Syphilis Treatment and HIV Infection in a Population-Based Study of Persons at High Risk for Sexually Transmitted Disease/HIV Infection in Lima, Peru

Comparisons of Serologic Responses of Early Syphilis to Treatment with a Single-Dose Benzathine Penicillin G Between HIV-Positive and HIV-Negative Patients

Introduction

Poorer serologic responses of early syphilis to treatment have been inconsistently reported in HIV-positive patients compared with HIV-negative patients, but the interpretation of previous studies is limited by discrepant study designs. The present study aimed to evaluate the effect of HIV infection on the treatment response to a single dose of benzathine penicillin G (BPG) for early syphilis.

Methods

From January 2015 to March 2020, adult patients with early syphilis who received a single dose of BPG were enrolled and rapid plasma reagin (RPR) titers were periodically determined. The primary outcome was serologic response, defined as at least a fourfold decline of RPR titer at 12 months of BPG treatment compared with that at baseline, which was examined in the intention-to-treat (ITT) and per-protocol analyses. Treatment failure included lack of at least a fourfold decline in RPR titers and at least a fourfold increase in RPR titers.

Results

We prospectively enrolled 184 HIV-positive and 68 HIV-negative participants with early syphilis, who were all men who have sex with men, with a higher proportion of previous syphilis (70.1%) and early latent syphilis (64.1%) among HIV-positive participants. In the ITT with last-observation-carried-forward analysis, HIV-positive participants had a significantly lower serologic response rate at 12 months of treatment than HIV-negative participants (73.4% vs. 91.2%). Of HIV-positive participants, 12.5% failed to achieve at least fourfold decline in RPR titers and 14.1% had at least a fourfold increase in RPR titers. The factors associated with 12-month serologic response were HIV infection (adjusted odds ratio [AOR] 0.33; 95% confidence interval [CI] 0.13–0.81) and RPR titer (per 1-log₂ increase, AOR 1.36; 95% CI 1.23–1.51).

Conclusion

HIV-positive patients with early syphilis had poorer serologic responses to BPG treatment than HIV-negative patients during a 12-month follow-up period.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40121-021-00450-6.

Time to Serological Cure and Associated Factors Among Syphilis Patients With and Without HIV in a Sexually Transmitted Infections Center, Thailand

BACKGROUND

Together with clinical correlation, nontreponemal titers are used to monitor treatment outcomes. Syphilis patients with HIV and without HIV coinfection were found to have different serological responses after treatment. This study aims to determine time to serological cure for treatment of syphilis and factors associated with it in patients with and without HIV.

METHOD

A descriptive study of syphilis patients who visited Bangrak STIs Center between January 1, 2007, and December 31, 2016. Univariate analysis was done to determine factors associated with serological outcomes. Survival curve analysis and multivariate Cox regression analysis were applied to compare time to serological cure between patients with various characteristics.

RESULTS

Of 497 syphilis patients, 62.1% had serological cure, 2.2% had nonresponse, 4.6% had treatment failure or reinfection, 9.9% had serofast status, and 21.2% were undetermined because of loss to follow-up. The time to serological cure was 110 days (95% confidence interval [CI], 59-163 days) and 102 days (95% CI, 94-110 days) among patients with HIV and without HIV, respectively (P = 0.162). Time to serological cure was significantly faster in early syphilis and baseline titer ≥1:32. After adjustment with the Cox regression model, patients with early syphilis were associated with serological cure with a hazard ratio of 1.75 (95% CI, 1.32-2.32). Time to serological cure among early syphilis patients was significantly longer in HIV-positive than HIV-negative patients (P = 0.002), whereas no difference was observed in late syphilis (P = 0.104).

CONCLUSION

Early syphilis was associated with faster time to serological cure. HIV patients with early syphilis took longer time to reach serological cure than did HIV-negative patients, whereas no such a difference was observed in late syphilis.

Strategic options for syphilis control in Papua New Guinea- impact and cost-effectiveness projections using the syphilis interventions towards elimination (SITE) model

Objectives

Papua New Guinea (PNG) has among the highest rates of sexually transmitted infections (STIs) globally and is committed to reducing their incidence. The Syphilis Interventions Towards Elimination (SITE) model was used to explore the expected impact and cost of alternative syphilis intervention scale-up scenarios.

Methods

SITE is a dynamical model of syphilis transmission among adults 15-49 years. Individuals are divided into nine groups based on sexual behaviour and into six stages of infection. The model was calibrated to PNG using data from routine surveillance, bio-behavioural surveys, research studies and program records. Inputs included syphilis prevalence, risk behaviours, intervention coverage and service delivery unit costs. Scenarios compared different interventions (clinical treatment, contact tracing, syphilis screening, and condom promotion) for incidence and cost per infection averted over 2021-2030.

Results

Increasing treatment coverage of symptomatic primary/secondary-stage syphilis cases from 25-35% in 2020 to 60% from 2023 onwards reduced estimated incidence over 2021-2030 by 55%, compared to a scenario assuming constant coverage at 2019-2020 levels. The introduction of contact tracing in 2020, assuming 0.4 contacts per symptomatic person treated, reduced incidence over 2021-2030 by 10%. Increasing screening coverage by 20-30 percentage points from the 2019-2020 level reduced incidence over 2021-2030 by 3-16% depending on the target population. Scaling-up clinical, symptom-driven treatment and contact tracing had the lowest cost per infection averted, followed by condom promotion and periodic screening of female sex workers and men who have sex with men.

Conclusions

PNG could considerably reduce its syphilis burden by scaling-up clinical treatment and contact tracing alongside targeted behavioural risk reduction interventions. SITE is a useful tool countries can apply to inform national STI programming and resource allocation.

Efficacy of linezolid on Treponema pallidum, the syphilis agent: A preclinical study

BACKGROUND

Penicillin G, the current standard treatment for syphilis, has important drawbacks, but virtually no preclinical or clinical studies have been performed to identify viable alternatives. We tested, both in vitro and in vivo, three marketed antibiotics with adequate pharmacological properties to treat syphilis.

METHODS

We used an in vitro culturing system of T. pallidum to perform drug susceptibility testing and applied quantitative PCR targeting the tp0574 gene to measure bacterial growth. To confirm in vivo efficacy, fifteen rabbits were infected intradermally with T. pallidum at eight sites each and randomly allocated to an experimental treatment (linezolid, moxifloxacin, clofazimine) or a control arm (benzathine penicillin G [BPG], untreated). The primary outcome was treatment efficacy defined as the time to lesion healing measured from the date of treatment start. Secondary outcomes were absence of treponemes or treponemal mRNA in injection sites, absence of seroconversion, and cerebrospinal fluid (CSF) abnormalities and negative rabbit infectivity tests (RIT).

FINDINGS

Linezolid showed in vitro bactericidal activity at concentrations of 0.5 µg/mL or higher. When administered orally to experimentally infected rabbits, it induced healing of early lesions at a time similar to BPG (hazard ratio 3.84; 95% CI 2.05-7.17; p < 0.0001 compared to untreated controls). In linezolid-treated animals, dark-field microscopy and qPCR assessment showed no presence of treponemes after day 3 post-treatment start, serologic test did not convert to positive, CSF had no abnormalities, and RIT was negative. Moxifloxacin and clofazimine failed to inhibit bacterial growth in vitro and could not cure the infection in the rabbit model.

INTERPRETATION

Linezolid, a low-cost oxazolidinone, has in vitro and in vivo activity against T. pallidum, with efficacy similar to BPG in treating treponemal lesions in the animal model. Our findings warrant further research to assess the efficacy of linezolid as an alternative to penicillin G to treat syphilis in human clinical trials.

FUNDING

European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (Grant agreement No. 850450).

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.

Sexually acquired syphilis: Laboratory diagnosis, management, and prevention

The methods used for the laboratory diagnosis of syphilis include direct detection of Treponema pallidum subspecies pallidum and serologic testing. Serologic testing relies on both nontreponemal and treponemal tests. In newly developed reverse-sequence screening algorithms, treponemal tests are performed before nontreponemal tests. The management of syphilis requires appropriate staging, treatment, and follow-up of patients along with the prompt reporting of infections to public health authorities to assist with prevention and control efforts. Benzathine penicillin G remains the treatment of choice for all stages of syphilis. Screening of populations at higher risk for syphilis is recommended by the US Centers for Disease Control and Prevention, the US Preventive Services Task Force, and the World Health Organization. The second article in this continuing medical education series reviews the testing for and the management of sexually acquired syphilis.

Traditional and Web-Based Technologies to Improve Partner Notification Following Syphilis Diagnosis Among Men Who Have Sex With Men in Lima, Peru: Pilot Randomized Controlled Trial

Background

Patient-initiated partner notification (PN) following the diagnosis of a sexually transmitted infection is a critical component of disease control in men who have sex with men (MSM) sexual networks. Both printed and internet-based technologies offer potential tools to enhance traditional partner notification approaches among MSM in resource-limited settings.

Objective

This randomized controlled trial aimed to evaluate the effect of 2 different PN technologies on notification outcomes following syphilis diagnosis among MSM in Peru: a Web-based notification system and patient-delivered partner referral cards.

Methods

During 2012-2014, we screened 1625 MSM from Lima, Peru, for syphilis infection and enrolled 370 MSM with symptomatic primary or secondary syphilis (n=58) or asymptomatic latent syphilis diagnosed by serology (rapid plasma reagin, RPR, and Microhemagglutination assay for Treponema pallidum antibody; n=312). Prior to enrollment, potential participants used a computer-based self-interviewing system to enumerate their recent sexual partnerships and provide details of their 3 most recent partners. Eligible participants were randomly assigned to one of 4 intervention arms: (1) counseling and patient-initiated Web-based PN (n=95), (2) counseling with Web-based partner notification and partner referral cards (n=84), (3) counseling and partner referral cards (n=97), and (4) simple partner notification counseling (control; n=94). Self-reported partner notification was assessed after 14 days among 354 participants who returned for the follow-up assessment.

Results

The median age of enrolled participants was 27 (interquartile range, IQR 23-34) years, with a median of 2 partners (IQR 1-5) reported in the past month. Compared with those who received only counseling (arm 4), MSM provided with access to Web-based partner notification (arms 1 and 2) or printed partner referral cards (arms 2 and 3) were more likely to have notified one or more of their sexual partners (odds ratio, OR, 2.18, 95% CI 1.30-3.66; P=.003 and OR 1.68, 95% CI 1.01-2.79; P=.045, respectively). The proportion of partners notified was also higher in both Web-based partner notification (241/421, 57.2%; P<.001) and referral card (240/467, 51.4%; P=.006) arms than in the control arm (82/232, 35.3%).

Conclusions

Both new Web-based technologies and traditional printed materials support patient-directed notification and improve self-reported outcomes among MSM with syphilis. Additional research is needed to refine the use of these partner notification tools in specific partnership contexts.

Trial Registration

ClinicalTrials.gov NCT01720641; https://clinicaltrials.gov/ct2/show/NCT01720641 (Archived by WebCite at http://www.webcitation.org/70A89rJL4)

Practice Bulletin No. 167: Gynecologic Care for Women and Adolescents With Human Immunodeficiency Virus

In the United States in 2013, there were an estimated 226,000 women and adolescents living with human immunodeficiency virus (HIV) infection (1). Women with HIV are living longer, healthier lives, so the need for routine and problem-focused gynecologic care has increased. The purpose of this document is to educate clinicians about basic health screening and care, family planning, prepregnancy care, and managing common gynecologic problems for women and adolescents who are infected with HIV. For information on screening guidelines, refer to the American College of Obstetricians and Gynecologists' Committee Opinion No. 596, Routine Human Immunodeficiency Virus Screening (2).

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.

A systematic review of syphilis serological treatment outcomes in HIV-infected and HIV-uninfected persons: rethinking the significance of serological non-responsiveness and the serofast state after therapy

BACKGROUND

Syphilis remains a global public health threat and can lead to severe complications. In addition to resolution of clinical manifestations, a reduction in nontreponemal antibody titers after treatment is regarded as "proof of cure." However, some patients manifest < 4-fold decline ("serological non-response") or persistently positive nontreponemal titers despite an appropriate decline ("serofast") that may represent treatment failure, reinfection, or a benign immune response. To delineate these treatment phenomena, we conducted a systematic review of the literature regarding serological outcomes and associated factors among HIV-infected and -uninfected subjects.

METHODS

Six databases (PubMed, Embase, CINAHL, Web of Science, Scopus, and BIOSIS) were searched with no date restrictions. Relevant articles that evaluated serological treatment responses and correlates of serological cure (≥ four-fold decline in nontreponemal titers) were included.

RESULTS

We identified 1693 reports in the literature, of which 20 studies met selection criteria. The median proportion of patients who had serological non-response was 12.1% overall (interquartile range, 4.9-25.6), but varied depending on the time points after therapy. The serofast proportion could only be estimated from 2 studies, which ranged from 35.2-44.4%. Serological cure was primarily associated with younger age, higher baseline nontreponemal titers, and earlier syphilis stage. The relationship between serological cure and HIV status was inconsistent; among HIV-infected patients, CD4 count and HIV viral load was not associated with serological cure.

CONCLUSIONS

Serological non-response and the serofast state are common syphilis treatment outcomes, highlighting the importance of determining the immunological and clinical significance of persistent nontreponemal antibody titers after therapy.

The syphilis care cascade: tracking the course of care after screening positive among men and transgender women who have sex with men in Lima, Peru

OBJECTIVES

Syphilis is endemic among men who have sex with men (MSM) and transgender women in Latin America. The objective of this study was to assess if those who screen positive for syphilis are receiving appropriate care and treatment.

METHODS

We use data from the 2011 Peruvian National HIV Sentinel Surveillance to describe the syphilis care cascade among high-risk MSM and transgender women. Medical records from participants who had a positive syphilis screening test at two of the enrolment sites in Lima were reviewed to determine their subsequent course of care.

RESULTS

We identified a cohort of 314 syphilis seropositive participants (median age: 30, 33.7% self-identified as transgender). Only 284/314 (90.4%) participants saw a physician for evaluation within 28 days of their positive test. Of these, 72/284 (25.4%) were asked to return for confirmatory results before deciding whether or not to start treatment; however, 45/72 (62.5%) of these participants did not follow up within 28 days. Of the people prescribed three weekly doses of penicillin, 34/63 (54%) received all three doses on time.

CONCLUSIONS

Many MSM and transgender women with a positive syphilis screening test are lost at various steps along the syphilis care cascade and may have persistent infection. Interventions in this population are needed to increase testing, link seropositive patients into care and ensure that they receive appropriate and timely treatment.

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.

Treatment of syphilis: a systematic review

IMPORTANCE

The incidence of syphilis in the United States is increasing; it is estimated that more than 55,000 new infections will occur in 2014. Treatment regimens are controversial, especially in specific populations, and assessing treatment response based on serology remains a challenge.

OBJECTIVE

To review evidence regarding penicillin and nonpenicillin regimens, implications of the "serofast state," and treatment of specific populations including those with neurosyphilis or human immunodeficiency virus (HIV) infection and pregnant women.

EVIDENCE REVIEW

We searched MEDLINE for English-language human treatment studies dating from January 1965 until July 2014. The American Heart Association classification system was used to rate quality of evidence.

FINDINGS

We included 102 articles in our review, consisting of randomized trials, meta-analyses, and cohort studies. Case reports and small series were excluded unless they were the only studies providing evidence for a specific treatment strategy. We included 11 randomized trials. Evidence regarding penicillin and nonpenicillin regimens was reviewed from studies involving 11,102 patients. Data on the treatment of early syphilis support the use of a single intramuscular injection of 2.4 million U of benzathine penicillin G, with studies reporting 90% to 100% treatment success rates. The value of multiple-dose treatment of early syphilis is uncertain, especially in HIV-infected individuals. Less evidence is available regarding therapy for late and late latent syphilis. Following treatment, nontreponemal serologic titers should decline in a stable pattern, but a significant proportion of patients may remain seropositive (the "serofast state"). Serologic response to treatment should be evident by 6 months in early syphilis but is generally slower (12-24 months) for latent syphilis. Evidence defining treatment for HIV-infected persons and for pregnant women is limited, but available data support penicillin as first-line therapy.

CONCLUSIONS AND RELEVANCE

The mainstay of syphilis treatment is parenteral penicillin G despite the relatively modest clinical trial data that support its use.

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.

Characterizing the syphilis epidemic among men who have sex with men in Lima, Peru to identify new treatment and control strategies

BACKGROUND

Syphilis is an important sexually transmitted infection (STI) with serious public health consequences. Among men who have sex with men (MSM) in Lima, the prevalence and incidence are extraordinarily high. Current syndromic approaches, however, fail to identify asymptomatic cases, and in settings where large proportions of individuals test positive again after treatment, it is frequently difficult to distinguish treatment failure from re-infection. Thus, new approaches are needed to improve treatment strategies and public health control efforts.

METHODS/DESIGN

Study participants will undergo baseline testing for syphilis infection along with a behavioral survey covering demographics, sexual behavior, drug and alcohol abuse and health-care seeking behavior. The cohort will be followed for 18 months at three-month intervals. Blood and earlobe scrapings will also be collected for T. pallidum DNA testing, to create molecular markers for subtyping. We will also perform cytokine testing on collected samples in order to create host immunologic profiles associated with recurrence, re-infection, treatment failure and success.

DISCUSSION

Advances in social epidemiology, molecular typing and characterization of host immune responses will offer promise in developing new understandings of syphilis management. We will share our findings with the Peruvian Ministry of Health and other public health organizations, to identify new approaches of case detection and successful treatment.

Syphilis in the AIDS era: diagnostic dilemma and therapeutic challenge

This review argues that syphilis has been underdiagnosed and undertreated, a problem that goes back to the beginning of the Wassermann era, and indeed long before. Non-treponemal tests do not detect the larger pool of persons with latent syphilis, the immunological consequences of which have not been systematically investigated in the context of HIV infection and progression to AIDS. Recent efforts to confirm the prevalence of syphilis in high-risk patients by reverse sequence screening, i.e. using a treponemal test first, as the screening test, have revealed untreated syphilis at higher rates than expected. Further testing using PCR discovered even more previously undetected cases. We suggest that latent syphilis is a chronic active immunological condition that drives the AIDS process and cannot be managed with the older Wassermann-based algorithm, and that non-treponemal tests have failed to associate syphilis with immune suppression since this screening concept was developed in 1906. In light of the overwhelming association between a past history of syphilis and HIV seroconversion, more sensitive tools, including recombinant antigen-based immunological tests and direct detection (PCR) technology, are needed to adequately assess the role of latent syphilis in persons with HIV/AIDS. Repeating older syphilis reinoculation studies may help establish a successful animal model for AIDS, and resolve many paradoxes in HIV science.

Serological response to treatment of syphilis according to disease stage and HIV status

The serological response to treatment was studied in 264 syphilis patients; it was influenced by syphilis stage but not by human immunodeficiency virus infection and reinfection. Some of the recommendations of current guidelines are critically discussed, and amendments are proposed.

Background. Serology is the mainstay for syphilis diagnosis and treatment monitoring. We investigated serological response to treatment of syphilis according to disease stage and HIV status.

Methods. A retrospective cohort study of 264 patients with syphilis was conducted, including 90 primary, 133 secondary, 33 latent, and 8 tertiary syphilis cases. Response to treatment as measured by the Venereal Disease Research Laboratory (VDRL) test and a specific IgM (immunoglobulin M) capture enzyme-linked immunosorbent assay (ELISA; Pathozyme-IgM) was assessed by Cox regression analysis.

Results. Forty-two percent of primary syphilis patients had a negative VDRL test at their diagnosis. Three months after treatment, 85%–100% of primary syphilis patients had reached the VDRL endpoint, compared with 76%–89% of patients with secondary syphilis and 44%–79% with latent syphilis. In the overall multivariate Cox regression analysis, serological response to treatment was not influenced by human immunodeficiency virus (HIV) infection and reinfection. However, within primary syphilis, HIV patients with a CD4 count of <500 cells/μL had a slower treatment response (P = .012). Compared with primary syphilis, secondary and latent syphilis showed a slower serological response of VDRL (P = .092 and P < .001) and Pathozyme-IgM tests (P < .001 and P = .012).

Conclusions. The VDRL should not be recommended as a screening test owing to lack of sensitivity. The syphilis disease stage significantly influences treatment response whereas HIV coinfection only within primary syphilis has an impact. VDRL test titers should decline at least 4-fold within 3–6 months after therapy for primary or secondary syphilis, and within 12–24 months for latent syphilis. IgM ELISA might be a supplement for diagnosis and treatment monitoring.

Management of syphilis in the HIV-infected patient: facts and controversies

After reaching an all time low at the turn of the millennium in several industrialized countries, the syphilis incidence is rising again, perhaps as a consequence of unsafe sexual behavior in response to improved antiretroviral therapeutic options for HIV. Since the beginning of the HIV pandemic, numerous reports on the various aspects of the interaction between syphilis and HIV have been published. Controversies persist on many issues of the management of coinfected patients. This contribution presents a critical appraisal of the available literature. Few large-scale, properly designed, controlled studies have compared syphilis baseline presentation and treatment response according to HIV status. Among the weakness are (1) high rates of patients lost to follow-up, (2) lack of long-term follow-up, (3) lack of gold standard criteria for treatment response, (4) small sample size, and (5) lack of stratification according to syphilis stage, ongoing antiretroviral treatment, CD4 cell count and HIV viral load. From the available data, and given the ever-possible publication bias, we conclude that if HIV has an effect on the course of syphilis, it is small and clinically manageable in most cases. The controversial issues discussed should furnish the rational for clinical research during the forthcoming decade.

Syphilis epidemiology and clinical outcomes in HIV-infected and HIV-uninfected patients in Kaiser Permanente Northern California

BACKGROUND

Syphilis rates are rising in California, but the impact of HIV infection on syphilis infection remains uncertain. We describe differences between HIV-infected and HIV-uninfected patients diagnosed with syphilis within Kaiser Permanente Northern California.

METHODS

We performed retrospective analyses of patients diagnosed with incident syphilis from 1995 to 2005 (622 cases/9989 HIV-infected patients and 3584/4,442,780 HIV-uninfected). Among cases, we ascertained demographic, clinical characteristics, and laboratory (including baseline labs and repeated RPR titers) data. We performed Poisson regression (incidence) and Cox proportional hazard modeling (reduction in RPR and serologic failure after syphilis therapy) adjusting for age, gender, and HIV status and among HIV-infected cases only by use of antiretroviral therapy (ART).

RESULTS

HIV-infected patients had incident syphilis rates of 62.3/1000 person-years compared with 0.8/1000 HIV-uninfected patients, corresponding to an adjusted rate ratio of 86.0 (P <0.001); rate differences increased significantly over time. HIV-infected patients had a greater likelihood of reduction in RPR and serologic failure after syphilis therapy (HR = 2.5 and 2.6 respectively [P <0.001 both]). Among HIV-infected only, patients on ART had lower rates of infection but higher likelihood of reduction in RPR after syphilis therapy and serologic failure compared with patients not on ART.

CONCLUSIONS

HIV-infected patients had greater rate of incident syphilis compared with HIV-uninfected, a disparity which increased over time. HIV-infected patients had greater likelihood of decline in RPR and serologic failure. HIV-infected patients should be screened for syphilis regularly.

Recent syphilis infection prevalence and risk factors among male low-income populations in coastal Peruvian cities

BACKGROUND

The objective of this study was to examine the epidemiology of syphilis among high-risk socially marginalized populations in urban, coastal Peru, to quantify the prevalence of recent syphilis infection and identify risk factors.

METHODS

Survey data and serologic specimens were collected from a population-based sample of 3 populations: men who have sex with only men (MSOM), socially marginalized heterosexual men, and socially marginalized women. Syphilis prevalence was determined for each population, and multivariate analysis was used to analyze risk factors for recent syphilis infection among the MSOM and among the socially marginalized men.

RESULTS

The prevalence of recent syphilis infection was 10.5% among the MSOM, 1.5% among the socially marginalized men, and 2.0% among the women. Among both MSOM and the socially marginalized men, recent syphilis infection was significantly associated with Herpes simplex virus Type 2 infection (prevalence ratio = 1.96; 95% confidence interval, 1.03-3.74, and PR = 3.72; 95% CI, 2.12-6.53, respectively). Recent syphilis infection was also significantly associated with HIV infection among the socially marginalized men (PR = 11.13; 95% CI, 4.50-27.51) and with the number of sexually active years among the MSOM (PR = 1.05, 95% CI, 1.01-1.10).

CONCLUSIONS

All 3 groups included in this study exhibited a high prevalence of recent syphilis infection, with recent infection being most prevalent among the MSOM. These findings demonstrate the need for more effective syphilis control services among those populations, to decrease syphilis-associated morbidity, transmission of syphilis, and the potential transmission of HIV.

Clinical and serologic baseline and follow-up features of syphilis according to HIV status in the post-HAART era

There is a lack of large studies appraising the effect of the human immunodeficiency virus (HIV) on the course of syphilis since the advent of highly active antiretroviral therapy (HAART). We aimed to appraise the effect of HIV on clinical and serologic features of syphilis at baseline and during follow-up in the post-HAART era.We designed a retrospective cohort study of consecutive syphilis cases, diagnosed between 2000 and 2007, in an academic venereal disease center. Data were collected using standardized medical forms. Patients were treated according to the European guidelines. Serologic failure was defined as either a 4-fold rise in Venereal Disease Research Laboratory (VDRL) titers 30-400 days posttreatment or a lack of 4-fold drop in VDRL titers at 270-400 days posttreatment.Among 279 syphilis cases with informative baseline clinical and serologic data, HIV infection was significantly associated with men having sex with men, French origin, multiple partners, lesser usage of condom, history of sexually transmitted disease, early syphilis, anal primary chancre, and cutaneous eruption. Median baseline titer from the Treponema pallidum hemagglutination assay (TPHA) was higher in HIV-infected patients (p = 0.02).Among 144 informative syphilis cases, there was a nonsignificant trend for a lower rate of serologic response among HIV-positive patients (91.8% vs. 98.3%, p = 0.14). Serologic failure was significantly associated with a history of previous syphilis (p < 0.05). The median delay to serologic response was similar in HIV-positive (117 d) and in HIV-negative (123 d) patients (p = 0.44).We conclude that for patients under HAART treatment, the effect of HIV on serologic response to syphilis treatment is likely minimal or absent.

A consequence of the syphilis epidemic among men who have sex with men (MSM): neurosyphilis in Los Angeles, 2001-2004

OBJECTIVES

To describe the epidemiology and clinical findings of neurosyphilis (NS) cases diagnosed during the current syphilis epidemic occurring predominantly among men who have sex with men.

METHODS

Syphilis cases reported to the health department were reviewed for diagnosis of NS, cerebrospinal fluid venereal disease research laboratory results, and/or treatment for NS.

RESULTS

During 2001-2004, 7083 cases of syphilis were diagnosed in Los Angeles. One hundred nine cases of confirmed or probable NS occurring among persons aged 19 to 65 years were identified during this period (1.5%). Symptomatic NS was present in 1.2% of reported syphilis cases (86 of 7083). NS cases were inclusive of 71 (65%) men who have sex with men. Forty-two (49%) of the symptomatic NS cases occurred during secondary (N = 28) or early latent (N = 14) syphilis. Sixty-eight percent (N = 74) of the NS cases were human immunodeficiency virus (HIV)-positive. The estimated incidence of symptomatic NS among HIV-infected persons with early syphilis was 2.1% as compared with 0.6% among HIV-negative persons.

CONCLUSION

Providers should maintain a high index of suspicion for NS among patients with syphilis, particularly those with HIV infection.

Infectious syphilis in high-income settings in the 21st century

In high-income countries after World War II, the widespread availability of effective antimicrobial therapy, combined with expanded screening, diagnosis, and treatment programmes, resulted in a substantial decline in the incidence of syphilis. However, by the turn of the 21st century, outbreaks of syphilis began to occur in different subpopulations, especially in communities of men who have sex with men. The reasons for these outbreaks include changing sexual and social norms, interactions with increasingly prevalent HIV infection, substance abuse, global travel and migration, and underinvestment in public-health services. Recently, it has been suggested that these outbreaks could be the result of an interaction of the pathogen with natural immunity, and that syphilis epidemics should be expected to intrinsically cycle. We discuss this hypothesis by examining long-term data sets of syphilis. Today, syphilis in western Europe and the USA is characterised by low-level endemicity with concentration among population subgroups with high rates of partner change, poor access to health services, social marginalisation, or low socioeconomic status.

Current Controversies in the Management of Adult Syphilis

Clinical management of patients with syphilis is controversial. This article summarizes recent research on syphilis treatment efficacy and outcomes and is based on a comprehensive systematic review of published literature, relevant abstracts, conference proceedings, technical reports, and guidelines. Penicillin remains the drug of choice for the treatment of syphilis. Although several studies have suggested that azithromycin may have clinical efficacy, macrolide resistance has been widely documented among strains of Treponema pallidum, and treatment failures have been reported. Ceftriaxone is effective for the treatment of syphilis when used in multiple-dose regimens. Lumbar puncture should be performed for human immunodeficiency virus-infected patients with syphilis of >1 year's duration and a serum nontreponemal test titer > or =1 : 32, as well for other patients for whom the clinical suspicion of neurosyphilis is high. Newer laboratory tests for syphilis are undergoing extensive evaluation and may prove to be useful for future clinical care. American and European approaches to syphilis treatment are similar, but they vary across several parameters.

Ethical issues in the NIMH Collaborative HIV/STD Prevention Trial

OBJECTIVE

To develop decision rules regarding key ethical dimensions in scientific protocols for the National Institute for Mental Health (NIMH) Collaborative HIV/STD Prevention Trial taking place in five countries (China, India, Peru, Russia, and Zimbabwe).

DESIGN

Countries had HIV rates from 27 to 0.1%, the standard of care varied from access to antiretroviral drugs to no availability, and the reporting of sexually transmitted diseases (STD) to government agencies was mandatory in some countries and not in others. These variations presented challenges when developing decision rules that could be uniformly adopted across countries and simultaneously follow the ethical principles of beneficence, respect, and justice.

METHODS

We used several strategies to identify and resolve ethical dilemmas for this international HIV prevention trial. First, we identified key principles, especially those derived for clinical therapeutic, biomedical preventive, or device trials. We convened a 'workgroup on protecting human participants' and charged them with identifying and implementing optimal procedures for ensuring the ethical and equitable treatment of participants and making recommendations to minimize physical, psychological, and social harm to the participants. Each site had a community advisory board, essential in identifying local ethical issues and possible resolutions to them. The NIMH established a data safety and monitoring board with ultimate responsibility for adjudicating ethical dilemmas and decisions. The protocols were deliberated thoroughly by the Trial steering committee, and approved by nine United States and five in-country institutional review boards.

RESULTS

We summarize the decision rules adopted to resolve the ethical dilemmas identified. Especially important were the translation of clinical trials principles for a behavioral intervention trial, strategies for ensuring confidentiality and informed consent, dilemmas relating to partner notification of sexually transmitted infections including HIV, minimizing the risks of social harm, establishing community partnerships, ensuring equity among United States and in-country principal investigators, and building capacity for additional research.

CONCLUSION

We document our processes and decisions, and their underlying rationales, and hope they contribute to the development of further thinking and practice regarding the ethics of social and behavioral HIV and STD prevention trials in resource-poor settings.

Syphilis and HIV infection: an update

The striking increase in the prevalence of concordant human immunodeficiency virus (HIV) infection and syphilis observed by clinicians and public health officers over the past decade has renewed interest in the subject. Although the effect of HIV infection on the natural history of syphilis has been known for a long time, it was not until recently that several studies documented that syphilis may also impact the course of HIV infection. Despite an improved understanding of the interaction of these 2 conditions, many controversies still exist. In this article, we focus on the most recent literature describing the epidemiology, clinical manifestations, and treatment of syphilis in the context of HIV infection.

Utility of the Determine Syphilis TP rapid test in commercial sex venues in Peru

OBJECTIVES

This study sought to evaluate the utility of the Determine Syphilis TP test performed in Peruvian commercial sex venues for the detection of active syphilis; and determine the feasibility of integrating rapid syphilis testing for female sex workers (FSW) into existing health outreach services.

METHODS

We tested 3586 female sex workers for syphilis by Determine in the field using whole blood fingerstick, and by rapid plasma reagin (RPR) and Treponema pallidum haemagglutination assay (TPHA) in a central laboratory in Lima using sera.

RESULTS

97.4% of the FSW offered rapid syphilis testing participated; and among those who tested positive, 87% visited the local health centre for treatment. More than twice as many specimens were RPR reactive using serum in Lima (5.7%) than tested positive by whole blood Determine in the field (2.8%), and although most were confirmed by TPHA, only a small proportion (0.7%) were RPR reactive at >or=1:8 dilutions, and likely indicating active syphilis. Sensitivity, specificity and positive predictive value of the Determine Syphilis TP test in whole blood when compared to serum RPR reactivity at any dilution confirmed by TPHA as the gold standard were 39.3%, 99.2% and 71.4%, respectively. Sensitivity improved to 64.0% when using serum RPR >or=1:8 confirmed by TPHA. Invalid tests were rare (0.3%).

CONCLUSIONS

Rapid syphilis testing in sex work venues proved feasible, but Determine using whole blood obtained by fingerstick was substantially less sensitive than reported in previous laboratory-based studies using serum. Although easy to perform in outreach venues, the utility of this rapid syphilis test was relatively low in settings where a large proportion of the targeted population has been previously tested and treated.

Serological response to syphilis treatment in HIV-positive and HIV-negative patients attending sexually transmitted diseases clinics

BACKGROUND

HIV-positive patients treated for syphilis may be at increased risk for serological failure.

OBJECTIVE

To compare follow-up serologies and serological responses to treatment between HIV-positive and HIV-negative patients attending two sexually transmitted disease (STD) clinics.

STUDY DESIGN

Existing records were reviewed from HIV-positive patients who were diagnosed and treated for syphilis at the public STD clinics in Baltimore, Maryland, USA, between 1992 and 2000. Results of their serological follow-up were compared with those of HIV-negative clinic patients at the time of syphilis treatment. Failure was defined as lack of a fourfold drop in rapid plasma reagin (RPR) titre by 400 days after treatment or a fourfold increased titre between 30 and 400 days.

RESULTS

Of the 450 HIV-positive patients with syphilis, 288 (64%) did not have documented follow-up serologies and 129 (28.5%) met the inclusion criteria; 168 (17%) of 1000 known HIV-negative patients were similarly eligible. There were 22 failures in the HIV-positive group and 5 in the HIV-negative group (p<0.001). The median times to successful serological responses in both groups were 278 (95% confidence interval (CI) 209 to 350) and 126 (95% CI 108 to 157) days, respectively (p<0.001). A multivariate Cox's proportional hazards model showed an increased risk of serological failure among the HIV-positive patients (hazards ratio 6.0, 95% CI 1.5 to 23.9; p = 0.01).

CONCLUSION

HIV-positive patients treated for syphilis may be at higher risk of serological failure. Despite recommendations for more frequent serological follow-up, most patients did not have documentation of serological response after standard treatment for syphilis.