompt a provider to consider neurosyphilis in their differential. This patient presented with Argyll-Robertson pupils and significant risk factors. The goal of this discussion is to bring awareness to this infrequent presentation and share simple examination techniques that could have been used to diagnose and treat this patient's symptoms more promptly. In doing so, the hope is to raise awareness for the diagnosis of neurosyphilis, especially in the elderly patient presenting with psychiatric symptoms.

Behavioural, not biological, factors drive the HCV epidemic among HIV-positive MSM: HCV and HIV modelling analysis including HCV treatment-as-prevention impact

Background

Uncertainty surrounds why hepatitis C virus (HCV) is concentrated among HIV-positive men who have sex with men (MSM). We used mathematical modelling to explore reasons for these infection patterns, and implications for HCV treatment-as-prevention.

Methods

Using a joint MSM HIV/HCV transmission model parameterized with UK behavioural data, we considered how biological (heightened HCV infectivity and reduced spontaneous clearance among HIV-positive MSM) and/or behavioural factors (preferential sexual mixing by HIV status and risk heterogeneity) could concentrate HCV infection in HIV-positive MSM as commonly observed (5-20 times the HCV prevalence in HIV-negative MSM; defined as the HCV ratio). We explored how HCV treatment-as-prevention impact varies under differing HCV ratios.

Results

Biological factors produced low HCV ratios (< 3), not explaining the skewed epidemic. However, combining preferential mixing by HIV status with sexual risk behaviour heterogeneity produced high HCV ratios (> 10) that were highly sensitive to both factors. Irrespective of the HCV ratio or behavioural/biological factors, HCV treatment of HIV-diagnosed MSM markedly reduced the HCV prevalence among HIV-positive MSM, but less impact was achieved among all MSM for lower HCV ratios.

Conclusions

Sexual behaviour patterns likely drive observed HCV infection patterns among HIV-positive MSM. Changes in these patterns could disseminate HCV amongst HIV-negative MSM, limiting the impact of targeting HCV treatment to HIV-diagnosed MSM.

Expanding syphilis testing: a scoping review of syphilis testing interventions among key populations

INTRODUCTION

Syphilis is an important sexually transmitted infection (STI). Despite inexpensive and effective treatment, few key populations receive syphilis testing. Innovative strategies are needed to increase syphilis testing among key populations. Areas covered: This scoping review focused on strategies to increase syphilis testing in key populations (men who have sex with men (MSM), sex workers, people who use drugs, transgender people, and incarcerated individuals). Expert commentary: We identified many promising syphilis testing strategies, particularly among MSM. These innovations are separated into diagnostic, clinic-based, and non-clinic based strategies. In terms of diagnostics, self-testing, dried blood spots, and point-of-care testing can decentralize syphilis testing. Effective syphilis self-testing pilots suggest the need for further attention and research. In terms of clinic-based strategies, modifying default clinical procedures can nudge physicians to more frequently recommend syphilis testing. In terms of non-clinic based strategies, venue-based screening (e.g. in correctional facilities, drug rehabilitation centres) and mobile testing units have been successfully implemented in a variety of settings. Integration of syphilis with HIV testing may facilitate implementation in settings where individuals have increased sexual risk. There is a strong need for further syphilis testing research and programs.

The Number of Interviews Needed to Yield New Syphilis and Human Immunodeficiency Virus Cases Among Partners of People Diagnosed With Syphilis, North Carolina, 2015

Compare syphilis investigation yield among patient groups using number needed to interview.

GOAL

To increase investigation efficiency.

STUDY DESIGN

Retrospective review of North Carolina 2015 syphilis investigations, using the number of cases needed to interview (NNTI) and the total number of cases and contacts needed to interview (TNTI) to compare yield of new syphilis and human immunodeficiency virus diagnoses between patient groups.

RESULTS

We reviewed 1646 early syphilis cases and 2181 contacts; these yielded 241 new syphilis cases (NNTI, 6.9; TNTI, 16.4) and 38 new human immunodeficiency virus cases (NNTI, 43). Interviews of women (prevalence difference [PD] = 6%, 95% confidence interval [CI], 12-16), patients <30 years old (PD = 5%, 95% CI, 1-8), and patients with titer >1:16 (PD = 5%, 95% CI, 1-9) yielded more new syphilis cases in our adjusted model; no other patient factors increased investigation yield.

CONCLUSIONS

The NNTI and TNTI are useful measures of efficiency. Prioritizing early syphilis investigation by gender, rapid plasmin reagin titer, and age provides small increases in efficiency; no other factors increased efficiency.

Evaluation of the Lumipulse G TP-N Chemiluminescent Immunoassay as a Syphilis Screening Test

A syphilis diagnosis is often aided by the detection of treponemal and nontreponemal antibodies. Automated treponemal antibody detection systems enable high-volume clinical laboratories to perform syphilis screening at a faster pace with lower labor costs. The Lumipulse G TP-N chemiluminescent immunoassay is an automated system that qualitatively detects IgG and IgM antibodies against Treponema pallidum antigens in human serum and plasma. To assess performance characteristics and workflow efficiency, the Lumipulse G TP-N assay was compared to the Bioplex 2200 Syphilis IgG multiplex flow immunoassay. Among the 4,134 routine and HIV samples tested by the two automated assays, the percentage of agreement was excellent at 99.0% (95% confidence interval [CI], 98.6% to 99.2%; κ, 0.89), with the Lumipulse G TP-N having a shorter time to first and subsequent results. All specimens with reactive syphilis screening results were further tested by rapid plasma reagin (RPR) and Treponema pallidum particle agglutination (TP·PA) testing (n = 231). The results from the RPR-reactive samples (n = 82) showed complete concordance with the two automated assays, while the TP·PA assay displayed some discrepancies. The positive percent agreement (PPA) and negative percent agreement (NPA) between the TP·PA test and the Lumipulse G TP-N test were 98.9% and 77.3%, respectively. The Bioplex 2200 Syphilis IgG immunoassay displayed a similar PPA (100%) but a substantially lower NPA (15.9%). Patient chart reviews of discrepant results suggested that the Lumipulse G TP-N assay produced 27 fewer falsely reactive results and can reduce the amount of additional confirmatory RPR and TP·PA testing needed. The analogous performance characteristics of the two automated systems indicate that the Lumipulse G TP-N assay is suitable for high-throughput syphilis screening.

Sexually transmitted infections: challenges ahead

WHO estimated that nearly 1 million people become infected every day with any of four curable sexually transmitted infections (STIs): chlamydia, gonorrhoea, syphilis, and trichomoniasis. Despite their high global incidence, STIs remain a neglected area of research. In this Commission, we have prioritised five areas that represent particular challenges in STI treatment and control. Chlamydia remains the most commonly diagnosed bacterial STI in high-income countries despite widespread testing recommendations, sensitive and specific non-invasive testing techniques, and cheap effective therapy. We discuss the challenges for chlamydia control and evidence to support a shift from the current focus on infection-based screening to improved management of diagnosed cases and of chlamydial morbidity, such as pelvic inflammatory disease. The emergence and spread of antimicrobial resistance in Neisseria gonorrhoeae is globally recognised. We review current and potential future control and treatment strategies, with a focus on novel antimicrobials. Bacterial vaginosis is the most common vaginal disorder in women, but current treatments are associated with frequent recurrence. Recurrence after treatment might relate to evidence that suggests sexual transmission is integral to the pathogenesis of bacterial vaginosis, which has substantial implications for the development of effective management approaches. STIs disproportionately affect low-income and middle-income countries. We review strategies for case management, focusing on point-of-care tests that hold considerable potential for improving STI control. Lastly, STIs in men who have sex with men have increased since the late 1990s. We discuss the contribution of new biomedical HIV prevention strategies and risk compensation. Overall, this Commission aims to enhance the understanding of some of the key challenges facing the field of STIs, and outlines new approaches to improve the clinical management of STIs and public health.

Frequency and determinants of consistent STI/HIV testing among men who have sex with men testing at STI outpatient clinics in the Netherlands: a longitudinal study

Objectives

Men who have sex with men (MSM) are at highest risk for STIs and HIV infections in the Netherlands. However, official guidelines on STI testing among MSM are lacking. They are advised to test for STIs at least every six months, but their testing behaviour is not well known. This study aimed to get insight into the proportion and determinants of consistent 6-monthly STI testing among MSM testing at STI outpatient clinics in the Netherlands.

Methods

This study included longitudinal surveillance data of STI consultations among MSM from all 26 STI outpatient clinics in the Netherlands between 1 June 2014 and 31 December 2015. Multinomial logistic regression analysis was used to identify determinants of consistent 6-monthly testing compared with single testing and inconsistent testing. Determinants of time between consultations among men with multiple consultations were analysed using a Cox Prentice-Williams-Peterson gap-time model.

Results

A total of 34 605 STI consultations of 18 634 MSM were included. 8966 (48.1%) men had more than one consultation, and 3516 (18.9%) men tested consistently 6-monthly. Indicators of high sexual risk behaviour, including having a history of STI, being HIV positive and having more than 10 sex partners, were positively associated with both being a consistent tester and returning to the STI clinic sooner. Men who were notified by a partner or who reported STI symptoms were also more likely to return to the STI clinic sooner, but were less likely to be consistent testers, identifying a group of event-driven testers.

Conclusions

The proportion of consistent 6-monthly testers among MSM visiting Dutch STI outpatient clinics was low. Testing behaviour was associated with sexual risk behaviour, but exact motives to test consistently remain unclear. Evidence-based testing guidelines are needed to achieve optimal reductions in STI transmission in the future.

Tracing partners of patients with syphilis infection remains challenging: experience of Geneva Hospital

Syphilis has been reinstated on the list of notifiable diseases in Switzerland since 2006 and the active management of sexual partners is encouraged to avoid reinfection. However, contact tracing has yielded unsatisfactory results and the incidence of syphilis remains important, especially in high-risk populations. The aim of this study was to compare the proportions of notified sexual partners of patients diagnosed with syphilis by the laboratories of Geneva University Hospitals (HUG) with those diagnosed in private laboratories (non-HUG) and to assess the risk factors for no notification to sexual partners. All syphilis cases notified to the Office of the Surgeon General in Geneva (Switzerland) between 1 January 2011 and 31 December 2013 were analysed. The proportions of partner notification (PN) between HUG and non-HUG laboratories were compared by Chi square test and the main risk factors for no notification to sexual partners were assessed by binomial log-linear regression. Among a total of 720 notifications reported, 244 cases were diagnosed with contagious syphilis stages and 263 with non-contagious stages (i.e. successfully treated patients with or late latent cases). Overall, PN was higher among contagious than non-contagious cases (58.4% versus 31.0%; p = 0.030) and it was significantly higher in the non-HUG compared to the HUG group (75.9% versus 50.0%, respectively; p < 0.001). Risk factors independently associated with no notification to sexual partners were the place of diagnosis (risk ratio [RR] 1.66; 95% confidence interval [CI] 1.21-2.27 for HUG versus non-HUG, respectively), age >45 years (RR 1.36; 95% CI: 1.05-1.76) and if the patient had received treatment for syphilis (RR 1.91; 95% CI: 1.38-2.66). Our results illustrate the difficulty of contact tracing in syphilis infection and the necessity to improve this crucial part of sexually transmitted infection management.

Rates and Correlates of Syphilis Reinfection in Men Who Have Sex with Men

PURPOSE

This study examined rates and correlates of syphilis reinfection in men who have sex with men (MSM).

METHODS

From 2012 to 2015, time to reinfection was assessed in 323 MSM receiving initial treatment for syphilis in San Francisco.

RESULTS

One in five men was reinfected (71/323; 22%). The rate of syphilis reinfection was greater among HIV-infected men (adjusted hazard ratio [aHR] = 1.96; 95% confidence interval [95% CI] = 1.16-3.31) and ketamine users (aHR = 2.76; 95% CI = 1.09-7.00).

CONCLUSION

Expanded prevention efforts are needed with HIV-infected and substance-using MSM to reduce the burden of reinfection in this population.

Increased incidence of syphilis in men who have sex with men and risk management strategies, Germany, 2015

In Germany, the number of reported syphilis cases increased between 11% and 22% per year between 2010 and 2014. We analysed syphilis surveillance data and data of four behavioural surveys on men who have sex with men (MSM) in Germany (2003, 2007, 2010, 2013) to assess if this rise is ongoing and to find possible explanations for it. Syphilis notifications increased in 2015 by 19% to a total of 6,834. This was mainly due to increasing notifications in MSM of all age groups in larger German cities. Data from the behavioural surveys on MSM in Germany showed a simultaneous increase of selective condom use as HIV-status-bases risk management strategy and the number of syphilis cases. MSM diagnosed with HIV reported condomless anal intercourse with non-steady partners more frequent than MSM not diagnosed with HIV or untested for HIV, but the latter also reported higher frequencies of this behaviour in the more recent surveys. Transmission in HIV-positive MSM probably plays an important, but not exclusive role, for the syphilis dynamics in Germany. A risk adapted routine screening for sexually active MSM and potentially innovative approaches to increase early screening and treatment of syphilis such as internet counselling, home sampling, home testing and broadening venue-based (rapid) testing, should be critically evaluated to effectively reduce syphilis infections.

Global challenges in human immunodeficiency virus and syphilis coinfection among men who have sex with men

INTRODUCTION

Syphilis and human immunodeficiency virus (HIV) coinfection disproportionately affects men who have sex with men (MSM), and the rate of coinfection has been increasing over the last decade. HIV and syphilis coinfection is particularly challenging because the infections interact synergistically thereby increasing the risk of acquisition and transmission as well as accelerating disease progression. Areas covered: This paper reviews and summarizes the epidemiology, pathogenesis, diagnosis, clinical management and prevention of HIV and syphilis coinfection among MSM. Expert commentary: Research does not support a different syphilis treatment for coinfected individuals; however, coinfection may warrant a recommendation for antiretroviral therapy. In order to reverse the epidemic of syphilis and HIV coinfection, there needs to be greater awareness, improved cultural sensitivity among health care providers, improved access to preventative services and increased screening for syphilis and HIV.

Community event-based outreach screening for syphilis and other sexually transmissible infections among gay men in Sydney, Australia

Objectives Increased testing frequency is a key strategy in syphilis control, but achieving regular testing is difficult. The objective of this study is to describe a sexually transmissible infection (STI) testing outreach program (the Testing Tent) at a gay community event.

METHODS

Gay men attending the testing tent in 2010-11 completed a computer-assisted self-interview and were screened for STIs. Clinical, demographic, behavioural and diagnostic data were compared with gay men attending a clinic-based service during 2009. The Testing Tent was marketed on social media sites and data were extracted on the number of times the advertisements were viewed. Staffing, laboratory, marketing and venue hire expenses were calculated to estimate the cost of delivering the service.

RESULTS

Ninety-eight men attended the Testing Tent. They were older (median age: 42 years v. 30 years; P<0.001), had more sex partners (median: five in 3 months v. two; P<0.001) and more likely to inject drugs (9% v. 4%; P=0.034) than the 1006 clinic attendees, but were more likely to have previously tested for STIs (81% v. 69%; P=0.028) and to always use condoms for anal sex (59% v. 43%; P=0.005). Five cases of STIs were detected; the diagnostic yield was not significantly different from that of the clinic. The cost of the Testing Tent was A$28?440.

CONCLUSION

Nonclinical testing facilities are an acceptable option and are accessed by gay men requiring regular testing, and may be an important addition to traditional testing environments.

Early Syphilis Among Men Who Have Sex with Men in the US Pacific Northwest, 2008-2013: Clinical Management and Implications for Prevention

Substantial increases in syphilis during 2008-2013 were reported in the US Pacific Northwest state of Oregon, especially among men who have sex with men (MSM). The authors aimed to characterize the ongoing epidemic and identify possible gaps in clinical management of early syphilis (primary, secondary, and latent syphilis ≤1 year) among MSM in Multnomah County, Oregon to inform public health efforts. Administrative databases were used to examine trends in case characteristics during 2008-2013. Medical records were abstracted for cases occurring in 2013 to assess diagnosis, treatment, and screening practices. Early syphilis among MSM increased from 21 cases in 2008 to 229 in 2013. The majority of cases occurred in HIV-infected patients (range: 55.6%-69.2%) diagnosed with secondary syphilis (range: 36.2%-52.4%). In 2013, 119 (51.9%) cases were diagnosed in public sector medical settings and 110 (48.0%) in private sector settings. Over 80% of HIV-infected patients with syphilis were in HIV care. Although treatment was adequate and timely among all providers, management differed by provider type. Among HIV-infected patients, a larger proportion diagnosed by public HIV providers than private providers were tested for syphilis at least once in the previous 12 months (89.6% vs. 40.0%; p < 0.001). The characteristics of MSM diagnosed with early syphilis in Multnomah County remained largely unchanged during 2008-2013. Syphilis control measures were well established, but early syphilis among MSM continued to increase. The results suggest a need to improve syphilis screening among private clinics, but few gaps in clinical management were identified.

Syphilis Experiences and Risk Perceptions Among Repeatedly Infected Men Who Have Sex with Men

CONTEXT

In urban areas of the United States, syphilis is a major public health issue for men who have sex with men, despite widespread efforts to curtail a growing epidemic; repeated infections are not uncommon in this population. The ways that men who have sex with men experience and conceptualize syphilis, and how their attitudes and beliefs impact their risk for infection, are poorly understood.

METHODS

In-depth interviews were conducted in 2010-2011 with 19 Los Angeles County men aged 21-54 who reported having male sex partners and had had two or more early syphilis infections within the previous five years. Interview transcripts were analyzed inductively to uncover themes.

RESULTS

Participants had considerable knowledge about syphilis symptoms, transmission and consequences, and most felt that syphilis was a highly stigmatized disease. They had had 2-5 infections in the past five years, and the majority believed they were at risk for another infection because of their sexual risk behaviors. Many had a sense of fatalism about being infected again, and some expressed that this possibility was an acceptable part of being sexually active. Concern about syphilis often decreased as men experienced more infections. Most participants reported short-term sexual behavior changes after a syphilis diagnosis to prevent transmission; however, few were willing to make long-term behavior changes.

CONCLUSIONS

Additional qualitative studies of men who have sex with men should be conducted to better understand the continuing syphilis epidemic and to help identify the most promising intervention strategies.

A Quality Improvement Project to Increase Early Detection of Syphilis Infection or Re-infection in HIV-infected Men Who Have Sex With Men

Our quality improvement project evaluated whether testing for syphilis every 3 to 6 months with routine HIV laboratory monitoring had an effect on early detection of asymptomatic syphilis infection/re-infection in HIV-infected men who have sex with men. Retrospective analysis of syphilis testing and infections in a sample of this population (N = 245) was conducted after establishing a change-of-practice quality improvement initiative in a not-for-profit, community-based, grant-funded clinic. We compared the clinic's annual rates of syphilis before and after intervention implementation. The detection rate was 6.6% in the preintervention practice change group and 15.5% in the postintervention group. Increased testing identified 27 syphilis cases that would not otherwise have been identified until the annual comprehensive examination. Increased testing frequency led to earlier detection of syphilis, which was clinically significant, showing a potential to decrease the number of new syphilis and HIV infections and to decrease health care expenditures.

Emerging trends and persistent challenges in the management of adult syphilis

There are an estimated 10.6 million incident cases of syphilis worldwide each year. We highlight some persistent challenges and emerging trends in the clinical management of syphilis with a particular focus on therapy, serology, diagnostics, and prevention. Decades after the introduction of penicillin, the optimal management of early syphilis continues to be a controversial topic, particularly in the setting of HIV co-infection. Similarly, the need for routine lumbar puncture in HIV co-infected asymptomatic persons is an unanswered question. Despite advances in both automation and point-of-care diagnostics, we continue to rely on indirect measures of disease activity to manage this infection. As syphilis rates in some populations continue to rise, novel and effective prevention strategies are needed.

Duration of syphilis symptoms at presentations in men who have sex with men in Australia: are current public health campaigns effective?

The rapid rise in syphilis cases has prompted a number of public health campaigns to assist men who have sex with men (MSM) recognize and present early with symptoms. This study aimed to investigate the temporal trend of the duration of self-report symptoms and titre of rapid plasma reagin (RPR) in MSM with infectious syphilis. Seven hundred and sixty-one syphilis cases in MSM diagnosed at the Melbourne Sexual Health Centre (MSHC) from 2007-2013 were reviewed. Median duration of symptoms and RPR titres in each year were calculated. The median durations of symptoms with primary and secondary syphilis were 9 [interquartile range (IQR) 6-14] days and 14 (IQR 7-30) days, respectively. The overall median titre of RPR in secondary syphilis (median 128, IQR 64-256) was higher than in primary syphilis (median 4, IQR 1-32) and in early latent syphilis (median 32, IQR 4-64). The median duration of symptoms for primary syphilis, secondary syphilis and titre of RPR level did not change over time. Public health campaigns were not associated with a significant shorter time from onset of symptoms to treatment. Alternative strategies such as more frequent testing of MSM should be promoted to control the syphilis epidemic in Australia.

Go big or go home: impact of screening coverage on syphilis infection dynamics

OBJECTIVES

Syphilis outbreaks in urban men who have sex with men (MSM) are an ongoing public health challenge in many high-income countries, despite intensification of efforts to screen and treat at-risk individuals. We sought to understand how population-level coverage of asymptomatic screening impacts the ability to control syphilis transmission.

METHODS

We developed a risk-structured deterministic compartmental mathematical model of syphilis transmission in a population of sexually active MSM. We assumed a baseline level of treatment of syphilis cases due to seeking medical care in all scenarios. We evaluated the impact of sustained annual population-wide screening coverage ranging from 0% to 90% on syphilis incidence over the short term (20 years) and at endemic equilibrium.

RESULTS

The relationship between screening coverage and equilibrium syphilis incidence displayed an inverted U-shape relationship, with peak equilibrium incidence occurring with 20-30% annual screening coverage. Annual screening of 62% of the population was required for local elimination (incidence <1 case per 100 000 population). Results were qualitatively similar in the face of differing programmatic, behavioural and natural history assumptions, although the screening thresholds for local elimination differed. With 6-monthly or 3-monthly screening, the population coverage required to achieve local elimination was reduced to 39% or 23%, respectively.

CONCLUSIONS

Although screening has the potential to control syphilis outbreaks, suboptimal coverage may paradoxically lead to a higher equilibrium infection incidence than that observed in the absence of intervention. Suboptimal screening programme design should be considered as a possible contributor to unsuccessful syphilis control programmes in the context of the current epidemic.

Incident sexually transmitted infection as a biomarker for high-risk sexual behavior after diagnosis of acute HIV

BACKGROUND

Sexually transmitted infection (STI) diagnosis after diagnosis of acute HIV infection (AHI) indicates ongoing high-risk sexual behavior and possible risk of HIV transmission. We assessed predictors of STI acquisition and the effect of time since care entry on STI incidence in patients with AHI in care and receiving consistent risk-reduction messaging.

METHODS

Data on incident gonorrhea, chlamydia, trichomoniasis, primary/secondary syphilis, demographic, and clinical risk factors were abstracted from medical charts for patients diagnosed as having AHI and engaged in care. Poisson regression models using generalized estimating equations were fit to estimate incidence rates (IRs), IR ratios, and robust 95% confidence intervals.

RESULTS

Among 185 patients with AHI, 26 (14%) were diagnosed as having at least 1 incident STI over 709.4 person-years; 46 STIs were diagnosed during follow-up (IR, 6.8/100 person-years). The median time from HIV care entry to first STI diagnosis was 609 days (range, 168-1681 days). Men who have sex with men (P = 0.03), a shorter time between presentation to medical care and AHI diagnosis (P = 0.06), and STI diagnosis before AHI diagnosis (P = 0.0003) were predictors of incident STI. Sexually transmitted infection IR greater than 1 year after entering care was double that of patients in care 1 year or less (IR ratio, 2.0; 95% confidence interval, 0.8-4.9). HIV viral load was above the limits of detection within 1 month of 11 STI diagnoses in 6 patients (23.1%) (median, 15,898 copies/mL; range, 244-152,000 copies/mL).

CONCLUSIONS

Despite regular HIV care, STI incidence was high among this primarily young, men who have sex with men AHI cohort. Early antiretroviral initiation may decrease HIV transmission given ongoing risk behaviors despite risk-reduction messaging.

Acceptable interventions to reduce syphilis transmission among high-risk men who have sex with men in Los Angeles

OBJECTIVES

We examined perceptions of and attitudes toward existing and potential syphilis interventions, including case management and Web-based programs, to increase syphilis testing among high-risk men who have sex with men (MSM).

METHODS

Between October 2010 and June 2011, we conducted in-depth interviews with 19 MSM in Los Angeles, California, with repeat early syphilis infections (primary, secondary, and early latent syphilis) within the previous 5 years. We analyzed the interviews inductively to determine the most acceptable potential interventions.

RESULTS

Experiences with health department and community-based standard of care case management were generally positive. The most popular interventions among respondents included a Web site providing information on syphilis and syphilis testing, automated Web reminders to test, being paid to test, free online home testing kits, and preexposure prophylactic medication. Respondents' beliefs that they would continue to practice high-risk sexual behaviors reinforced their reasons for wanting increased accessibility and convenient testing strategies.

CONCLUSIONS

Public health officials should consider participant responses to potential interventions for syphilis, which suggest that high-risk MSM would consider testing more often or using other interventions.

Syphilis transmission: a review of the current evidence

Syphilis remains widespread worldwide, with increasing rates among men who have sex with men. This paper reviews available evidence regarding syphilis transmission, including data on: sexual transmission (transmission probability per sexual partnership), vertical transmission, transmission via blood products and organ donation, and other rare modes of transmission. In addition, host susceptibility to syphilis infection is discussed. Syphilis screening and treatment, condoms and risk-reduction counselling and how they modify syphilis transmission dynamics are considered.

Sexual behaviors and risk for sexually transmitted infections among teenage men who have sex with men

OBJECTIVES

To report on sexual behaviors and sexually transmitted infections (STIs) among men who have sex with men (MSM) in their teens, when many MSM engage in their first sexual experiences.

METHODS

MSM aged 16 to 20 years were recruited via community and other sources. Men completed a questionnaire about their sexual behaviors and were screened for gonorrhea, chlamydia, syphilis, and HIV.

RESULTS

Two hundred men were included. The median age was 19 years. The median age at first insertive or receptive anal intercourse was 17 years. Half of men reported sex with mainly older men: these men were more likely to engage in receptive anal intercourse (48% vs. 25%, p < .001) than other men. Most men had engaged in insertive (87%) and receptive (85%) anal intercourse in the prior 12 months with 60% and 53% reporting inconsistent condom use with insertive and receptive anal intercourse partners, respectively. The median number of insertive anal intercourse partners was 3 and 1.5 (p < .001) among men reporting inconsistent and consistent condom use with insertive anal intercourse over the prior 12 months. The median number of receptive anal intercourse partners was 3 and 2 (p = .006) among men reporting inconsistent and consistent condom use with receptive anal intercourse over the prior 12 months. Pharyngeal gonorrhea, rectal gonorrhea, urethral chlamydia, rectal chlamydia, and syphilis were detected in 3.0%, 5.5%, 3.0%, 4%, and 2.0% of men, respectively. All men were HIV negative.

CONCLUSION

Many of the teenage MSM in this study were at risk for STI. Preventative messages and STI screening interventions that are age appropriate need to be developed to reduce HIV and STI risk in this under-recognized group.

Eradicating syphilis, hepatitis C and HIV in MSM through frequent testing strategies

PURPOSE OF REVIEW

The rates of sexual transmission of HIV, syphilis and hepatitis C in MSM are rising in most countries. Recent research has raised the question of whether increasing testing and treatment of these infections could substantially reduce their transmission.

RECENT FINDINGS

Although mathematical models suggest this strategy could be potentially effective in reducing transmission, there is currently very limited evidence that community-wide incidence has been curtailed by this strategy.

SUMMARY

If increasing in testing is to substantially reduce the incidence of these infections then significant increases in testing are required together with innovative approaches to testing and healthcare delivery. Notwithstanding this, relatively simple approaches to increasing testing are currently underutilized.

Cost-effectiveness of enhanced syphilis screening among HIV-positive men who have sex with men: a microsimulation model

BACKGROUND

Syphilis co-infection risk has increased substantially among HIV-infected men who have sex with men (MSM). Frequent screening for syphilis and treatment of men who test positive might be a practical means of controlling the risk of infection and disease sequelae in this population.

PURPOSE

We evaluated the cost-effectiveness of strategies that increased the frequency and population coverage of syphilis screening in HIV-infected MSM receiving HIV care, relative to current standard of care.

METHODS

We developed a state-transition microsimulation model of syphilis natural history and medical care in HIV-infected MSM receiving care for HIV. We performed Monte Carlo simulations using input data derived from a large observational cohort in Ontario, Canada, and from published biomedical literature. Simulations compared usual care (57% of the population screened annually) to different combinations of more frequent (3- or 6-monthly) screening and higher coverage (100% screened). We estimated expected disease-specific outcomes, quality-adjusted survival, costs, and cost-effectiveness associated with each strategy from the perspective of a public health care payer.

RESULTS

Usual care was more costly and less effective than strategies with more frequent or higher coverage screening. Higher coverage strategies (with screening frequency of 3 or 6 months) were expected to be cost-effective based on usually cited willingness-to-pay thresholds. These findings were robust in the face of probabilistic sensitivity analyses, alternate cost-effectiveness thresholds, and alternate assumptions about duration of risk, program characteristics, and management of underlying HIV.

CONCLUSIONS

We project that higher coverage and more frequent syphilis screening of HIV-infected MSM would be a highly cost-effective health intervention, with many potentially viable screening strategies projected to both save costs and improve health when compared to usual care. The baseline requirement for regular blood testing in this group (i.e., for viral load monitoring) makes intensification of syphilis screening appear readily practicable.

Can an asymptomatic screening pathway for men who have sex with men be introduced safely at a level 3 sexual health service in the UK?

Summary

To manage the rising demand on sexual health services in the UK, many clinics have introduced asymptomatic screening pathways for heterosexuals, which omit examination. In men who have sex with men however the screening of extragenital sites poses additional challenges. This study aimed to establish whether omitting examination of asymptomatic men who have sex with men would lead to clinically significant diagnoses being missed. The notes of all men who have sex with men who attended a UK level 3 sexual health clinic between 1 July 2011 and 30 June 2012 were retrospectively reviewed. Exclusion criteria included HIV-positive patients attending for HIV-related care, attendances for follow-up consultations not requiring a full sexual health screen, symptomatic patients, contacts of sexually transmitted infections and patients requesting an examination or a repeat prescription of a regularly used medication. In all, 920 consultations occurred during 12 months, of which 893 were reviewed; 476 (53.3%) consultations would have been eligible for screening on an asymptomatic pathway and, of these, 21 (4.4%) had abnormalities found at examination. Findings included genital warts, minor dermatological conditions and three cases of minor asymptomatic urological conditions. There were no clinically significant findings on examination of asymptomatic men who have sex with men requiring treatment, indicating that examination in this cohort may be of little benefit.