Risk Factors for Repeat Syphilis in Men Who Have Sex With Men, San Francisco

Reduced Risk of Syphilis Reinfection in Men Interviewed by Disease Intervention Specialists: A Pilot Study

Introduction

Syphilis is a highly transmissible sexually transmitted infection. Rising rates of infection and reinfection are of great concern to public health officials. In local health departments across the U.S., disease intervention specialists attempt to interview all people diagnosed with early syphilis, to elicit sexual partner information, and to trace and treat the partners. This method of interviewing and contact tracing is an evidence-based practice that reduces the spread of the disease in the community, but few studies address the relationship between the disease intervention specialists' interviews and index patient reinfections. We hypothesized that patients who were interviewed, patients who provided partner information, and patients with more treated partners would have a reduced risk of reinfection.

Methods

Our sample consisted of 82 men listed in the Suffolk County Department of Health Services syphilis log who were diagnosed with primary, secondary, or early latent syphilis. We determined whether and when the patients were reinfected during a set time period, from 2016 to 2020. Kaplan-Meier analyses with log-rank statistics and Cox hazard proportional models were used to calculate time to reinfection and hazard ratios.

Results

Although none of the models produced p<0.05, notable trends were observed. In subset analyses of interviewed patients, 23.8% of patients who named partners were reinfected during the study period, whereas 50% of those who did not name partners were reinfected during that time. In addition, the hazard ratio for index patients who named partners was 0.51 (95% CI=0.225, 1.170, p=0.113). When some or all the patients' partners were treated, 20% were reinfected by the end of the study, whereas 33.3% of cases with no partners treated were reinfected by the end of the study. The hazard ratio for patients with some or all partners treated was 0.48 (95% CI=0.136, 1.711, p=0.258).

Conclusions

Although none of the results was statistically significant, trends suggest that partner elicitation and partner treatment status could be associated with reduced risk of syphilis reinfection. Because this pilot study utilized a small convenience sample that was not tested for statistical power, we could not adequately address these trends. Future studies, with larger sample sizes, should address these relationships.

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.

Syphilis: recommendations for dermatologists on a resurgent epidemic

Despite reaching historical lows in the early 2000s, cases of both primary and secondary syphilis and congenital syphilis have increased dramatically in the U.S. over the last decade. In the U.S., the current syphilis epidemic is disproportionately impacting communities that have been historically underserved in medicine. These include men who have sex with men, especially those infected with HIV; people of color; and reproductive-age women with poor access to prenatal care. With syphilis now being more commonly diagnosed in non-STI than STI clinics in all genders, and since primary and secondary syphilis and congenital syphilis present with characteristic mucocutaneous manifestations, dermatologists are in a position to help reduce the advance of this preventable epidemic, by actively considering this diagnosis and incorporating syphilis screening into their practice. Herein, we delineate strategies by which dermatologists can contribute to this critical effort in their roles as clinicians, public health advocates, and researchers. In particular, we discuss the rapidly changing demographics of syphilis, nuances in serologic testing and treatment, strategies to increase public healthcare access and equity in these underserved populations, and research gaps in this field.

Correlates of prevalent syphilis infection among men who have sex with men (MSM) living with HIV attending the HIV clinic in Trinidad

Background

Syphilis among men who have sex with men (MSM) living with HIV is of public health concern, thus the objective of the study is to determine the correlates of prevalent syphilis infection in this population so that urgent interventions could be instituted.

Methods

A cross-sectional study was conducted during the period September 2020-June 2021 among MSM who attended a large HIV Clinic in Trinidad. A questionnaire was administered to obtain socio-demographic data and correlates of prevalent syphilis and patients were screened for syphilis using the traditional algorithm. Descriptive and bivariate analyses were conducted and multivariable logistic regression factors was used to assess factors significantly associated with a syphilis diagnosis.

Results

Two hundred and sixty four MSM were enrolled; age range 18–64 years, median age 33 years and 89 (34.4%) were actively bisexual. The prevalence of syphilis was 28% (74/264) and 89.2% (66/74) of these infections were asymptomatic. Multivariable logistic regression analysis showed that those patients who participated in sex with anonymous partners (OR 2.09; 95% CI, 1.03–4.26), those with a previous diagnosis of syphilis (OR 5.16; 95% CI, 1.03–25.83) and those who used marijuana in the last 12 months (OR 2.13; 95% CI, 1.14–3.96) were more likely to be diagnosed with syphilis.

Conclusion

There is a high prevalence of asymptomatic syphilis among MSM living with HIV in Trinidad. Repeat episodes of syphilis and anonymous sex may play a role in the transmission dynamics of T pallidum infection in this population, thus urgent public health prevention interventions are warranted.

Repeat Syphilis Among HIV-Infected Men in Florida and Louisiana 2000-2018: Implications for Screening Recommendations

Syphilis rates have continued to rise in the United States. Florida and Louisiana consistently report high numbers of cases. We evaluated rates of reinfection to see if frequent rescreening might lead to earlier treatment and prevent infections. All syphilis records of all stages for males and females aged 15-70 years from the Florida and Louisiana Departments of Health surveillance databases 2000-2018 were evaluated. The first episode of syphilis during this period was considered the initial diagnosis for each person. Demographics of cases and repeaters (individuals reported with two or more cases of syphilis) were examined. Percentages of syphilis cases from repeaters by year were calculated as were percentages from HIV+ males. During 2000-2018, 124,827 syphilis cases were reported from 107,405 individuals: 73,811 (68.7%) males; 33,594 (31.3%) females. There were 12,545 individuals (repeaters) with two or more syphilis diagnoses (n = 17,422 cases; range, 2-10). From 2010 to 2018, repeaters accounted for steadily increasing percentage of all syphilis reported: 2010 (11%), 2013 (16%), 2015 (20%), and 2018 (26%). Among HIV+ male cases the percentage from repeaters also increased: 2010 (28%), 2013 (35%), 2015 (42%), and 2018 (50%). In 2018, 19% of all cases (n = 2455) were from HIV+ males who had a previous syphilis diagnosis. Among HIV+ males diagnosed with syphilis in 2015, 34% had a repeat syphilis diagnosis within 3 years. Most syphilis diagnosed in Florida and Louisiana was among persons infected for the first time. However, some subgroups could possibly benefit from more frequent screening. Males living with HIV who had a prior syphilis diagnosis were at very high risk of repeat infection.

Clinical presentation and serological diagnosis of syphilis reinfection in men living with HIV: a retrospective cohort study

OBJECTIVES

Studies on the characteristics of syphilis reinfection are scarce despite increasing numbers and proportions of cases. We aimed to gain insights into the clinical and serological presentation of reinfected men living with HIV and to evaluate diagnostic criteria for syphilis reinfection.

METHODS

We conducted a retrospective cohort study of 259 HIV-positive men diagnosed with syphilis between January 1999 and September 2015 at the University Hospital Zurich. We compared patients with a single syphilis infection (n=109) to patients with reinfections (n=150).

RESULTS

The two groups matched in age, sexual orientation and numbers of other STIs. Reinfected patients more often presented with latent syphilis than patients with a single syphilis episode (41.9% vs 8.9%; p<0.001). Although generally high venereal diseases research laboratory (VDRL) or rapid plasma reagin (RPR) titres (median 1:32) were seen in reinfected patients, 19.4% had titres ≤1:8. Treponema pallidum passive particle agglutination (TPPA) titres were significantly higher (1:81 840 vs 1:10 240; p<0.001), while IgM values were significantly lower (1.27 vs 3.5; p<0.001) in syphilis reinfections than in first infections. The TPPA increased ≥fourfold in >92.3% of reinfected patients.

CONCLUSIONS

Our data highlight the paramount importance of regularly screening patients at risk as syphilis reinfections in men living with HIV are more likely to be latent infections, that is, without symptoms. As non-treponemal tests might be biologically false-positive (up to a titre of 1:8) due to various conditions, a ≥fourfold increase of the TPPA might be considered as optional criterion for the diagnosis of syphilis reinfections. This could be especially valuable for diagnosing reinfected latent stage patients.

HIV and syphilis: incidence rate of co-infection and syphilis re-infection in a cohort of newly diagnosed HIV patients

BACKGROUND

Syphilis represents a major public health concern disproportionately affecting HIV positive patients and in many cases both infections are newly diagnosed at the same time. To date, limited studies are available on syphilis incidence in patients with a new HIV diagnosis.

METHODS

Patients newly diagnosed with HIV in 2010-2018 were included in the study and screening tests for syphilis were performed at baseline and at least once a year. Primary aims were to analyse the incidence rate of HIV-syphilis co-infection and syphilis re-infection. Secondary objective was to identify characteristics independently associated with co-infection and re-infection.

RESULTS

Of 500 newly diagnosed HIV patients, 20% presented a concomitant positive syphilis serology. Among them, 54 patients had a serology indicative for an active syphilis requiring therapy, while 46 had a history of prior treatments. The independent factors for syphilis acquisition were: MSM contact (OR:2.64; 95%CI 1.48-4.72; p<0.001), male gender (OR:2.43; 95%CI 1.08-5.48; p=0.032), and age (OR:1.03; 95%CI 1.01-1.05; p=0.005 per year increasing). Presence of syphilis at the time of HIV diagnosis remained fairly stable during the study period (P for trend, p=0.689). We observed 52 syphilis re-infections related to 37 people. Patients with at least one re-infection were all males and 86.5% MSM.

CONCLUSIONS

Males and MSM with HIV presented high rates of syphilis co-infection and re-infection suggesting persistent high-risk sexual behaviours and the need for appropriate intervention strategies in order to early detect and treat syphilis avoiding life-threatening complications and the spread of the infection in the community.

Previous Syphilis Alters the Course of Subsequent Episodes of Syphilis

BACKGROUND

The influence of previous syphilis on the course of a subsequent episode is unknown.

METHODS

Individuals enrolled in a study of cerebrospinal fluid (CSF) abnormalities in syphilis were allowed to enroll in the study again with subsequent syphilis. For each participant, the index episode was defined as the most recent syphilis episode for which the study entry visit was performed within 30 days of the syphilis diagnosis date. Venipuncture and lumbar puncture (LP) were performed. Total number of syphilis episodes was determined by review of medical and public health records. T. pallidum DNA in blood and rRNA in CSF were detected by polymerase chain reaction (PCR) and reverse transcriptase PCR. Odds ratios (ORs) with 95% confidence intervals (95% CI) were determined by logistic regression.

RESULTS

651 individuals had one (n = 482), two (n = 121) or three or more (n = 48) episodes of syphilis. The proportion of individuals whose index episode was early latent stage was significantly higher in those with ≥3 syphilis episodes; this relationship was reduced to a trend when rate of testing was taken into account. Adjusted odds (aOR) of detection of T. pallidum DNA in blood or rRNA in CSF at the index episode were significantly lower in those with previous syphilis (0.17 [95% CI, 0.09-0.31] and 0.15 [95% CI, 0.07-0.35]). The aOR for neurosyphilis at the index episode was also significantly lower in individuals with previous syphilis (0.54 [95% CI, 0.34-0.87]).

CONCLUSIONS

Previous syphilis attenuates the manifestations of subsequent infection with T. pallidum.

Recurrent ocular syphilis in a patient living with HIV

A 26-year-old male living with human immunodeficiency virus (HIV) and who had previously been treated for ocular syphilis presented to the Emergency Department with progressive vision loss and uveitis. The efficacy of standard management for neurosyphilis in HIV and recurrence was examined.

Previous Syphilis Alters the Course of Subsequent Episodes of Syphilis

BACKGROUND

Individuals with previous syphilis may be more likely to be asymptomatic when they are reinfected with Treponema pallidum.

METHODS

Individuals enrolled in a study of cerebrospinal fluid (CSF) abnormalities in syphilis were allowed to enroll in the study again with subsequent syphilis. For each participant, the index episode was defined as the most recent syphilis episode for which the study entry visit was performed within 30 days of the syphilis diagnosis date. Venipuncture and lumbar puncture were performed. The total number of syphilis episodes was determined by review of medical and public health records. Treponema pallidum DNA in blood and rRNA in CSF were detected using polymerase chain reaction (PCR) and reverse transcriptase PCR. Odds ratios (ORs) with 95% confidence intervals (CIs) were determined using logistic regression.

RESULTS

701 individuals had 1 (n = 478), 2 (n = 155), or ≥3 (n = 68) episodes of syphilis. The proportion of individuals whose index episode was asymptomatic significantly increased with increased number of syphilis episodes (P < .001). This difference was not explained by frequency of serological tests. Adjusted ORs (aORs) of detection of T. pallidum DNA in blood or rRNA in CSF at the index episode were significantly lower in those with previous syphilis (0.13; 95% CI, .08-.23, and 0.06, 95% CI, .02-.17). The aOR of neurosyphilis at the index episode was also significantly lower in individuals with previous syphilis (0.43; 95% CI, .27-.68).

CONCLUSIONS

Previous syphilis attenuates clinical and laboratory manifestations of infection with T. pallidum.

Increased repeat syphilis among HIV-infected patients: A nationwide population-based cohort study in Taiwan

Among human immunodeficiency virus (HIV)-infected individuals, syphilis is an important sexually transmitted infection (STI), and repeat infections are common. Identifying risk factors for delineating the trends in repeat syphilis are essential for STI and HIV prevention.This study is to investigate the dynamic of the syphilis epidemic among HIV-infected patients and to identify the risk factors associated with repeat syphilis.A population-based cohort design was used to analyze claim data between January 2000 and December 2010 using the Taiwan National Health Insurance Research Database. The Poisson regression test was used to identify risk factors for repeat syphilis.Of 13,239 HIV-infected patients, annual syphilis screen tests have been performed in 4,907 (37.1%) of these patients. Syphilis has been diagnosed in 956 (19.5%) patients, and 524 (10.7%) had repeat syphilis. The annual trend in repeat syphilis showed a significant increase in the study period (β = 0.23, P < .001). Younger age (adjusted incidence rate ratio [aIRR] 1.43; 95% CI 1.11-1.86), male gender (aIRR 11.14, 95% CI 4.16-29.79), a history of STIs (aIRR 1.39, 95% CI 1.21-1.59) were independently associated with repeat syphilis. The retention in HIV care and adherence to antiretroviral therapy ≥85% ([aIRR] 0.77, 95% CI 0.61-0.98; P < .001) were associated with a reduced risk of repeat syphilis.The incidence of repeat syphilis increased during 11 years of follow-up. The screening of syphilis for early diagnosis and retention in HIV care with medication adherence should be encouraged to minimize the risk of repeat syphilis in the targeted population.

Enhancing the Control of Syphilis Among Men Who Have Sex With Men by Focusing on Acute Infectious Primary Syphilis and Core Transmission Groups

The syphilis epidemic among men who have sex with men (MSM) has been increasing steadily. Many syphilis control programs focus on assuring treatment of all persons diagnosed with early syphilis without prioritizing acute primary syphilis or specific subgroups. Acute primary syphilis is highly infectious and contributes to a high proportion of new cases. Surveillance data show that among MSM with incident syphilis (primary or secondary) only about 35% are identified in the primary stage, indicating that most primary cases are missed and untreated. Patients with primary syphilis and large numbers of sex partners may play a major role in maintaining syphilis transmission. Considering those issues, sexually transmitted disease (STD) programs should consider increasing their focus on primary syphilis by assigning primary cases the highest priority, expanding client and clinician health education, and increasing the detection of primary syphilis through increased serologic screening frequency among high-risk MSM. Furthermore, syphilis control programs should implement steps to identify asymptomatic high-probable occult primary cases based on low titer (≤1:8) and recent seroconversion. Finally, to address core transmission groups, programs should implement periodic risk assessment to identify persons with a high number of sex partners and offer these individuals risk-reduction counseling, case management, and selective syphilis preexposure or postexposure doxycycline chemoprophylaxis. Although reprioritizing prevention efforts might be challenging, the Centers for Disease Control and Prevention, community advocacy groups, university STD research centers, and national STD prevention training centers can assist by providing support for consensus discussions and direction in developing operational guidance, some of which may be best delivered through STD and human immunodeficiency virus program partnerships.

Evaluation of 4 Algorithms to Identify Incident Syphilis Among HIV-Positive Men Who Have Sex With Men Engaged in Primary Care

We developed 4 algorithms for syphilis among HIV-positive men who have sex with men who engaged in primary care in 2016 to 2017. Clinician-based diagnosis from chart reviews was the gold standard. Sensitivities ranged from 74.2% to 93.9%. Specificities were greater than 99% with positive and negative predictive values of greater than 95%. Algorithms that incorporated treatment data performed best.

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.

Proctitis: a glance beyond inflammatory bowel diseases

Proctitis is an inflammation involving the anus and the distal part of the rectum, frequently diagnosed in the context of inflammatory bowel diseases (IBD). Nevertheless, when the standard therapy for IBD is ineffective, it becomes necessary for the clinician to review alternative etiologies, beginning from the broad chapter of infectious causes up to rare causes such as radiation, ischemia, diversion and traumatisms. While it is possible to find infectious proctitides caused by pathogens generally inducing extensive colitis, the growing incidence of both sexually transmitted infections and isolated proctitis reported in the recent years require a lot of attention. The risk appears to be higher in individuals participating in anal intercourse, especially men having sex with men (MSM) or subjects who use sex toys and participate to sex parties, dark rooms and so on. The commonest implicated pathogens are Neysseria gonorrhoeae, Chlamydia trachomatis, Herpes Simplex virus and Treponema pallidum. Herpes and Chlamydia infections mainly occur in HIV-positive MSM patients. Since symptoms and signs are common independently from etiology, performing a differential diagnosis based on clinical manifestations is complicated. Therefore, the diagnosis is supported by the combination of clinical history and physical examination and, secondly, by endoscopic, serologic and microbiologic findings. Particular emphasis should be given to simultaneous infections by multiple organisms. The involvement of experts in infectious diseases and in sexual health is crucial for the diagnostic and therapeutic management. The available therapies, empirically initiated or specific, in many cases are able to guarantee a good prognosis and to prevent relapses.

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.

Characteristics of Persons With Repeat Syphilis-Idaho, 2011 to 2015

During 2011 through 2015 in Idaho, 14 (7%) of 193 persons with early syphilis had repeat syphilis. Persons with repeat infections were more likely to have had secondary or early latent syphilis (P = 0.037) and be infected with human immunodeficiency virus (P < 0.001) compared with those having 1 infection.

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.

Seroepidemiology of syphilis among men who have sex with men in Burkina Faso, West Africa

Men who have sex with men (MSM) have a disproportionate risk of acquiring sexually transmitted infections (STIs), such as syphilis. However, prevalence and determinants of syphilis among this population are less known in West Africa. This study aims to estimate syphilis prevalence among MSM in Burkina Faso. We conducted a cross-sectional biological and behavior survey in the two main cities of Burkina Faso, Ouagadougou and Bobo-Dioulasso. MSM were recruited using Respondent Driven Sampling (RDS) methods. Data were collected from January to April 2013 in Ouagadougou and from May to August 2013 in Bobo-Dioulasso. Out of the 657 MSM screened for syphilis, 6.1% (40/657) tested positive for Treponema pallidum antibodies and 1.1% (7/657) for active syphilis. Population-weighted prevalence of active syphilis was 2.1% (95% CI, 01.1-04.4) in Ouagadougou and 0.0% in Bobo-Dioulasso. Serologic markers of syphilis (anti-Treponema antibodies) were found among 7.4% (95% CI 5.0-10.8) of MSM in Ouagadougou and 5.0% (95% CI 3.1-8.0) in Bobo-Dioulasso. No significant differences were found in syphilis serological markers prevalence by participants' sociodemographic and behavioral characteristics. The prevalence of syphilis among MSM is low and comparable to that of other individuals of reproductive age in Burkina Faso. This low prevalence is very encouraging and suggests implementation of effective public health intervention programs which direct resources and services toward MSM to prevent further spread of syphilis infection and to limit HIV transmission in this group.

HIV infection and sex in sex-on-premises venues are associated with a higher risk of syphilis reinfection among men who have sex with men

Introduction

Recent outbreaks of syphilis occurred predominantly in men who have sex with men (MSM). A significant proportion of syphilis cases occur in MSM who had more than one episode of syphilis. This group may play an important role in syphilis transmission.

Aim

To identify factors associated with the risk of syphilis reinfection.

Material and methods

Forty-four MSM patients with the first episode of syphilis who were treated at the Department of Dermatology at the Jagiellonian University School of Medicine in Krakow, Poland were included in this study. After completing the treatment, the RPR testing was done every 3 months for 2 years in every patient. In the study period, we identified 12 (22%) cases of syphilis reinfection, eight of which were asymptomatic. Clinical, demographic and behavior data from patients with only one episode of syphilis were compared with those collected from repeaters.

Results

Individuals with syphilis reinfection had concomitant HIV infection more frequently, reported a higher number of sexual partners and had sex in sex on premises venues more frequently (p < 0.05). In the multivariate analysis, we found that being HIV-infected MSM and having sex in sex on premises venues independently correlated with a higher risk of syphilis reinfection (OR = 9.6, 95% CI: 2.2–42.5 and OR = 5.6, 95% CI: 1.4–22.5, respectively).

Conclusions

Results of our study highlight a strong need for frequent and repeated screening among MSM patients (especially those with concomitant HIV infection) with the first episode of syphilis and taking detailed patient’s history regarding also demographic and behavior data. We should also improve prevention policies to reduce risk behaviors in this population.

Increasing incidence of syphilis among patients engaged in HIV care in Alberta, Canada: a retrospective clinic-based cohort study

BACKGROUND

Syphilis is a global health concern disproportionately affecting HIV-infected populations. In Alberta, Canada, the incidence of syphilis in the general population has recently doubled with 25% of these infections occurring in HIV-infected patients. The Southern Alberta HIV Clinic (SAC) and Calgary STI Program (CSTI) analyzed the epidemiologic characteristics of incident syphilis infections in our well-defined, HIV-infected population over 11 years.

METHODS

Since 2006, as routine practice of both the Southern Alberta Clinic (SAC) and Calgary STI Programs (CSTI), syphilis screening has accompanied HIV viral load measures every four months. All records of patients who, while in HIV care, either converted from being syphilis seronegative to a confirmed seropositive or were re-infected as evidenced by a four-fold increase in rapid plasma reagin (RPR) after past successful treatment, were reviewed.

RESULTS

Incident syphilis was identified 249 times in 194 HIV-infected individuals. There were 36 individuals with repeated infections (28.5% of episodes). Following a prior decline in annual incident syphilis rates, the rates have tripled from 8.08/1000 patient-years (95% confidence interval (CI): 4.14-14.75) in 2011, to 27.04 per 1000 person-years (95% CI: 19.45-36.76) in 2016. Half of the syphilis episodes were asymptomatic. Patients diagnosed with syphilis were twice as likely not to be taking ART and had a higher likelihood of having plasma HIV RNA viral loads > 1000 copies/mL (19%). Incident syphilis was seen predominantly in Caucasians (72%, P < 0.001), males (94%, P < 0.001) and men who have sex with men (MSM) as their HIV risk activity (75%, P < 0.001).

CONCLUSIONS

We have highlighted the importance of a regular syphilis screening program in HIV-infected individuals demonstrated by increasing rates of incident syphilis in our region. Targeted preventative strategies should be directed towards HIV-infected populations identified at highest risk, including; MSM, prior alcohol abuse, prior recreational drug use and those with prior syphilis diagnoses.

Factors associated with repeat diagnosis of syphilis in genitourinary medicine (GUM) clinic attendees in the North East of England, 2002-2014

This study aimed to identify factors associated with repeat syphilis infection in North East England, in order to inform local prevention and control opportunities. We undertook a case-case study comparing individuals diagnosed with single or multiple episodes of syphilis infection within genitourinary medicine (GUM) clinics in NE England (12 clinics serving a population of 2.5 million). Study cases were verified as having had true re-infection by a GUM clinician (using serological and/or clinical parameters) and control cases (3 per case) frequency matched to cases by age and year of presentation. The odds of exposure to sexual behavioural and clinical factors were compared for cases and control cases using stepwise multivariable logistic regression. We included 66 cases and 235 control cases. The majority of cases (62/66) and control cases (165/235) were men who had sex with men (MSM). Data were missing for 0-64% of cases across different variables. Following multivariable analysis HIV seropositivity (OR 23.3, 95% CI 4.32-125.9), failure to attend follow-up (OR 4.63, 95% CI 1.11-19.31), stage of infection and deprivation were associated with re-infection ( p < 0.001). In this study, HIV seropositivity and failure to attend follow-up were associated with re-infection with syphilis. Actions targeted at these groups may help to reduce ongoing transmission.

Factors associated with syphilis treatment failure and reinfection: a longitudinal cohort study in Shenzhen, China

Background

The treatment failure and reinfection rates among syphilis patients are high, and relevant studies in China are limited. The aim of this study was to detect the rates of treatment failure and reinfection after syphilis treatment and to explore the potential associated factors.

Methods

We conducted a longitudinal cohort study in a sexually transmitted disease clinic, the Department of Dermatology and Venereology in Nanshan Center for Chronic Disease Control. Serological testing was performed at baseline and throughout the 2-year follow-up for syphilis patients. To identify potential predictors of treatment outcomes, multivariate logistics analyses were utilized to compare the demographic and clinical characteristics of patients with serological failure/reinfection to those with serological cure/serofast.

Results

From June 2011 to June 2016, a total of 1133 patients were screened for syphilis. Among the 770 patients who completed the 2-year follow-up, 510 first-diagnosed patients were included in the final analysis. Multivariate logistics analysis revealed the stage of syphilis (secondary syphilis VS. primary syphilis: adjusted odds ratio, 3.50; 95% confidence interval, 1.11-15.47; p = 0.04), HIV status (positive VS. negative: adjusted odds ratio, 3.06; 95% confidence interval, 1.15-8.04; p = 0.02) and frequency of condom use (always use VS. never use: adjusted odds ratio, 0.28; 95% confidence interval 0.08-0.75; p = 0.02) were significantly associated with the serological outcome.

Conclusions

The clinical implications of our findings suggest that it is very important to perform regular clinical and serologic evaluations after treatment. Health counseling and safety education on sex activity should be intensified among HIV-infected patients and secondary syphilis patients after treatment.

A double-edged sword: does highly active antiretroviral therapy contribute to syphilis incidence by impairing immunity to Treponema pallidum?

BACKGROUND AND HYPOTHESIS

Recently, the world has experienced a rapidly escalating outbreak of infectious syphilis primarily affecting men who have sex with men (MSM); many are taking highly active antiretroviral therapy (HAART) for HIV-1 infection. The prevailing hypothesis is that HAART availability and effectiveness have led to the perception among both individuals who are HIV-1 infected and those who are uninfected that HIV-1 transmission has become much less likely, and the effects of HIV-1 infection less deadly. This is expected to result in increased sexual risk-taking, especially unprotected anal intercourse, leading to more non-HIV-1 STDs, including gonorrhoea, chlamydia and syphilis. However, syphilis incidence has increased more rapidly than other STDs. We hypothesise that HAART downregulates the innate and acquired immune responses to Treponema pallidum and that this biological explanation plays an important role in the syphilis epidemic.

METHODS

We performed a literature search and developed a mathematical model of HIV-1 and T. pallidum confection in a population with two risk groups with assortative mixing to explore the consequence on syphilis prevalence of HAART-induced changes in behaviour versus HAART-induced biological effects.

CONCLUSIONS AND IMPLICATIONS

Since rising syphilis incidence appears to have outpaced gonorrhoea and chlamydia, predominantly affecting HIV-1 positive MSM, behavioural factors alone may be insufficient to explain the unique, sharp increase in syphilis incidence. HAART agents have the potential to alter the innate and acquired immune responses in ways that may enhance susceptibility to T. pallidum. This raises the possibility that therapeutic and preventative HAART may inadvertently increase the incidence of syphilis, a situation that would have significant and global public health implications. We propose that additional studies investigating the interplay between HAART and enhanced T. pallidum susceptibility are needed. If our hypothesis is correct, HAART should be combined with enhanced patient management including frequent monitoring for pathogens such as T. pallidum.

Can enhanced screening of men with a history of prior syphilis infection stem the epidemic in men who have sex with men? A mathematical modelling study

OBJECTIVES

The aim of this study is to determine the transmission impact of using prior syphilis infection to guide a focused syphilis screening intervention among men who have sex with men (MSM).

METHODS

We parameterised a deterministic model of syphilis transmission in MSM to reflect the 2011-2015 syphilis outbreak in Winnipeg, Canada. Enhanced screening of 75% of men with prior syphilis every 3 months (A) was compared with distributing equivalent number tests to all MSM (B) or those with the highest partner number (C). We compared early syphilis incidence, diagnoses and prevalence after 10 years, relative to a base case of 30% of MSM screened annually.

RESULTS

Strategy A was expected to avert 52% of incident infections, 44% of diagnosed cases and reduce early syphilis prevalence by 89%. Strategy B had the least impact. Strategy C was most effective, averting 59% of incident cases. When screening frequency was semiannual or annual, strategy A was the most effective.

CONCLUSIONS

Enhanced screening of MSM with prior syphilis may efficiently reduce transmission, especially when identification of high-risk men via self-reported partner numbers or high-frequency screening is difficult to achieve.

Factors associated with reinfection of syphilis in reference centers for sexually transmitted infections

OBJECTIVE

We aim to analyze trend of syphilis and factors associated with recurrent episodes of syphilis among adults and adolescents attended in a STI/AIDS reference centers in Campinas, state of São Paulo, 2004 to 2012.

METHODS

Medical records, pharmacy data, and notification database were accessed to analyze trends of syphilis and sociodemographic, epidemiological and clinical variables associated with reinfection of syphilis. After univariate analysis, a hierarchical logistic regression model was adjusted to analyze variables associated with more than one episode of syphilis (dependent variable). First step (sex, age, and years of schooling) were tested and in the second, epidemiological and clinical variables.

RESULTS

A total of 1,009 episodes of syphilis were identified among 860 adolescents and adults, 117 individuals (13.6%) presented with more than one episode of syphilis. Factors associated with more than one episode of syphilis were sex (male) (OR = 4.28; 95%CI 1.31–14.0), age (OR = 1.02; 95%CI 1.00–1.04), homosexual/bisexual orientation (OR = 2.29; 95%CI 1.22–4.32), HIV coinfection (OR = 3.54; 95%CI 2.22–5.63), and absence of STI symptoms at the time of syphilis diagnostic (OR = 1.70; 95%CI 1.03–2.80).

CONCLUSIONS

The number of cases of syphilis and proportion in relation to STI increased in recent years in a specific population attended in a STI/AIDS reference centers in Campinas. Association with HIV, homosexual/bisexual orientation and the silent clinical characteristic of cases confirm the necessity to implement more aggressive strategies to prevent the occurrence of syphilis and other STI in specific populations with higher disease risk.

Syphilis

Syphilis is a chronic bacterial infection caused by Treponema pallidum that is endemic in low-income countries and and occurs at lower rates in middle-income and high-income countries. The disease is of both individual and public health importance and, in addition to its direct morbidity, increases risk of HIV infection and can cause lifelong morbidity in children born to infected mothers. Without treatment the disease can progress over years through a series of clinical stages and lead to irreversible neurological or cardiovascular complications. Although syphilis is an ancient disease and the principles of recommended management have been established for decades, diagnosis and management are often challenging because of its varied manifestations and difficulty in interpretation of serological tests used to confirm diagnosis and evaluate response to therapy. In North America and western Europe, incidence of syphilis has increased dramatically in the past decade among men who have sex with men, particularly those with coexistent HIV infection. Only one drug, penicillin, is recommended for syphilis treatment and response to therapy is assessed based on changes over months in serological test titres. Treatment for patients who cannot receive penicillin and management of patients who do not serologically respond to treatment are common clinical problems.

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.

Risk Factors Associated with Incident Syphilis in a Cohort of High-Risk Men in Peru

BACKGROUND

Syphilis is concentrated among high-risk groups, but the epidemiology of syphilis reinfection is poorly understood. We characterized factors associated with syphilis incidence, including reinfection, in a high-risk cohort in Peru.

METHODS

Participants in the NIMH CPOL trial were assessed at baseline and 2 annual visits with HIV/STI testing and behavioral surveys. Participants diagnosed with syphilis also attended 4- and 9-month visits. All participants underwent syphilis testing with RPR screening and TPPA confirmation. Antibiotic treatment was provided according to CDC guidelines. Reinfection was defined as a 4-fold titer increase or recurrence of seroreactivity after successful treatment with subsequent negative RPR titers. The longitudinal analysis used a Possion generalized estimating equations model with backward selection of variables in the final model (criteria P <0.02).

RESULTS

Of 2,709 participants, 191 (7.05%) were RPR-reactive (median 1:8, range 1:1-1:1024) with TPPA confirmation. There were 119 total cases of incident syphilis, which included both reinfection and first-time incident cases. In the bivariate analysis, the oldest 2 quartiles of age (incidence ratio (IR) 3.84; P <0.001 and IR 8.15; P <0.001) and being MSM/TW (IR 6.48; P <0.001) were associated with higher risk of incident syphilis infection. Of the sexual risk behaviors, older age of sexual debut (IR 12.53; P <0.001), not being in a stable partnership (IR 1.56, P = 0.035), higher number of sex partners (IR 3.01; P <0.001), unprotected sex in the past 3 months (IR 0.56; P = 0.003), HIV infection at baseline (IR 3.98; P <0.001) and incident HIV infection during the study period (IR 6.26; P = 0.003) were all associated with incident syphilis. In the multivariable analysis, older age group (adjusted incidence ratio (aIR) 6.18; P <0.001), men reporting having sex with a man (aIR 4.63; P <0.001), and incident HIV infection (aIR 4.48; P = 0.008) were significantly associated.

CONCLUSIONS

We report a high rate of syphilis reinfection among high-risk men who have evidence of previous syphilis infection. Our findings highlight the close relationship between HIV incidence with both incident syphilis and syphilis reinfection. Further studies on syphilis reinfection are needed to understand patterns of syphilis reinfection and new strategies beyond periodic testing of high-risk individuals based on HIV status are needed.

Vaccine development for syphilis

INTRODUCTION

Syphilis, caused by the spirochete Treponema pallidum subspecies pallidum, continues to be a globally prevalent disease despite remaining susceptible to penicillin treatment. Syphilis vaccine development is a viable preventative approach that will serve to complement public health-oriented syphilis prevention, screening and treatment initiatives to deliver a two-pronged approach to stemming disease spread worldwide. Areas covered: This article provides an overview of the need for development of a syphilis vaccine, summarizes significant information that has been garnered from prior syphilis vaccine studies, discusses the critical aspects of infection that would have to be targeted by a syphilis vaccine, and presents the current understanding within the field of the correlates of protection needed to be achieved through vaccination. Expert commentary: Syphilis vaccine development should be considered a priority by industry, regulatory and funding agencies, and should be appropriately promoted and supported.

A mathematical model of syphilis transmission in an MSM population

Syphilis is caused by the bacterium Treponema pallidum subspecies pallidum, and is a sexually transmitted disease with multiple stages. A model of transmission of syphilis in an MSM population (there has recently been a resurgence of syphilis in such populations) that includes infection stages and treatment is formulated as a system of ordinary differential equations. The control reproduction number is calculated, and it is proved that if this threshold parameter is below one, syphilis dies out; otherwise, if it is greater than one, it is shown that there exists a unique endemic equilibrium and that for certain special cases, this equilibrium is globally asymptotically stable. Using data from the literature on MSM populations, numerical methods are used to determine the variation and robustness of the control reproduction number with respect to the model parameters, and to determine adequate treatment rates for syphilis eradication. By assuming a closed population and no return to susceptibility, an epidemic model is obtained. Final outbreak sizes are numerically determined for various parameter values, and its variation and robustness to parameter value changes is also investigated. Results quantify the importance of early treatment for syphilis control.

Sexual Behavior and Network Characteristics and Their Association with Bacterial Sexually Transmitted Infections among Black Men Who Have Sex with Men in the United States

Background

Black men who have sex with men (MSM) have a high prevalence of bacterial sexually transmitted infections (STIs), and individual risk behavior does not fully explain the higher prevalence when compared with other MSM. Using the social-ecological framework, we evaluated individual, social and sexual network, and structural factors and their association with prevalent STIs among Black MSM.

Methods

The HIV Prevention Trials Network 061 was a multi-site cohort study designed to determine the feasibility and acceptability of a multi-component intervention for Black MSM in six US cities. Baseline assessments included demographics, risk behavior, and social and sexual network questions collected information about the size, nature and connectedness of their sexual network. Logistic regression was used to estimate the odds of having any prevalent sexually transmitted infection (gonorrhea, chlamydia, or syphilis).

Results

A total of 1,553 Black MSM were enrolled in this study. In multivariate analysis, older age (aOR = 0.57; 95% CI 0.49–0.66, p<0.001) was associated with a lower odds of having a prevalent STI. Compared with reporting one male sexual partner, having 2–3 partners (aOR = 1.74; 95% CI 1.08–2.81, p<0.024) or more than 4 partners (aOR = 2.29; 95% CI 1.43–3.66, p<0.001) was associated with prevalent STIs. Having both Black and non-Black sexual partners (aOR = 0.67; 95% CI 0.45–0.99, p = 0.042) was the only sexual network factor associated with prevalent STIs.

Conclusions

Age and the number and racial composition of sexual partners were associated with prevalent STIs among Black MSM, while other sexual network factors were not. Further studies are needed to evaluate the effects of the individual, network, and structural factors on prevalent STIs among Black MSM to inform combination interventions to reduce STIs among these men.

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 review of the guidelines for the evaluation and treatment of congenital syphilis

Congenital syphilis (CS) is a disease that continues to persist in the United States despite its preventable nature. Mother-to-child transmission of CS can be avoided with appropriate maternal diagnosis and treatment during the pregnancy. Diagnosing CS and determining the therapeutic course can be challenging. This review covers the recent guidelines for the diagnosis and treatment of CS and the various factors that affect management decisions. These factors include the mother's antenatal management, the infant's clinical presentation and results, laboratory and serologic testing, and more.

Clinical Aspects of Syphilis Reinfection in HIV-Infected Patients

BACKGROUND

The incidence of HIV-syphilis co-infection has risen since 2000, especially among men having sex with men (MSM). Syphilis reinfection can occur, but the clinical features of such events remain poorly characterized.

OBJECTIVE

To compare the cutaneous lesions seen with syphilis reinfections with those of first episodes in HIV-infected patients.

METHODS

In a cohort of HIV-infected patients, syphilis reinfection was established both clinically and biologically by evaluating changes in Venereal Disease Research Laboratory titers. Photographs and medical records were studied in order to determine the type of skin lesions and their quantification.

RESULTS

Among 533 HIV-infected patients, 42 (8%) experienced a first syphilis infection. Thirteen episodes of reinfection occurred in 12/42 (28%) patients, all MSM. In 78% of cases, reinfections were less symptomatic than first episodes. All patients presented classical syphilis lesions.

CONCLUSIONS

We observed a high rate of reinfection, but with less severe skin manifestations during reinfection episodes.

Clinical and epidemiological characteristics of patients with early syphilis from three academic centres in Poland, Germany and Ireland: initial findings from the POETS study

OBJECTIVES

Syphilis recognition in HIV-positive patients has important implications. Initial data from this study, established in June 2012 to better understand the natural history of syphilis and treatment response, examine the characteristics of patients including sexual behaviour, rates of concurrent sexually transmitted infections (STI) and type of treatment given.

METHODS

Patients were recruited from Ireland, Poland and Germany. Data gathered included demographics, method of syphilis acquisition, stage of syphilis infection, HIV status, nadir and current CD4 counts and HIV viral suppression rates. Data were then subanalysed into HIV-positive and HIV-negative groups.

RESULTS

Of 175 patients recruited, 68% were HIV-positive and 86.3% were men who have sex with men. Most HIV-positive patients presented with secondary syphilis (55.7% vs 13.2%) (p=0.0001) while the majority of HIV-negative patients had primary syphilis noted at the time of recruitment (47.2% vs18.9%, p=0.0002). Approximately half of all patients had a HIV RNA viral load <40 copies/mL (55%). Previous syphilis infection occurred more frequently in HIV-positive than HIV-negative patients (p=0.0001). Concurrent STIs at the time of syphilis diagnosis were found in 26.8%, of whom 31 (25.4%) were HIV-positive (p=0.64). HIV-positive patients received doxycycline more frequently than their HIV-negative counterparts (33.6% vs 1.9%, p=0.0001) while HIV-negative patients were treated with long-acting penicillin in 88.7% of cases vs 58% of HIV-positive patients (p=0.0002).

CONCLUSIONS

A 40% rate of unsuppressed viraemia, high levels of STIs and varying treatment regimens represent a public health risk for Europe, suggesting the model of sexual healthcare delivery in HIV-positive patients requires further evaluation.

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.

The prevalence and correlates of syphilis and HIV among homosexual and bisexual men in Shijiazhuang, China

Bisexual men (men who have sex with men and women) are potential epidemiological bridges responsible for the spread of HIV and other sexually transmitted infections from men who have sex with men only to the heterosexual population. We aimed to estimate the prevalence of syphilis and HIV and the factors associated with syphilis infection among men who have sex with men and women and men who have sex with men only from Shijiazhuang, China. In 2011-2013, a cross-sectional cohort of 427 men who have sex with men was recruited by a snowball sampling method and tested for syphilis and HIV. Chi square and logistic regression were performed to identify syphilis risk factors. Among the 427 men who have sex with men, 71 (16.6%) cases were syphilis-positive and 16 cases (3.7%) were HIV-positive. The proportions of men who have sex with men and women and men who have sex with men only in the total sample were 31.4% and 68.6%, respectively. Men who have sex with men and women exhibited double the syphilis prevalence of men who have sex with men only and were more likely to practice insertive anal sex. Higher education level, being married, having more male partners, and both receptive and insertive anal sex roles were associated with syphilis among men who have sex with men and women. Residing in suburban areas, being married, being HIV positive, and an absence of desire to change sexual orientation were associated with syphilis among men who have sex with men only. Therefore, men who have sex with men and women represent an important sub-group in the syphilis epidemic and further interventions should be developed to reduce risk among different sub-sets of men who have sex with men.

Syphilis in the modern era: an update for physicians

Syphilis is a complex, systemic disease caused by the spirochete Treponema pallidum. Syphilis is most commonly transmitted sexually or congenitally and can involve nearly every organ system. Its clinical progression involves several well-characterized stages: an incubation period, a primary stage, a secondary stage, a latent stage, and a late or tertiary stage. Syphilis during pregnancy is a leading cause of perinatal mortality in sub-Saharan Africa and can cause spontaneous abortion, stillbirth, prematurity, low birth weight, or congenital syphilis. Penicillin is highly effective against syphilis and remains the treatment of choice. This article reviews the epidemiology, clinical features, diagnostic approach, treatment, and prevention of syphilis.

Multicentre surveillance of prevalence of the 23S rRNA A2058G and A2059G point mutations and molecular subtypes of Treponema pallidum in Taiwan, 2009-2013

Resistance mutations A2058G and A2059G, within the 23S rRNA gene of Treponema pallidum, have been reported to cause treatment failures in patients receiving azithromycin for syphilis. Genotyping of T. pallidum strains sequentially isolated from patients with recurrent syphilis is rarely performed. From September 2009 to August 2013, we collected 658 clinical specimens from 375 patients who presented with syphilis for genotyping to examine the number of 60-bp repeats in the acidic repeat protein (arp) gene, T. pallidum repeat (tpr) polymorphism, and tp0548 gene, and to detect A2058G and A2059G point mutations by restriction fragment length polymorphism. Treponemal DNA was identified in 45.2% (n = 298) of the specimens that were collected from 216 (57.6%) patients; 268 (40.7%) specimens tested positive for the 23S rRNA gene, and were examined for macrolide resistance. Two isolates (0.7%) harboured the A2058G mutation, and no A2059G mutation was identified. A total of 14 strains of T. pallidum were identified, with 14f/f (57.5%) and 14b/c (10.0%) being the two predominant strains. Forty patients who presented with recurrent episodes of syphilis had T. pallidum DNA identified from the initial and subsequent episodes, with five cases showing strain discrepancies. One patient had two strains identified from different clinical specimens collected in the same episode. Our findings show that 14f/f is the most common T. pallidum strain in Taiwan, where the prevalence of T. pallidum strains that show A2058G or A2059G mutation remains low. Different genotypes of T. pallidum can be identified in patients with recurrent episodes of syphilis.

Characteristics of LGV repeaters: analysis of LGV surveillance data

Objectives

A number of individuals have acquired lymphogranuloma venereum (LGV) infection multiple times since its re-emergence. We describe the characteristics of reinfections and those who acquire them.

Methods

The LGV Enhanced Surveillance system collected detailed information on LGV episodes in the UK from 2004 to 2010. Using logistic regression we compared the baseline characteristics of men who have sex with men (MSM) who had a repeat LGV episode (‘repeaters’) to MSM with a single reported episode (‘non-repeaters’).

Results

There were 66 individuals among the 1281 MSM (5.2%) with LGV episode who had a recorded reinfection during the data collection period. Those who acquired LGV reinfection were more likely to be HIV positive (97% vs 79%), visit a clinic in London (OR 2.0, 95% CI 1.1 to 3.8), and have hepatitis C (OR 2.2, 95% CI 1.1 to 4.6) or concurrent gonorrhoea (OR 2.2, 95% CI 1.2 to 3.8) on their first recorded LGV episode. Repeaters reported higher levels of unprotected sex, but behavioural variables were not significantly different between repeaters and non-repeaters.

Conclusions

Among LGV repeaters, risk behaviour alone did not explain subsequent reinfection. LGV repeaters have a high level of other sexually transmitted infections (STIs) which may be linked to their central position in the sexual network that contributes to their heightened risk of STI acquisition. Given the low prevalence of LGV in the general MSM population, momentary increases in incidence in subsets of the population may be an important factor for LGV risk where the overall level of sexual risk behaviour is higher. Validating this would require research into sexual network structures.

Screen more or screen more often? Using mathematical models to inform syphilis control strategies

Background

Syphilis incidence among men who have sex with men (MSM) continues to rise despite attempts to increase screening and treatment uptake. We examined the marginal effect of increased frequency versus increased coverage of screening on syphilis incidence in Toronto, Canada.

Methods

We developed an agent-based, network model of syphilis transmission, representing a core population of 2,000 high-risk MSM. Epidemiological and biological parameters were drawn from regional surveillance data and literature-derived estimates. The pre-intervention period of the model was calibrated using surveillance data to identify 1000 credible simulations per strategy. Evaluated strategies included: annual syphilis screening at baseline coverage, increased screening frequency at baseline coverage, and increased coverage of annual screening. Intervention impact was measured as annual prevalence of detected infectious cases and syphilis incidence per year over 10 years.

Results

Of the strategies evaluated, increasing the frequency of syphilis screening to every three months was most effective in reducing reported and incident syphilis infections. Increasing the fraction of individuals tested, without increasing test frequency, resulted a smaller decline in incidence, because reductions in infectious syphilis via treatment were counterbalanced by increased incident syphilis among individuals with prior latent syphilis. For an equivalent number of additional tests performed annually, increased test frequency was consistently more effective than improved coverage.

Conclusions

Strategies that focus on higher frequency of testing in smaller fractions of the population were more effective in reducing syphilis incidence in a simulated MSM population. The findings highlight how treatment-induced loss of immunity can create unexpected results in screening-based control strategies.

Repeat syphilis among men who have sex with men--San Diego County, 2004-2009

Among 614 men who have sex with men in San Diego County with early syphilis during January 2004 to June 2007, 74 (11.7%; 95% confidence interval: 9.3%-14.4%) had repeat syphilis within 2 years. HIV-infected MSM were more likely to have repeat syphilis (odds ratio: 1.9; 95% confidence interval: 1.1, 3.4).

Infectious proctitis: when to suspect it is not inflammatory bowel disease

BACKGROUND

Proctitis is a common problem and is most frequently associated with inflammatory bowel diseases. However, the incidence of infectious proctitis appears to be rising, especially in men who have sex with men. This may be due to the rise of people participating in receptive anal sex as well as the increase in sexually transmitted infections. The most frequently reported pathogens include Neisseria gonorrhoeae, Chlamydia trachomatis, Treponema pallidum, and herpes simplex.

DIAGNOSIS

Symptoms of infectious proctitis can include rectal blood and mucous discharge, anorectal pain, ulcers, and occasionally lymphadenopathy and fever. History and physical examination are crucial in establishing a diagnosis, supported by endoscopy, histology, serology, culture and PCR.

TREATMENT

Treatment with antibiotics or antivirals is usually initiated, either empirically or after establishing a diagnosis. Co-infections, HIV testing, and treatment of sexual partners should always be considered.

Syphilis resurgence in Dublin, Ireland

A large outbreak of syphilis was reported in Dublin, Ireland, in 2001. The mean age of patients in 2001 was 35 years and 22.5% of patients were HIV-positive. The number of new cases decreased from 2003 on, however, new diagnoses have again increased. All positive syphilis serology results from 2007-09 were identified. Patients were included if they had a newly positive syphilis serology or, in the case of patients with previously treated syphilis, had a four-fold rise in rapid plasma reagin titre. Four hundred and thirty-nine new diagnoses of syphilis were made. The mean age of patients at diagnosis was 35.7 years (range 17-73 years). Four hundred and twelve (93.8%) cases occurred in men. Three hundred and eighty-one (86.8%) cases occurred in men who have sex with men (MSM). The estimated crude incidence rate among MSM is 378.16 per 100,000 population. Where known, 126/421 (28.7%) occurred in HIV-positive patients. Sixty-eight (15.5%) episodes of syphilis infection were diagnosed in patients who had had previously been diagnosed and treated for syphilis; 43/68 (63.2%) cases of re-infection occurred in HIV-positive patients. The rising number of syphilis diagnoses and high associated HIV co-infection rate is concerning and prevention efforts must continue to decrease the number of new syphilis cases.

Repeat syphilis among men who have sex with men in California, 2002-2006: implications for syphilis elimination efforts

OBJECTIVES

We examined rates of and risk factors for repeat syphilis infection among men who have sex with men (MSM) in California.

METHODS

We analyzed 2002 to 2006 California syphilis surveillance system data.

RESULTS

During the study period, a mean of 5.9% (range: 4.9%-7.1% per year) of MSM had a repeat primary or secondary (PS) syphilis infection within 2 years of an initial infection. There was no significant increase in the annual proportion of MSM with a repeat syphilis infection (P = .42). In a multivariable model, factors associated with repeat syphilis infection were HIV infection (odds ratio [OR] = 1.65; 95% confidence interval [CI] = 1.14, 2.37), Black race (OR = 1.84; 95% CI = 1.12, 3.04), and 10 or more recent sex partners (OR = 1.99; 95% CI = 1.12, 3.50).

CONCLUSIONS

Approximately 6% of MSM in California have a repeat PS syphilis infection within 2 years of an initial infection. HIV infection, Black race, and having multiple sex partners are associated with increased odds of repeat infection. Syphilis elimination efforts should include messages about the risk for repeat infection and the importance of follow-up testing. Public health attention to individuals repeatedly infected with syphilis may help reduce local disease burdens.

Reinfections during the Florida syphilis epidemic, 2000-2008

BACKGROUND

The last 3 syphilis epidemics in the United States peaked after 5 to 6 years, but rates have now increased for 8 years. We questioned whether persons with multiple syphilis diagnoses (repeaters) are fueling the epidemic.

METHODS

The Florida Department of Health database of all syphilis cases reported between 2000 and 2008 was used to examine demographics and disease presentation of repeaters and nonrepeaters using bivariate and multivariate analyses.

RESULTS

Of 26,070 persons diagnosed with syphilis, 643 (2.5%) were repeaters (range, 2-5 diagnoses): 82 women, 444 men who have sex with men (MSM), and 117 men identified as either heterosexual (n = 43) or unknown sexual orientation (n = 74). The mean time between first and second diagnosis was approximately 3 years. Median titer increase among those with a second diagnosis of early latent was 32-fold. In multivariate analysis, compared with nonrepeaters, repeaters were more likely to be MSM (odds ratio [OR], 5.3), human immunodeficiency virus (HIV)-infected (OR, 2.0), white (OR, 1.5), ages 35 to 39 (OR, 1.8), and to live in Miami-Dade or Broward Counties (OR, 1.7). Overall, the stage at diagnosis was similar for repeaters, whether it was their initial or subsequent diagnosis. However, HIV-infected MSM were more likely to be diagnosed with early latent at second diagnosis compared with initial diagnosis (P ≤ 0.01).

CONCLUSIONS

Most syphilis diagnosed in the current Florida epidemic is among persons infected for the first time. Repeaters are mainly MSM who present with symptoms or large increases in titers. HIV-infected MSM may have higher rates of early asymptomatic disease because of more frequent screening. These are likely to be true new infections.