BASHH UK guidelines for the management of syphilis 2024

The 2024 UK guidelines for the management of syphilis are in line with current evidence and practice within the UK. Key updates are detailed at the start of the article. These guidelines are accompanied by the first UK guidelines for the management of syphilis in pregnant people and children, 2024.

Congenital Syphilis: A Re-Emerging but Preventable Infection

Congenital syphilis presents a significant global burden, contributing to fetal loss, stillbirth, neonatal mortality, and congenital infection. Despite the target established in 2007 by the World Health Organization (WHO) of fewer than 50 cases per 100,000 live births, the global incidence is on the rise, particularly in low- and middle-income regions. Recent data indicate a rate of 473 cases per 100,000 live births, resulting in 661,000 total cases of congenital syphilis, including 355,000 adverse birth outcomes such as early fetal deaths, stillbirths, neonatal deaths, preterm or low-birth-weight births, and infants with clinical congenital syphilis. Alarmingly, only 6% of these adverse outcomes occurred in mothers who were enrolled, screened, and treated. Unlike many neonatal infections, congenital syphilis is preventable through effective antenatal screening and treatment of infected pregnant women. However, despite available screening tools, affordable treatment options, and the integration of prevention programs into antenatal care in various countries, congenital syphilis remains a pressing public health concern worldwide. This review aims to summarize the current epidemiology, transmission, and treatment of syphilis in pregnancy, as well as to explore global efforts to reduce vertical transmission and address the reasons for falling short of the WHO elimination target.

Syphilis Treatment: Systematic Review and Meta-Analysis Investigating Nonpenicillin Therapeutic Strategies

Background

Penicillin's long-standing role as the reference standard in syphilis treatment has led to global reliance. However, this dependence presents challenges, prompting the need for alternative strategies. We performed a systematic literature review and meta-analysis to evaluate the efficacy of these alternative treatments against nonneurological syphilis.

Methods

We searched MEDLINE, the Cumulative Index to Nursing and Allied Health Literature, Embase, Cochrane, Scopus, and Web of Science from database inception to 28 August 2023, and we included studies that compared penicillin or amoxicillin monotherapy to other treatments for the management of nonneurological syphilis. Our primary outcome was serological cure rates. Random-effect models were used to obtain pooled mean differences, and heterogeneity was assessed using the I2 test.

Results

Of 6478 screened studies, 27 met the inclusion criteria, summing 6710 patients. The studies were considerably homogeneous, and stratified analyses considering each alternative treatment separately revealed that penicillin monotherapy did not outperform ceftriaxone (pooled odds ratio, 1.66 [95% confidence interval, .97-2.84]; I2 = 0%), azithromycin (0.92; [.73-1.18]; I2 = 0%), or doxycycline (0.82 [.61-1.10]; I2 = 1%) monotherapies with respect to serological conversion.

Conclusions

Alternative treatment strategies have serological cure rates equivalent to penicillin, potentially reducing global dependence on this antibiotic.

Oral linezolid compared with benzathine penicillin G for treatment of early syphilis in adults (Trep-AB Study) in Spain: a prospective, open-label, non-inferiority, randomised controlled trial

BACKGROUND

Management of syphilis, a sexually transmitted infection (STI) with increasing incidence, is challenged by drug shortages, scarcity of randomised trial data, an absence of non-penicillin alternatives for pregnant women with penicillin allergy (other than desensitisation), extended parenteral administration for neurosyphilis and congenital syphilis, and macrolide resistance. Linezolid was shown to be active against Treponema pallidum, the causative agent of syphilis, in vitro and in the rabbit model. We aimed to assess the efficacy of linezolid for treating early syphilis in adults compared with the standard of care benzathine penicillin G (BPG).

METHODS

We did a multicentre, open-label, non-inferiority, randomised controlled trial to assess the efficacy of linezolid for treating early syphilis compared with BPG. We recruited participants with serological or molecular confirmation of syphilis (either primary, secondary, or early latent) at one STI unit in a public hospital and two STI community clinics in Catalonia (Spain). Participants were randomly allocated in a 1:1 ratio using a computer-generated block randomisation list with six participants per block, to receive either oral linezolid (600 mg once per day for 5 days) or intramuscular BPG (single dose of 2·4 million international units) and were assessed for signs and symptoms (once per week until week 6 and at week 12, week 24, and week 48) and reagin titres of non-treponemal antibodies (week 12, week 24, and week 48). The primary endpoint was treatment response, assessed using a composite endpoint that included clinical response, serological response, and absence of relapse. Clinical response was assessed at 2 weeks for primary syphilis and at 6 weeks for secondary syphilis following treatment initiation. Serological cure was defined as a four-fold decline in rapid plasma reagin titre or seroreversion at any of the 12-week, 24-week, or 48-week timepoints. The absence of relapse was defined as the presence of different molecular sequence types of T pallidum in recurrent syphilis. Non-inferiority was shown if the lower limit of the two-sided 95% CI for the difference in rates of treatment response was higher than -10%. The primary analysis was done in the per-protocol population. The trial is registered at ClinicalTrials.gov (NCT05069974) and was stopped for futility after interim analysis.

FINDINGS

Between Oct 20, 2021, and Sept 15, 2022, 62 patients were assessed for eligibility, and 59 were randomly assigned to linezolid (n=29) or BPG (n=30). In the per-protocol population, after 48 weeks' follow-up, 19 (70%) of 27 participants (95% CI 49·8 to 86·2) in the linezolid group had responded to treatment and 28 (100%) of 28 participants (87·7 to 100·0) in the BPG group (treatment difference -29·6, 95% CI -50·5 to -8·8), which did not meet the non-inferiority criterion. The number of drug-related adverse events (all mild or moderate) was similar in both treatment groups (five [17%] of 29, 95% CI 5·8 to 35·8 in the linezolid group vs five [17%] of 30, 5·6 to 34·7, in the BPG group). No serious adverse events were reported during follow-up.

INTERPRETATION

The efficacy of linezolid at a daily dose of 600 mg for 5 days did not meet the non-inferiority criteria compared with BPG and, as a result, this treatment regimen should not be used to treat patients with early syphilis.

FUNDING

European Research Council and Fondo de Investigaciones Sanitarias.

Treatment of bacterial sexually transmitted infections in Europe: gonorrhoea, Mycoplasma genitalium, and syphilis

This review explores the therapeutic challenges of sexually transmitted infections (STI) in Europe, which include increasing antimicrobial resistance and limited progress in drug discovery. We primarily focus on gonorrhoea, Mycoplasma genitalium, and syphilis infections. For gonorrhoea with escalating resistance rates we explore the possibility of combining ceftriaxone with another antibiotic or using alternative antibiotics to mitigate resistance emergence, and we provide insights on the ongoing evaluation of new antimicrobials, like gepotidacin and zoliflodacin. In the case of M. genitalium, which exhibits high resistance rates to first and second-line treatments, we emphasize the importance of resistance-guided therapy in regions with elevated resistance levels, and highlight the limited alternative options, such as pristinamycin and minocycline. Furthermore, we address the challenges posed by syphilis, where the primary treatment consists of penicillin or doxycycline, with challenges arising in neurosyphilis, allergy, pregnancy, and supply shortages and discuss the ongoing evaluation of alternative antimicrobials (e.g., ceftriaxone, cefixime, linezolid). Our findings identify priority actions and provide concrete solutions for long-term effective management of STIs and antimicrobial resistance mitigation.

Syphilis

Syphilis is a sexually and vertically transmitted bacterial infection caused by the bacterium Treponema pallidum. Its prevalence is high in low-income and middle-income countries, and its incidence has increased in high-income countries in the last few decades among men who have sex with men. Syphilis is a major cause of adverse pregnancy outcomes in low-income and middle-income countries. Clinical features include a primary chancre at the point of inoculation, followed weeks later by the rash of secondary syphilis, a latent period, and in some cases, involvement of the eyes, CNS, and cardiovascular systems. It is diagnosed serologically. A single intramuscular dose of long-acting benzathine penicillin is recommended for people who have had syphilis for less than 1 year and longer courses for people with late latent syphilis. Control strategies include screening and treatment of all pregnant women, and targeted interventions for groups at high risk. Vaccine development, research on antibiotic prophylaxis, and digital messaging as prevention strategies are ongoing.

High-throughput nanopore sequencing of Treponema pallidum tandem repeat genes arp and tp0470 reveals clade-specific patterns and recapitulates global whole genome phylogeny

Sequencing of most Treponema pallidum genomes excludes repeat regions in tp0470 and the tp0433 gene, encoding the acidic repeat protein (arp). As a first step to understanding the evolution and function of these genes and the proteins they encode, we developed a protocol to nanopore sequence tp0470 and arp genes from 212 clinical samples collected from ten countries on six continents. Both tp0470 and arp repeat structures recapitulate the whole genome phylogeny, with subclade-specific patterns emerging. The number of tp0470 repeats is on average appears to be higher in Nichols-like clade strains than in SS14-like clade strains. Consistent with previous studies, we found that 14-repeat arp sequences predominate across both major clades, but the combination and order of repeat type varies among subclades, with many arp sequence variants limited to a single subclade. Although strains that were closely related by whole genome sequencing frequently had the same arp repeat length, this was not always the case. Structural modeling of TP0470 suggested that the eight residue repeats form an extended α-helix, predicted to be periplasmic. Modeling of the ARP revealed a C-terminal sporulation-related repeat (SPOR) domain, predicted to bind denuded peptidoglycan, with repeat regions possibly incorporated into a highly charged β-sheet. Outside of the repeats, all TP0470 and ARP amino acid sequences were identical. Together, our data, along with functional considerations, suggests that both TP0470 and ARP proteins may be involved in T. pallidum cell envelope remodeling and homeostasis, with their highly plastic repeat regions playing as-yet-undetermined roles.

The treatment outcome and predictors of serological response in syphilis in a sexually transmitted infections center, China

Serology is the mainstay for syphilis treatment monitoring. Baseline rapid plasma reagin (RPR) titre, HIV status, and syphilis stage have been found to be associated with the time to serological response among syphilis patients. This study mainly aims to evaluate the time to serological response, and to identify factors affecting the serological outcome. Medical records of syphilis cases diagnosed in Peking Union Medical College Hospital (PUMCH) between 2008 and 2018 were retrospectively reviewed. Kaplan-Meier analysis was performed to evaluate the median time to serologic response and cumulative probability of serologic response over time according to different variables. Cox regression model was conducted to find factors associated with serological response. There were 984 patients diagnosed with primary, secondary, or latent syphilis cases and receiving injections of benzathine penicillin G (BPG) as initial treatment at the Peking Union Medical College Hospital (PUMCH) between 2008 and 2018. Finally, data on 571 patients, including 49 (8.6%) primary syphilis, 261 (45.7%) secondary syphilis, and 261 (45.7%) latent syphilis, were used for analysis. It took longer time to achieve serological response for subjects aged ≥45 years than younger individuals (89 days versus 58 days; p=0.008). Males achieved serological response more quickly than females (71 days versus 83 days; p = 0.011). There was a significant difference in the time to serological response according to different syphilis stages (p < 0.001), with 55 days (95% CI, 43-67 days) for primary, 57 days (95% CI, 51-63 days) for secondary, and 117 days for latent syphilis. In addition, patients with lower baseline RPR titre had longer period to achieve serological response (252 days [95% CI, 129-375 days] for RPR titre ≤1:8, 78 days [95% CI, 63-93 days] for RPR titres from 1:16 to 1:32, and 53 days [95% CI, 49-57 days] for RPR titres ≥1:64, respectively; p<0.001). However, no significant difference in time to serological response to treatment was found according to HIV coinfection status. The result of multivariate Cox regression analysis showed that being older than 45 years with latent syphilis, HIV coinfection, or with baseline RPR titre ≤1:8 was associated with slow response. Among patients followed for at least 1 year or seroreverted, 128 (36.9%) had seroreverted within a year, and 219 (63.1%) still had a positive RPR after 1 year. For multiple logistical regression, being female and HIV coinfection were significantly associated with the failure of seroreversion (OR, 0.42 [95% CI, 0.26-0.68]; p <0.001). This study revealed that younger age, higher initial RPR titre, early syphilis stage, and HIV-negative status were associated with faster serological cure. Female sex, individuals with HIV coinfection, and latent syphilis were significantly associated with the failure of seroreversion.

Penicillin Reactions in Patients With Severe Rheumatic Heart Disease: A Presidential Advisory From the American Heart Association

Secondary antibiotic prophylaxis with regular intramuscular benzathine penicillin G (BPG) is the cornerstone of rheumatic heart disease management. However, there is a growing body of evidence that patients with rheumatic heart disease who have severe valvular heart disease with or without reduced ventricular function may be dying from cardiovascular compromise following BPG injections. This advisory responds to these concerns and is intended to: (1) raise awareness, (2) provide risk stratification, and (3) provide strategies for risk reduction. Based on available evidence and expert opinion, we have divided patients into low- and elevated-risk groups, based on symptoms and the severity of underlying heart disease. Patients with elevated risk include those with severe mitral stenosis, aortic stenosis, and aortic insuffiency; those with decreased left ventricular systolic dysfunction; and those with no symptoms. For these patients, we believe the risk of adverse reaction to BPG, specifically cardiovascular compromise, may outweigh its theoretical benefit. For patients with elevated risk, we newly advise that oral prophylaxis should be strongly considered. In addition, we advocate for a multifaceted strategy for vasovagal risk reduction in all patients with rheumatic heart disease receiving BPG. As current guidelines recommend, all low-risk patients without a history of penicillin allergy or anaphylaxis should continue to be prescribed BPG for secondary antibiotic prophylaxis. We publish this advisory in the hopes of saving lives and avoiding events that can have devastating effects on patient and clinician confidence in BPG.

Diagnosis and treatment of syphilis: 2019 Belgian National guideline for primary care

OBJECTIVES

In the last 10 years, Belgium and countries of the European Economic Area and other high-income countries observed an increasing trend in syphilis diagnoses. Men who have sex with men (MSM) are the most affected population explained by high rates of unprotected sex, a greater number of sexual partners, and risk compensation as a result of pre-exposure prophylaxis use. The 2019 European Centre for Disease Prevention and Control (ECDC) technical report on syphilis proposed interventions such as enhanced screening of specific populations at risk. This guideline will address these issues.

METHODS

We performed a systematic review of the evidence for diagnosing and treating syphilis.

RESULTS

Based on the results, recommendations were formulated for primary health care professionals in Belgium. This syphilis guideline addresses prioritised testing, the sample and test for the diagnosis, the treatment of a person with syphilis including syphilis serology follow-up, and partner management.

CONCLUSION

The identification and management of patients with syphilis will benefit from the application of this guideline.

Detection A2058G and A2059G on the 23S rRNA Gene by Multiplex Nested PCR to Identify Treponema pallidum Resistance to Azithromycin in Indonesia

Azithromycin is one of the antibiotics used to treat syphilis, especially in the context of penicillin allergy. Resistance to azithromycin is widely reported associated with one and/or two point mutations on the 23S rRNA gene but has yet to be described in Indonesia. Specimens were collected from 220 patients diagnosed with secondary syphilis. A multiplex nested PCR testing system using the 23S rRNA target gene of Treponema pallidum was designed using three pairs of primers. The first step used PCR pairs of primers to detect T. pallidum. In the second step of PCR using 2 pairs of primers were achieved to identify azithromycin resistant T. pallidum based on A2058G and A2059G point mutations. There was no T.pallidum identified resistant to azithromycin in Jakarta and Bandung. T. pallidum resistance to azithromycin were found in Makassar, Medan, and Bali. The majority of azithromycin resistance was found among heterosexual males and in patients living with HIV. This study has demonstrated T. pallidum resistance to azithromycin in Indonesia appears to be a novel variant of resistance, containing both the A2058G and A2059G mutations that was found in Medan and Makassar.

Treponema pallidum genome sequencing from six continents reveals variability in vaccine candidate genes and dominance of Nichols clade strains in Madagascar

In spite of its immutable susceptibility to penicillin, Treponema pallidum (T. pallidum) subsp. pallidum continues to cause millions of cases of syphilis each year worldwide, resulting in significant morbidity and mortality and underscoring the urgency of developing an effective vaccine to curtail the spread of the infection. Several technical challenges, including absence of an in vitro culture system until very recently, have hampered efforts to catalog the diversity of strains collected worldwide. Here, we provide near-complete genomes from 196 T. pallidum strains-including 191 T. pallidum subsp. pallidum-sequenced directly from patient samples collected from 8 countries and 6 continents. Maximum likelihood phylogeny revealed that samples from most sites were predominantly SS14 clade. However, 99% (84/85) of the samples from Madagascar formed two of the five distinct Nichols subclades. Although recombination was uncommon in the evolution of modern circulating strains, we found multiple putative recombination events between T. pallidum subsp. pallidum and subsp. endemicum, shaping the genomes of several subclades. Temporal analysis dated the most recent common ancestor of Nichols and SS14 clades to 1717 (95% HPD: 1543-1869), in agreement with other recent studies. Rates of SNP accumulation varied significantly among subclades, particularly among different Nichols subclades, and was associated in the Nichols A subclade with a C394F substitution in TP0380, a ERCC3-like DNA repair helicase. Our data highlight the role played by variation in genes encoding putative surface-exposed outer membrane proteins in defining separate lineages, and provide a critical resource for the design of broadly protective syphilis vaccines targeting surface antigens.

Sexually Transmitted Infections Treatment Guidelines, 2021

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

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).

Background review for the '2020 European guideline for the diagnosis and treatment of gonorrhoea in adults'

Gonorrhoea is a major public health concern globally. Increasing incidence and sporadic ceftriaxone-resistant cases, including treatment failures, are growing concerns. The 2020 European gonorrhoea guideline provides up-to-date evidence-based guidance regarding the diagnosis and treatment of gonorrhoea. The updates and recommendations emphasize significantly increasing gonorrhoea incidence; broad indications for increased testing with validated and quality-assured nucleic acid amplification tests (NAATs) and culture; dual antimicrobial therapy including high-dose ceftriaxone and azithromycin (ceftriaxone 1 g plus azithromycin 2 g) OR ceftriaxone 1 g monotherapy (ONLY in well-controlled settings, see guideline for details) for uncomplicated gonorrhoea when the antimicrobial susceptibility is unknown; recommendation of test of cure (TOC) in all gonorrhoea cases to ensure eradication of infection and identify resistance; and enhanced surveillance of treatment failures when recommended treatment regimens have been used. Improvements in access to appropriate testing, test performance, diagnostics, antimicrobial susceptibility surveillance and treatment, and follow-up of gonorrhoea patients are essential in controlling gonorrhoea and to mitigate the emergence and/or spread of ceftriaxone resistance and multidrug-resistant and extensively drug-resistant gonorrhoea. This review provides the detailed background, evidence base and discussions, for the 2020 European guideline for the diagnosis and treatment of gonorrhoea in adults (Unemo M, et al. Int J STD AIDS. 2020).

2020 European guideline for the diagnosis and treatment of gonorrhoea in adults

Gonorrhoea is a major public health concern globally. Increasing incidence and sporadic ceftriaxone-resistant cases, including treatment failures, are growing concerns. The 2020 European gonorrhoea guideline provides up-to-date evidence-based guidance regarding the diagnosis and treatment of gonorrhoea. The updates and recommendations emphasize significantly increasing gonorrhoea incidence; broad indications for increased testing with validated and quality-assured nucleic acid amplification tests and culture; dual antimicrobial therapy including high-dose ceftriaxone and azithromycin (ceftriaxone 1 g plus azithromycin 2 g) OR ceftriaxone 1 g monotherapy (ONLY in well-controlled settings, see guideline for details) for uncomplicated gonorrhoea when the antimicrobial susceptibility is unknown; recommendation of test of cure (TOC) in all gonorrhoea cases to ensure eradication of infection and identify resistance; and enhanced surveillance of treatment failures when recommended treatment regimens have been used. Improvements in access to appropriate testing, test performance, diagnostics, antimicrobial susceptibility surveillance and treatment, and follow-up of gonorrhoea patients are essential in controlling gonorrhoea and to mitigate the emergence and/or spread of ceftriaxone resistance and multidrug-resistant and extensively drug-resistant gonorrhoea. For detailed background, evidence base and discussions, see the background review for the present 2020 European guideline for the diagnosis and treatment of gonorrhoea in adults (Unemo M, et al. Int J STD AIDS. 2020).

2020 European guideline on the management of syphilis

The 2020 edition of the European guideline on the management of syphilis is an update of the 2014 edition. Main modifications and updates include: -The ongoing epidemics of early syphilis in Europe, particularly in men who have sex with men (MSM) -The development of dual treponemal and non-treponemal point-of-care (POC) tests -The progress in non-treponemal test (NTT) automatization -The regular episodic shortage of benzathine penicillin G (BPG) in some European countries -The exclusion of azithromycin as an alternative treatment at any stage of syphilis -The pre-exposure or immediate post-exposure prophylaxis with doxycycline in populations at high risk of acquiring syphilis.

Phase II trial evaluating the clinical efficacy of cefixime for treatment of active syphilis in non-pregnant women in Brazil (CeBra)

BACKGROUND

Syphilis is a sexually and vertically transmitted infection caused by the bacteria Treponema pallidum for which there are few proven alternatives to penicillin for treatment. For pregnant women infected with syphilis, penicillin is the only WHO-recommended treatment that will treat the mother and cross the placenta to treat the unborn infant and prevent congenital syphilis. Recent shortages, national level stockouts as well as other barriers to penicillin use call for the urgent identification of alternative therapies to treat pregnant women infected with syphilis.

METHODS

This prospective, randomized, non-comparative trial will enroll non-pregnant women aged 18 years and older with active syphilis, defined as a positive rapid treponemal and a positive non-treponemal RPR test with titer ≥1:16. Women will be a, domized in a 2:1 ratio to receive the oral third generation cephalosporin cefixime at a dose of 400 mg two times per day for 10 days (n = 140) or benzathine penicillin G 2.4 million units intramuscularly based on the stage of syphilis infection (n = 70). RPR titers will be collected at enrolment, and at three, six, and nine months following treatment. Participants experiencing a 4-fold (2 titer) decline by 6 months will be considered as having an adequate or curative treatment response.

DISCUSSION

Demonstration of efficacy of cefixime in the treatment of active syphilis in this Phase 2 trial among non-pregnant women will inform a proposed randomized controlled trial to evaluate cefixime as an alternative treatment for pregnant women with active syphilis to evaluate prevention of congenital syphilis.

TRIAL REGISTRATION

Trial identifier: www.Clinicaltrials.gov, NCT03752112. Registration Date: November 22, 2018.

The resurgence of syphilis in high-income countries in the 2000s: a focus on Europe

Syphilis can cause severe complications and sequelae. Following a decrease in reported cases in European Union/European Economic Area (EU/EEA) and other high-income countries in the 1980s and 1990s as a result of the HIV epidemic and ensuing changes in sexual behaviour, trends started to increase in the 2000s in a number of EU/EEA Member States with higher rates among men and a large proportion of cases reported among men who have sex with men (MSM), particularly HIV-positive MSM. Trends in EU/EEA Member States vary however with some countries continuing to report decreases in the number of reported cases (mostly in the Eastern part of EU/EEA) whereas many Western European countries report increasing numbers of cases. Increasing rates among women, although still relatively low, have been observed in a number of countries leading to concerns around mother-to-child transmission of syphilis and congenital syphilis. Similar overall trends are observed in other high-income countries with the exception of Japan where rates among heterosexual men and women have been rising at alarming levels. Control of syphilis requires use of comprehensive, evidence-based strategies which take into account lessons learned from previous control efforts as well as consideration of biomedical interventions.

Diagnosing acquired syphilis through oral lesions: the 12 year experience of an Oral Medicine Center

INTRODUCTION

A resurgence of syphilis in Brazil has been reported in recent years.

OBJECTIVE

With this in mind, the present study sought to investigate the frequency, demographics, and clinical characteristics of patients with acquired syphilis with oral involvement who received medical care at an Oral Medicine Reference Center in a Brazilian Public Hospital.

METHODS

A retrospective study, spanning a period of 12 years, was performed to identify changing trends in syphilis over time. Medical records from all patients diagnosed with acquired syphilis who received medical care at the Hospital's Oral Medicine Clinic from 2005 to 2016 were reviewed, and the demographic and clinical data were collected.

RESULTS

A total of 85 patients had been diagnosed with acquired syphilis, with a significant increase in the number of cases over the past 5 years. Patients ranged from 16 to 76 years of age, with a peak in the third and fourth decades. Forty-eight cases affected males (56.5%), while 37 cases affected females (43.5%). Most of the oral lesions appeared as unique ulcers or plaques, with the lips and tongue representing the most affected sites. All cases were positive for Venereal Disease Research Laboratory or Fluorescent Treponemal Antibody Absorption, and treatment was performed with Penicillin G benzathine in most cases (84.7%).

CONCLUSION

The frequency of oral syphilis has been rising over time and oral lesions may well represent a diagnostic clue; therefore, oral health professionals must be made aware and properly trained in an attempt to develop a high degree of clinical suspicion in the diagnosis of syphilis.

Syphilis

Syphilis is an infectious disease caused by the spirochaete Treponema pallidum subsp. pallidum which is transmitted by sexual contact or vertical transmission during pregnancy. The incidence of syphilis has increased in the last years, mainly among men who have sex with men. Without treatment, the disease develops into different clinical stages, being able to present cardiovascular or irreversible neurological complications after a number of years. The disease is classified as early syphilis - primary, secondary and early latent syphilis (less than 12 months) - which is contagious, and as late syphilis - late latent and tertiary syphilis- which is rarely contagious. Diagnosis and management are often a challenge because of its diversity of manifestations and the difficulty of interpretation of serological tests. The treatment of syphilis is based on penicillin or doxycycline in allergic patients. Treatment failure because of resistance has been described with azithromycin. The follow up with a serological test is recommended in all patients with syphilis in order to ascertain cure after the treatment and to diagnose possible reinfections.

Gene subtype analysis of Treponema pallidum for drug resistance to azithromycin

Azithromycin has been widely used for the treatment of Treponema pallidum. However, the drug resistance of T. pallidum for azithromycin is currently increasing. The aim of the present study was to analyze the association between gene subtypes of T. pallidum and drug resistance for azithromycin. The gene subtypes of T. pallidum were assayed by a polymerase chain reaction technique. Drug resistance of T. pallidum was analyzed using an antimicrobial susceptibility test. The results demonstrated that gene type tpr presented higher drug resistance compared with arp and tp0548 gene types of T. pallidum. Gene type tpr was identified as eight gene subtypes (14a/f, 14e/f, 12e/f, 12d/f, 6d/f, 11d/f, 14j/f and 8d/f) among 324 cases. It was identified that 23S rRNA A2058G mutation was observed in gene subtypes 14a/f, 14e/f and 12e/f. A2059G mutation occurred in the gene subtypes 8d/f, 12d/f, 6d/f, 11d/f and 14j/f. The proportions of azithromycin-resistant genotypes harboring either the A2058G or the A2059G mutation among the T. pallidum strains were 34.2 and 65.8%, respectively. The antimicrobial susceptibility test demonstrated that A2059G mutations exhibited a higher drug resistance for azithromycin compared with A2058G mutations. In conclusion, these results indicate that azithromycin resistance in T. pallidum is associated with gene subtype, which may contribute to the treatment of T. pallidum.

Evaluation of the Microbiological Efficacy of a Single 2-Gram Dose of Extended-Release Azithromycin by Population Pharmacokinetics and Simulation in Japanese Patients with Gonococcal Urethritis

The objective of this study was to analyze the relationship between the pharmacokinetic (PK)/pharmacodynamic (PD) parameters of a single 2-g dose of extended-release formulation of azithromycin (AZM-SR) and its microbiological efficacy against gonococcal urethritis. Fifty male patients with gonococcal urethritis were enrolled in this study. In 36 patients, the plasma AZM concentrations were measured using liquid chromatography-tandem mass spectrometry, the AZM MIC values for the Neisseria gonorrhoeae isolates were determined, and the microbiological outcomes were assessed. AZM-SR monotherapy eradicated N. gonorrhoeae in 30 (83%) of the 36 patients. AZM MICs ranged from 0.03 to 2 mg/liter. The mean value of the area under the concentration-time curve (AUC), estimated by population PK analysis using a two-compartment model, was 20.8 mg · h/liter. Logistic regression analysis showed that the PK/PD target value required to predict an N. gonorrhoeae eradication rate of ≥95% was a calculated AUC/MIC of ≥59.5. The AUC/MIC value was significantly higher in patients who achieved microbiological cure than in patients who achieved microbiological failure. Monte Carlo simulation using this MIC distribution revealed that the probability that AZM-SR monotherapy would produce an AUC/MIC exceeding the AUC/MIC target of 59.5 was 47%. Furthermore, the MIC distribution for strains isolated in this study was mostly consistent with that for strains currently circulating in Japan. In conclusion, in Japan, AZM-SR monotherapy may not be effective against gonococcal urethritis. Therefore, use of a single 2-g dose of AZM-SR either with or without other antibiotics could be an option to treat gonococcal urethritis if patients are allergic to ceftriaxone and spectinomycin or are diagnosed to be infected with an AZM-sensitive strain.

Rate of Decline in Nontreponemal Antibody Titers and Seroreversion After Treatment of Early Syphilis

BACKGROUND

Syphilis management is complex and demonstration of treatment response requires monitoring of nontreponemal antibody titers for a ≥ 4-fold decline and/or seroreversion to nonreactive titers.

METHODS

We evaluated data from a multicenter clinical trial of syphilis treatment conducted from 2000 to 2009 involving human immunodeficiency virus (HIV)-negative patients 18 years or older with early syphilis. To assess the rate of titer decline and seroreversion after effective therapy, rapid plasma reagin (RPR) titers were analyzed at 1, 3, 6, 9, and 12 months among patients with an appropriate treatment response. We plotted the rate of RPR titer decline after treatment, estimated the frequency of seroreversion, and conducted multivariate analyses to assess characteristics associated with seroreversion.

RESULTS

Among 369 (79.4%) of 465 HIV-negative patients with early syphilis who had an appropriate treatment response, 333 participants had complete RPR data over 12 months. Although the decline in RPR titers was ≥ 4-fold among 88.0% (293/333) of participants at 3 months and ≥ 8-fold among 77.8% at 6 months, only 9.6% achieved complete RPR seroreversion at 6 months and 17.1% at 12 months after therapy. Male sex (adjusted odds ratio, 4.3; 95% confidence interval, 1.8-10.5) and baseline RPR titers ≤ 1:32 (adjusted odds ratio, 14.5; 95% confidence interval, 6.8-31.2) were associated with higher odds of seroreversion compared with females and titers > 1:32, respectively.

CONCLUSIONS

Despite a ≥ 4-fold RPR titer decline after treatment, the majority of HIV-negative patients with early syphilis failed to have seroreversion at 12 months. Nontreponemal antibody titers often persist despite an appropriate treatment response.

Sexual health knowledge and practices and STI/HIV prevalence among long-distance truck drivers in Peru

Objectives

HIV and other sexually transmitted infections remain a challenge globally and many key groups have yet to be studied. Evidence shows that truck drivers may have high-risk behaviors and higher sexually transmitted infection/HIV prevalence because they are a highly mobile population. However, there is little to no information on this group in Peru. Therefore, we explored the sexual health knowledge and practices and carried out sexually transmitted infection/HIV testing among male truck drivers and their assistants in Peru.

Methods

We conducted a cross-sectional study utilizing cell phone-based behavioral surveys and sexually transmitted infection testing, including HIV, syphilis, gonorrhea, and chlamydia, with truck drivers and their assistants who were traveling on two major international highways in Peru.

Results

A total of 1150 truck drivers and assistants participated. Participants were middle-aged men (average age = 39.8 years), 96.0% had complete secondary education, 78.4% were in stable relationships, and 88.7% earned more than minimum wage. The majority were aware of sexually transmitted infections/HIV, but very few recognized sexually transmitted infection symptoms. Few participants (under 5%) reported recent sexually transmitted infection symptoms. Prevalence of sexually transmitted infections was also low: no one had gonorrhea; 0.1% had HIV; 0.4% had recent syphilis infection (rapid plasma reagin ≥1:8); and 2.0% had chlamydia. The prevalence of these diseases is not different from that of the general population in Peru.

Conclusion

When compared to other truck drivers worldwide, Peruvian truck drivers appear to have a lower risk of HIV/sexually transmitted infections. This may be since Peruvian drivers are older, more educated, have higher income, and spend fewer days away from home than their peers globally.

Effectiveness of single-dose azithromycin to treat latent yaws: a longitudinal comparative cohort study

BACKGROUND

Treatment of latent yaws is a crucial component of the WHO yaws eradication strategy to prevent relapse and the resulting transmission to uninfected children. We assessed the effectiveness of single-dose azithromycin to treat patients with latent yaws.

METHODS

This population-based cohort study included children (age <20 years) living on Lihir Island, Papua New Guinea, with high-titre (rapid plasma reagin titre ≥1:8) latent or active yaws, between April, 2013, and May, 2015. Latent yaws was defined as lack of suspicious skin lesions or presence of ulcers negative for Treponema pallidum subsp pertenue on PCR, and active yaws was defined as ulcers positive for T pertenue on PCR. All children received one oral dose of 30 mg/kg azithromycin. The primary endpoint was serological cure, defined as a two-dilution decrease in rapid plasma reagin titre by 24 months after treatment. Treatment of latent yaws was taken to be non-inferior to that of active yaws if the lower limit of the two-sided 95% CI for the difference in rates was higher than or equal to -10%. This study is registered with ClinicalTrials.gov, number NCT01955252.

FINDINGS

Of 311 participants enrolled, 273 (88%; 165 with latent yaws and 108 with active yaws) completed follow-up. The primary endpoint was achieved in 151 (92%) participants with latent yaws and 101 (94%) with active yaws (risk difference -2·0%, 95% CI -8·3 to 4·3), meeting the prespecified criteria for non-inferiority.

INTERPRETATION

On the basis of decline in serological titre, oral single-dose azithromycin was effective in participants with latent yaws. This finding supports the WHO strategy for the eradication of yaws based on mass administration of the entire endemic community irrespective of clinical status.

FUNDING

Newcrest Mining Limited and ISDIN laboratories.

Syphilis

Treponema pallidum subspecies pallidum (T. pallidum) causes syphilis via sexual exposure or via vertical transmission during pregnancy. T. pallidum is renowned for its invasiveness and immune-evasiveness; its clinical manifestations result from local inflammatory responses to replicating spirochaetes and often imitate those of other diseases. The spirochaete has a long latent period during which individuals have no signs or symptoms but can remain infectious. Despite the availability of simple diagnostic tests and the effectiveness of treatment with a single dose of long-acting penicillin, syphilis is re-emerging as a global public health problem, particularly among men who have sex with men (MSM) in high-income and middle-income countries. Syphilis also causes several hundred thousand stillbirths and neonatal deaths every year in developing nations. Although several low-income countries have achieved WHO targets for the elimination of congenital syphilis, an alarming increase in the prevalence of syphilis in HIV-infected MSM serves as a strong reminder of the tenacity of T. pallidum as a pathogen. Strong advocacy and community involvement are needed to ensure that syphilis is given a high priority on the global health agenda. More investment is needed in research on the interaction between HIV and syphilis in MSM as well as into improved diagnostics, a better test of cure, intensified public health measures and, ultimately, a vaccine.

Comparison of efficacy of treatments for early syphilis: A systematic review and network meta-analysis of randomized controlled trials and observational studies

BACKGROUND

Parenteral penicillin is the first-line regimen for treating syphilis, but unsuitable for some patients due to penicillin allergy and lacking health resources. Unfortunately, the efficacy of penicillin alternatives remains poorly understood. This study aimed to assess the efficacy of ceftriaxone and doxycycline/tetracycline in treating early syphilis relative to that of penicillin, and thereby to determine which antibiotic is a better replacement for penicillin.

METHOD

By searching literature from PubMed, Cochrane Central Register of Controlled Trials, Embase, the Web of Science, and ClinicalTrials.gov and systematically screening relevant studies, eligible randomized controlled trials (RCTs) and observational studies on treatments with penicillin, doxycycline/tetracycline, and ceftriaxone for early syphilis were identified and combined in this systematic review. Estimated risk ratios (RRs) and 95% confidence intervals (CIs) were utilized to compare their serological response and treatment failure rates. At 12-month follow up, serological response rates were compared by a direct meta-analysis and network meta-analysis (NMA), while treatment failure rates were compared with a direct meta-analysis.

RESULT

Three RCTs and seven cohort studies were included in this research. The results of NMA demonstrated that no significant differences existed in serological response rate at 12-month follow-up between any two of the three treatments (doxycycline/tetracycline vs. penicillin RR = 1.01, 95%CI 0.89-1.14; ceftriaxone vs. penicillin RR = 1.00, 95%CI 0.89-1.13; ceftriaxone vs. doxycycline/tetracycline RR = 0.99, 95%CI 0.96-1.03), which was consistent with the outcomes of the direct meta-analysis. In addition, the direct meta-analysis indicated that, at 12-month follow-up, penicillin and ceftriaxone treatment groups had similar treatment failure rates (RR = 0.92, 95%CI 0.12-6.93), while treatment failure rate was significantly lower among penicillin recipients than among doxycycline/tetracycline recipients (RR = 0.58, 95%CI 0.38-0.89).

CONCLUSION

Ceftriaxone is as effective as penicillin in treating early syphilis with regard to serological response and treatment failure rate. Compared with doxycycline/tetracycline, ceftriaxone appears to be a better choice as the substitution of penicillin.

Single Dose Versus 3 Doses of Intramuscular Benzathine Penicillin for Early Syphilis in HIV: A Randomized Clinical Trial

Background

Patients coinfected with syphilis and human immunodeficiency virus (HIV) may have a slower decrease in rapid plasma reagin (RPR) titers. Currently a single dose of 2.4 million units of intramuscular benzathine penicillin G (BPG) is recommended for the treatment of early syphilis. Some observational studies have suggested that this regimen may lead to high failure rates in coinfected patients.

Methods

We conducted an open-label randomized clinical trial to compare the efficacy of single-dose and 3-dose regimens of BPG for the treatment of early syphilis in HIV-infected individuals. RPR titers were monitored every 3 months. Treatment success was defined as a decrease in RPR titers of ≥2 dilutions (4-fold) during a 12-month follow-up period.

Results

Sixty-four patients were included. In the intention-to-treat analysis, treatment success rates were 80% (28 of 35 subjects) and 93% (27 of 29 subjects) in the single-dose and 3-dose regimens, respectively (absolute difference, 13% [95% confidence interval {CI}, -5% to 30%; P = .17). In the per-protocol analysis, success rates were 93% (27 of 29) and 100% in the single-dose and 3-dose regimens, respectively (absolute difference, 7% [95% CI, -7% to 22%]; P = .49). CD4 T-cell count, RPR titer and syphilis stage did not affect treatment results.

Conclusions

When compared with a single dose of BPG, a 3-dose regimen did not improve syphilis serological outcomes. Our results support the Centers for Disease Control and Prevention recommendation of a single dose of BPG in HIV-infected patients with early syphilis.

Clinical Trials Registration

NCT02611765.

Efficacy of Doxycycline in the Treatment of Syphilis

Doxycycline is an alternative antibiotic drug for the treatment of syphilis, but data on its efficacy, especially data on its efficacy against late latent syphilis, are limited. A retrospective study was conducted to evaluate the effectiveness of doxycycline for the treatment of patients with different stages of syphilis. Patients who received doxycycline treatment between June 2011 and June 2014 were involved. The serological response to doxycycline was defined as either a negative toluidine red unheated serum test (TRUST) result or a ≥4-fold decrease in titer at 12 months following the treatment. Univariate and multivariate logistic regression analyses were performed to identify factors associated with the serological response. During the study period, a total of 163 syphilis patients were treated with doxycycline, and 118 patients completed doxycycline treatment and the 12-month follow-up. Among the 118 patients, the serological response rate at 12 months was 100.0% (7/7) in patients with primary syphilis, 96.9% (62/64) in patients with secondary syphilis, 91.3% (21/23) in patients with early latent syphilis, and 79.2% (19/24) in patients with late latent syphilis. The total serological response rates were 92.4% (109/118) for preprotocol (PP) patients and 66.9% (109/163) for all intention-to-treat (ITT) patients. In multivariate analysis, patients who serologically responded at 12 months following treatment were positively associated with a higher baseline TRUST titer and an earlier syphilis stage than nonresponders. Our study showed excellent treatment outcomes in patients with different stages of syphilis. Our data, along with those from other reports, support the usage of doxycycline as a good alternative therapeutic option in the treatment of syphilis.

Macrolide Resistance in Treponema pallidum Correlates With 23S rDNA Mutations in Recently Isolated Clinical Strains

BACKGROUND

High rates of 23S rDNA mutations implicated in macrolide resistance have been identified in Treponema pallidum samples from syphilis patients in many countries. Nonetheless, some clinicians have been reluctant to abandon azithromycin as a treatment for syphilis, citing the lack of a causal association between these mutations and clinical evidence of drug resistance. Although azithromycin resistance has been demonstrated in vivo for the historical Street 14 strain, no recent T. pallidum isolates have been tested. We used the well-established rabbit model of syphilis to determine the in vivo efficacy of azithromycin against 23S rDNA mutant strains collected in 2004 to 2005 from patients with syphilis in Seattle, Wash.

METHODS

Groups of 9 rabbits were each infected with a strain containing 23S rDNA mutation A2058G (strains UW074B, UW189B, UW391B) or A2059G (strains UW228B, UW254B, and UW330B), or with 1 wild type strain (Chicago, Bal 3, and Mexico A). After documentation of infection, 3 animals per strain were treated with azithromycin, 3 were treated with benzathine penicillin G, and 3 served as untreated control groups. Treatment efficacy was documented by darkfield microscopic evidence of T. pallidum, serological response, and rabbit infectivity test.

RESULTS

Azithromycin uniformly failed to cure rabbits infected with strains harboring either 23S rDNA mutation, although benzathine penicillin G was effective. Infections caused by wild type strains were successfully treated by either azithromycin or benzathine penicillin G.

CONCLUSIONS

A macrolide resistant phenotype was demonstrated for all strains harboring a 23S rDNA mutation, demonstrating that either A2058G or A2059G mutation confers in vivo drug resistance.

Management of Gonorrhea in Adolescents and Adults in the United States

Gonorrhea is the second most commonly reported notifiable disease in the United States and is associated with serious health sequelae, including pelvic inflammatory disease, infertility, and ectopic pregnancy. Treatment for gonorrhea has been complicated by antimicrobial resistance. Neisseria gonorrhoeae has developed resistance to each of the antimicrobials that were previously recommended as first-line treatment regimens, and current treatment options are severely limited. This article summarizes the key questions and data that were discussed at the Sexually Transmitted Diseases (STD) Treatment Guidelines Expert Consultation meeting in April 2013, and the rationale for the 2015 Centers for Disease Control and Prevention STD treatment guidelines for gonococcal infections in adolescents and adults. Key issues addressed include whether to change the dosage of ceftriaxone and azithromycin used in the recommended dual treatment regimen, whether to continue to list dual treatment with cefixime and azithromycin as an alternative treatment regimen, and management of gonococcal infections in persons with severe cephalosporin allergy or suspected treatment failure.

Syphilis: Re-emergence of an old foe

Syphilis is caused by infection with Treponema pallidum subsp. pallidum, a not-yet-cultivable spiral-shaped bacterium that is usually transmitted by sexual contact with an infected partner or by an infected pregnant woman to her fetus. There is no vaccine to prevent syphilis. Diagnosis and treatment of infected individuals and their contacts is key to syphilis control programs that also include sex education and promotion of condom use to prevent infection. Untreated syphilis can progress through four stages: primary (chancre, regional lymphadenopathy), secondary (disseminated skin eruptions, generalized lymphadenopathy), latent (decreased re-occurrence of secondary stage manifestations, absence of symptoms), and tertiary (gummas, cardiovascular syphilis and late neurological symptoms). The primary and secondary stages are the most infectious. WHO estimates that each year 11 million new cases of syphilis occur globally among adults aged 15-49 years. Syphilis has re-emerged in several regions including North America, Western Europe, China and Australia. Host-associated factors that drive the re-emergence and spread of syphilis include high-risk sexual activity, migration and travel, and economic and social changes that limit access to health care. Early, uncomplicated syphilis is curable with a single intramuscular injection of benzathine penicillin G (BPG), the first line drug for all stages of syphilis. Emergence of macrolide-resistant T. pallidum has essentially precluded the empirical use of azithromycin as a second-line drug for treatment of syphilis. Virulence attributes of T. pallidum are poorly understood. Genomic and proteomic studies have provided some new information concerning how this spirochete may evade host defense mechanisms to persist for long periods in the host.

Syphilis: presentations in general medicine

Syphilis is caused by the spirochete bacteriumTreponema pallidumand can be transmitted both sexually and from mother to child.T pallidumcan infect any organ and produces a clinical disease with a relapsing and remitting course. It is not hard to see, therefore, why it is often described as the great mimic. In this review, we provide an update of modern syphilis epidemiology, clinical presentations, and testing and treatment strategies.

UK national guidelines on the management of syphilis 2015

These guidelines are an update for 2015 of the 2008 UK guidelines for the management of syphilis. The writing group have piloted the new BASHH guideline methodology, notably using the GRADE system for assessing evidence and making recommendations. We have made significant changes to the recommendations for screening infants born to mothers with positive syphilis serology and to facilitate accurate and timely communication between the teams caring for mother and baby we have developed a birth plan. Procaine penicillin is now an alternative, not preferred treatment, for all stages of syphilis except neurosyphilis, but the length of treatment for this is shortened. Other changes are summarised at the start of the guideline.

Comparison of serological responses to single-dose azithromycin (2 g) versus benzathine penicillin G in the treatment of early syphilis in HIV-infected patients in an area of low prevalence of macrolide-resistant Treponema pallidum infection

OBJECTIVES

Effectiveness of single-dose azithromycin (2 g) in the treatment of early syphilis among HIV-infected patients has rarely been evaluated in the era of combination ART.

METHODS

Consecutive HIV-infected patients with early syphilis, who received 2 g single-dose azithromycin or 2.4 MU benzathine penicillin G, between 2007 and 2014, were prospectively observed. Genotypic resistance to macrolides was determined in Treponema pallidum isolates identified from clinical specimens using PCR assays. Rapid plasma reagin (RPR) titres were determined at baseline and every 3 months after treatment. Primary outcome was a decline of RPR titre by ≥4-fold at 12 months after treatment.

RESULTS

During the study period, 162 HIV-infected patients with early syphilis received benzathine penicillin G and 237 patients received azithromycin. At 12 months follow-up, the serological response rate for penicillin and azithromycin groups was 61.1% and 56.5% (P = 0.41), respectively; respective response rate was 61.1% and 65.9% (P = 0.49) if we only included patients infected with T. pallidum not harbouring macrolide resistance in the azithromycin group. In multivariate analysis, RPR titres ≥1:32 (OR 2.56; 95% CI 1.55-4.21) and prior syphilis (OR 0.54; 95% CI 0.35-0.81) were predictors of serological response. Most common adverse effects of azithromycin included diarrhoea (52.7%), nausea (22.4%), abdominal pain (18.6%), bloating (17.7%) and lassitude/somnolence (27.4%).

CONCLUSIONS

In the setting of a low prevalence of macrolide-resistant T. pallidum, 2 g single-dose azithromycin achieved a similar serological response to benzathine penicillin G in HIV-infected patients with early syphilis. Major adverse effects of azithromycin were gastrointestinal symptoms and lassitude/somnolence.

Syphilis testing, typing, and treatment follow-up: a new era for an old disease

PURPOSE OF REVIEW

The past 15 years have seen a dramatic increase in syphilis diagnoses in several regions including China, North America, Western Europe and Australia. Worldwide, the disease remains prevalent, contributing to substantial adult morbidity and neonatal mortality. Testing and treatment strategies are largely informed by data from the early antibiotic era, but increasing use of molecular diagnostics and new screening strategies could improve the management of syphilis substantially.

RECENT FINDINGS

The review explores new testing strategies for syphilis, including the importance of screening test selection and advances in point-of-care diagnostics. It then examines molecular studies of Treponema pallidum, covering typing; macrolide resistance; association between genotype and phenotype and the use of PCR in testing and monitoring strategies.

SUMMARY

Clinicians should be aware of testing strategies employed by their laboratories to ensure optimal sensitivity and specificity. Locally available T. pallidum PCR assays may improve the diagnosis of early disease and inform antibiotic choice. Robust serologic follow-up is still required, but predictors of potential treatment failure, including PCR-measured bacterial load, have been identified. Re-treatment should be considered for patients in the serofast state. The publication of T. pallidum genomes would allow further and more detailed study of strains and disease pathogenesis.

Syphilis treatment in the presence of HIV: the debate goes on

PURPOSE OF REVIEW

Benzathine Penicillin G has been used to treat syphilis for over 50 years; however, the precise regimen of penicillin for treatment of syphilis in HIV-positive individuals remains a hot topic of debate. Although international guidelines recommend the same treatment for syphilis, regardless of HIV status, there are inconsistencies in prescribing practices among clinicians.

RECENT FINDINGS

Two previous systematic reviews have found limited evidence for enhanced treatment of syphilis in the presence of HIV. However, a growing body of literature indicates that the rate of asymptomatic neurosyphilis may be higher in HIV, and that syphilis infection is associated with poorer long-term neurocognitive outcomes. A number of retrospective studies propose that serological response may be slower, or serological failure may be higher, among HIV-positive individuals, but these studies are limited by high loss to follow-up, high reinfection rates and a focus on serological rather than clinical response. Beyond penicillin, some evidence suggests equivalence of macrolides, cephalosporins and doxycycline, although macrolide resistance is an increasing concern.

SUMMARY

Until a prospective, randomized study is conducted, inconsistency with treatment will continue. We offer a pragmatic approach to recognizing patients who may require further investigation or neuropenetrative antibiotic treatment.

Tonsillar Syphilis: an Unusual Site of Infection Detected by Treponema pallidum PCR

With the reemergence of syphilis, it is important that both clinical and public health practitioners recognize the various clinical manifestations of this disease (formerly known as "the great imitator") and become familiar with the newer diagnostic tests. Here we report the first case of tonsillar syphilis diagnosed by PCR.

Current standards for syphilis treatment: comparing the russian and foreign guidelines (part II)

The introduction of penicillin has been a breakthrough in the treatment of syphilis. For 70 years, penicillin remains the preferred drug for the treatment of all forms of the disease; its effectiveness has been proven by wide experience gained from clinical observations. However, a very limited number of published meta-analyzes, systematic reviews and data from randomized controlled trials on the comparative assessment of the effectiveness of various antibiotics and treatment regimens are currently available. Some aspects of syphilis treatment are insufficiently developed, particularly, the treatment schedules for neurosyphilis, syphilis in pregnancy, syphilis in HIV-infected individuals and persons allergic to penicillin. There are disagreements in the assessment of the clinical significance of serofast state after a course of antibiotic therapy. There is no uniform approach to the management of patients with treatment failures. This article compares the Russian standards for syphilis treatment set out in the «Federal guidelines for the management of patients with syphilis» with the current European recommendations of the International Union against Sexually Transmitted Infections (IUSTI) and the recommendations of the US Centers for Disease Control and Prevention (CDC). The peculiarities of these guidelines, their strengths and shortcomings, as well as controversial issues of syphilis therapy are discussed. The differences between the domestic and foreign recommendations are more significant in the section concerning the treatment of syphilis than in the section of diagnosis.

The molecular epidemiology of Treponema pallidum subspecies pallidum

Pathogens adapt and evolve in response to pressures exerted by host environments, leading to generation of genetically diverse variants. Treponema pallidum subspecies pallidum displays a substantial amount of interstrain diversity. These variants have been identified in various parts of the world, indicating transmission linkage between geographical regions. Genotyping is based on molecular characterisation of various loci in the syphilis treponeme genome, but still require further development and continued research, as new bacterial types are continually being detected. The goal for studying the molecular epidemiology of Treponema pallidum variants is the global monitoring of the transmission of genetically distinct organisms with different drug sensitivities and, potentially, different virulence proprieties.

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.

Management of syphilis in HIV-positive individuals

Since the turn of the millennium a sustained outbreak of syphilis among men who have sex with men continues, approximately 20–50% of whom have concurrent HIV infection. In this paper we aim to explore the controversies that exist around the management of syphilis in HIV-positive individuals. Not only do HIV-positive people have different clinical manifestations of syphilis they have higher rates of asymptomatic neurological involvement, slower serological response to treatment and higher serological failure than HIV-negative individuals in most studies. Whether long-term clinical outcomes are different or affected by the antibiotic regimen selected remains to be established. The optimal antimicrobial regimen to treat syphilis in HIV is unknown due to a dearth of randomised controlled trial data. International guidelines state that the antibiotic management of syphilis is the same regardless of HIV status, with early syphilis treated with a single dose of benzathine penicillin G 2.4mU intrmuscularly. In practice, however, the majority of surveyed clinicians do treat HIV-positive people with more intensive antibiotics suggesting a lack of faith in guidelines. Factors which appear to affect the likelihood of developing neurological disease include CD4+ count of <350 cells/μL, absence of antiretroviral therapy, rapid plasma regain (RPR) or venereal diseases reference laboratory titre (VDRL) >1 : 32, late-latent disease or lack of response to standard antibiotic treatment. We recommend a low-threshold for offering antibiotic treatment effective against neurosyphilis in HIV-positive people with syphilis, especially if they exhibit any of the above factors.

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.