Laboratory Diagnostic Tools for Syphilis: Current Status and Future Prospects

Neurosyphilis-Induced Psychosis in Europe: A Systematic Review of Case Reports

The tertiary stage of syphilis appears to be the most diverse of the three recognized, with a number of cardiovascular, gummatous, neurological and psychiatric symptoms. This systematic review's aim is to analyze cases of organic psychoses secondary to tertiary syphilis, inspect the diagnostic procedures and assess the effectiveness of treatment. Case studies from Pubmed and MEDLINE Ultimate were sought out with the Boolean expression '((neurosyphilis) OR (syphilis) OR (treponema pallidum)) AND (case report) AND ((psychosis) OR (psychotic))' to later undergo screening for exclusion criteria (according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) 2020 guidelines). Each report was accepted independently by two authors. Case reports were later appraised using the JBI Critical Appraisal Checklist for Case Reports. Finally, 11 case reports were included in the study. The most frequently reported psychiatric symptoms were delusions (91%) and hallucinations (81%), disorientation (about 42%) and sleep disturbances and memory loss (36%). Several inconsistencies in diagnostic processes were found in some of the case reports, while treatment procedures were more in line with the guidelines. A disease as complex as neurosyphilis requires great awareness and cooperation between various medical specialties. Despite its mimicry and variability in presentation, the discussed case reports prove that it can be successfully dealt with.

A Loop-Mediated Isothermal Amplification Assay Utilizing Hydroxy Naphthol Blue (LAMP-HNB) for the Detection of Treponema pallidum Subspp. pallidum

Treponema pallidum subspp. pallidum is a spirochaete bacterium that causes syphilis, one of the most common sexually transmitted diseases. Syphilis progresses through four distinct stages, each characterized by specific symptoms, namely primary, secondary, latent, and late (tertiary) syphilis. Serology has been considered the primary diagnostic approach. However, it is plagued by problems such as the limited specificity of nontreponemal tests and the inadequate correlation of treponemal tests with disease activity. In this study, we focused on the development of a loop-mediated isothermal amplification assay utilizing hydroxy naphthol blue (LAMP-HNB) for the diagnosis of T. pallidum subspp. pallidum. Specifically, this study seeks to determine the analytical sensitivity (limit of detection; LOD) and analytical specificity. Four hundred clinical serum samples were analyzed for diagnostic sensitivity, specificity, and predictive value, and each technique's 95% confidence intervals (95% CI, p < 0.05) were evaluated. The limit of detection for polymerase chain reaction with agarose gel electrophoresis (PCR-AGE), the loop-mediated isothermal amplification assay combined with agarose gel electrophoresis (LAMP-AGE), and LAMP-HNB were 116 pg/µL, 11.6 pg/µL, and 11.6 pg/ µL, respectively. Analytical specificity examinations indicated the absence of cross-reactivity with Leptospira interrogans, Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, human immunodeficiency virus (HIV), and healthy human serum in PCR-AGE, LAMP-AGE, and LAMP-HNB. The diagnostic sensitivity, diagnostic specificity, positive predictive value (PPV), and negative predictive value (NPV) for PCR-AGE were 100.00 (100.00)%, 94.50 (94.40-94.60)%, 94.79 (94.69-94.88)%, and 100.00 (100.00)%, respectively. While, for LAMP-AGE and LAMP-HNB, they were 100.00 (100.00)%, 91.00 (90.87-91.13)%, 91.74 (91.63-91.86)%, and 100.00 (100.00)%, respectively. The LAMP-HNB test is simple, rapid, highly sensitive, and highly specific, without requiring expensive equipment. In the future, the LAMP-HNB assay may develop into a single-step diagnostic process, enabling the use as point-of-care testing for the diagnosis, prevention, and management of syphilis infection.

Clinical and Laboratory Characteristics, Diagnosis, and Treatment of Patients with Neurosyphilis in Emergency Department: A Retrospective Study of 12 Patients

Purpose

Syphilis, caused by Treponema pallidum, presents a diagnostic challenge due to its diverse clinical manifestations. Neurosyphilis has seen a resurgence in recent years, particularly among men who have sex with men and those living with HIV. Diagnosis of neurosyphilis in emergency settings is challenging due to its varied neurological presentations. This study aims to serve as a reference for dermatologists and neurologists in diagnosing and treating neurosyphilis.

Patients and Methods

This retrospective study analyzed patients who presented with neuropsychiatric symptoms and were ultimately diagnosed with neurosyphilis. These patients were collected from the emergency department in Peking Union Medical College Hospital between January 2018 and November 2023. The medical history, clinical symptoms, laboratory examinations, cranial MRI characteristics, and treatment regimens of these patients were investigated.

Results

Among the included 12 neurosyphilis patients, memory deterioration was observed in 8 out of the 12 neurosyphilis patients. Diagnosis often resulted in delays, with misdiagnoses mainly including Alzheimer's disease, stroke, and epilepsy. Neuroimaging revealed various abnormalities, predominantly affecting ventricular and temporal regions. Treatment with penicillin-based regimens varied in compliance, with only a minority of patients adhering to guidelines. Treatment outcomes were inconsistent, with some patients experiencing irreversible neurological damage and fluctuating serum rapid plasma reagin (RPR) titers.

Conclusion

Diagnosis of neurosyphilis in the emergency department remains challenging, necessitating awareness of its varied neurological presentations. Enhanced diagnostic strategies are imperative to accelerate treatment initiation and improve outcomes for affected individuals.

High rates of Treponema pallidum, Neisseria gonorrhoeae, Chlamydia trachomatis, or Trichomonas vaginalis co-infection in people with HIV: a systematic review and meta-analysis

PURPOSE

People living with HIV (PWH) experience a disproportionate burden of sexually transmitted infections (STIs), leading to more severe health outcomes and increasing the risk of HIV transmission. The presence of untreated STIs can accelerate HIV disease progression, while HIV infection can complicate STI diagnosis and treatment. Despite this interconnectedness, comprehensive data on the global prevalence of specific STIs among PWH remain limited. This systematic review aims to synthesize existing data to provide a more accurate picture of the prevalence of co-infection with Treponema pallidum, Neisseria gonorrhoeae, Chlamydia trachomatis or Trichomonas vaginalis in PWH, while also identifying critical knowledge gaps and informing future research priorities.

METHODS

We searched databases for eligible studies reporting the prevalence of Treponema pallidum, Neisseria gonorrhoeae, Chlamydia trachomatis, or Trichomonas vaginalis among PWH, published from January 1, 2000, to February 1, 2023. From 22,290 identified articles, 127 independent studies meeting the inclusion criteria were included in this meta-analysis.

RESULTS

The overall global co-infection prevalence of Treponema pallidum, Neisseria gonorrhoeae, Chlamydia trachomatis, and Trichomonas vaginalis in PWH, was 4.8% (95%CI: 4.7-5.0%), 0.8% (95%CI: 0.6-0.9%), 2.5% (95%CI: 2.2-2.7%), and 3.0% (95%CI: 2.7-3.3%), respectively. The global prevalence of these four STIs in PWH is high, especially in Africa and Southeast Asia and in MSM and TGW populations. Based on the subgroup analyses, we further found that there was a high prevalence of Treponema pallidum and Chlamydia trachomatis in Southeast Asia and a high infection of Trichomonas vaginalis in the whole of Africa. Treponema pallidum infection was more common in males than females, and Chlamydia trachomatis and Trichomonas vaginalis infections were more common in females than males. Besides, high infection rates of Treponema pallidum, Neisseria gonorrhoeae, and Chlamydia trachomatis were detected in men who have sex with men (MSM) + transgender women (TGW), while high infection rates of Trichomonas vaginalis were found in sex workers and pregnant women.

CONCLUSION

The study confirmed high prevalence of four sexually transmitted pathogens in PWH, noting regional, gender, and subpopulation-specific differences. It offered insights for targeted interventions and healthcare strategies. The research underscored the necessity for enhanced data collection and expanded screening/treatment for vulnerable populations and regions.

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.

Ion-sensitive field effect transistor biosensors for biomarker detection: current progress and challenges

The ion-sensitive field effect transistor (ISFET) has emerged as a crucial sensor device, owing to its numerous benefits such as label-free operation, miniaturization, high sensitivity, and rapid response time. Currently, ISFET technology excels in detecting ions, nucleic acids, proteins, and cellular components, with widespread applications in early disease screening, condition monitoring, and drug analysis. Recent advancements in sensing techniques, coupled with breakthroughs in nanomaterials and microelectronics, have significantly improved sensor performance. These developments are steering ISFETs toward a promising future characterized by enhanced sensitivity, seamless integration, and multifaceted detection capabilities. This review explores the structure and operational principles of ISFETs, highlighting recent research in ISFET biosensors for biomarker detection. It also examines the limitations of these sensors, proposes potential solutions, and anticipates their future trajectory. This review aims to provide a valuable reference for advancing ISFETs in the field of biomarker measurement.

Multiplex Loop-Mediated Isothermal Amplification Coupled Lateral Flow Assay for Point-of-Care Detection of Syphilis

Syphilis is a re-emerging sexually transmitted disease caused by the pathogenic spirochete T. pallidum. Every year more than 5 million cases are reported globally. The current diagnostic methods are primarily based on serological assays, which are less sensitive at an early stage of infection. To improve the disease diagnosis, there is a need to develop a rapid, simple, sensitive, and cost-effective point-of-care application, which plays an effective role in the detection of syphilis infection. In this study, we developed a multiplex loop-mediated isothermal amplification coupled lateral flow assay (multiplex LAMP-LFA) for the detection of syphilis. Two different genes, the target amplicon (polA) and the internal control amplicon (human RNase P) were amplified using multiplex LAMP assay. The amplified products were detected using LFA strips coated with Anti-FITC and Anti-DIG antibodies within 5 minutes of flowthrough. Multiplex LAMP LFA detection limit was found to be 3.8 × 103 copies/mL with high specificity. The developed strip was tested with 130 clinically suspected cases and 50 healthy individuals. With the clinical samples, the method shows a sensitivity of 93.84% and a specificity of 100%. The Multiplex LAMP LFA has the potential to overcome the limitations of both Non Treponemal tests and Treponemal tests which are prone to prozone effects and expensive reagents respectively. The proposed method holds promise for sensitive, rapid, and visual detection of T. pallidum, thereby offering a facile and affordable alternative to existing diagnostic methods. This approach is poised to advance the development of point-of-care diagnostics, addressing a critical need in public healthcare, particularly in resource-limited settings.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12088-024-01308-4.

Immunohistochemistry and RT-PCR as ancillary tools in the diagnosis of acquired oral syphilis

OBJECTIVE

To investigate Treponema pallidum detection using immunohistochemistry (IHC) and reverse transcription-polymerase chain reaction (RT-PCR) assays in acquired oral syphilis (AOS).

MATERIALS AND METHODS

Thirty-seven paraffin-embedded tissue specimens of AOS (32 secondary and five primary) were analyzed, integrating double-positive serological results with clinicodemographic and histopathological data. T. pallidum presence was semiquantitatively assessed by IHC, while RT-PCR targeted T. pallidum DNA. Sensitivity, specificity, and the area under the curve (AUC) were calculated with 95% confidence intervals (CI).

RESULTS

The study included mostly females (62.2%) with a mean age of 27.1 years. T. pallidum was detected in all samples by IHC, predominantly in the epithelium across all layers (43.2%). RT-PCR identified T. pallidum DNA in 32 cases, with negative results observed in cases of secondary AOS. The AUC for IHC versus disease stage was 62.5% (95% CI: 45.1-77.8), and for RT-PCR, it was 57.8% (95% CI: 40.5-73.8). The AUC comparing IHC to RT-PCR was 83.8% (95% CI: 67.9-93.8).

CONCLUSION

This study represents the first attempt to evaluate the proposed direct detection algorithm for AOS. IHC and RT-PCR serve as ancillary tools for detecting T. pallidum in both primary and secondary stages of AOS.

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.

Tick-borne diseases in Europe: Current prevention, control tools and the promise of aptamers

In Europe, tick-borne diseases (TBDs) cause significant morbidity and mortality, affecting both human and animal health. Ticks can transmit a wide variety of pathogens (bacteria, viruses, and parasites) and feed on many vertebrate hosts. The incidence and public health burden of TBDs are tending to intensify in Europe due to various factors, mainly anthropogenic and often combined. Early detection of tick-borne pathogens (TBPs), preventive measures and treatment are of great importance to control TBDs and their expansion. However, there are various limitations in terms of the sensitivity and/or specificity of detection and prevention methods, and even in terms of feasibility. Aptamers are single-stranded DNA or RNA that could address these issues as they are able to bind with high affinity and specificity to a wide range of targets (e.g., proteins, small compounds, and cells) due to their unique three-dimensional structure. To date, aptamers have been selected against TBPs such as tick-borne encephalitis virus, Francisella tularensis, and Rickettsia typhi. These studies have demonstrated the benefits of aptamer-based assays for pathogen detection and medical diagnosis. In this review, we address the applications of aptamers to TBDs and discuss their potential for improving prevention measures (use of chemical acaricides, vaccination), diagnosis and therapeutic strategies to control TBDs.

Treponematosis in critically endangered Western chimpanzees (Pan troglodytes verus) in Senegal

Treponematoses encompass a group of chronic and debilitating bacterial diseases transmitted sexually or by direct contact and attributed to Treponema pallidum. Despite being documented since as far back as 1963, the epidemiology of treponematoses in wild primates has remained an uninvestigated territory due to the inherent challenges associated with conducting examinations and obtaining invasive biological samples from wild animals. The primary aim of this study was to investigate the presence of treponemal infections in the critically endangered Western chimpanzees in Senegal, utilizing an innovative non-invasive stool serology method. We provide compelling evidence of the existence of anti-Treponema-specific antibodies in 13 out of 29 individual chimpanzees. Our study also underscores the significant potential of stool serology as a valuable non-invasive tool for monitoring and surveilling crucial emerging diseases in wild animals. We recognize two major implications: (1) the imperative need to assess the risks of treponematosis in Western chimpanzee populations and (2) the necessity to monitor and manage this disease following a holistic One Health approach.

Clostridioides difficile Infection: Diagnosis and Treatment Challenges

Clostridioides difficile is the most important cause of healthcare-associated diarrhea in the United States. The high incidence and recurrence rates of C. difficile infection (CDI), associated with high morbidity and mortality, pose a public health challenge. Although antibiotics targeting C. difficile bacteria are the first treatment choice, antibiotics also disrupt the indigenous gut flora and, therefore, create an environment that is favorable for recurrent CDI. The challenge of treating CDI is further exacerbated by the rise of antibiotic-resistant strains of C. difficile, placing it among the top five most urgent antibiotic resistance threats in the USA. The evolution of antibiotic resistance in C. difficile involves the acquisition of new resistance mechanisms, which can be shared among various bacterial species and different C. difficile strains within clinical and community settings. This review provides a summary of commonly used diagnostic tests and antibiotic treatment strategies for CDI. In addition, it discusses antibiotic treatment and its resistance mechanisms. This review aims to enhance our current understanding and pinpoint knowledge gaps in antimicrobial resistance mechanisms in C. difficile, with an emphasis on CDI therapies.

The association between non-viral sexually transmitted infections and pregnancy outcome in Latin America and the Caribbean: A systematic review

Introduction

Non-viral sexually transmitted infections are known to be associated with adverse pregnancy outcomes. For these pathogens, standard antenatal screening is not broadly performed in Latin America and the Caribbean. The aim of this study was to comprehensively review the association of non-viral sexually transmitted infections and neonatal outcomes among pregnant women in the region.

Methods

Four databases (PubMed, Embase, SciELO and LILACS) were examined to identify eligible studies published up to September 2022. English or Spanish cross-sectional, case-control and cohort studies assessing the association of non-viral sexually transmitted infections and adverse pregnancy outcomes were evaluated. Articles were firstly screened by means of title and abstract. Potential articles were fully read and assessed for inclusion according to the eligibility criteria. Snowballing search was performed by screening of bibliographies of the chosen potentially relevant papers. Risk of bias within studies was assessed using the Joanna Briggs Institute reviewer's manual.

Results

A selection of 10 out of 9772 search records from five Latin America and the Caribbean countries were included. Six studies associated Treponema pallidum infection with preterm birth (1/6), history of previous spontaneous abortion (2/6), fetal and infant death (1/6), low birth weight (1/6) and funisitis of the umbilical cord (1/6). Three studies associated Chlamydia trachomatis infection with preterm birth (2/3), ectopic pregnancy (1/3) and respiratory symptoms on the newborn (1/3). One study associated Mycoplasma genitalium infection with preterm birth.

Conclusion

This review provides evidence on the association of non-viral sexually transmitted infections with adverse pregnancy outcomes. Further investigation is needed to establish more associations between non-viral sexually transmitted infections and pregnancy outcome, especially for Mycoplasma genitalium, Trichomonas vaginalis and Neisseria gonorrhoeae. Overall, this review calls for more research for public health interventions to promote screening of non-viral sexually transmitted infections during pregnancy, among high-risk population groups of pregnant women living in the region.

Resurgence of syphilis: focusing on emerging clinical strategies and preclinical models

Syphilis, a sexually transmitted disease (STD) caused by Treponema pallidum (T. pallidum), has had a worldwide resurgence in recent years and remains a public health threat. As such, there has been a great deal of research into clinical strategies for the disease, including diagnostic biomarkers and possible strategies for treatment and prevention. Although serological testing remains the predominant laboratory diagnostic method for syphilis, it is worth noting that investigations pertaining to the DNA of T. pallidum, non-coding RNAs (ncRNAs), chemokines, and metabolites in peripheral blood, cerebrospinal fluid, and other bodily fluids have the potential to offer novel perspectives on the diagnosis of syphilis. In addition, the global spread of antibiotic resistance, such as macrolides and tetracyclines, has posed significant challenges for the treatment of syphilis. Fortunately, there is still no evidence of penicillin resistance. Hence, penicillin is the recommended course of treatment for syphilis, whereas doxycycline, tetracycline, ceftriaxone, and amoxicillin are viable alternative options. In recent years, efforts to discover a vaccine for syphilis have been reignited with better knowledge of the repertoire of T. pallidum outer membrane proteins (OMPs), which are the most probable syphilis vaccine candidates. However, research on therapeutic interventions and vaccine development for human subjects is limited due to practical and ethical considerations. Thus, the preclinical model is ideal for conducting research, and it plays an important role in clinical transformation. Different preclinical models have recently emerged, such as in vitro culture and mouse models, which will lay a solid foundation for clinical treatment and prevention of syphilis. This review aims to provide a comprehensive summary of the most recent syphilis tactics, including detection, drug resistance treatments, vaccine development, and preclinical models in clinical practice.

Treponema pallidum Detection at Asymptomatic Oral, Anal, and Vaginal Sites in Adults Reporting Sexual Contact with Persons with Syphilis

We investigated Treponema pallidum PCR positivity at mucosal sites (oral, anal, and vaginal sites) among adults who had sexual contact with a person with syphilis (syphilis contacts). All syphilis contacts had oral rinse and swab samples collected for testing. Men who have sex with men had anal swab and women had vaginal swab samples collected for testing, regardless of the presence of lesions. Of 407 persons tested, 42 (10%) had early syphilis diagnosed; of those, 19 (45%) tested positive by PCR from any anatomic site and had a positive serologic test. T. pallidum was positive from vaginal samples in 3 women, anal samples in 3 men, and oral cavity samples in 2 women and 3 men, without symptoms at those sites. Three women had no prior syphilis serologic test. T. pallidum detection at asymptomatic mucosal sites suggests early syphilis infections, particularly in cases that would conventionally be staged as latent syphilis of unknown duration.

Treponema pallidum PCR screening at mucosal sites of asymptomatic men who have sex with men taking HIV pre-exposure prophylaxis

Early detection and treatment of syphilis will reduce the infectious period and transmission. We aimed to determine whether screening men who have sex with men (MSM) taking HIV pre-exposure prophylaxis (PrEP) for syphilis using Treponema pallidum polymerase chain reaction (PCR) could detect syphilis before the appearance of syphilis antibodies in serology. MSM attending 3-monthly PrEP clinic visits in Melbourne, Australia, were screened with a PCR assay targeting the polA gene of T. pallidum from an anal swab and an oral rinse between November 2019 and March 2020. Participants were serologically screened for syphilis using chemiluminescence immunoassay. A total of 309 asymptomatic participants provided an anal swab and oral rinse sample for T. pallidum PCR screening. Two syphilis cases (0.6%) were detected: one man had a positive serology only; another man had T. pallidum detected by PCR from an anal swab and a positive serology. PCR positivity was 0.3% (n = 1) for anal swabs and 0% (n = 0) for oral rinse. In this study, T. pallidum PCR screening at routine PrEP clinic visits did not identify additional cases of early syphilis over serological screening performed at these visits. IMPORTANCE With the ongoing syphilis epidemic in men who have sex with men (MSM), we investigated the role of using Treponema pallidum polymerase chain reaction (PCR) testing at the oral cavity and anus in MSM taking pre-exposure prophylaxis for the early detection of syphilis. We evaluated whether the PCR tests from these mucosal sites can detect syphilis infection early, before the development of syphilis antibodies in serology. Our study found two syphilis cases among 309 MSM, and only one syphilis case had a positive anal PCR swab, although serology was positive. We conclude that additional PCR testing is likely to be expensive and would not be cost effective for individuals who regularly screen for syphilis. However, future studies with a larger sample size are required.

Epidemiological analysis of syphilis surveillance among entry-exit population at Shanghai Port, China from 2014 to 2022

OBJECTIVE

To investigate the epidemiological characteristics of syphilis cases detected among entry-exit personnel at Shanghai ports from 2014 to 2022 and the changing trend of the syphilis epidemic in the region so as to provide data support for the scientific and effective prevention and control of syphilis at ports.

METHODS

From January 2014 to December 2022, the subjects of syphilis screening at Shanghai port were selected. Physical examination and serological testing were used to confirm syphilis. All the data used were downloaded from the HIS system of Shanghai International Travel Healthcare Center. Descriptive epidemiology was used to analyze the characteristics of the detected cases, and the linear trend Chi-square test was used to analyze the trend between groups.

RESULTS

From 2014 to 2022, a total of 918 cases of syphilis were detected among entry-exit personnel at Shanghai port, with a total detection rate of 154.68/100 000. The detection rate was the highest in 2015 and the lowest in 2022, showing a downward trend year by year since 2015. 54.36% of syphilis patients from East Asia were detected. Syphilis cases were reported in all age groups; most cases were under 39 years old, accounting for 36.06%. The syphilis detection rate in males was significantly higher than in females (79.63% vs. 20.4%). The main way of transmission was sexual transmission, accounting for 60.89%, among which male-to-male transmission was the primary way (22.36%).

CONCLUSION

The detection rate of syphilis among entry-exit personnel at Shanghai port has been decreasing continuously in recent years. Targeted health intervention should be carried out according to the monitoring results.

Evaluation of the AIX1000 Automated Rapid Plasma Reagin Assay in a High-Prevalence Setting

BACKGROUND

Manually performed nontreponemal assays, such as rapid plasma reagin (RPR), are labor intensive and time consuming. Recently, commercial automated RPR assays gained attention. The aim of this study was to compare the qualitative and quantitative performance of the AIX1000 (RPR-A; Gold Standard Diagnostics) to a manual RPR test (RPR-M; Becton Dickinson Macrovue) within a high-prevalence setting.

METHODS

A retrospective panel of 223 samples was selected for comparison between RPR-A and RPR-M, including 24 samples from patients with known syphilis stages and 57 samples from 11 patients in follow-up. In addition, 127 samples obtained during routine syphilis diagnosis with RPR-M were analyzed prospectively with AIX1000.

RESULTS

Overall qualitative concordance (percent agreement) between both assays was 92.0% in the retrospective and 89.0% in the prospective panel. Of 32 discordances, 28 were explained by a treated syphilis infection still positive in one assay and already negative in the other. One sample was false positive with RPR-A, 1 infection remained undetected by RPR-M, and 2 remained undetected by RPR-A. A hook effect was apparent on the AIX1000 at RPR-A titers from 1:32 onward; however, no infections were missed. Accepting a ±1 titer difference, quantitative concordance between both assays reached 73.1% and 98.4% for the retrospective and prospective panels, respectively, with an upper limit of reactivity for RPR-A at 1:256.

CONCLUSIONS

The AIX1000 showed a similar performance to Macrovue RPR with the exception of a negative deviation for high-titer samples. Within the reverse algorithm used in our high-prevalence setting, AIX1000's main advantage is automation.

A ruptured thoracic aortic aneurysm and the difficulties of confirming syphilis

A 43-year-old woman died suddenly and was found at PM to have a ruptured thoracic aortic aneurysm. The endothelial surface of the aorta showed a 'tree-bark' appearance. Histology of the aneurysm wall showed a patchy, mainly perivascular, plasma cell infiltrate. Multiple spirochete-like organisms were identified on T. pallidum IHC. However, PM syphilis serology (screen including rapid plasma reagin (RPR) and T. pallidum particle agglutination (TPPA)) on femoral blood was negative. PCR testing on FFPE aortic wall tissue was negative. Further history revealed routine antenatal syphilis screening tests had been negative, no known history or risk of exposure to syphilis or other treponemes. This case raises the possibility of false negative syphilis testing. While acknowledged in RPR testing, with the modern testing regime using multiple methods, the rate of false negative results is now thought to be markedly reduced, and false positive results are a much greater problem in clinical medicine. The most common cause of false negative results is early in primary infection before an immune response has been mounted and in those patients that are immunocompromised. False negative results are also more often seen in tertiary syphilis, as in this case. Newer testing methods which include 16S rRNA sequencing have become available and early discussion with a microbiologist would be recommended. Strong macroscopic and microscopic suggestion of syphilis as the cause of the aneurysm makes it necessary to include the possibility of infection in the Post Mortem Report to Coroner as this will have implications for her sexual partners and children.

Unique Presentation of Syphilis With Ocular Involvement: A Case Report

Ocular syphilis could be the first sign of undiagnosed syphilis. In addition to otosyphilis, it can be observed in the primary, secondary, or tertiary stages of syphilis. Nonspecific clinical symptoms make diagnosis difficult. We report a patient who presented with generalized weakness and blurry vision for the past four to five days. In this case, we emphasize the importance of repeated cerebrospinal fluid (CSF) examinations as they led to the diagnosis of ocular syphilis and appropriate neurosyphilis treatment. It must be suspected in patients with primary or secondary neurological symptoms, such as blurred vision and weakness. Treponema, the causative organism, is invisible under light microscopy and is mostly identified by its distinct spiral movements under darkfield microscopy. Once the diagnosis was made, the patient was started on penicillin treatment to prevent spread to the brain and dorsal spinal cord. The patient responded well to antibiotic treatment, with improvement in visual acuity, and was discharged with close neurological and ophthalmological follow-up.

A Man With Asymptomatic Ulcerated White Plaques on the Soft Palate

A man in his 60s had irregular gray-white ulcers with a surrounding erythema on the soft palate, uvula, and tonsils that did not improve with oral cefuroxime. He reported sexual contact with 1 male partner over the prior 6 months; history and physical examination findings were otherwise unremarkable. What is the diagnosis and what would you do next?

Rapid Point-of-Care Tests Using Staphylococcal Protein A Can Detect Early IgM Responses in HIV-1 and Treponema pallidum Infections

Serological assays detecting IgM antibodies in addition to IgG antibodies have a diagnostic advantage in finding early infections. Staphylococcal protein A (SpA), widely used as an antibody-detecting reagent in various immunoassays, is considered to have a high binding affinity mainly to IgG, although its interaction with other classes of immunoglobulins has also been documented. Using 28 samples from 22 HIV-1 seroconversion panels, the present study demonstrated detection of early IgM antibodies by SpA-based rapid point-of-care tests, including DPP HIV 1/2, DPP HIV-Syphilis, STAT-PAK HIV 1/2, and Sure Check HIV 1/2. Samples with predominant IgM antibodies were identified by in-house IgM assays and confirmed by pretreatment with 0.1 M 2-mercaptoethanol. Likewise, the detection of treponemal IgM antibodies was shown by DPP HIV-Syphilis assay in eight samples collected at early syphilis infection. Direct interaction between IgM and SpA immobilized in solid phase or in solution was demonstrated with purified human polyclonal IgM. A strong correlation was found between the antibody levels detected by SpA and anti-IgM reagent in the early seroconversion samples, thus supporting the evidence for IgM binding by SpA. These assays demonstrated the ability to detect IgM antibodies, which may increase test sensitivity in early infections due to a reduced serodiagnostic window. IMPORTANCE Sexually transmitted infections, including HIV and syphilis, remain a global public health concern. The main laboratory testing approach for HIV and syphilis relies on serological assays. Detection of the IgM class of antibodies may have a diagnostic advantage in finding early infections. The present study using well-characterized HIV-1 and syphilis samples has demonstrated that staphylococcal protein A employed for antibody detection in rapid point-of-care tests, including DPP HIV 1/2, DPP HIV-Syphilis, STAT-PAK HIV 1/2, and Sure Check HIV 1/2, can capture IgM antibodies in addition to IgG antibodies. The findings strongly suggest that the ability to detect IgM antibodies by these immunoassays may facilitate the identification of acute-stage HIV and syphilis infections.

Syphilis as Re-Emerging Disease, Antibiotic Resistance, and Vulnerable Population: Global Systematic Review and Meta-Analysis

Syphilis is a sexually transmitted disease that has become a public health problem, especially in vulnerable populations. A systematic review and time-free meta-analysis of the publications on the molecular detection of syphilis and mutations associated with antibiotic resistance, CORE group, and syphilis genotypes in PubMed databases, Scielo, and Cochrane was performed, and the last search was conducted in June 2022. Proportions were calculated, and standard errors and confidence intervals were reported for all results of interest. We included 41 articles for quantitative extraction and data synthesis. An increase was observed in the proportion of subjects diagnosed with syphilis and the presence of the A2058G mutation during the 2018−2021 period compared to 2006 (70% 95%CI 50−87 vs. 58% 95%CI 12−78), and we observed that the greater the proportion of the population participating in men who have sex with men (MSM) (<50% and >50%) syphilis increased (78% 95%CI 65−90 vs. 33% 95%CI 19−49). In conclusion, we suggest that there are a set of characteristics that are contributing to the resurgence of syphilis and the selective pressure of bacteria. The MSM population could be a vulnerable factor for this scenario and the global presence of A2058G and A2059G mutations that confer resistance to macrolides.

Making a Comeback: Syphilitic Hepatitis in a Patient with Late Latent Syphilis-Case Report and Review of the Literature

Treponema pallidum infection has emerged in recent years as an important community threat and burden to the health care system. Here, we report the case of a patient with cholestatic liver disease secondary to late latent syphilis. A 41 year-old male patient was referred to the clinic for assessment of an abnormal liver function panel. Ultrasound of the abdomen demonstrated an intense liver echogenicity, normal bile ducts, and no ascites. Virologic study revealed negative results for antibodies against common viral hepatitis and metabolic and autoimmune disease. The patient was tested for syphilis and a positive result was reported. The patient was diagnosed with late latent syphilis and syphilitic hepatitis and initiated benzathine penicillin at G 7.2 million units total, delivered as three doses of 2.4 million units intramuscular each at one-week intervals. He was assessed monthly and by the end of the sixth month, he had nonreactive VDRL (seroconversion), which confirmed recovery. Syphilitic hepatitis is an overlooked type of hepatitis and should be kept in mind as a differential diagnosis in an abnormal liver panel of uncertain etiology. Health care providers should be advised that higher levels of ALP may be the single landmark in cases of syphilitic hepatitis.

A Promising Tool in Serological Diagnosis: Current Research Progress of Antigenic Epitopes in Infectious Diseases

Infectious diseases, caused by various pathogens in the clinic, threaten the safety of human life, are harmful to physical and mental health, and also increase economic burdens on society. Infections are a complex mechanism of interaction between pathogenic microorganisms and their host. Identification of the causative agent of the infection is vital for the diagnosis and treatment of diseases. Etiological laboratory diagnostic tests are therefore essential to identify pathogens. However, due to its rapidity and automation, the serological diagnostic test is among the methods of great significance for the diagnosis of infections with the basis of detecting antigens or antibodies in body fluids clinically. Epitopes, as a special chemical group that determines the specificity of antigens and the basic unit of inducing immune responses, play an important role in the study of immune responses. Identifying the epitopes of a pathogen may contribute to the development of a vaccine to prevent disease, the diagnosis of the corresponding disease, and the determination of different stages of the disease. Moreover, both the preparation of neutralizing antibodies based on useful epitopes and the assembly of several associated epitopes can be used in the treatment of disease. Epitopes can be divided into B cell epitopes and T cell epitopes; B cell epitopes stimulate the body to produce antibodies and are therefore commonly used as targets for the design of serological diagnostic experiments. Meanwhile, epitopes can fall into two possible categories: linear and conformational. This article reviews the role of B cell epitopes in the clinical diagnosis of infectious diseases.

Large-Scale Sequencing of Borreliaceae for the Construction of Pan-Genomic-Based Diagnostics

The acceleration of climate change has been associated with an alarming increase in the prevalence and geographic range of tick-borne diseases (TBD), many of which have severe and long-lasting effects-particularly when treatment is delayed principally due to inadequate diagnostics and lack of physician suspicion. Moreover, there is a paucity of treatment options for many TBDs that are complicated by diagnostic limitations for correctly identifying the offending pathogens. This review will focus on the biology, disease pathology, and detection methodologies used for the Borreliaceae family which includes the Lyme disease agent Borreliella burgdorferi. Previous work revealed that Borreliaceae genomes differ from most bacteria in that they are composed of large numbers of replicons, both linear and circular, with the main chromosome being the linear with telomeric-like termini. While these findings are novel, additional gene-specific analyses of each class of these multiple replicons are needed to better understand their respective roles in metabolism and pathogenesis of these enigmatic spirochetes. Historically, such studies were challenging due to a dearth of both analytic tools and a sufficient number of high-fidelity genomes among the various taxa within this family as a whole to provide for discriminative and functional genomic studies. Recent advances in long-read whole-genome sequencing, comparative genomics, and machine-learning have provided the tools to better understand the fundamental biology and phylogeny of these genomically-complex pathogens while also providing the data for the development of improved diagnostics and therapeutics.

Laboratory Evaluation of the DPP Syphilis Screen & Confirm Assay

Because syphilis is a public health concern, new strategies and tools for detecting active syphilis cases should be evaluated for future implementation. We assessed the laboratory performance of the DPP Syphilis Screen & Confirm rapid immunodiagnostic test (Chembio Diagnostics, Medford, NY, USA), using visual reading and the manufacturer's electronic test microreader, for detection of treponemal and nontreponemal antibodies in 383 fully characterized stored serum specimens. We used the Treponema pallidum particle agglutination (TPPA) test and rapid plasma reagin (RPR) test as reference tests for the DPP Syphilis Screen & Confirm assay treponemal and nontreponemal components, respectively. The sensitivity values for treponemal antibody detection by electronic reader and visual interpretation were 83.2% and 85.9%, respectively, with 100% specificity. For nontreponemal antibody detection, the sensitivity values were 65.7% and 69.0% and the specificity values were 88.7% and 89.4% for electronic reader and visual interpretation, respectively. There was excellent correlation between visual interpretation and the microreader for either component (kappa coefficient, 0.953). When restricting the analysis to RPR titers of ≥1:8, the sensitivity was 96.9% for either reading method; numerical microreader values showed good correlation with RPR titers (Spearman rho of 0.77). The DPP Syphilis Screen & Confirm assay showed good performance, compared to reference syphilis tests, using serum. Field evaluation studies should be done to validate its use for detection of active cases and for monitoring of treated syphilis patients. IMPORTANCE Syphilis remains a public health problem; therefore, health systems must incorporate screening tools that allow a rapid and accurate diagnosis to provide adequate treatment. The DPP Syphilis Screen & Confirm Assay simultaneously detects treponemal and nontreponemal antibodies, emerging as an alternative for identifying cases in situations in which there is no infrastructure to perform conventional syphilis testing, but it is necessary to generate evidence regarding the performance of this technology in various scenarios. We found that the test performs well, compared to TPPA and RPR tests, using stored samples from participants at high risk of acquiring syphilis. Additionally, when the Chembio microreader was incorporated, similar results are obtained by the device, compared to those reported by trained laboratory professionals, and correlated with the semiquantitative results of the RPR test. We think that the use of the DPP Syphilis Screen & Confirm Assay with the microreader might help in detecting active syphilis cases and perhaps in monitoring treatment responses in the field.

Direct fluorescence antibody testing augments syphilis diagnosis, compared to serology alone

In Ottawa, Canada, we initiated protocols to include non-serologic syphilis testing, as direct fluorescence antibody (DFA) for patients with syphilis symptoms. The purpose was to assess the ability of DFA to detect syphilis during acute infection and to determine if non-serologic testing could yield an increased number of syphilis diagnoses. We reviewed charts of patients of our local sexual health clinic for whom syphilis was suspected. A total of 69 clinical encounters were recorded for 67 unique patients, most of whom were male. The most common symptom was a painless genital lesion. Of the 67 patients, 29 were found to have a new syphilis diagnosis, among whom, 52% had positive syphilis serology and positive DFA, 34% had a positive syphilis serology and negative DFA, and 14% had negative syphilis serology and positive DFA. While DFA testing did not yield an abundance of new cases, it was useful to support findings from syphilis serology or confirm diagnosis where serology was negative. Where available, alternate non-serologic tests, such as nucleic acid amplification tests, should be considered above DFA due to its higher sensitivity for detecting syphilis in primary lesions; however, in clinical situations, when new syphilis infection is suspected, empiric treatment should not be delayed.

Hard bilateral syphilitic testes with vasculitis: a case report and literature review

BACKGROUND

We report the case of a patient with syphilitic testicular gumma and vasculitis with adrenal failure due to chronic steroid use.

CASE PRESENTATION

A 63-year-old male presented with hard right eye swelling and very firm bilateral testes on palpation, which he had for 2 years. Testicular tumor markers were negative; syphilis test was positive. Radiological examination suggested aortitis and bilateral testicular malignancy. The patient received ampicillin for the infection and prednisolone for vasculitis. Left orchidectomy was performed to confirm the presence of testicular tumor; histological examinations revealed granulomatous orchitis. The prednisolone doses were adjusted because of relapses and adverse effects of steroid use. Unfortunately, the patient died in the intensive care unit because of uncontrolled blood pressure and pneumonia.

CONCLUSIONS

This is a rare case of syphilis with testicular involvement and vasculitis. This report shows the importance of broadening the differential diagnoses of testicular firmness.

Penicillin Treatment Failure in Rabbit Syphilis Due to the Persistence of Treponemes (Treponema paraluisleporidarum Ecovar Cuniculus) in the Focus of Infection

Rabbit venereal spirochetosis, a disease caused by Treponema paraluisleporidarum ecovar Cuniculus (TPeC), affects both wild and pet rabbits, and is transmitted sexually and via direct contact among animals. Treatment of syphilis in pet rabbits requires administration of antibiotics, including penicillin G, chloramphenicol, or fluoroquinolones. The aim of this work was to elucidate the cause of penicillin treatment failure in rabbit syphilis in a pet rabbit treated in Brno, Czech Republic, and to assess the phylogenetic relatedness of the agent to previously characterized pathogenic treponemes. Following amputation of the infected digits, the second round of penicillin treatment using the same dosage and application route resulted in the disappearance of clinical symptoms within a period of two weeks. The bacterium was successfully isolated from the claws, propagated in three experimental rabbits, and the resulting TPeC strain was designated as Cz-2020. Analysis of four genetic loci revealed that the Cz-2020 strain was similar but also clearly distinct from the only TPeC strain, which had been characterized in detail to date, i.e., the Cuniculi A strain, which was isolated in North America. The strain Cz-2020 represents the first available viable TPeC strain of European origin. DNA sequences encoding five penicillin-binding proteins of the strain Cz-2020 were compared to those of Cuniculi A, which is known to be sensitive to penicillin. The sequences differed in six nucleotides resulting in single amino acid changes in Penicillin-binding protein 1, 2, and 3. Since the second round of treatment was successful, we conclude that the penicillin treatment failure in the first round resulted from the presence of infection foci in claws where treponemes persisted.