Antiretroviral therapy is associated with reduced serologic failure rates for syphilis among HIV-infected patients

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.

Prevalence and Treatment Outcomes of Syphilis among People with Human Immunodeficiency Virus (HIV) Engaging in High-Risk Sexual Behavior: Real World Data from Northern Greece, 2019-2022

In this study, we aimed to assess the prevalence of syphilis among people with human immunodeficiency virus (HIV; PWH) engaging in high-risk sexual behavior, determine the stage of syphilis, and evaluate treatment efficacy. A retrospective single-center cohort study was conducted at the AHEPA University General Hospital of Thessaloniki, focusing on PWH at high risk for sexually transmitted infections (STIs) attending outpatient care from January 2019 to December 2022. Sociodemographic and clinical data were collected, incident syphilis rates were identified, associations with HIV-related characteristics were explored, and the treatment response was assessed. Among 991 participants, 94 PWH were diagnosed with syphilis, representing 9.4% of the cohort. Incident syphilis cases experienced a decrease in the early COVID-19 era compared to 2019, followed by a gradual increase leading up to 2022. The majority of syphilis cases were asymptomatic latent syphilis (71.1%). Men who have sex with men (MSM) and younger individuals exhibited higher rates of co-infection during the study period. No significant association was found between incident syphilis and HIV-related factors. Most syphilis cases (86%) were treated with benzathine penicillin G (BPG). Treatment with BPG and doxycycline showed an increased success rate (96.7% vs. 92.9%), with no statistically significant difference observed between them (p = 0.438). This study highlights the alarming incidence of syphilis among PWH engaging in high-risk sexual behavior, particularly among younger MSM. BPG remains effective, and alternative regimens like doxycycline show promise, especially in settings with penicillin shortages or patient allergies.

Changes in rapid plasma reagin titers in patients with syphilis before and after treatment: A retrospective cohort study in an HIV/AIDS referral hospital in Tokyo

INTRODUCTION

Although the rapid plasma reagin (RPR) test is used to determine treatment efficacy for syphilis, animal studies show that it decreases gradually after an initial increase even without treatment. Pre-treatment changes in RPR titer in humans and its relationship with post-treatment changes in RPR titer are not well known.

METHODS

We retrospectively analyzed the clinical records of syphilitic patients who underwent automated RPR (Mediace) testing twice before treatment (i.e., at diagnosis and treatment initiation) within 1-3 months at an HIV/AIDS referral hospital in Japan between 2006 and 2018. The RPR values were expressed as the ratio to the value at treatment initiation. The mean monthly relative change in the RPR after treatment was calculated on the log2 scale for each patient and analyzed by multivariable linear regression.

RESULTS

Sixty-eight patients were identified. The median age was 45 (interquartile range [IQR], 38-50), 98.5% (67/68) were men, and 97.1% (66/68) had HIV. The median RPR titer ratio at treatment initiation/diagnosis was 0.87 (IQR, 0.48-1.30). The RPR titer decreased more than twofold in 26.5% (18/68) and more than fourfold in 10.3% (7/68) before treatment. In the multivariable analysis, higher age (predicted monthly RPR relative change on the log2 scale 0.23/10 years [95% confidence interval [CI], 0.090-0.37]), history of syphilis (0.36 [95% CI, 0.07-0.65]), and a lower ratio of RPR at treatment initiation/diagnosis (-0.52/every 10-fold increase [95% CI, -0.81 to -0.22]) were associated with a slower RPR decrease after treatment.

CONCLUSIONS

In a mostly HIV patient population, RPR titer can show more than four-fold spontaneous increase or decrease within 1-3 months. Pre-treatment spontaneous decrease of RPR titer was associated with a slower decrease in post-treatment RPR titer.

Syphilis Infections, Reinfections and Serological Response in a Large Italian Sexually Transmitted Disease Centre: A Monocentric Retrospective Study

Background: Syphilis infection does not confer definitive and protective immunity against reinfection, and crucial aspects of repeated episodes of syphilis are far from being understood, especially among people living with HIV (PLWH). Methods: In order to explore the burden of syphilis in a large cohort of HIV-negative patients and PLWH, this retrospective study describes the demographics, clinical presentation and treatment outcome of patients with syphilis treated at our clinic from 2013 to 2021. Results: Within the study period, 1859 syphilis episodes (827, 44.5% first infections and 1032, 55.5% reinfections) were recorded. A total of 663 patients, of whom 347 (52%) had PLWH, were considered. Syphilis was mostly diagnosed in males (77%) and European (79%) patients. More than half of syphilis episodes were recorded during the late latent stage (64%) or during follow-up/screening visits for other diseases, while symptomatic stages led to a diagnosis in almost half of HIV-negative patients (p < 0.001). PLWH with syphilis infection were predominantly homo/bisexual (p < 0.001). A significantly higher rate of syphilis reinfection was observed in PLWH, who also demonstrated a higher range of subsequent episodes. The serofast state was found to be similar at the 6- and 12-month follow-up visits. The multivariate analysis carried out in the HIV-positive group showed that an RPR titre >1:16 was an independent predictor for serological non-response. Conclusions: Syphilis reinfections are predominantly diagnosed in HIV-positive MSM. The high rate of asymptomatic presentation among PLWH supports the role of periodical syphilis screening. In PLWH, the only baseline factor associated with an increased risk of non-response was an RPR titre >1:16, while assessment at 12 months after treatment increased the possibility of detecting a serological response, indicating that PLWH have a slower serological response to treatment.

Investigating latent syphilis in HIV treatment-experienced Ethiopians and response to therapy

Objectives

We investigated people with HIV (PWH) receiving combination antiretroviral therapy (cART) for latent syphilis infection prevalence, risk factors, treatment response, and neurosyphilis.

Methods

A prospective follow-up study was conducted on PWH and latent syphilis. The cases were randomly assigned to receive either benzathine penicillin G (BPG) or doxycycline (DOXY), and the posttreatment response was evaluated after 12 and 24 months. The traditional algorithm was used for serodiagnosis, and a semi-quantitative rapid plasma reagin (RPR) test monitored disease activity and treatment effectiveness.

Results

Of the 823 participants, 64.8% were women, and the mean age was 41.7±10 years. Thirty-one (3.8%) of the participants (22 males and nine females) had latent syphilis. The risk factors were male sex (aOR = 3.14), increasing age (aOR = 1.04 per year), and cART duration (aOR = 1.01 per month). Baseline RPR titers were: ≤1:4 in 19 (61.3%), between 1:8 and 1:32 in 10 (32.2%), and >1:32 in 2 (6.4%). None of the seven cerebrospinal fluid analyses supported a neurosyphilis diagnosis. In the 12^th month of treatment, 27 (87.1%) had adequate serological responses, three (9.7%) had serological nonresponse, and one (3.2%) had treatment failure. Syphilis treatment was repeated in the last four cases with the alternative drug. In terms of adequate serologic response, both therapies were comparable at the 12^th month, p = 0.37. All cases responded to treatment in the 24^th month.

Conclusion

In PWH receiving cART, latent syphilis occurred more in men than women, suggesting an investigation of sexual practices and the impact of antenatal syphilis screening. Syphilis disease activity reduces in the latent stage. Therefore, the routine cerebrospinal fluid analysis contributes little to the diagnosis of asymptomatic neurosyphilis and the treatment success of latent syphilis. DOXY is an alternative to BPG, and cART improves serologic response to latent syphilis treatment.

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.

Seroreduction of syphilis nontreponemal titers during pregnancy for women with and without HIV coinfection

OBJECTIVE

To evaluate the effect of HIV coinfection on nontreponemal titers during pregnancy in women with syphilis.

METHODS

This is a secondary analysis of pregnant women with syphilis in the prospective, observational Zambian Preterm Birth Prevention Study (ZAPPS). Treponemal (TPPA) and nontreponemal (RPR) testing were performed on serum biospecimens, resulting in 47 participants with serologically-confirmed syphilis (27 HIV-positive, 20 HIV-negative). The primary outcome, achievement of RPR titer seroreduction during pregnancy, was analyzed by logistic regression. Secondary outcomes included overall titer reduction, seroreduction rate, serologic cure, and adverse pregnancy outcomes.

RESULTS

Seroreduction of RPR titer occurred in 78% (21/27) of women with HIV versus 45% (9/20) of women without (aOR 4.66; 95%CI 1.14-19.08). Overall RPR titer reduction, rates of seroreduction per week, and the proportion achieving serologic cure each trended higher among women with HIV compared to those without HIV. There was a trend toward decreased stillbirth incidence in participants achieving seroreduction (OR 0.15, 95%CI 0.01-1.58).

CONCLUSION

HIV coinfection in this cohort of Zambian women with syphilis was associated with greater odds of RPR titer seroreduction during pregnancy. Pregnant women with syphilis and HIV may not be at increased risk for delayed syphilis treatment response compared to women without HIV.

Effects of Case Management on Risky Sexual Behaviors and Syphilis Among HIV-Infected Men Who Have Sex With Men in China: A Randomized Controlled Study

BACKGROUND

The prevalence of syphilis is very high in human immunodeficiency virus (HIV)-positive men who have sex with men (MSM), and effective interventions are needed to educate HIV-positive individuals about behavioral and biological risk factors. Therefore, we developed a standard case management process and conducted a randomized controlled study to investigate the impact on risky sexual behaviors and syphilis in HIV-positive MSM.

METHODS

Men who have sex with men (n = 220) were enrolled and randomized to the case management intervention group and the control group between May 2016 and January 2017. The control group received routine HIV-related care. In addition to routine HIV-related care, those in the intervention group regularly received extended services from a well-trained case manager. Epidemiological information was collected during the baseline face-to-face interviews by a trained investigator. Serological tests for syphilis and assessments of risky sexual behaviors were performed at baseline and 6 and 12 months after the initiation of treatment.

RESULTS

The syphilis incidence rates in the intervention and control groups were 11.3 per 100 person-years and 20.6 per 100 person-years, respectively. The multivariable-adjusted hazard ratio (95% confidence inter) for syphilis in case management group was 0.34 (0.14-0.87). The percentages of participants who resumed risky sexual behaviors in both groups were significantly reduced (P < 0.05) but did not significantly differ between the 2 groups.

CONCLUSIONS

A case management intervention reduced the incidence of syphilis in HIV-positive MSM. We should further increase the content of case management on the basis of providing routine HIV-related care to those people.

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.

Clinical and Ophthalmological Characteristics of Ocular Syphilis in a Retrospective Tertiary Hospital Cohort

BACKGROUND

Data on ocular syphilis (OS) and its clinical presentation are currently insufficient. This study aimed to investigate the characteristics of a cohort with a high OS incidence at a university hospital in Germany, focusing on the clinical presentation of OS.

METHODS

This single-center cohort study retrospectively analyzed data on 90 patients with 109 episodes of syphilis between 2008 and 2018. Cases of OS were identified and additionally reevaluated through a study-specific secondary assessment by an ophthalmologist specializing in uveitis.

RESULTS

Twenty-three patients (26%) were diagnosed with OS, 16 (70%) of whom were with binocular involvement. Uveitis, especially that of the posterior segment, showed a high prevalence. Lumbar puncture was performed in 20 OS patients (87%), of whom 17 (85% of those with lumbar puncture/74% in total) met the 2018 Centers for Disease Control and Prevention criteria for likely neurosyphilis. Five (22%) of 23 patients had HIV infection, of whom 2 did not receive antiretroviral therapy. The preferred syphilis treatment regimens were benzylpenicillin and ceftriaxone, which yielded favorable serological, clinical, and ophthalmological outcomes.

CONCLUSIONS

A high incidence of OS was identified, and physicians should be aware of uveitis as a manifestation of syphilis. Most patients presented with uveitis and syphilis in an early or late latent stage and showed central nervous system involvement.

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.

Ocular and neurosyphilis: epidemiology and approach to management

PURPOSE OF REVIEW

In the context of a resurgence of syphilis worldwide, it can be anticipated that a rise in cases of ocular, otic, and neurosyphilis will also be seen. This article reviews the current epidemiology, manifestations, and approach to management and treatment.

RECENT FINDINGS

Although studies continue investigating alternate approaches and new diagnostic tests for ocular and neurosyphilis, few data exist to change current diagnostic algorithms and approaches to diagnosis, management, or follow up.

SUMMARY

The diagnosis of neurologic and eye/ear involvement with syphilis may be delayed because of a lack of specificity of findings, low suspicion for syphilis, fluctuation in symptoms, and/or similarities in presentation to other diseases. A high index of suspicion for syphilis and re-education about the protean manifestations of syphilis by all clinicians is required provide timely diagnosis and management of ocular, otic, and neurosyphilis.

Neurosyphilis Treatment Outcomes After Intravenous Penicillin G Versus Intramuscular Procaine Penicillin Plus Oral Probenecid

BACKGROUND

Data comparing neurosyphilis treatment regimens are limited.

METHODS

Participants were enrolled in a study of cerebrospinal fluid (CSF) abnormalities in syphilis that was conducted at the University of Washington between April 2003 to May 2014. They were diagnosed with syphilis and referred by their providers due to concerns for neurosyphilis. We evaluated 150 people with CSF abnormalities who were treated with either intravenous aqueous penicillin G (PenG) or intramuscular aqueous procaine penicillin G plus oral probenecid (APPG-P). An abnormal CSF diagnosis was defined as a white blood cell (WBC) count >20/µL, a CSF protein reading >50 mg/dL, or a reactive CSF-Venereal Disease Research Laboratory test (VDRL). Hazard ratios for normalization of CSF or serum measures were determined using Cox regression.

RESULTS

In individuals treated with either PenG or APPG-P, CSF WBCs and CSF-VDRL reactivity normalized within 12 months after treatment, while protein normalized more slowly and less completely. There was no relationship between treatment regimen or human immunodeficiency virus (HIV) status and likelihood of normalization of any measure. Among those living with HIV, CSF WBC counts and CSF-VDRL reactivity were more likely to normalize in those treated with antiretrovirals. Unexpectedly, CSF WBCs were more likely to normalize in those with low CD4+ T cell counts. When neurosyphilis was more stringently defined as a reactive CSF-VDRL, the relationship with the CD4+ T cell count remained unchanged.

CONCLUSIONS

In the current antiretroviral treatment era, neurosyphilis treatment outcomes are not different for PenG and APPG-P, regardless of HIV status. The relationship between the normalization of CSF WBC counts and CD4+ T cell counts may indicate continued imprecision in neurosyphilis diagnostic criteria, due to HIV-related CSF pleocytosis.

Neurosyphilis and Lyme neuroborreliosis

PURPOSE OF REVIEW

Neurosyphilis (NS) and Lyme neuroborreliosis (LNB) are spirochetal diseases with distinct clinical manifestations. The diagnosis of NS remains challenging due to imperfect diagnostic criteria and testing modalities. With LNB, misconceptions about diagnosis and treatment lead to considerable morbidity and drug related adverse effects.

RECENT FINDINGS

Although studies continue investigating alternate approaches and new diagnostic tests for NS, few data exist to change current approaches to diagnosis, management or follow up. In the diagnosis of LNB, the chemokine CXCL13 shows promising diagnostic accuracy. A systematic review discourages the use of cell-based assays when investigating Lyme disease. Clinical studies show no benefit from extended antibiotic treatment for patients with unspecific symptoms labelled as having Lyme disease.

SUMMARY

The diagnosis of NS may be delayed due to a lack of specificity of findings, low suspicion for syphilis, and/or similarities in presentation to other diseases. A high index of suspicion for syphilis is required provide timely diagnosis and management of NS. Fortunately, penicillin remains the treatment of choice. Overdiagnosis and overtreatment in patients labelled as having Lyme disease can be avoided by an evidence-based approach towards diagnosis and treatment.

Deciphering the serological response to syphilis treatment in men living with HIV

OBJECTIVE

To examine syphilis serology after treatment in people living with HIV. No unanimous guidelines exist in the era of increasing coinfection.

DESIGN

Retrospective review using a tertiary care clinic in Toronto from 2000 to 2017.

METHODS

The 2015 Centers for Diseases Control and Prevention syphilis guidelines were used to define an adequate serologic response. Cumulative distribution estimates and proportional hazards models accounting for interval censoring estimated the time to serologic response and seroreversion. Multistate models were used to investigate extended periods of serofast serology.

RESULTS

A total of 171 patients with syphilis met our inclusion criteria (16 primary, 53 secondary, 26 early latent, 46 late latent, 30 neurosyphilis). Serologic response was achieved by 12 months for 65 (94%) patients and by 12-18 months for four (6%) patients with primary/secondary syphilis. For latent and neurosyphilis, 94 (92%) achieved serologic response by 24 months and one (1%) at 24.1 months. 84 (49%) patients achieved seroreversion with a median (95% confidence interval) time of 2 (1.44, 2.68) years. Latent syphilis was associated with a lower likelihood of achieving serologic response [hazard ratio (HR) = 0.52, P = 0.05] and seroreversion (HR = 0.27, P < 0.001) compared with primary/secondary syphilis. The probability of moving from a new infection state to a serofast state within 1 year was high (0.65) but the 1-year probability of transitioning from a serofast state to seroreversion was low (0.27).

CONCLUSION

The majority of people living with HIV infected with syphilis will achieve an adequate serologic response as per the Centers for Diseases Control and Prevention guidelines. Seroreversion was observed in about half but can take years to occur.

Predictors of serofast state after treatment for early syphilis in HIV-infected patients

OBJECTIVES

Non-treponemal serological tests are used to monitor treatment response during syphilis infection. Syphilis- and HIV-coinfected patients may experience incomplete resolution in non-treponemal titres, which is referred to as the serofast state. The goal of this study was to evaluate risk factors for serofast state in HIV-infected patients.

METHODS

From November 2015 to June 2018, 1530 HIV-positive patients were tested for syphilis using a Treponema pallidum particle agglutination (TPPA) assay. Among TPPA-positive patients, medical records were reviewed for early syphilis infection. Serofast state was defined as a less than four-fold decrease in non-treponemal antibody titres during a 6-month follow-up period in the absence of symptoms of syphilis. Baseline characteristics were tested as predictive factors of serological response.

RESULTS

In all, 515 patients (33.7%) tested positive in TPPA assays, and in 163 patients at least one previous syphilis infection was documented. A total of 61 out of 163 patients (37.4%) were in a serofast state. A history of previous syphilis infection (61 vs. 43%; P = 0.04) was more common in serofast patients than in patients with serological cure after 6 months. Non-treponemal titres ≥ 1:32 before therapy (47 vs. 25%; P = 0.005) and adjunctive corticosteroids to prevent the Jarisch-Herxheimer reaction (35% vs 15%; P = 0.006) were associated with serological cure after 6 months, but corticosteroid therapy had no influence at 12 months. The intensity of syphilis treatment did not affect serological cure.

CONCLUSION

Corticosteroids for prevention of the Jarisch-Herxheimer reaction were associated with earlier serological cure. Although serological response is the accredited surrogate method to monitor syphilis treatment, the biological significance of the serofast state remains unclear.

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

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

Incidence and Predictors of Serological Treatment Response in Early and Late Syphilis Among People Living With HIV

Background

Few studies have investigated predictors of serological response to syphilis treatment in people living with HIV (PLWH).

Methods

This was a retrospective, longitudinal study on PLWH who were diagnosed with and treated for syphilis who had an assessable serological response between January 2004 and June 2016. Serological treatment response (TR) was defined as a ≥4-fold decline in rapid plasma reagin (RPR) titers or a reversion to nonreactive (if RPR ≤1:4 at diagnosis) 12 months after treatment for early syphilis and 24 months after treatment for late syphilis. Factors associated with a TR were assessed with multivariate Cox proportional hazard models for recurrent events.

Results

A total of 829 episodes of syphilis (686 early, 143 late) in 564 patients were recorded. TR was observed in 732 (88%) syphilis episodes. The proportion of TR differed between early and late syphilis (89% vs 83%, respectively; P = .045). For early syphilis, TR was associated with a higher nadir CD4+ cell count (adjusted hazard ratio [AHR], 1.06; P = .029), an RPR titer >1:32 at diagnosis (AHR, 1.26; P = .009), secondary syphilis (AHR, 1.29; P = .008), and cases of syphilis diagnosed in more recent calendar years (AHR, 1.36; P < .0001). In late syphilis, TR was more likely to occur for first infections (AHR, 1.80; P = .027), for episodes that occurred in more recent years (AHR, 1.62; P = .007), and for RPR titers >1:32 at diagnosis (AHR, 2.04; P = .002). TR was not associated with the type of treatment regimen in early and late syphilis.

Conclusions

Higher RPR titers at diagnosis and a diagnosis of syphilis that was made in more recent years were associated with TR in early and late syphilis.

Risk Factors and Incidence of Syphilis in Human Immunodeficiency Virus (HIV)-Infected Persons: The HIV Outpatient Study, 1999-2015

Background

Since 2000, the incidence of syphilis has been increasing, especially among gay, bisexual, and other men who have sex with men (MSM) in the United States. We assessed temporal trends and associated risk factors for newly diagnosed syphilis infections among human immunodeficiency virus (HIV)-infected patients during a 16-year period.

Methods

We analyzed data from the HIV Outpatient Study (HOPS) cohort participants at 10 US HIV clinics during 1999-2015. New syphilis cases were defined based on laboratory parameters and clinical diagnoses. We performed Cox proportional hazards regression analyses of sociodemographic, clinical, and behavioral risk factors for new syphilis infections.

Results

We studied 6888 HIV-infected participants; 641 had 1 or more new syphilis diagnoses during a median follow-up of 5.2 years. Most participants were male (78%), aged 31-50 years, and 57% were MSM. The overall incidence was 1.8 (95% confidence interval [CI], 1.6-1.9) per 100 person-years (PY) and it increased from 0.4 (95% CI, .2-.8) to 2.2 (95% CI, 1.4-3.5) per 100 PY during 1999-2015. In multivariable analyses adjusting for calendar year, risk factors for syphilis included age 18-30 years (hazard ratio [HR], 1.3 [95% CI, 1.1-1.6]) vs 31-40 years, being MSM (HR, 3.1 [95% CI, 2.4-4.1]) vs heterosexual male, and being non-Hispanic black (HR, 1.6 [95% CI, 1.4-1.9]) vs non-Hispanic white.

Conclusions

The increases in the syphilis incidence rate through 2015 reflect ongoing sexual risk and highlight the need for enhanced prevention interventions among HIV-infected patients in care.

Association of interleukin-10 promoter polymorphisms with serofast state after syphilis treatment

OBJECTIVES

Recent studies suggested that upregulation of anti-inflammatory immune response during early syphilis may be associated with persistence of Treponema pallidum infection despite adequate treatment, resulting in a serofast state. The objective of this study was to determine whether enhanced interleukin (IL)-10-related response during early T. pallidum infection increased the risk of serofast syphilis.

METHODS

Two IL10 gene promoter polymorphisms affecting IL-10 production (-1082A>G [rs1800896], -592C>A [rs1800872]) and serum levels of IL-10 were measured in 80 patients with early syphilis before and 6 months after penicillin treatment and in 24 healthy volunteers (control group).

RESULTS

After 6 months, patients were stratified based on serological response into two groups: (1) serofast state (n = 28) and (2) serologically cured (n = 52). Pretreatment and post-treatment serum IL-10 levels were significantly higher in patients who remained serofast compared with those who had a serological cure (p<0.001). The GG genotype of the -1082A>G (rs1800896) polymorphism and the CC genotype of the -592C>A (rs1800872) polymorphism were significantly correlated with higher serum IL-10 levels. Moreover, the OR for remaining serofast for carriers of these genotypes was 16.2 (95% CI: 4.1 to 65.0, p<0.0001) and 2.9 (95% CI: 1.4 to 5.9, p=0.002), respectively.

CONCLUSIONS

We showed that a pronounced anti-inflammatory immune response may be an important predictor for the serofast state. Additionally, host-related factors such as polymorphisms of immune regulatory genes may influence the risk of remaining serofast after syphilis therapy.

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.

Factors associated with syphilis incidence in the HIV-infected in the era of highly active antiretrovirals

After several years of steady decline, syphilis is reemerging globally as a public health hazard, especially among people living with human immunodeficiency virus (HIV). Syphilis resurgence is observed mainly in men who have sex with men (MSM), yet other transmission groups are affected too. In this manuscript, we study the factors associated with syphilis incidence in the Swiss HIV cohort study in the era of highly effective antiretrovirals. Using parametric interval censored models with fixed and time-varying covariates, we studied the immunological, behavioral, and treatment-related elements associated with syphilis incidence in 3 transmission groups: MSM, heterosexuals, and intravenous drug users. Syphilis incidence has been increasing annually since 2005, with up to 74 incident cases per 1000 person-years in 2013, with MSM being the population with the highest burden (92% of cases). While antiretroviral treatment (ART) in general did not affect syphilis incidence, nevirapine (NVP) was associated with a lower hazard of syphilis incidence (multivariable hazard ratio 0.5, 95% confidence interval 0.2-1.0). We observed that condomless sex and younger age were associated with higher syphilis incidence. Moreover, time-updated CD4, nadir CD4, and CD8 cell counts were not associated with syphilis incidence. Finally, testing frequency higher than the recommended once a year routine testing was associated with a 2-fold higher risk of acquiring syphilis. Condomless sex is the main driver of syphilis resurgence in the Swiss HIV Cohort study; ART and immune reconstitution provide no protection against syphilis. This entails targeted interventions and frequent screening of high-risk populations. There is no known effect of NVP on syphilis; therefore, further clinical, epidemiological, and microbiological investigation is necessary to validate our observation.

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

INTRODUCTION

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

Necrotizing retinitis due to syphilis in a patient with AIDS

The ocular manifestations of syphilis are varied. Ocular syphilis can occur during any stage of infection and involve virtually any part of the eye. In immunocompetent individuals, the most common etiologies include syphilitic uveitis. Although the clinical presentation of ocular syphilis in HIV-infected patients is also widespread, posterior segment involvement has been more commonly described particularly in patients with AIDS. The diagnosis of syphilitic retinitis is challenging since its clinical presentation mimics retinitis caused by other viral etiologies. In addition, HIV-infected individuals with syphilis are more likely to develop aberrant serologic responses. Recognition of syphilitic retinitis and prompt initiation of penicillin therapy is of critical importance since syphilitic retinitis generally responds well to treatment and loss of vision is reversible. In this report, we describe a 39-year-old female with advanced stages of AIDS who developed necrotizing retinitis due to syphilis. Prompt initiation of intravenous penicillin led to excellent visual outcome for this patient despite significantly decreased visual acuity on presentation.

Incidence of Co-Infections of HIV, Herpes Simplex Virus Type 2 and Syphilis in a Large Cohort of Men Who Have Sex with Men in Beijing, China

BACKGROUND

The HIV-epidemic among MSM in China has worsened. In this key population, prevalence of HSV-2 and syphilis infection and co-infection with HIV is high.

METHODS

A longitudinal study was conducted (n = 962) in Beijing, China, with three overlapping cohorts (n = 857, 757 and 760) consisting of MSM that were free from pairs of infections of concern (i.e. HIV-HSV-2, HIV-syphilis, HSV-2-syphilis) at baseline to estimate incidence of HIV, HSV-2, syphilis, and those of co-infection.

RESULTS

The incidence of HIV, HSV-2 and syphilis in the overall cohort was 3.90 (95% CI = 2.37, 5.43), 7.87 (95% CI = 5.74, 10.00) and 6.06 (95% CI = 4.18, 7.94) cases per 100 person-years (PYs), respectively. The incidence of HIV-HSV-2, HIV-Syphilis and HSV-2-Syphilis co-infections was 0.30 (95% CI = 0.29, 0.88), 1.02 (95% CI = 0.13, 2.17) and 1.41 (95% CI: 0.04, 2.78) cases per 100 PYs, respectively, in the three sub-cohorts constructed for this study.

CONCLUSIONS

The incidence of HIV, HSV-2 and syphilis was very high and those of their co-infections were relatively high. Such co-infections have negative impacts on the HIV/STI epidemics. Prevention practices need to take such co-infections into account.

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.

Reduced Treponema pallidum-Specific Opsonic Antibody Activity in HIV-Infected Patients With Syphilis

BACKGROUND

Human immunodeficiency virus (HIV)-infected individuals may have poorer serological responses to syphilis treatment and may be more likely to experience neurosyphilis. Treponema pallidum is cleared from sites of infection by opsonization, ingestion, and killing by macrophages.

METHODS

Serum samples from 235 individuals with syphilis were tested for T. pallidum-specific opsonic activity. Blood T. pallidum concentrations were determined by real-time polymerase chain reaction amplification of the tp0574 gene, and T. pallidum was detected in cerebrospinal fluid (CSF) by reverse-transcriptase polymerase chain reaction of 16S ribosomal RNA.

RESULTS

Opsonic activity was higher with higher serum rapid plasma reagin titers (P < .001), and in those treated for uncomplicated syphilis before serum collection (P < .001). Opsonic activity was lower in HIV-infected than in HIV-uninfected individuals even after the above factors were taken into account (P = .006). In participants in whom blood T. pallidum was detectable, those with the highest opsonic activity had lower blood T. pallidum concentrations. In multivariable analyses, there was not a significant relationship between opsonic activity and detection of T. pallidum in CSF or CSF-VDRL reactivity.

CONCLUSIONS

Serum T. pallidum-specific opsonic activity is significantly lower in HIV-infected individuals. Impaired T. pallidum-specific immune responses could contribute to differences in the course of disease or treatment response.

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.

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.

Sexually transmitted diseases treatment guidelines, 2015

These guidelines for the treatment of persons who have or are at risk for sexually transmitted diseases (STDs) were updated by CDC after consultation with a group of professionals knowledgeable in the field of STDs who met in Atlanta on April 30-May 2, 2013. The information in this report updates the Sexually Transmitted Diseases Treatment Guidelines, 2010 (MMWR Recomm Rep 2010;59 [No. RR-12]). These updated guidelines discuss 1) alternative treatment regimens for Neisseria gonorrhoeae; 2) the use of nucleic acid amplification tests for the diagnosis of trichomoniasis; 3) alternative treatment options for genital warts; 4) the role of Mycoplasma genitalium in urethritis/cervicitis and treatment-related implications; 5) updated HPV vaccine recommendations and counseling messages; 6) the management of persons who are transgender; 7) annual testing for hepatitis C in persons with HIV infection; 8) updated recommendations for diagnostic evaluation of urethritis; and 9) retesting to detect repeat infection. Physicians and other health-care providers can use these guidelines to assist in the prevention and treatment of STDs.

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.

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.

Impact of HIV-1 infection on the clinical presentation of syphilis in men who have sex with men

Men who have sex with men (MSM), especially those with HIV-1 infection, are disproportionately affected by syphilis in higher income countries. The course, and some of the clinical features of the disease, especially the development of neurosyphilis, can be affected by HIV-1 co-infection. This review documents potential differences in the clinical features of syphilis in HIV-1 infected and uninfected MSM and highlights the importance of a thorough examination and high index of suspicion when seeing and treating MSM at risk of sexually transmissible infections.

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.

A single dose of benzathine penicillin G is as effective as multiple doses of benzathine penicillin G for the treatment of HIV-infected persons with early syphilis

BACKGROUND

Treatment guidelines recommend the use of a single dose of benzathine penicillin G (BPG) for treating early syphilis in human immunodeficiency virus (HIV)-infected persons. However, data supporting this recommendation are limited. We examined the efficacy of single-dose BPG in the US Military HIV Natural History Study.

METHODS

Subjects were included if they met serologic criteria for syphilis (ie, a positive nontreponemal test [NTr] confirmed by treponemal testing). Response to treatment was assessed at 13 months and was defined by a ≥4-fold decline in NTr titer. Multivariate Cox proportional hazard regression models were utilized to examine factors associated with treatment response.

RESULTS

Three hundred fifty subjects (99% male) contributed 478 cases. Three hundred ninety-three cases were treated exclusively with BPG (141 with 1 dose of BPG). Treatment response was the same among those receiving 1 or >1 dose of BPG (92%). In a multivariate analysis, older age (hazard ratio [HR], 0.82 per 10-year increase; 95% confidence interval [CI], .73-.93) was associated with delayed response to treatment. Higher pretreatment titers (reference NTr titer <1:64; HR, 1.94 [95% CI, 1.58-2.39]) and CD4 counts (HR, 1.07 for every 100-cell increase [95% CI, 1.01-1.12]) were associated with a faster response to treatment. Response was not affected by the number of BPG doses received (reference, 1 dose of BPG; HR, 1.11 [95% CI, .89-1.4]).

CONCLUSIONS

In this cohort, additional BPG doses did not affect treatment response. Our data support the current recommendations for the use of a single dose of BPG to treat HIV-infected persons with early syphilis.

One dose versus three weekly doses of benzathine penicillin G for patients co-infected with HIV and early syphilis: a multicenter, prospective observational study

BACKGROUND

One dose of benzathine penicillin G (BPG) has been recommended for HIV-infected patients with early syphilis (primary, secondary, and early latent syphilis) in the sexually transmitted diseases treatment guidelines, but clinical data to support such a recommendation are limited.

METHODS

We prospectively observed the serological response to 1 or 3 weekly doses of BPG in HIV-infected adults who sought treatment of early syphilis at 8 hospitals around Taiwan. Rapid plasma reagin (RPR) titers were followed every 3-6 months after treatment. The serological response was defined as a 4-fold or greater decline in RPR titers at 12 months of treatment. The missing values were treated by following the last-observed-carried-forward principle. We hypothesized that 1 dose was non-inferior to 3 weekly doses of BPG with the non-inferiority margin for the difference of serological response set to 10%.

RESULTS

Between 2007 and 2012, 573 patients completed at least 12 months of follow-up: 295 (51.5%) receiving 1 dose of BPG (1-dose group) and 278 (48.5%) 3 doses (3-dose group). Overall, 198 patients (67.1%; 95% confidence interval [CI], 61.4-72.5%) in the 1-dose group achieved serological response at 12 months, as did 208 patients (74.8%; 95% CI, 69.3-79.8%) in the 3-dose group (one-sided 95% CI of the difference, 15.1%). In the multivariate analysis, secondary syphilis (adjusted odds ratio [AOR], 1.90; 95% CI 1.17-3.09), RPR titer ≥32 (AOR, 1.93; 95% CI, 1.38-2.69), and 3 doses of BPG (AOR, 1.68; 95% CI, 1.20-2.36) were independently associated with a serological response. The time to the first episode of treatment failure was 1184 (standard deviation [SD], 70.5) and 1436 (SD, 80.0) days for 1- and 3-dose group, respectively.

CONCLUSIONS

Single-dose BPG resulted in a higher serological failure rate and shorter time to treatment failure than 3 weekly doses of BPG in the treatment of early syphilis in HIV-infected patients.

Predictors of serological failure after treatment in HIV-infected patients with early syphilis in the emerging era of universal antiretroviral therapy use

BACKGROUND

The optimal treatment of early syphilis (primary, secondary and early latent) in HIV-infected patients remains controversial. The Center for Diseases Control STD Treatment Guidelines recommended 1 dose of benzathine penicillin G (BPG) regardless of HIV infection. However, many providers modify the treatment for early syphilis.

METHODS

We performed a retrospective chart review of all cases of early syphilis with positive serologic test results in HIV-infected patients from May 2006 to May 2011 in 2 large, urban HIV clinics. Early syphilis includes primary, secondary, and early latent syphilis. Serological failure was defined as a lack of 4-fold decrease in rapid plasma reagent (RPR) titers 9 to 12 months after syphilis treatment. Patients whose RPR titers decreased after treatment and subsequently increased 4-fold at 9 to 12 months were excluded from the analysis of serological response because of possibility as "reinfection". Baseline characteristics were tested as predictive factors of serological failure using a univariate and multivariate logistic regression model, respectively.

RESULTS

Of 560 patients with confirmed cases of early syphilis, 51 (9.0%) experienced serological failure. Multivariate logistic regression modeling demonstrated that the predictive factors associated with serological failure after early syphilis treatment were baseline RPR titer ≤ 1:16 (OR 3.91 [95% CI, 2.04-7.47]), a previous history of syphilis (OR 3.12 [95% CI, 1.55-6.26]), and a CD4 T-cell count below 350 cells/ml (OR 2.41 [95% CI, 1.27-4.56]). Of note, type of syphilis treatment (1 dose versus 3 doses of BPG) did not appear to affect the proportion of serological failure (4% versus 10%, P = 0.29), however the power of this study to detect small differences was limited.

CONCLUSIONS

HIV-infected patients with baseline RPR titer ≤1:16, syphilis history, and/or a CD4 T-cell count <350 cells/ml should be closely monitored for serologic failure after early syphilis treatment. This study did not detect a substantial difference between treatment with > 1 dose of BPG and decreased frequency of serological failure, supporting the current recommendation that one dose of BPG is adequate treatment for early syphilis in HIV-infected patients.

The impact of combined antiretroviral therapy on biologic false-positive rapid plasma reagin serologies in a longitudinal cohort of HIV-infected persons

BACKGROUND

Our objective was to determine the impact of combination antiretroviral therapy (cART) and the degree of immunosuppression on biologic false-positive (BFP) rapid plasma reagin (RPR) tests among persons infected with human immunodeficiency virus (HIV).

METHODS

This was a nested retrospective study of HIV-infected patients enrolled in the Johns Hopkins HIV Clinical Cohort. BFP RPR was defined as a reactive RPR and a nonreactive fluorescent treponemal antibody-absorption (FTA-ABS) test. Patients with BFP tests were compared to 2 control groups: HIV-infected patients (1) with active syphilis (reactive RPR and FTA-ABS) and (2) without current syphilis (nonreactive RPR). A persistent BFP test was defined by having at least 2 visits with consistent BFP at all visits.

RESULTS

Of 711 patients with HIV, 96 (13.5%) had BFP tests and 342 (48.1%) had syphilis. Twenty-two of 96 (23%) had persistent BFP tests. cART use was associated with decreased odds of BFP tests compared to having syphilis (adjusted odds ratio [AOR], 0.31; 95% CI, .15-.63) and those with nonreactive RPR (AOR, 0.42; 95% CI, .22-.81). cART use was also associated with decreased odds of BFP persistence (AOR, 0.07; 95% CI, .01-.33). Neither CD4 count nor HIV RNA was significantly associated with BFP test results. Lower RPR titers, younger age, and injection drug use were associated with increased odds of BFP.

CONCLUSIONS

The use of cART appears to decrease the odds of BFP RPR tests. This finding suggests that nontreponemal titer fluctuations in persons with HIV may reflect the influence of factors unrelated to syphilis disease activity.

The Role of Sexually Transmitted Infections in HIV-1 Progression: A Comprehensive Review of the Literature

Due to shared routes of infection, HIV-infected persons are frequently coinfected with other sexually transmitted infections (STIs). Studies have demonstrated the bidirectional relationships between HIV and several STIs, including herpes simplex virus-2 (HSV-2), hepatitis B and C viruses, human papilloma virus, syphilis, gonorrhea, chlamydia, and trichomonas. HIV-1 may affect the clinical presentation, treatment outcome, and progression of STIs, such as syphilis, HSV-2, and hepatitis B and C viruses. Likewise, the presence of an STI may increase both genital and plasma HIV-1 RNA levels, enhancing the transmissibility of HIV-1, with important public health implications. Regarding the effect of STIs on HIV-1 progression, the most studied interrelationship has been with HIV-1/HSV-2 coinfection, with recent studies showing that antiherpetic medications slow the time to CD4 <200 cells/µL and antiretroviral therapy among coinfected patients. The impact of other chronic STIs (hepatitis B and C) on HIV-1 progression requires further study, but some studies have shown increased mortality rates. Treatable, nonchronic STIs (i.e., syphilis, gonorrhea, chlamydia, and trichomonas) typically have no or transient impacts on plasma HIV RNA levels that resolve with antimicrobial therapy; no long-term effects on outcomes have been shown. Future studies are advocated to continue investigating the complex interplay between HIV-1 and other STIs.

Syphilis treatment response among HIV-discordant couples in Zambia and Rwanda

BACKGROUND

Syphilis continues to be a common sexually transmitted infection, despite the availability of inexpensive and effective treatment. Infection in human immunodeficiency virus (HIV)-discordant couples is important because syphilis increases the risk of HIV acquisition. Current US treatment guidelines recommend 1 dose of benzathine penicillin for early syphilis, irrespective of HIV status, but data from coinfected patients are limited.

METHODS

Retrospective analysis of 1321 individuals in 2 African HIV-discordant couple cohorts was performed. Cox proportional hazards analysis and multivariable modeling were used to assess predictors of serologic response to treatment at 180 days and 400 days. Modeling was performed for all episodes of positive rapid plasma reagin (RPR) test results and on a subset with higher RPR titers (≥1:4).

RESULTS

A total of 1810 episodes of syphilis among 1321 individuals were treated with penicillin between 2002 and 2008. Although a positive RPR was more common in the HIV-infected partners, HIV infection did not impact the likelihood of serologic response to therapy (odds ratio [OR], 1.001; P = .995). By 400 days, 67% had responded to therapy, 27% were serofast, and 6.5% had documented reinfection. Prevalent infections were more likely to remain serofast than incident infections (33% vs 20% at 400 days).

CONCLUSIONS

In 2 HIV-serodiscordant couple cohorts in Africa, incident syphilis had a very good likelihood of response to penicillin therapy, irrespective of HIV infection. This supports current Centers for Disease Control and Prevention treatment guidelines. A high proportion of prevalent RPR-positive infections remain serofast despite treatment.

Long-term neurological follow-up of HIV-positive patients diagnosed with syphilis

No cerebrospinal fluid (CSF) abnormalities are found in HIV-positive patients in long-term follow-up after standard syphilis treatment. Syphilis has been reported to have immunological effects on HIV infection and HIV is known to modulate both the manifestations of syphilis and the serological response to therapy. HIV-positive patients who had been diagnosed with and treated for syphilis prior to 2007 were identified. Patients were consented for lumbar puncture. Serum HIV viral load, CD4 count and CSF were recorded. Thirty-five patients with previously diagnosed and treated syphilis underwent lumbar puncture. Thirty-four patients had a normal neurological exam. Only one patient had an abnormal mean white cell count (10.7 cells per high-power field). The finding that those with previously diagnosed syphilis had normal CSF and clinical findings is reassuring and supports the practice of using standard syphilis therapy in HIV-positive patients.

Syphilis and neurosyphilis in human immunodeficiency virus-infected patients: a retrospective study at a teaching hospital in Taiwan

BACKGROUND AND PURPOSE

Some studies have reported that the risk factors for neurosyphilis in patients with human immunodeficiency virus (HIV) and syphilis co-infection, include CD4 cell counts ≤350cells/μL and rapid plasma reagin (RPR) titer ≥1:32. However, neurosyphils can develop even in patients with CD4 cell counts >350cells/μL or RPR titer <1:32. In this study, we evaluated the outcome of syphilis to treatment in HIV-infected patients, and analysed the predictors of neurosyphilis in this population.

METHODS

We retrospectively reviewed medical records of HIV-infected patients with syphilis who visited the China Medical University Hospital between January 2000 and December 2009. Neurosyphilis was defined by white blood cell (WBC) counts >20cells/μL in the cerebrospinal fluid (CSF) sample or elevated Venereal Disease Research Laboratory (VDRL) titers of the CSF samples. Treatment failure was defined as less than 4-fold decrease in the serum RPR titer at or beyond 12 months post-treatment in case of early syphilis, and, at or beyond 24 months in case of late syphilis.

RESULTS

One hundred and twenty-one HIV-infected patients (average age, 32 years) with syphilis were included in this study. Of 63 patients who had follow-up of serologic responses, 30 (47.6%) failed to respond to treatment. CD4 cell counts ≤200cells/μL was the indicator for treatment failure (P=.029). Lumbar puncture was performed in 65 patients, and 14 patients were diagnosed with neurosyphilis. At the time of lumbar puncture, 31 and 19 of the 65 patients showed CD4 cell counts of >350cells/μL and RPR of <1:32, respectively. An HIV viral load (VL) ≥10000copies/mL was found to be associated with the development of neurosyphilis (P=.016).

CONCLUSION

In HIV-infected patients with syphilis, RPR titer should be evaluated more frequently when CD4 count ≤200cell/μL is associated with treatment failure. Lumbar puncture for the diagnosis of neurosyphilis should be considered in patients with HIV and syphilis co-infection, even in patients with CD4 cell counts >350cells/μL, and particularly when the HIV VL ≥10000copies/mL.