Syphilis

Syphilis vaccine development: Aligning vaccine design with manufacturing requirements

Syphilis, caused by Treponema pallidum subsp. pallidum, is a global health concern with increasing rates worldwide. Current prevention strategies, including screen-and-treat approaches, are not sufficient to resolve rising infection rates, emphasizing the need for a vaccine. Developing a syphilis vaccine necessitates a range of cross-disciplinary considerations, including essential disease-specific protection, technical requirements, economic feasibility, manufacturing constraints, public acceptance, equitable vaccine access, alignment with global public vaccination programs, and identification of essential populations to be vaccinated to achieve herd immunity. Central to syphilis vaccine development is prioritization of global vaccine availability, including access in low- to middle-income settings. Various vaccine platforms, including subunit, virus-like particle (VLP), mRNA, and outer membrane vesicle (OMV) vaccines, present both advantages and challenges. The proactive consideration of both manufacturing feasibility and efficacy throughout the pre-clinical research and development stages is essential for producing an efficacious, inexpensive, and scalable syphilis vaccine to address the growing global health burden caused by this disease.

Maternal and neonatal outcomes of congenital syphilis at a tertiary care center in Turkey; a retrospective observational study

BACKGROUND

Maternal syphilis (MS) can lead to significant maternal morbidity and neonatal morbidity and mortality if inadequately treated. This study is aimed to retrospectively analyse the maternal and neonatal outcomes of pregnant women diagnosed with MS at our clinic.

MATERIALS AND METHODS

We accessed the medical records of 64 cases diagnosed with MS between 2020 and 2022 from our hospital database and the perinatology clinic archives in this retrospective observational study. Case distributions by years, sociodemographic characteristics, and maternal and neonatal outcomes were recorded.

RESULTS

The distribution of MS cases was 16 (25.0%) in 2020, 20 (31.25%) in 2021, and 28 (43.75%) in 2022. The mean age of the patients was 26.4 ± 6.3 years, mean BMI was 23.36 ± 3.14, the smoking rate was 31.25%, and the majority of patients were educated to primary level (37.5%). Most were housewives (43.75%), lived in urban areas (43.75%), and had lower-level incomes (68.75%). In addition, 43.75% received adequate maternal treatment, the caesarean delivery rate was 43.25%, 31.25% had preterm births, and the mean birth weight was 2956.36 + 514.46 g. CS was largely diagnosed during delivery or the postpartum period (43.75%). Fifty percent of patients were in the latent stage, gestational hypertension and preeclampsia were present in four case each (6.25%), and gestational diabetes mellitus in eight (12.5%). Twenty babies (31.25%) were admitted to the neonatal intensive care unit, eight (12.5%) had congenital anomalies, 12 had foetal growth restriction (18.25%), stillbirth was present in four (6.25%) case, and early neonatal death in four (6.25%).

CONCLUSIONS

Delayed diagnosis and inadequate treatment of MS can lead to significant maternal and neonatal morbidity and mortality. Well-planned antenatal care services should be provided for all expectant mothers in order to reduce these adverse outcomes.

Early neurosyphilis with serofast state

We report a rare case of confirmed early neurosyphilis with serofast state in HIV-negative patient, with uncontrolled type 2 diabetes mellitus. Syphilitic meningitis was diagnosed initially on serology and cerebrospinal fluid (CSF) analysis. The patient had persistently raised non-treponemal titres on serum with negative CSF venereal disease research laboratory result, following treatment during 3 years of follow-up.

Treponema pallidum recombinant protein Tp0768 enhances the ability of HUVECs to promote neutrophil chemotaxis through the TLR2/ER stress signaling pathway

Neutrophils are essential cells involved in inflammation. However, the specific mechanism of neutrophil chemotaxis induced by Treponema pallidum remains unknown. In this study, human umbilical vein endothelial cells (HUVECs) were utilized as target cells to investigate the expression levels of chemokines when stimulated with different concentrations of Tp0768 (also known as TpN44.5 or TmpA, a T. pallidum infection dependent antigen). The results indicated that Tp0768 treatment enhanced neutrophil chemotaxis in HUVECs, which was closely associated with the expression levels of CXCL1, CXCL2, and CXCL8 (also known as interleukin-8). At the same time, the results show that the Toll-like receptor 2 (TLR2) signaling pathway is activated and that endoplasmic reticulum (ER) stress occurs. Furthermore, the findings revealed that the use of protein kinase RNA-like endoplasmic reticulum kinase (PERK) and immunoglobulin-regulated enhancer 1 (IRE1) inhibitors reduced the expression levels of CXCL1, CXCL2, and CXCL8. Additionally, inhibiting TLR2 significantly decreased the expression levels of ER stress-related proteins (PERK and IRE1), CXCL1, CXCL2, and CXCL8. Consequently, neutrophil chemotaxis was significantly inhibited after treatment with TLR2, PERK, and IRE1 inhibitors. These findings shed light on the role of Tp0768 in enhancing neutrophil chemotaxis in endothelial cells, providing a foundation for further exploration of syphilis pathogenesis and offering a new direction for the diagnosis and treatment of T. pallidum infection.

Loop-Mediated Isothermal Amplification Assay Using Gold Nanoparticles for Detecting Treponema pallidum subspp. pallidum

BACKGROUND

Venereal syphilis in humans is caused by Trepenoma pallidum subspp. pallidum. A study has shown that 30,302 individuals in Thailand had syphilis in 2020, with a male-to-female ratio of 1:0.8 and the highest incidence rate at ages between fifteen and twenty-four.

METHODS

This research aimed to develop a loop-mediated isothermal amplification assay using gold nanoparticles (LAMP-AuNPs). Analytical sensitivity, diagnostic specificity, accuracy, and predictive values for each technique are provided.

RESULTS

The diagnosis sensitivities of polymerase chain reaction using agarose gel electrophoresis (PCR-AGE), loop-mediated isothermal amplification assay using agarose gel electrophoresis (LAMP-AGE), and LAMP-AuNPs were 116 ng/µL, 11.6 ng/µL, and 11.6 ng/µL, respectively. We evaluated the analytical specificity using PCR and a LAMP-based assay, and there was no cross-reactivity to Leptospira interrogans, Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, human immunodeficiency virus (HIV), and healthy humans. After analyzing 400 serum samples of patients suspected of syphilis, the LAMP-AGE and LAMP-AuNPs assays displayed 100% diagnostic sensitivity scores, 91% diagnostic specificity scores, 95.5% accuracy rates, 100% positive predictive values (PPVs), and 91% negative predictive values (NPVs), the positive likelihood ratio (LR+) was 11.11, while the negative likelihood ratio (LR-) was 0. Conversely, for PCR assays displayed 100% diagnostic sensitivity scores, 94.5% diagnostic specificity scores, 97.25% accuracy rates, 100% PPVs, and 94.5% NPVs, LR+ was 18.18, and LR- was 0.

CONCLUSIONS

The LAMP-AuNPs technique demonstrates rapidity, affordability, and convenience, rendering it well-suited for point-of-care applications in the diagnosis, prevention, and management of pathogenic infections.

Secondary Syphilis Can Simultaneously Mimic Cholestatic Liver Injury and Glomerular Nephropathy

Syphilis, a disease affecting millions, still poses challenges for men who have sex with men in high-income countries and often presents in varying ways. It is exceedingly rare for syphilis to simultaneously cause an acute liver injury and nephropathy. This case describes the concomitant clinical presentation of these abnormalities and also describes a liver injury that mimicked cholestatic disease. Treatment of syphilis led to complete resolution of the liver and kidney injury. This case demonstrates a need to exclude syphilis in patients with high-risk behaviors who present with cholestatic liver injury in atypical fashions.

Molecular Detection and Typing of Treponema pallidum in Non-Ocular Samples from Patients with Ocular Syphilis

INTRODUCTION

Ocular syphilis is a rare but potentially sight-threatening manifestation of infection with the spirochete Treponema pallidum subspecies pallidum. Molecular strain typing of clinical specimens obtained from patients with syphilis can provide useful epidemiological and clinical information. In this study, we assess the utility of non-ocular clinical samples in strain typing for patients with diagnosed ocular syphilis.

METHODS

We collected samples of excess blood, serum, and cerebrospinal fluid (CSF) from 6 patients with ocular syphilis treated in 2013-2016. DNA was extracted, purified, and then analyzed using an enhanced molecular typing method including sequence analysis of tp0548, number of repeats in the arp gene, and restriction fragment length polymorphism of the tpr gene.

RESULTS

Molecular strain typing based on tp0548 gene sequence analysis revealed two cases of type F and two cases of type G in 3 of 6 (50%) cases with CSF samples, 1 of which was obtained after starting antibiotics. In a patient with 2 distinct episodes, the same tp0548 type (type G) was identified in both episodes using different sample types (CSF, whole blood). Serum samples were available in 6 cases, but none were successfully typed with any of the methods. Amplification of the tpr and arp genes was unsuccessful in all cases. Overall, strain types were identified in 4 of the 7 episodes.

CONCLUSION

Treponema pallidum strain types F and G were detected in CSF or whole blood in 4 of 7 episodes in this series. We demonstrate moderate sensitivity of strain typing in ocular syphilis using non-ocular clinical specimens.

Oral syphilis - the great imitator: a series of six cases

Syphilis is an infectious disease which can present with multitudinous mucocutaneous manifestations. Often referred to as the 'great mimicker', syphilis can present with non-specific symptoms and has a tropism for various organ systems. The oral cavity has been identified as a site commonly affected in the early stages of syphilis infection. Identification of the diverse presentations seen across the different stages of syphilis infection can assist in early diagnosis and treatment for this cohort of patients. Despite accurate diagnostic tools and the susceptibility of the infection to standard antimicrobial therapy, syphilis infections continue to rise worldwide.We present the clinical features and management of six cases of oral syphilis who presented to our unit. One case presented in 2008, but the other five cases presented between 2016 and 2023, reflecting the increasing incidence of syphilis infection. Five cases presented in the secondary stage of the infection while one presented with a primary infection in the form of a single chancre.The documented cases demonstrate the non-specific and variable clinical features of oral syphilis and highlight the importance of awareness in the dental profession of these manifestations. Dentists have an important role to play in recognising the disease and arranging appropriate testing for early intervention. This will not only reduce the incidence of the devastating consequences of tertiary infections but will also result in reduced spread of the disease.

Sexually transmitted infections in the context of haematological malignancies

Sexually transmitted infections (STIs) are a difficult health challenge for immunocompromised patients. Patients treated for several haematological malignancies have further compromised immune systems. Furthermore, many chemotherapies, alone or associated with haematopoietic stem-cell transplantation, make the body's natural barriers extremely fragile. STIs can negatively impact both patient morbidity and mortality. In this Series paper, we discuss Chlamydia trachomatis, Neisseria gonorrhoeae, syphilis, human immunodeficiency virus, herpes simplex virus, human papilloma virus, and hepatitis B virus, as we found them to be associated with increased risks for haematological malignancy treatments, either by incidence or by severity. Protective measures and vaccines for patients with haematological malignancies are also discussed. Large, well conducted studies should be encouraged, with the aim to systematically analyse the impacts of STIs in patients with haematological malignancies, especially given the difficulties that antimicrobial resistance can confer to patient management.

A Peculiar Pattern: Nodular Secondary Syphilis with Granulomatous Dermatitis

Nodular syphilis with a granulomatous inflammatory histopathologic pattern is an uncommon cutaneous presentation of secondary syphilis which could pose a diagnostic challenge for clinicians and pathologists alike. A 33-year-old male diagnosed with HIV presented with a 5-week history of asymptomatic generalized erythematous papules and nodules with overlying scales, with involvement of the palms and soles. Histopathologic examination of a nodule from the forearm revealed non-caseating granulomas in a background of a mixed cell inflammatory infiltrate composed of lymphocytes, epithelioid and foamy histiocytes, plasma cells, neutrophils, and multinucleated giant cells. Warthin-Starry Stain revealed spirochetal organisms, while Fite-Faraco and Periodic Acid-Schiff stains were negative for acid-fast bacilli and fungal elements, respectively. Rapid plasma reagin (RPR) was reactive (1:256). Patient was given a single dose of benzathine penicillin G 2.4 million units intramuscularly, with noted complete resolution of skin lesions as well as an 8-fold decrease in RPR titers. Nodular lesions are an uncommon cutaneous manifestation of secondary syphilis, and the associated histopathologic finding of granulomatous inflammatory pattern is also unusual, posing a diagnostic challenge. With the increasing prevalence of syphilis, especially among HIV patients, dermatologists, dermatopathologists, internists, and infectious disease specialists should be aware of such presentations of syphilis.

Syphilis and pregnancy

•Although congenital syphilis has a known etiological agent, accessible diagnosis and low-cost, effective treatment with low fetal toxicity, it continues to challenge obstetric and antenatal care services. •The increasing rates of syphilis in the general population have direct repercussions on the increase in cases of congenital syphilis, a situation of objective interest for public health. •Although transforming the recording of syphilis and congenital syphilis into notifiable diseases improved the records and has made it possible to measure the occurrence of these diseases and create solutions, no effects on reducing their frequency have been reached yet. •The failure to control syphilis/congenital syphilis is multifactorial, and associates variables that range from the deficiency in teaching about these diseases in schools and in the training system of the various health professional segments, as well as the lack of rigid policies for quality control from antenatal care until the clinical follow-up of children exposed to Treponema pallidum during pregnancy. •To date, benzathine penicillin is the only antimicrobial accepted as effective by the main health authorities on the planet for the treatment of syphilis in pregnant women. •The fear of anaphylaxis in response to the treatment of syphilis with benzathine penicillin is an important factor hindering the prompt and correct treatment of pregnant women with syphilis, even though health authorities have made efforts to face the problem with solid arguments, still insufficient to resolve the question. •Although specific protocols are published, the failure to control the treatment of syphilis in pregnant women is still observed with high frequency, indicating and reinforcing a failure in the quality control of these care principles. The National Specialized Commission on Infectious Diseases of the Brazilian Federation of Gynecology and Obstetrics Associations (Febrasgo) endorses this document. Content production is based on scientific evidence on the proposed topic and the results presented contribute to clinical practice.

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.

Global patterns of syphilis, gonococcal infection, typhoid fever, paratyphoid fever, diphtheria, pertussis, tetanus, and leprosy from 1990 to 2021: findings from the Global Burden of Disease Study 2021

BACKGROUND

Certain infectious diseases are caused by specific bacterial pathogens, including syphilis, gonorrhea, typhoid and paratyphoid fever, diphtheria, pertussis, tetanus, leprosy, and tuberculosis. These diseases significantly impact global health, contributing heavily to the disease burden. The study aims to thoroughly evaluate the global burden of syphilis, gonorrhea, typhoid and paratyphoid fever, diphtheria, pertussis, tetanus, and leprosy.

METHODS

Leveraging the Global Burden of Disease (GBD) study 2021, age-specific and Socio-demographic Index (SDI)-specific incidence, disability-adjusted life-years (DALYs), and death for eight specific bacterial infections across 204 countries and territories from 1990 to 2021 were analyzed. Percentage changes in age-standardized incidence rate (ASIR), DALY rate, and mortality rate (ASMR) were also examined, with a focus on disease distribution across different regions, age groups, genders, and SDI.

RESULTS

By 2021, among the eight diseases, gonococcal infection had the highest global ASIR [1096.58 per 100,000 population, 95% uncertainty interval (UI): 838.70, 1385.47 per 100,000 population], and syphilis had the highest global age-standardized DALY rate (107.13 per 100,000 population, 95% UI: 41.77, 212.12 per 100,000 population). Except for syphilis and gonococcal infection, the age-standardized DALY rate of the remaining diseases decreased by at least 55% compared to 1990, with tetanus showing the largest decrease by at least 90%. Globally, significant declines in the ASIR, age-standardized DALY rate, and ASMR for these eight bacterial infections have been observed in association with increases in the SDI. Regions with lower SDI, such as sub-Saharan Africa, experienced a relatively higher burden of these eight bacterial infections.

CONCLUSIONS

Although there has been an overall decline in these eight diseases, they continue to pose significant public health challenges, particularly in low SDI regions. To further reduce this burden in these areas, targeted intervention strategies are essential, including multi-sectoral collaboration, policy support, improved WASH management, and enhanced research efforts.

Acquired syphilis in older people in Brazil from 2010-2020

BACKGROUND

The infection caused by Treponema pallidum remains a severe public health problem, with a high prevalence in individuals over 60 years. However, research into infections such as syphilis continues to be neglected in geriatrics. This study aims to evaluate data on the detection rate of syphilis in Brazil, in individuals between 60 and 120 years, by characterizing the epidemiological profile and respective factors associated with it, in addition to performing a temporal trend analysis, from 2010 to 2020.

METHODOLOGY

Ecological, time-series study, which started with the collection of notifications from the database of the Information System on Compulsory Notification of Diseases. The epidemiological profile was characterized based on sociodemographic variables. The Statistical Package for the Social Sciences program, version 19.0, was used for incidence and prevalence analysis. The 2010 census by the Brazilian Institute of Geography and Statistics and projections for older people were considered. In the trend analysis, the Joinpoint regression model was used.

MAIN FINDINGS

There was an upward variation in the detection of syphilis in older people from 2010 to 2018, with a peak in 2018. In 2019, there was a slight reduction in the notification of cases, which was accentuated in 2020. The prevalence of the infection was equivalent to 12.84 cases for each 100,000 Brazilians, with a mean age of 68.04 years (±7.15) for those between 60 and 120 years, being higher in white and black males. The highest proportion of older people with syphilis occurred in the South and Southeast regions. However, the trend analysis showed a significant and homogeneous increase in all regions of Brazil, for both sexes and all age groups.

CONCLUSIONS

There is a tendency for an increase in cases of syphilis in older people, which reinforces the need to plan health actions to combat the disease in this population.

Condyloma lata of the umbilicus: A case report highlighting the present syphilis emergency

Syphilis is an ancient sexually transmitted infection that plagues communities across the United States and the world. Cutaneous syphilis has a wide variety of manifestations and presentations, and is notoriously difficult to identify clinically as a result. In this report, we describe the case of a 30-year-old patient with condyloma lata on the umbilicus, an extremely rare site for the presentation of these lesions. With the recent surge in syphilis infections nationwide, including congenital infections, this case underscores the urgent necessity for heightened syphilis awareness and suspicion among clinicians.

Phosphorylated vimentin-triggered fibronectin matrix disaggregation enhances the dissemination of Treponema pallidum subsp. pallidum across the microvascular endothelial barrier

Fibronectin (FN) is an essential component of the extracellular matrix (ECM) that protects the integrity of the microvascular endothelial barrier (MEB). However, Treponema pallidum subsp. pallidum (Tp) breaches this barrier through elusive mechanisms and rapidly disseminates throughout the host. We aimed to understand the impact of Tp on the surrounding FN matrix of MEB and the underlying mechanisms of this effect. In this study, immunofluorescence assays (IF) were conducted to assess the integrity of the FN matrix surrounding human microvascular endothelial cell-1 (HMEC-1) with/without Tp co-culture, revealing that only live Tp exhibited the capability to mediate FN matrix disaggregation in HMEC-1. Western blotting and IF were employed to determine the protein levels associated with the FN matrix during Tp infection, which showed the unaltered protein levels of total FN and its receptor integrin α5β1, along with reduced insoluble FN and increased soluble FN. Simultaneously, the integrin α5β1-binding protein-intracellular vimentin maintained a stable total protein level while exhibiting an increase in the soluble form, specifically mediated by the phosphorylation of its 39th residue (pSer39-vimentin). Besides, this process of vimentin phosphorylation, which could be hindered by a serine-to-alanine mutation or inhibition of phosphorylated-AKT1 (pAKT1), promoted intracellular vimentin rearrangement and FN matrix disaggregation. Moreover, within the introduction of additional cellular FN rather than other Tp-adhered ECM protein, in vitro endothelial barrier traversal experiment and in vivo syphilitic infectivity test demonstrated that viable Tp was effectively prevented from penetrating the in vitro MEB or disseminating in Tp-challenged rabbits. This investigation revealed the active pAKT1/pSer39-vimentin signal triggered by live Tp to expedite the disaggregation of the FN matrix and highlighted the importance of FN matrix stability in syphilis, thereby providing a novel perspective on ECM disruption mechanisms that facilitate Tp dissemination across the MEB.

Global, regional, and national burden of syphilis, 1990-2021 and predictions by Bayesian age-period-cohort analysis: a systematic analysis for the global burden of disease study 2021

Objective

To comprehensively assess the global burden of syphilis and related risk factors over 1990-2021, forecast future disease trends, and understand the impact of syphilis on global health.

Methods

Global Burden of Disease Study 2021 (GBD 2021) data were used for age-, sex-, and region-stratified analysis of the numbers and age-standardized rates (per 100,000 population) of syphilis incidence, prevalence, deaths, and disability-adjusted life years (DALYs). Next, a differential analysis of syphilis risk factors was performed. Finally, trends for years after 2021 were predicted using Bayesian age-period-cohort (BAPC) prediction models.

Results

In 2021, the total number of syphilis prevalence globally was 70,541,482.80 (95% uncertainty interval: 54,910,897.66-88,207,651.97), with the highest numbers noted in Central Sub-Saharan Africa [4,622.60 (95% uncertainty interval: 3,591.97-5,753.45)]. Over 1990-2021, the global age-standardized prevalence and incidence rates increased, whereas the age-standardized death and DALY rates decreased. Among all groups, infants aged <5 years demonstrated the highest age-standardized DALY rates. Moreover, the lower the sociodemographic index (SDI), the higher was the age-standardized rate. The primary factor contributing to syphilis disease burden was identified to be unsafe sex. BAPC analysis revealed an overall increase in age-standardized prevalence rate in the <5-year age group over 1990-2035, and the highest age-standardized prevalence rate occurred in the 25-34-year age group.

Conclusion

Between 1990 and 2021, syphilis occurrence and prevalence increased consistently. Projections indicated a continual increase in syphilis incidence in children aged <5 years, and age-standardized prevalence rates were the highest in adults aged 25-34 years. Our results regarding the epidemiological trends of syphilis and its variations across regions, age groups, and sexes may aid policymakers in addressing the global impact of the disease effectively.

Endothelial dysfunction of syphilis: Pathogenesis

Treponema pallidum is the causative factor of syphilis, a sexually transmitted disease (STD) characterized by perivascular infiltration of inflammatory cells, vascular leakage, swelling and proliferation of endothelial cells (ECs). The endothelium lining blood and lymphatic vessels is a key barrier separating body fluids from host tissues and is a major target of T. pallidum. In this review, we focus on how T. pallidum establish intimate interactions with ECs, triggering endothelial dysfunction such as endothelial inflammation, abnormal repairment and damage of ECs. In addition, we summarize that migration and invasion of T. pallidum across vascular ECs may occur through two pathways. These two mechanisms of transendothelial migration are paracellular and cholesterol-dependent, respectively. Herein, clarifying the relationship between T. pallidum and endothelial dysfunction is of great significance to provide novel strategies for diagnosis and prevention of syphilis, and has a great potential prospect of clinical application.

"Syphilitic Hepatitis": A Comprehensive Review of Clinical Features, Diagnostic Approaches, and Management Considerations

Syphilitic hepatitis is a very rare presentation of syphilis infection, characterized by inflammation of the liver due to the invasion of hepatic tissue by the bacterium Treponema pallidum. This review article provides an in-depth analysis of the existing body of information pertaining to syphilitic hepatitis. The article primarily concentrates on key aspects such as the epidemiology, clinical manifestations, diagnostic methods, and therapeutic approaches associated with this condition. Despite its rarity, awareness of syphilitic hepatitis is vital for accurate diagnosis and appropriate intervention. The clinical presentations frequently exhibit similarities with many liver illnesses, hence presenting difficulties in making an accurate diagnosis. Common symptoms include fatigue, stomach pain, and jaundice. Diagnostic procedures encompass the use of serological assays, including rapid plasma reagin (RPR) and fluorescent treponemal antibody absorption (FTA-ABS), in conjunction with imaging modalities to evaluate hepatic engagement. The primary therapeutic approach is the prompt initiation of antibiotic therapy, with a particular emphasis on penicillin, to eradicate the causative bacterial infection and facilitate the restoration of liver function. Failure to swiftly manage this condition may result in substantial morbidity. In summary, syphilitic hepatitis is a very uncommon but medically relevant manifestation of syphilis infection. The significance of increased clinical suspicion, precise diagnostic techniques, and prompt antibiotic administration is emphasized in this review since these are crucial in reducing the potentially severe outcomes associated with this illness.

Syphilis susceptibility factors atlas: A wide-angled Mendelian randomization study

OBJECTIVE

The pathogenic mechanisms of syphilis and the host defense mechanisms against syphilis remain poorly understood. Exploration of the susceptibility factors of syphilis may provide crucial clues for unraveling its underlying mechanisms.

METHODS

A two-sample Mendelian Randomization framework was utilized, and the inverse-variance weighted method was used as the main analysis. All data was sourced from Genome-wide association studies datasets from 2015 to 2022 in Europe, and all participants were of European descent. Only summary-level statistics were used. Sensitivity analyses were conducted to evaluate the heterogeneity and pleiotropy of the datasets.

RESULTS

Our study established 18 exposure factors (12 risk factors and 6 protective factors) for syphilis susceptibility. Twelve factors encompassing body mass index, waist circumference, darker natural skin, cooked vegetable intake, processed meat intake, diabetes mellitus, glucose regulation disorders, gout, autoimmune diseases, rheumatoid arthritis, diverticulitis, and longer menstrual cycles were found to increase susceptibility to syphilis. In contrast, 6 factors including easier skin tanning, blonde natural hair color, irritability, higher neuroticism scores, extended sleep duration, and delayed age at first sexual intercourse were connected to a reduced risk of syphilis infection (all P < 0.05).

CONCLUSIONS

This study identified 18 influencing factors of syphilis susceptibility. These findings offered novel insights for further probing into the underlying pathogenic mechanisms of syphilis and underscored the importance of multifaceted prevention strategies against syphilis.

Immunity to Sexually Transmitted Bacterial Infections of the Female Genital Tract: Toward Effective Vaccines

Sexually transmitted infections (STIs) caused by bacterial pathogens Chlamydia trachomatis, Neisseria gonorrhoeae, and Treponema pallidum present significant public health challenges. These infections profoundly impact reproductive health, leading to pelvic inflammatory disease, infertility, and increased susceptibility to other infections. Prevention measures, including antibiotic treatments, are limited by the often-asymptomatic nature of these infections, the need for repetitive and continual screening of sexually active persons, antibiotic resistance for gonorrhea, and shortages of penicillin for syphilis. While vaccines exist for viral STIs like human papillomavirus (HPV) and hepatitis B virus (HBV), there are no vaccines available for bacterial STIs. This review examines the immune responses in the female genital tract to these bacterial pathogens and the implications for developing effective vaccines against bacterial STIs.

Is syphilis infection a risk factor for cervicovaginal HPV occurrence? A case-control study

BACKGROUND

Syphilis and human papillomavirus (HPV) are sexually transmitted infections affecting women in the same risk group. Thus, the main objective of the present study was to investigate the prevalence of HPV in a population of women with and without syphilis and observe the characteristics of HPV cervical lesions when coinfection occurs. Sociodemographic factors associated with coinfection were also evaluated.

METHODS

This case-control study was conducted at a Brazilian HIV/STD testing and training center. Study groups were composed of women with (case) and without syphilis (control), paired by age. The presence of HPV, HPV subtype, and lesion severity were investigated. All women were subjected to a sociodemographic interview, clinical data collection, cell collection for cytopathological analysis, and a hybrid capture test for HPV diagnosis. The chi-square test was used for statistical analysis.

RESULTS

The sample consisted of 176 women, 88 in each group. The prevalence of HPV was 14.8 % in the case (n = 13) and 18.1 % in the control group (n = 16), and there was no statistically significant difference between them. Illiterate individuals were more prevalent in the control group (p = 0.023). Considering women with suggestive signs of STIs, 30 % (6) of the patients and controls had high-risk HPV, and 15 % (3) had coinfection. The cytopathological assessment showed no differences between the groups concerning cellular atypia. However, ASC-US and ASC-H (atypical squamous cells of undetermined significance and high-grade) were only found in women with coinfections, with 75 % of these patients testing positive for high-risk HPV. Considering the distribution of lesions on the cervix, the HSIL (high-grade intraepithelial lesion) was assessed in high-risk HPV patients, both cases and controls.

CONCLUSIONS

The prevalence of HPV was not increased in patients infected with syphilis. In addition, coinfection does not seem to be an aggravating factor for the presence of precursor lesions of cervical cancer.

Characteristic Profiling of Soluble Factors in the Cerebrospinal Fluid of Patients With Neurosyphilis

BACKGROUND

Soluble inflammatory factors in the cerebrospinal fluid (CSF) of patients with neurosyphilis have been investigated with low-throughput technology. This study aimed to illustrate the characteristics of soluble factor profiles in CSF of patients with neurosyphilis.

METHODS

We measured the concentrations of 45 cytokines, chemokines, and growth factors in CSF from 112 untreated syphilis cases, including latent syphilis (LS), asymptomatic neurosyphilis (ANS), meningeal neurosyphilis (MNS), meningovascular neurosyphilis (MVNS), paralytic dementia (PD), and ocular syphilis (OS).

RESULTS

Thirty-three differentially expressed soluble factors (DeSFs) were categorized into 3 clusters. DeSF scores of clusters 1 and 2 (DeSFS1 and DeSFS2) were positively correlated with elevated neopterin and neurofilament light subunit (NF-L) concentration, respectively. DeSF scores of cluster 3 were positively correlated with white blood cells, protein, NF-L, and neopterin. Patients with LS, ANS, and OS exhibited an overall lower abundance of DeSFs. Patients with PD exhibited significantly increased levels of clusters 1 and 3, and the highest total DeSF score, whereas patients with MNS and MVNS showed enhanced levels of cluster 2. Receiver operating characteristic analysis revealed that DeSFS1 effectively discriminated PD, and DeSFS2 discriminated MNS/MVNS with high accuracy.

CONCLUSIONS

Patients with neurosyphilis at different stages have distinctive patterns of soluble factors in CSF, which are correlated with immune status and neuronal damage.

Treponema pallidum genetic diversity and its implications for targeted vaccine development: A cross-sectional study of early syphilis cases in Southwestern Colombia

BACKGROUND

Venereal syphilis, caused by the spirochete Treponema pallidum subsp. pallidum (TPA), is surging worldwide, underscoring the need for a vaccine with global efficacy. Vaccine development requires an understanding of syphilis epidemiology and clinical presentation as well as genomic characterization of TPA strains circulating within at-risk populations. The aim of this study was to describe the clinical, demographic, and molecular features of early syphilis cases in Cali, Colombia.

METHODS AND FINDINGS

We conducted a cross-sectional study to identify individuals with early syphilis (ES) in Cali, Colombia through a city-wide network of public health centers, private sector HIV clinics and laboratory databases from public health institutions. Whole blood (WB), skin biopsies (SB), and genital and oral lesion swabs were obtained for measurement of treponemal burdens by polA quantitative polymerase chain reaction (qPCR) and for whole-genome sequencing (WGS). Among 1,966 individuals screened, 128 participants met enrollment criteria: 112 (87%) with secondary (SS), 15 (12%) with primary (PS) and one with early latent syphilis; 66/128 (52%) self-reported as heterosexual, while 48 (38%) were men who have sex with men (MSM). Genital ulcer swabs had the highest polA copy numbers (67 copies/μl) by qPCR with a positivity rate (PR) of 73%, while SS lesions had 42 polA copies/μl with PR of 62%. WB polA positivity was more frequent in SS than PS (42% vs 7%, respectively; p = 0.009). Isolation of TPA from WB by rabbit infectivity testing (RIT) was achieved in 5 (56%) of 9 ES WB samples tested. WGS from 33 Cali patient samples, along with 10 other genomic sequences from South America (9 from Peru, 1 from Argentina) used as comparators, confirmed that SS14 was the predominant clade, and that half of all samples had mutations associated with macrolide (i.e., azithromycin) resistance. Variability in the outer membrane protein (OMP) and vaccine candidate BamA (TP0326) was mapped onto the protein's predicted structure from AlphaFold. Despite the presence of mutations in several extracellular loops (ECLs), ECL4, an immunodominant loop and proven opsonic target, was highly conserved in this group of Colombian and South American TPA isolates.

CONCLUSIONS

This study offers new insights into the sociodemographic and clinical features of venereal syphilis in a highly endemic area of Colombia and illustrates how genomic sequencing of regionally prevalent TPA strains can inform vaccine development.

Advancing Precise Syphilis Diagnosis: A Nontreponemal IgM Antibody-Based Model for Latent Syphilis Staging

Purpose

Accurate differentiation between early and late latent syphilis stages is pivotal for patient management and treatment strategies. Nontreponemal IgM antibodies have shown potential in discriminating latent syphilis staging by differentiating syphilis activity. This study aimed to develop a predictive nomogram model for latent syphilis staging based on nontreponemal IgM antibodies.

Patients and Methods

We explored the correlation between nontreponemal IgM antibodies and latent syphilis staging and developed a nomogram model to predict latent syphilis staging based on 352 latent syphilis patients. Model performance was assessed using AUC, calibration curve, Hosmer-Lemeshow χ2 statistics, C-index, Brier score, decision curve analysis, and clinical impact curve. Additionally, an external validation set was used to further assess the model's stability.

Results

Nontreponemal IgM antibodies correlated with latent syphilis staging. The constructed model demonstrated a strong discriminative capability with an AUC of 0.743. The calibration curve displayed a strong fit, key statistics including Hosmer-Lemeshow χ² at 2.440 (P=0.486), a C-index score of 0.743, and a Brier score of 0.054, all suggesting favorable model calibration performance. Decision curve analysis and clinical impact curve highlighted the model's robust clinical applicability. The external validation set yielded an AUC of 0.776, Hosmer-Lemeshow χ² statistics of 2.440 (P=0.486), a C-index score of 0.767, and a Brier score of 0.054, further underscored the reliability of the model.

Conclusion

The nontreponemal IgM antibody-based predicted model could equip clinicians with a valuable tool for the precise staging of latent syphilis and enhancing clinical decision-making.

Associations between maternal syphilis infection during pregnancy and low birth weight and preterm birth: a prospective cohort study

BACKGROUND

In recent years, syphilis is still the most common sexually transmitted disease worldwide. Pregnant women infected with syphilis can transmit it to the fetus in utero through mother-to-child transmission, which can directly lead to adverse pregnancy outcomes. The aim of this study was to investigate the associations between maternal syphilis infection and low birth weight and preterm birth in offspring.

METHODS

Multinomial logistic regression model was used to analyze the associations between maternal syphilis infection and low birth weight and preterm birth, and to explore its stability through subgroup analysis.

RESULTS

A total of 34,074 subjects were included in the study. After adjusting for potential confounders, maternal syphilis infection during pregnancy was associated with a 2.60-fold (95% CI 1.83-3.69) increased risk of low birth weight and a 1.91-fold (95% CI 1.35-2.69) increased risk of preterm birth. Subgroup analysis showed that the association was stable.

CONCLUSION

We found that maternal syphilis infection during pregnancy was significantly associated with an increased risk of low birth weight and preterm birth. The implementation of reasonable syphilis screening and standardized treatment and follow-up of pregnant syphilis may have important practical significance in reducing the low birth weight and preterm birth rate in offspring.

Clinical presentation of early syphilis and genomic sequences of Treponema pallidum strains in patient specimens and isolates obtained by rabbit inoculation

BACKGROUND

The global resurgence of syphilis necessitates vaccine development.

METHODS

We collected ulcer exudates and blood from 17 primary syphilis (PS) participants and skin biopsies and blood from 51 secondary syphilis (SS) participants in Guangzhou, China for Treponema pallidum subsp. pallidum (TPA) qPCR, whole genome sequencing (WGS), and isolation of TPA in rabbits.

RESULTS

TPA DNA was detected in 15 of 17 ulcer exudates and 3 of 17 blood PS specimens. TPA DNA was detected in 50 of 51 SS skin biopsies and 27 of 51 blood specimens. TPA was isolated from 47 rabbits with success rates of 71% (12/17) and 69% (35/51), respectively, from ulcer exudates and SS bloods. We obtained paired genomic sequences from 24 clinical samples and corresponding rabbit isolates. Six SS14- and two Nichols-clade genome pairs contained rare discordances. Forty-one of the 51 unique TPA genomes clustered within SS14 subgroups largely from East Asia, while 10 fell into Nichols C and E subgroups.

CONCLUSIONS

Our TPA detection rate was high from PS ulcer exudates and SS skin biopsies and over 50% from SS blood, with TPA isolation in over two-thirds of samples. Our results support the use of WGS from rabbit isolates to inform vaccine development.

Serofast status in syphilis: Pathogenesis to therapeutics

Syphilis, a sexually transmitted infection caused by Treponema pallidum, has been experiencing a rise in prevalence in recent years. "Syphilis serofast" describes a unique serological reaction in patients with syphilis whose clinical symptoms have resolved following consistent anti-syphilitic therapy, but the non-Treponema pallidum antigen serologic test is still positive. Syphilis serofast is a risk factor for syphilis recurrence, neurosyphilis, and multisystem involvement. Considering the current lack of comprehensive knowledge about the epidemiological characteristics, pathogenesis, and therapies of syphilis serofast, we conducted an online search of research relating to syphilis serofast over the last twenty years. Previous research has shown that the pathogenesis of syphilis serofast is mainly related to clinical factors, immune factors, syphilis subtypes, and T.pallidum membrane protein repeat gene antigen. There are two distinct viewpoints on the treatment of serofast: no excessive treatment and active treatment. In addition, serofast patients also showed two clinical outcomes: syphilis recurrence and persistent serofast status. This article systematically reviews the related factors, treatment, and clinical outcomes of syphilis serofast, provides a theoretical basis for its research, diagnosis, and treatment, and helps clinicians develop a follow-up treatment management plan for syphilis serofast.

Prevalence and Predictors of Oral Treponema pallidum Detection by Quantitative Polymerase Chain Reaction in Early Syphilis

BACKGROUND

Treponema pallidum prevalence and burden at oral and lesion sites in adults with early syphilis were assessed by quantitative polymerase chain reaction (qPCR). Factors associated with oral shedding were also examined.

METHODS

Pretreatment oral and lesion swabs were collected from adults with early syphilis in a US multicenter syphilis treatment trial. Oral swabs were collected in the presence and absence of oral lesions. Following DNA extraction, qPCR and whole-genome sequencing (WGS) were performed to assess burden and strain variability.

RESULTS

All 32 participants were male, mean age was 35 years, and 90.6% with human immunodeficiency virus (HIV). T. pallidum oral PCR positivity varied by stage: 16.7% primary, 44.4% secondary, and 62.5% in early latent syphilis. Median oral T. pallidum burden was highest in secondary syphilis at 63.2 copies/µL. Lesion PCR positivity was similar in primary (40.0%) and secondary syphilis (38.5%). Age 18-29 years was significantly associated with oral shedding (vs age 40+ years) in adjusted models. WGS identified 2 distinct strains.

CONCLUSIONS

T. pallidum DNA was directly detected at oral and lesion sites in a significant proportion of men with early syphilis. Younger age was associated with oral shedding. Ease of oral specimen collection and increased PCR availability suggest opportunities to improve syphilis diagnostic testing. Clinical Trials Registration. NCT03637660.

Sexual health beliefs and prevention of sexually transmitted infections among cisgender women sex workers in Colombia

INTRODUCTION

The stigma and social discrimination against cisgender women sex workers lead many of them to live in conditions characterized by social inequality, marginalization, persecution, and limited opportunities for sexual health literacy. Consequently, they are often compelled to establish a framework of preventive beliefs with little scientific validity, which they use to identify, mitigate, or avoid sexual health risks arising from their interactions with clients. This study investigates the sexual health beliefs that influence self-care practices aimed at preventing sexually transmitted infections among cisgender women sex workers in Colombia.

METHODS

We conducted a qualitative study framed in Hermeneutic Phenomenology. In-depth interviews and discussion groups were conducted with 34 cisgender women sex workers over 18 years of age in the center of the cities of Bogotá and Barranquilla in Colombia.

RESULTS

Seven themes emerged from the reflective and inductive thematic analysis of the narratives: (1) popular habits for the prevention of contagion, (2) ocular assessment of genitals, (3) condom lubrication, (4) suspicion of a hidden infection in the client, (5) saliva and oral contact as a source of contagion, (6) avoidance of semen contact, (7) and trust in God as protection.

CONCLUSIONS

The findings reflect the need for health and social professionals to promote participatory and inclusive cooperation with sex workers to update the framework of preventive beliefs that help them guide sexual health self-care with autonomy and self-efficacy, strengthening favorable beliefs and negotiating unfavorable ones. It is also essential to have a sex worker-informed sexual health policy that guides the promotion of sexual health that is sensitive to the needs and consistent with the risks of sex work and ensures friendly and non-oppressive preventive care environments for sex workers.

A Retrospective Cohort Study on Treponema pallidum Infection: Clinical Trends and Treatment Outcomes for Congenital Syphilis in Guangxi, China (2013-2023)

Background

Syphilis, a prevalent sexually transmitted infection, poses severe risks, especially during pregnancy. This study aimed to elucidate the trends and impacts of syphilis in Guangxi, China, focusing on prevalence, clinical manifestations, and treatment outcomes in pregnant women and newborns. The objectives included understanding the demographic characteristics of affected pregnant women, analysing the clinical manifestations in newborns, and assessing the effectiveness of the treatment protocol.

Methods

Conducted in adherence to ethical guidelines, a retrospective cohort study from January 2013 to December 2023 included 54,048 pregnant women tested for T. pallidum. Diagnosis involved a comprehensive approach, utilizing tests like the Toluidine Red Unheated Serum Test (TRUST) and the Treponema pallidum Particle Agglutination (TPPA) assay. Infant diagnosis and clinical manifestations were evaluated through a decade-long follow-up. Treatment protocols, including Benzathine penicillin, were implemented. Statistical analyses were conducted using SAS version 9.4.

Results

Among 54,048 pregnant women, 0.10% were syphilis positive, correlating with a rise in hospitalizations. Newborns exhibited varied clinical manifestations, with neonatal pneumonia and jaundice being prevalent. The treatment protocol, especially with Benzathine penicillin, achieved a remarkable 100% cure success rate. The study noted a significant reduction in mother-to-child transmission. Syphilis in mothers and babies was diagnosed at different clinical stages, including primary, secondary, latent, and tertiary.

Conclusion

This study underscores the escalating impact of syphilis on pregnant women and newborns in Guangxi, China. The findings highlight the necessity for robust preventive measures, early diagnosis, and effective treatment strategies. The observed 100% cure success rate with Benzathine penicillin emphasizes the importance of strict treatment protocols in mitigating the adverse effects of congenital syphilis and reducing its transmission.

Case Report: Concomitant presence of two STIs in a male patient

Background

The spirochaete Treponema pallidum subsp. pallidum, which causes the infectious disease syphilis, can be spread through sexual contact or perinatal transmission. In recent years, cases of syphilis have increased, especially among individuals engaging in behaviour that makes them more vulnerable (condomless sex and multiple sexual partners). Condylomata acuminata (external genital warts) is one of the most common viral sexually transmitted infections (STIs). Individuals who are behaviourally vulnerable are also highly prone to two or more STIs. Our case exemplifies the occurrence of two STIs in a young man who was behaviourally vulnerable to acquiring STIs.

Case

We report a case of a 21-year-old year old heterosexual man presenting with concomitant primary syphilis and genital warts. He presented with a painless genital ulcer and warty growths on his glans penis. Examination showed a painless indurated ulcer and multiple genital warts. Serology was positive for quantitative Venereal disease research laboratory test (1:16 titre). The patient was diagnosed with two concomitant STIs. He was treated as per the latest Centers for Disease Control and Prevention (CDC) guidelines for primary syphilis and podophyllin resin for genital warts. After four weeks, the genital ulcer showed complete healing and there was a significant reduction of genital warts.

Conclusions

Individuals with multiple sexual partners engaging in sexual activity without the use of prevention tools are at a greater chance of acquiring two or more STIs. To reduce concomitant transmission, preventive measures against genital ulcer diseases like syphilis, herpes, and chancroid, such as early identification and treatment, and condom distribution, must be strengthened as part of national STI prevention. Patients with two or more STIs should be followed regularly to assess the progress of infection and should be offered timely medical treatment.

Performance Assessment of Treponemal and Nontreponemal Tests for the Diagnosis of Acquired Syphilis

There are a variety of nontreponemal test (NTT) and treponemal test (TT) kits for the serologic diagnosis of syphilis. Because of the complexity of the infection (multiple clinical stages) and the different antigens used in these kits, a systematic evaluation of the accuracy of the currently available commercial tests is warranted. Our objective was to evaluate the performance of commercially available tests for the diagnosis of syphilis infection. In this study, we analyzed one NTT (Venereal Disease Research Laboratory [VDRL] test, Wiener Laboratories, Rosario, Argentina) and two TTs (fluorescent treponemal antibody absorption [FTA-ABS] test, Euroimmun, Lübeck, Germany, and syphilis recombinant ELISA v. 4.0 test [ELISA], Wiener Laboratories, Rosario, Argentina) using a panel of 187 samples, including serum samples from 31 individuals with primary syphilis, 77 with secondary syphilis, and 79 with latent syphilis. An additional 192 samples from uninfected individuals and 323 serum samples from individuals with other diseases were included. The sensitivities of the VDRL, ELISA, and FTA-ABS tests were 97.9%, 100%, and 96.3%, respectively. The VDRL and ELISA tests showed a specificity of 100%, and the FTA-ABS test showed a specificity of 99.5%. Accuracy was 98.9% for the VDRL test, 100% for the ELISA, and 97.9% for the FTA-ABS test. For primary, secondary, and latent syphilis, the ELISA achieved a diagnostic performance of 100%, whereas the sensitivity for the VDRL and FTA-ABS tests ranged from 96.8% to 98.7% and 93.7% to 98.7%, respectively. No difference was observed when the tests were used as traditional or reverse algorithms. In general, all three tests are able to discriminate positive and negative samples for syphilis, regardless of the diagnostic algorithm.

Syphilis in Hematopathology Practice: A Diagnostic Challenge

CONTEXT.—

Syphilis, a reemerging disease caused by the spirochete Treponema pallidum, is becoming more frequent in surgical pathology and hematopathology practices. Hematopathologists typically receive lymph node biopsies from patients with syphilis who have localized or diffuse lymphadenopathy. Occasionally, syphilis infection in the aerodigestive tract can show a prominent lymphoplasmacytic infiltrate and mimic lymphoma. Besides the varying and occasional atypical morphology, the fact that clinical suspicion tends to be low or absent when histologic evaluation is requested adds to the importance of making this diagnosis.

OBJECTIVE.—

To summarize histologic features of syphilitic lymphadenitis and syphilis lesions in the aerodigestive tract, and to review differential diagnosis and potential diagnostic pitfalls.

DATA SOURCES.—

Literature review via PubMed search.

CONCLUSIONS.—

Characteristic histologic findings in syphilitic lymphadenitis include thickened capsule with plasma cell-rich inflammatory infiltrate, reactive follicular and paracortical hyperplasia with prominent lymphoplasmacytic infiltrate, and vasculitis. Lymph nodes, however, can show a number of other nonspecific histologic features, which frequently makes the diagnosis quite challenging. In the aerodigestive tract, syphilis is characterized by plasma cell-rich infiltrates. Immunohistochemistry for T pallidum is the preferred method for detecting spirochetes; however, this immunohistochemical stain shows cross-reactivity with other treponemal and commensal spirochetes. Differential diagnosis of syphilis in lymph nodes and the aerodigestive tract is broad and includes reactive, infectious, and neoplastic entities. Pathologists should be aware of the histologic features of syphilis and keep this challenging entity in the differential diagnosis.

An observational prospective study based on a large cohort of HIV-negative neurosyphilis patients with particular reference to the Jarisch-Herxheimer reaction

PURPOSE

The purpose of this study is to outline a complete picture of Jarisch-Herxheimer reaction (JHR) in the central nervous system among HIV-negative neurosyphilis patients.

METHODS

A prospective study cohort of 772 cases with almost all stages of neurosyphilis depicted the features of JHR including occurrence rate, risk profiles, clinical manifestations, medical management and prognosis.

RESULTS

The total occurrence rate of JHR was 9.3% (95% CI, 7.3-11.4%), including 4.1% (95% CI, 2.7-5.6%) with severe JHR. The reaction started 5 h after treatment initiation, peaked after 8 h, and subsided after 18 h. Patients with severe JHR experienced a longer recovery time (26 h). Patients with general paresis (OR = 6.825), ocular syphilis (OR = 3.974), pleocytosis (OR = 2.426), or a high CSF-VDRL titre (per log2 titre increase, OR = 2.235) were more likely to experience JHR. Patients with general paresis had an 11.759-fold increased risk of severe JHR. Worsening symptoms included cognitive impairment, mania, nonsense speech, and dysphoria, while symptoms of hallucination, urination disorder, seizures, myoclonus, or aphasia appeared as new-onset symptoms. Neurosyphilis treatment did not need to be interrupted in most patients with JHR and could be reinstated in patients with seizures under supportive medication when JHR subsided.

CONCLUSION

Severe JHR displayed a 4.1% occurrence rate and clinicians should pay particular attention to patients at a higher risk of JHR. The neurosyphilis treatment regime can be restarted under intensive observation for patients with severe JHR and, if necessary, supportive medication should be initiated and continued until the end of therapy.

Treponema Pallidum rapid syphilis compared diagnostic algorithm syphilis in men who have sex with men (MSM)

BACKGROUND

Syphilis infection can be asymptomatic and difficult to diagnose based on clinical symptoms. Early detection and treatment are critical for preventing and controlling syphilis as well as long-term serious complications. A serological examination based on the diagnostic algorithm was used to confirm the diagnosis of syphilis. Syphilis is frequent in high-risk groups, such as men who have sex with men (MSM). Treponema pallidum (TP) rapid can be used for early syphilis detection. The diagnostic value of TP rapid with diagnostic algorithm (RPR-TPHA) utilizing whole blood in MSM should be studied.

OBJECTIVES

To determine the diagnostic value of TP rapid syphilis test compared to a diagnostic algorithm (RPR-TPHA) among MSM.

METHODS

A diagnostic test with a cross-sectional design at Dr Mohammad Hoesin Palembang General Hospital from November 2022 to January 2023. The sampling method was consecutive sampling with a total sample of 83 MSM based on inclusion and exclusion criteria. All samples were tested for RPR, TPHA, and TP rapid. The diagnostic value of TP rapid was evaluated with RPR-TPHA as a diagnostic algorithm for syphilis.

RESULTS

The sensitivity and specificity value of the TP rapid compare diagnostic algorithm as gold standard were 95.8% and 96.6% respectively. Other metrics: positive predictive value (PPV) 92%, negative predictive value (NPV) 98%, positive likelihood ratio (PLR) 28.27, negative likelihood ratio (NLR) 0.04, accuracy 96% and AUC 0.962.

CONCLUSION

The TP rapid test has a high diagnostic value and can be used to establish an early diagnosis of syphilis in MSM.

The Great Mimicker: Secondary Syphilis-Associated Nephrotic Syndrome in an Adolescent Patient

BACKGROUND

Syphilis is long regarded as the "great mimicker" for its variety of symptoms and clinical manifestations. Rarely, it can present with renal involvement, particularly nephrotic syndrome. This is an uncommon initial presentation, particularly in pediatrics.

CASE REPORT

We present the case of a 17-year-old male adolescent who presented to the emergency department with a chief symptom of abdominal pain. In addition, he was found to have a number of stigmata characteristic of both syphilis and nephrotic syndrome, including a rash and diffuse edema, particularly in the lower extremities. This led to the diagnosis of nephrotic syndrome secondary to syphilis infection. Prompt diagnosis and treatment of syphilis resulted in resolution of both kidney injury and symptoms of the underlying infection. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This case highlights the variety of manifestations of sexually transmitted infections, particularly in the pediatric population. It demonstrates how identifying syphilis as the inciting event led to the correct treatment management for the patient. This presentation serves to teach and remind emergency physicians of the wide-ranging presentations for sexually transmitted infections, particularly syphilis, and the necessity of obtaining a sexual history even in adolescent patients.

Treponema pallidum protein Tp47 induced prostaglandin E2 to inhibit the phagocytosis in human macrophages

BACKGROUND

During Treponema pallidum (T. pallidum) infection, the host's immune system actively engages in pursuit and elimination of T. pallidum, while T. pallidum skillfully employs various mechanisms to evade immune recognition. Macrophages exhibit incomplete clearance of T. pallidum in vitro and the underlying mechanism of how T. pallidum resists the attack of macrophage remains unclear.

OBJECTIVES

To investigate the effect of T. pallidum membrane protein Tp47 on the phagocytosis of macrophages.

METHODS

THP-1-derived macrophages were used to investigate the role of Tp47 in the secretion of Prostaglandin E2 (PGE2) in macrophages and the mechanism by which Tp47 induced the production of PGE2, as well as the impact of PGE2 on the macrophage's phagocytosis.

RESULTS

Tp47 (1-10 μg/mL) significantly inhibited the phagocytosis of latex beads and T. pallidum in macrophages (p ≤ 0.05). PGE2 production by macrophages could be induced by Tp47, and the phagocytic function of macrophages could be restored using PGE2 antibody. Tp47 produced PGE2 by activating the PERK/NF-κB/COX-2 pathway in macrophages. Inhibitors targeting PERK, NF-κB and COX-2, respectively, reduced the level of PGE2 and restored the phagocytic function of macrophages.

CONCLUSION

Tp47-induced PGE2 production via the PERK/NF-κB/COX-2 pathway contributed to macrophage phagocytosis inhibition, which potentially contributes to immune evasion during the T. pallidum infection.

Treponema pallidum-induced prostaglandin E2 secretion in skin fibroblasts leads to neuronal hyperpolarization: A cause of painless ulcers

BACKGROUND

Primary syphilis is characterized by painless ulcerative lesions in the genitalia, the aetiology of painless remains elusive.

OBJECTIVES

To investigate the role of Treponema pallidum in painless ulcer of primary syphilis, and the mechanisms underlying painless ulcers caused by T. pallidum.

METHODS

An experimental rabbit model of primary syphilis was established to investigate its effects on peripheral nerve tissues. Human skin fibroblasts were used to examine the role of T. pallidum in modulating neurotransmitters associated with pain and to explore the signalling pathways related to neurotransmitter secretion by T. pallidum in vitro.

RESULTS

Treponema pallidum infection did not directly lead to neuronal damage or interfere with the neuronal resting potential. Instead, it facilitated the secretion of prostaglandin E2 (PGE2) through endoplasmic reticulum stress in both rabbit and human skin fibroblasts, and upregulation of PGE2 induced the hyperpolarization of neurones. Moreover, the IRE1α/COX-2 signalling pathway was identified as the underlying mechanism by which T. pallidum induced the production of PGE2 in human skin fibroblasts.

CONCLUSION

Treponema pallidum promotes PGE2 secretion in skin fibroblasts, leading to the excitation of neuronal hyperpolarization and potentially contributing to the pathogenesis of painless ulcers in syphilis.

State-of-the-Art Review: Neurosyphilis

We review key concepts in the diagnosis, treatment, and follow-up of individuals with neurosyphilis. We describe the epidemiology of syphilis in the United States, highlight populations that are markedly affected by this infection, and attempt to estimate the burden of neurosyphilis. We describe the cardinal clinical features of early and late (tertiary) neurosyphilis and characterize the clinical significance of asymptomatic neurosyphilis in the antibiotic era. We review the indications for cerebrospinal fluid (CSF) examination and the performance characteristics of different CSF assays including treponemal and lipoidal antibodies, white cell count, and protein concentration. Future biomarkers and the role of imaging are briefly considered. We review preferred and alternative treatments for neurosyphilis and evidence for their use, including evidence for the use of enhanced intramuscular benzathine penicillin G to supplement intravenous penicillin.

Single-test syphilis serology: A case of not seeing the forest for the trees

INTRODUCTION

There have been few empirical studies for diagnostic test accuracy of syphilis using a sequence of rapid tests in populations with low prevalence of syphilis such as pregnant women. This analysis describes syphilis test positivity frequency among pregnant women at an antenatal clinic in Zambia using a reverse-sequence testing algorithm for antenatal syphilis screening.

METHODS

Between August 2019 and May 2023, we recruited 1510 pregnant women from a peri-urban hospital in Lusaka, Zambia. HIV positive and HIV negative women were enrolled in a 1:1 ratio. Blood collected at recruitment from the pregnant mothers was tested on-site for syphilis using a rapid treponemal test. Samples that tested positive were further tested at a different laboratory, with rapid plasma reagin using archived plasma.

RESULTS

Of the total 1,421 sera samples which were screened with a rapid treponemal test, 127 (8.9%) were positive and 1,294 (91.1%) were negative. Sufficient additional samples were available to perform RPR testing on 114 of the 127 (89.8%) RDT positive specimens. Thirty-one (27.2%) of these 114 were reactive by RPR and 83 (72.8%) were negative, resulting in a syphilis overtreatment rate of 3 fold (i.e, 84/114). Insufficient sample or test kit availability prevented any testing for the remaining 89 (5.9%) participants.

CONCLUSION

Use of only treponemal tests in low prevalence populations, like pregnant women, subjects individuals with non-active syphilis to the costs and possible risks of overtreatment. The use of the dual treponemal and non-treponemal tests would minimize this risk at some additional cost.

Digital dual test syphilis/HIV detection based on Fourier Descriptors of Cyclic Voltammetry curves

BACKGROUND

Effective and timely detection is vital for mitigating the severe impacts of Sexually Transmitted Infections (STI), including syphilis and HIV. Cyclic Voltammetry (CV) sensors have shown promise as diagnostic tools for these STI, offering a pathway towards cost-effective solutions in primary health care settings.

OBJECTIVE

This study aims to pioneer the use of Fourier Descriptors (FDs) in analyzing CV curves as 2D closed contours, targeting the simultaneous detection of syphilis and HIV.

METHODS

Raw CV signals are filtered, resampled, and transformed into 2D closed contours for FD extraction. Essential shape characteristics are captured through selected coefficients. A complementary geometrical analysis further extracts features like curve areas and principal axes lengths from CV curves. A Mahalanobis Distance Classifier is employed for differentiation between patient and control groups.

RESULTS

The evaluation of the proposed method revealed promising results with classification performance metrics such as Accuracy and F1-Score consistently achieving values rounded to 0.95 for syphilis and 0.90 for HIV. These results underscore the potential efficacy of the proposed approach in differentiating between patient and control samples for STI detection.

CONCLUSION

By integrating principles from biosensors, signal processing, image processing, machine learning, and medical diagnostics, this study presents a comprehensive approach to enhance the detection of both syphilis and HIV. This setts the stage for advanced and accessible STI diagnostic solutions.

Phase transforming in situ gels for sustained and controlled transmucosal drug delivery via the intravaginal route

Direct, reliable, controlled, and sustained drug delivery to female reproductive tract (FRT) remains elusive, with conventional dosage forms falling way short of the mark, leading to premature leakage, erratic drug delivery, and loss of compliance. Historically, the intravaginal route remains underserved by the pharmaceutical sector. To comprehensively address this, we turned our focus to phase-transforming sol-gels, using poloxamers, a thermosensitive polymer and, doxycycline (as hyclate salt, DOXH) as our model agent given its potential use in sexually transmitted infections (STIs). We further enhanced mucoadhesiveness through screening of differing viscosity grade hydroxypropyl methyl celluloses (HPMCs). The optimised sol-gels remained gelled at body temperature (<37 °C) and were prepared in buffer aligned to vaginal cavity pH and osmolality. Lead formulations were progressed based on their ability to retain key rheological properties, and acidic pH in the presence of simulated vaginal fluid (SVF). From a shelf-life perspective, DOXH stability, gelation temperature (Tsol-gel), and pH to three months (2-8 °C) was attained. In summary, the meticulously engineered, phase-transforming sol-gels provided sustained mucoretention despite dilution by vaginal fluid, paving the way for localised antimicrobial drug delivery at concentrations that potentially far exceed the minimum inhibitory concentration (MIC) for target STI-causing bacteria of the FRT.

Using circulating microbial cell-free DNA to identify persistent Treponema pallidum infection in serofast syphilis patients

The question of whether serofast status of syphilis patients indicates an ongoing low-grade Treponema pallidum (T. pallidum) infection remains unanswered. To address this, we developed a machine learning model to identify T. pallidum in cell-free DNA (cfDNA) using next-generation sequencing (NGS). Our findings showed that a TP_rate cut-off of 0.033 demonstrated superior diagnostic performance for syphilis, with a specificity of 92.3% and a sensitivity of 71.4% (AUROC = 0.92). This diagnosis model predicted that 20 out of 92 serofast patients had a persistent low-level infection. Based on these predictions, re-treatment was administered to these patients and its efficacy was evaluated. The results showed a statistically significant decrease in RPR titers in the prediction-positive group compared to the prediction-negative group after re-treatment (p < 0.05). These findings provide evidence for the existence of T. pallidum under serofast status and support the use of intensive treatment for serofast patients at higher risk in clinical practice.

Large-Scale Proteome Profiling Identifies Biomarkers Associated with Suspected Neurosyphilis Diagnosis

Neurosyphilis (NS) is a central nervous system (CNS) infection caused by Treponema pallidum (T. pallidum). NS can occur at any stage of syphilis and manifests as a broad spectrum of clinical symptoms. Often referred to as "the great imitator," NS can be easily overlooked or misdiagnosed due to the absence of standard diagnostic tests, potentially leading to severe and irreversible organ dysfunction. In this study, proteomic and machine learning model techniques are used to characterize 223 cerebrospinal fluid (CSF) samples to identify diagnostic markers of NS and provide insights into the underlying mechanisms of the associated inflammatory responses. Three biomarkers (SEMA7A, SERPINA3, and ITIH4) are validated as contributors to NS diagnosis through multicenter verification of an additional 115 CSF samples. We anticipate that the identified biomarkers will become effective tools for assisting in diagnosis of NS. Our insights into NS pathogenesis in brain tissue may inform therapeutic strategies and drug discoveries for NS patients.

A multi-country comparative study of two treponemal tests for the serodiagnosis of syphilis amongst men who have sex with men (MSM): Chemo-luminescent assay vs Treponema pallidum particle agglutination assay

INTRODUCTION

International guidelines recommend routine screening for syphilis (aetiological agent: Treponema pallidum subspecies pallidum) amongst key populations and vulnerable populations using tests detecting treponemal and non-treponemal antibodies. Whilst treponemal tests have high sensitivities and specificities, they differ regarding subjective or objective interpretation, throughput and workload. Chemiluminescence immunoassays (CLIAs) are cost- and time-effective automated methods for detecting treponemal antibodies. The Treponema pallidum particle agglutination assay (TPPA) has been considered the "gold standard" treponemal assay, however, this includes a highly manual procedure, low throughput and subjective interpretation. The present multi-country study evaluated the ADVIA Centaur® Syphilis CLIA (Siemens Healthcare) assay compared to the reference SERODIA-TP·PA® (Fujirebio Diagnostics) for the serodiagnosis of syphilis amongst men who have sex with men (MSM).

METHOD

1,485 MSM were enrolled in Brighton (UK), Malta, and Verona (Italy) as part of a larger WHO multi-country and multi-site ProSPeRo study. Ethical approval was obtained. Serum was tested with the ADVIA Centaur® Syphilis CLIA assay and SERODIA-TP·PA®, in accordance with the manufacturers' instructions, for a first round of validation. A second round of validation was carried out for discrepant results that were additionally tested with both Western Blot (Westernblot EUROIMMUN®) and an Immunoblot (INNO-LIA, Fujirebio Diagnostics). Sensitivity, specificity, positive and negative predictive value (PPV and NPV), likelihood ratios (positive/negative), and the Diagnostic Odds Ratio (DOR)/pre-post-test probability (Fagan's nomogram) were calculated.

RESULTS

Out of 1,485 eligible samples analysed in the first phase, the SERODIA-TP·PA® identified 360 positive and 1,125 negative cases. The ADVIA Centaur® Syphilis CLIA assay (Siemens) identified 366 positives, missclassifying one TPPA-positive sample. In the second phase, the ADVIA Centaur® Syphilis CLIA resulted in 1 false negative and 4 false positive results. Considering the syphilis study prevalence of 24% (95% CI: 22-26.7), The sensitivity of the ADVIA Centaur® Syphilis CLIA assay was 99.7% (95% CI: 98.5-100), and the specificity was 99.4% (95% CI: 98.7-99.7). The ROC area values were 0.996 (95% CI: 0.992-0.999), and both the PPV and NPV values were above 98% (PPV 98.1%, 95% CI: 96.1-99.2; NPV 99.9%, 95% CI: 99.5-100).

CONCLUSIONS

The ADVIA Centaur® Syphilis CLIA assay showed similar performance compared to the SERODIA-TP·PA®. Considering the study is based on QUADAS principles and with a homogeneous population, results are also likely to be generalisable to MSM population but potentially not applicable to lower prevalence populations routinely screened for syphilis. The automated CLIA treponemal assay confirmed to be accurate and appropriate for routine initial syphilis screening, i.e. when the reverse testing algorithm is applied.