Syphilis

Universal All-In-One Lateral Flow Immunoassay with Triple Signal Amplification for Ultrasensitive and Simple Self-Testing of Treponema pallidum Antibodies

Lateral flow immunoassay (LFIA) is valued for its simplicity and rapidity for on-site screening, however, it experienced false negatives in real sample analysis due to low sensitivity. Although many signal amplification techniques can improve the sensitivity, they usually require additional complicated steps. To address these issues, taking Treponema pallidum (T. pallidum) antibodies as a model detecting target, herein, we report an all-in-one LFIA (AIO-LFIA) with triple-step signal amplification to significantly improve sensitivity while maintaining simplicity. This LFIA utilizes a biotin-streptavidin system for initial signal amplification, followed by introducing a release controller with a specific imprinted structure for timed multicomponent release, which avoids the extra steps when adding components in traditional LFIA. Particularly, a 3D-printed programmed metal in situ growth (MISG) device is integrated to localize signal enhancement at specific sites, overcoming limitations of traditional MISG and substantially reducing reagent usage and assay time, and the nitrocellulose membrane surface was much cleaner than the conventional approach, which facilitates signal readout. After optimization, the proposed AIO-LFIA is capable of visual detection down to 1 pg/mLT. pallidum antibodies in 15 min, 1000-fold lower than the gold nanoparticle-based LFIA. In clinical testing of 152 samples, the AIO-LFIA can distinguish all positive samples, outperforming commercial LFIA which missed those positive samples with relatively low antibody levels. Thus, this study presents a universal ultrasensitive and reliable AIO-LFIA strategy for infectious diseases self-testing, providing an effective promising prospect to address the challenge over emerging infectious diseases in the future.

Sexually transmitted infections in the middle east and North Africa: comprehensive systematic review and meta-analysis

BACKGROUND

Globally, sexually transmitted infections (STIs) collectively cause 2.3 million deaths and 1.2 million cases of cancer annually. However, the epidemiology of STIs in the Middle East and North Africa (MENA) is not well assessed because of various social and cultural factors.

METHODS

A systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and covering 23 MENA countries, 19 STIs, and data from 20,435,971 participants. PubMed, Embase, regional and international databases, and country-level reports were searched up to May 2024.

RESULTS

The analysis revealed significant regional variations in the prevalence of STIs within the MENA region. In North Africa, the most common STIs were bacterial vaginosis (31%), human papillomavirus (HPV, 23%), and Candida spp. (15%). In the Gulf Cooperation Council region and Yemen, Ureaplasma (25%), nongonococcal urethritis (NGU, 16%), and Mycoplasma spp. (12%) were the predominant infections. In the Levant region, the top STIs were HPV (20%), hepatitis B virus (HBV, 9%), and Candida spp. (9%). In Iran, Ureaplasma spp. (18%), HPV (17%), and cytomegalovirus (8%) were the most prevalent infections, whereas Ureaplasma spp. (20%), Candida spp. (18%), and HPV (16%) were most frequently detected in Türkiye. Gender-based disparities were observed, with a higher prevalence of Ureaplasma spp., Neisseria gonorrhoeae, and herpes in men and higher rates of Mycoplasma spp., HPV, HBV, and Candida spp. in women. Overall, high rates of nongonococcal urethritis (16.3%), Ureaplasma spp. (13.7%), HPV (12.7%), and Candida spp. (9.4%) were recorded in the MENA region.

CONCLUSIONS

Most MENA countries lack national STI screening programs, and the reported data are primarily from symptomatic individuals. Establishing robust surveillance systems, addressing stigma and barriers to healthcare access, and expanding STIs screening and vaccination programs are crucial for accurately capturing the true burden of STIs in MENA countries.

Development and utilization of Treponema pallidum expressing green fluorescent protein to study spirochete-host interactions and antibody-mediated clearance: expanding the toolbox for syphilis research

Syphilis is a sexually transmitted infection caused by the highly invasive and immunoevasive spirochetal pathogen Treponema pallidum subsp. pallidum (TPA). Untreated syphilis can lead to infection of multiple organ systems, including the central nervous system. The alarming increase in syphilis cases globally underscores the importance of developing novel strategies to understand the complexities of syphilis pathogenesis. In this study, we took advantage of recent advances in in vitro cultivation and genetic manipulation of syphilis spirochetes to engineer a TPA strain that constitutively expresses green fluorescent protein (GFP). GFP+ TPA grew identically to the Nichols parent strain in vitro and exhibited wild-type infectivity in the rabbit model. We then used the GFP+ strain to visualize TPA interactions with host cells during co-cultivation in vitro, within infected rabbit testes, and following opsonophagocytosis by murine bone marrow-derived macrophages. Development of fluorescent strain also enabled us to develop a flow cytometric-based assay to assess antibody-mediated damage to the spirochete's fragile outer membrane (OM), demonstrating dose-dependent growth inhibition and OM disruption in vitro. Notably, we observed greater OM disruption of GFP+ TPA with sera from immune rabbits infected with the TPA Nichols strain compared to sera generated against the genetically distinct SS14 strain. These latter findings highlight the importance of OM protein-specific antibody responses for clearance of TPA during syphilitic infection. The availability of fluorescent TPA strains paves the way for future studies investigating spirochete-host interactions as well as functional characterization of antibodies directed treponemal OM proteins, the presumptive targets for protective immunity.

A case of early-onset congenital syphilitic osteomyelitis of the calcaneus and literature review

BACKGROUND

Congenital syphilis (CS) is a sexually transmitted disease caused by Treponema pallidum (TP). When the skeletal system is involved, it often results in multiple, symmetrical bone destruction at the epiphyses of long tubular bones such as the humerus and radius, rarely involving the calcaneus. This article reports a case of calcaneal osteomyelitis caused by TP in a child with no other bone damage and subtle clinical manifestations, No similar cases have been reported.

CASE PRESENTATION

A 4-month-old male infant presented with right foot swelling without any obvious cause and no history of trauma. X-ray and CT scans showed bone loss in the calcaneus and surrounding soft tissue swelling. Review of past medical records revealed that the infant had been diagnosed with CS infection during a hospital stay for "pneumonia" at one month old. The parents refused surgery, opting for conservative treatment at an external hospital for three weeks, during which the symptoms of the affected foot showed no significant improvement. Subsequently, the child was treated at our hospital with surgery, including lesion removal and cast fixation, followed by oral antibiotic treatment. The last follow-up showed no swelling or tenderness in the affected foot, with good mobility, and X-rays indicated that the bone had essentially returned to normal.

CONCLUSIONS

Early CS rarely involves the calcaneus. When diagnosing unexplained calcaneal osteomyelitis in infants, this rare cause should be considered. A thorough medical history should be taken and a careful physical examination conducted. Once diagnosed, timely surgical debridement and appropriate antibiotic therapy targeting TP infection are required. Early identification and intervention can result in a good prognosis without related complications.

[Translated article] AEDV Expert Consensus for the Management of Syphilis

Syphilis -the "great simulator" for classical venereologists-is re-emerging in Western countries despite adequate treatment; several contributing factors have been identified, including changes in sexual behaviour, which won't be the topic of this article though. In 2021, a total of 6613 new cases of syphilis were reported in Spain, representing an incidence of 13.9×100 000 inhabitants (90.5%, men). Rates have increased progressively since 2000. The clinical presentation of syphilis is heterogeneous. Although chancroid, syphilitic roseola and syphilitic nails are typical lesions, other forms of the disease can be present such as non-ulcerative primary lesions like Follmann balanitis, chancres in the oral cavity, patchy secondary lingual lesions, or enanthema on the palate and uvula, among many others. Regarding diagnosis, molecular assays such as PCR have been replacing dark-field microscopy in ulcerative lesions while automated treponemal tests (EIA, CLIA) are being used in serological tests, along with classical tests (such as RPR and HAART) for confirmation and follow-up purposes. The interpretation of these tests should be assessed in the epidemiological and clinical context of the patient. HIV serology and STI screening should be requested for anyone with syphilis. Follow-up of patients under treatment is important to ensure healing and detect reinfection. Serological response to treatment should be assessed with the same non-treponemal test (RPR/VDRL); 3-, 6-, 12-, and 24-month follow-up is a common practice in people living with HIV (PLHIV). Sexual contacts should be assessed and treated as appropriate. Screening is advised for pregnant women within the first trimester of pregnancy. Pregnant women with an abortion after week 20 should all be tested for syphilis. The treatment of choice for all forms of syphilis, including pregnant women and PLHIV, is penicillin. Macrolides are ill-advised because of potential resistance.

AEDV Expert Consensus for the Management of Syphilis

Syphilis -the "great simulator" for classical venereologists-is re-emerging in Western countries despite adequate treatment; several contributing factors have been identified, including changes in sexual behaviour, which won't be the topic of this article though. In 2021, a total of 6613 new cases of syphilis were reported in Spain, representing an incidence of 13.9×100 000 inhabitants (90.5%, men). Rates have increased progressively since 2000. The clinical presentation of syphilis is heterogeneous. Although chancroid, syphilitic roseola and syphilitic nails are typical lesions, other forms of the disease can be present such as non-ulcerative primary lesions like Follmann balanitis, chancres in the oral cavity, patchy secondary lingual lesions, or enanthema on the palate and uvula, among many others. Regarding diagnosis, molecular assays such as PCR have been replacing dark-field microscopy in ulcerative lesions while automated treponemal tests (EIA, CLIA) are being used in serological tests, along with classical tests (such as RPR and HAART) for confirmation and follow-up purposes. The interpretation of these tests should be assessed in the epidemiological and clinical context of the patient. HIV serology and STI screening should be requested for anyone with syphilis. Follow-up of patients under treatment is important to ensure healing and detect reinfection. Serological response to treatment should be assessed with the same non-treponemal test (RPR/VDRL); 3-, 6-, 12-, and 24-month follow-up is a common practice in people living with HIV (PLHIV). Sexual contacts should be assessed and treated as appropriate. Screening is advised for pregnant women within the first trimester of pregnancy. Pregnant women with an abortion after week 20 should all be tested for syphilis. The treatment of choice for all forms of syphilis, including pregnant women and PLHIV, is penicillin. Macrolides are ill-advised because of potential resistance.

Potential mechanisms of Treponema pallidum breaching the blood-brain barrier

Syphilis, a sexually transmitted disease caused by Treponema pallidum subsp. pallidum (T. pallidum), can lead to a complication known as neurosyphilis. Neurosyphilis affects multiple components of the nervous system, including the meninges, blood vessels, brain parenchyma, and others, significantly impacting the central nervous system (CNS). Despite the effective control of syphilis spread by antibiotics, recent years have seen a resurgence in incidence among high-risk populations. The blood-brain barrier (BBB) is a critical defense for the CNS, preventing toxins and pathogens, including viruses, from entering and ensuring CNS function. The exact mechanisms of how T. pallidum penetrates the BBB are still not fully understood. Extensive research suggests that T. pallidum can disrupt endothelial cells and intercellular junctions, as well as induce abnormal activation of immune cells and aberrant cytokine expression, potentially facilitating its breach of BBB. Based on current research, we focus on the detrimental effects of cytokines on BBB integrity. We have also summarized the pathways T. pallidum uses to penetrate cellular barriers. Understanding the interaction between T. pallidum and the BBB is essential for revealing neurosyphilis pathogenesis and developing new therapies. DATA AVAILABILITY: Data used to support the findings of this study are included in the article.

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.

Typing of Treponema pallidum in a Brazilian sample and follow-up of treatment using molecular assays

Syphilis remains a significant public health concern, with serological assays being the primary method for diagnosis. However, molecular techniques have proven to be reliable tools for the diagnosis and understanding of the transmission dynamics of Treponema pallidum infection. This study aimed to evaluate the efficacy of syphilis treatment using molecular assays, perform Enhanced Centers for Disease Control and Prevention (ECDC) typing, and analyze resistance (macrolide and doxycycline) in the T. pallidum isolate. PCR assay amplified treponemal DNA only from the lesion sample, whereas qPCR was able to amplify DNA in both lesion and blood samples before treatment. Throughout the treatment follow-up, qPCR effectively did not identify treponemal DNA in the blood for up to one to two weeks after treatment. ECDC typing revealed the genotype 14 e/g in the Brazilian T. pallidum isolate, and the presence of the A2058G mutation in 23 S rRNA gene, indicating macrolide resistance. Although, the G1058C mutation in 16 S rRNA gene was not detected. Notably, qPCR demonstrated its potential for diagnosing T. pallidum in blood samples, even when the treponemal DNA levels were low, enabling more accurate and sensitive diagnosis and guiding better syphilis therapy. In addition, to the best of our knowledge, this study represents the first identification of subtype 14 e/g and azithromycin resistance in a Brazilian T. pallidum isolate.

Fighting fire with fire: using infectious agents to treat persistent infection

Infectious diseases lead to significant morbidity and mortality. Often, resolution of the acute stage of the disease leads to microbial persistence, resulting in chronic debilitating disease. Management of persistent infections frequently requires lifelong therapy with antimicrobial agents. These infections could be chronic viral infections like HIV, hepatitis B or chronic bacterial persistent infections like prosthetic joint infections caused by multi-drug resistant organisms. Bacteriophages have been designed specifically to target recalcitrant bacterial infections, such as prosthetic joint infections with varying success. In this review, we describe the historic evolution of scenarios and risks associated with innovative therapy using infectious agents to treat other persistent infections.

Development of toluidine red particle agglutination-based turbidimetric immunoassay for anticardiolipin antibody detection in syphilis

INTRODUCTION

Serological tests of non-treponemal and treponemal types are the most frequently used for syphilis diagnosis. Nontreponemal tests are used to monitor disease activity. Toluidine red unheated serum test (TRUST), as one of nontreponemal tests, is generally applicable to hospitals at different levels. However, accurate judgment of TRUST results is inseparable from an experienced and accurate operator. To reduce current shortcomings of manual TRUST method, we attempted to convert the manual TRUST test into automatic TRUST test, that is, to determine the degree of aggregation of toluidine red particles by detecting the absorbance value of serum after reaction with toluidine red particles.

METHODS

50 μL of serum sample and 80 μL toluidine red particles were added to 96-well plate. Then, the 96-well plate was placed on a microplate reader at medium grade for 8 min to mix. Then, plasma reagin reacted with toluidine red particles and promoted the aggregation of toluidine red particles to form a large clot, which eventually caused a decrease in the absorbance at 540 nm.

RESULTS

The results showed that the specificity of the automatic TRUST test was 100%, the sensitivity was 87%. And this method showed 93.5% correlation with manual TRUST test. The developed method is simple and involves less subjectivity in reading results, opening new avenues for syphilis diagnostic testing.

CONCLUSION

Turbidimetric immunoassay can avoid the shortcomings of subjective interpretation, time-consuming and manual operation of manual TRUST method, and is more suitable for large-scale screening in health examination.

Syphilis among Roma community: a single-center experience in Bulgaria (socio-demographic data collection, 2008-2022)

INTRODUCTION

With a population of roughly 11 million, the Roma (Gypsies) are the largest ethnic minority in Europe, particularly in the countries of Central and Eastern Europe. A number of serious socioeconomic issues, such as poor health, low levels of education, unemployment, discrimination, criminal activity, high-risk sexual behavior, and a high rate of illnesses, including STDs, are present in their society.

Evaluation of Combined Strategy to Reduce the Pain of Penicillin G Benzathine Injection in Primary Syphilis

Background

Intramuscular (IM) injection of penicillin G Benzathine (PGB) is widely recognized as the primary treatment for patients at all stages of syphilis. However, the discomfort and induration associated with PGB injections are often a challenge for patients. While lidocaine is already known to reduce injection pain and is standard practice in some countries, the added value of combining lidocaine with the z-track technique has not been thoroughly investigated. This study aims to observe the use of combining lidocaine with the Z-track technique in the treatment of syphilis, and to explore less painful methods of administering IM PGB for the treatment of syphilis in adult patients.

Methods

32 syphilis patients requiring penicillin treatment were injected with 1.2 million units of penicillin on both sides of the buttocks. The left side was injected using the traditional method with 0.9% saline as the solvent (control Group), while the right side was injected using a "z" injection method with 0.2% lidocaine as the solvent (experimental Group). The success rate of the single injection, the intensity and duration of the post-injection pain and the induration reaction were observed and recorded.

Results

There was no statistically significant difference in single injection success rate and immediate post injection pain score between the two sides (P>0.05). However, the right side had a lower pain score at 30 minutes post injection and fewer induration reactions, showing a statistically significant difference between the two sides (P<0.05). Chi-squared analysis showed that age, gender and BMI had no significant effect on pain scores 30 minutes after injection in either the control or intervention groups. (P>0.05).

Conclusion

The lidocaine + Z-track penicillin method can reduce delayed pain and induration reactions in patients with syphilis, and provides an additional approach to improving patient comfort beyond the standard use of lidocaine alone. This method merits clinical promotion.

Mucocutaneous relapse during late latent syphilis as initial presentation of HIV infection

Syphilis is a re-emerging sexually transmitted infection. According to the definition, latent syphilis is characterized by seroreactivity without clinical manifestations. Here, we reported an atypical case of syphilis in a patient with HIV naïve to the antiretroviral treatment characterized by mucocutaneous relapse that occurred in the late latent stage. The patient reported his last sexual intercourse about 18 months ago and had self-healing genital and palmoplantar lesions more than 1 year before the presentation. He denied any other types of sexual relationship. He presented with mucocutaneous scattered lesions on his face, neck, palms, soles, penis, and scrotum. He was compliant with arthralgias, myalgias, asthenia, new onset stypsis, and mild anorectal pain. Testing for Syphilis and HIV returned positive. Opportunistic infections were excluded, and antiretroviral therapy with a bictegravir-based regimen was started. Syphilis was treated successfully with three doses of 2.4 million units of benzathine penicillin.

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.

Immunodominant extracellular loops of Treponema pallidum FadL outer membrane proteins elicit antibodies with opsonic and growth-inhibitory activities

The global resurgence of syphilis has created a potent stimulus for vaccine development. To identify potentially protective antibodies (Abs) against Treponema pallidum (TPA), we used Pyrococcus furiosus thioredoxin (PfTrx) to display extracellular loops (ECLs) from three TPA outer membrane protein families (outer membrane factors for efflux pumps, eight-stranded β-barrels, and FadLs) to assess their reactivity with immune rabbit serum (IRS). Five ECLs from the FadL orthologs TP0856, TP0858 and TP0865 were immunodominant. Rabbits and mice immunized with these five PfTrx constructs produced ECL-specific Abs that promoted opsonophagocytosis of TPA by rabbit peritoneal and murine bone marrow-derived macrophages at levels comparable to IRS and mouse syphilitic serum. ECL-specific rabbit and mouse Abs also impaired viability, motility, and cellular attachment of spirochetes during in vitro cultivation. The results support the use of ECL-based vaccines and suggest that ECL-specific Abs promote spirochete clearance via Fc receptor-independent as well as Fc receptor-dependent mechanisms.

Two-Stage Syphilis Testing

A 54-year-old woman presented with erythematous annular and indurated plaques on her face, trunk, and extremities and had false-positive syphilis test results during 2 pregnancies 25 and 22 years prior. What would you do next?

Influence of gender on clinical presentation, management practices and outcomes of ocular syphilis

Ocular syphilis is a re-emerging inflammatory eye disease with a clear gender imbalance, disproportionately affecting men. We investigated the impact of gender on the presentation, management practices and clinical outcomes of this condition. Data generated from a study of patients consecutively diagnosed with ocular syphilis who attended a subspecialist uveitis service at one of four hospitals in Brazil over a 30-month period were disaggregated for analysis by gender. Two-hundred and fourteen eyes (161 men and 53 women) of 127 patients (96 men and 31 women) were included. Posterior uveitis was the most common presentation in both men and women (80.1% vs. 66.7%, p > 0.05), but men were significantly more likely to have vitritis as a feature of their disease (49.4% versus 28.8%, p = 0.019). Three eyes of women had nodular anterior scleritis (p = 0.015). Men were more likely to undergo a lumbar puncture to assess for neurosyphilis (71.9% vs. 51.6%, p = 0.048), but men and women undergoing a lumbar puncture were equally likely to have a cerebrospinal fluid abnormality (36.2% vs. 25.0%, p = 0.393). All patients were treated with aqueous penicillin G or ceftriaxone, and there was a trend towards more men receiving adjunctive systemic corticosteroid treatment as part of their management (65.2% vs. 46.7%, p = 0.071). There were no significant differences in the age of presentation, bilaterality of disease, anatomical classification of uveitis, initial or final visual acuity, and rates of ocular complications between men and women. Our findings indicate that ocular syphilis has comparable outcomes in men and women, but that there are differences in the type of ocular inflammation and management practices between the genders.

Risk for Donor-Derived Syphilis after Kidney Transplantation, China, 2007-2022

To evaluate the risk of acquiring syphilis from a donated kidney, we evaluated kidney transplantation pairs from West China Hospital, Sichuan, China, during 2007-2022. Donor-derived syphilis was rare. Risk may be higher if donors have active syphilis and may be reduced if recipients receive ceftriaxone.

Molecular characterization of Treponema pallidum isolates from Brazil

Syphilis remains a public health concern in Brazil, and the data on the characterization and resistance of Treponema pallidum in Brazil is limited. The present study aimed to detect Treponema DNA in the lesions and blood samples obtained from individuals diagnosed with syphilis. The Brazilian isolates were submitted to the Enhanced Centers for Disease Control and Prevention (ECDC) scheme and also analyzed for resistance gene. Treponemal DNA from 18 lesions and 18 blood specimens were submitted for amplification using Polymerase Chain Reaction (PCR) and Polymerase Chain Reaction in Real Time (RT-PCR). Eight samples from lesions and eight from blood were positive in the RT-PCR analysis. Eight lesions and three blood samples were positive using PCR. Two samples exhibited azithromycin resistance. The Brazilian isolate types 14d/g, 14 d/c, 15d/c, and 15d/e were identified using the ECDC scheme. The three subtypes 14d/c, 15d/c, and 15d/e have been identified in Brazil for the first time.

Antimicrobial treatment and resistance in sexually transmitted bacterial infections

Sexually transmitted infections (STIs) have been part of human life since ancient times, and their symptoms affect quality of life, and sequelae are common. Socioeconomic and behavioural trends affect the prevalence of STIs, but the discovery of antimicrobials gave hope for treatment, control of the spread of infection and lower rates of sequelae. This has to some extent been achieved, but increasing antimicrobial resistance and increasing transmission in high-risk sexual networks threaten this progress. For Neisseria gonorrhoeae, the only remaining first-line treatment (with ceftriaxone) is at risk of becoming ineffective, and for Mycoplasma genitalium, for which fewer alternative antimicrobial classes are available, incurable infections have already been reported. For Chlamydia trachomatis, in vitro resistance to first-line tetracyclines and macrolides has never been confirmed despite decades of treatment of this highly prevalent STI. Similarly, Treponema pallidum, the cause of syphilis, has remained susceptible to first-line penicillin.

Diagnosing Tabes Dorsalis in HIV-Negative Patients: Clinical Features, Neuroimaging, and Laboratory Insights in the Modern Antibiotic Era

Background

Tabes dorsalis is a late manifestation of neurosyphilis, characterized by progressive ataxia, lightning pains, loss of proprioception, and urinary incontinence. The absence of a definitive diagnostic standard and the non-specific clinical manifestations have led to a significant rate of misdiagnoses.

Methods

Hospitalized patients with tabes dorsalis at Peking Union Medical College Hospital between January 2010 and December 2023 were reviewed.

Results

A total of 13 patients were included, with 10 males and 3 females. The median age was 50 years (range, 34-64). The most frequent initial symptoms were limb numbness (30.8%) and lightning pains (30.8%). Eleven patients (84.6%) received misdiagnoses prior to the final diagnosis. The most frequently observed physical sign was positive Romberg's sign (84.6%). Notably, Argyll Robertson pupil was presented in 7 subjects (53.8%). Serological tests revealed positive rapid plasma regain (RPR) and Treponema pallidum particle agglutination (TPPA) for all patients. All CSF samples were TPPA-reactive. Intramedullary hyperintensity on T2-weighted imaging of spinal MRI was found in 5 patients (38.5%). All patients received anti-syphilitic treatment, with effective treatment recorded in five cases.

Conclusion

This study underscores the importance of neurological symptoms and signs in diagnosing tabes dorsalis. Individuals with progressive ataxia and positive Romberg's sign should be closely monitored for potential neurosyphilis. Integrating clinical features, laboratory tests, and neuroimaging could reduce misdiagnosis and expedite the initiation of anti-syphilitic therapy.

Unique presentation of acute neuro-Behçet's disease involving a cytotoxic edema core surrounded by vasogenic edema

A 53-year-old woman with recurrent stomatitis, genital ulcers, and folliculitis was admitted to our hospital after experiencing visual disturbances for the past two weeks, and a non-throbbing headache for the past three days. She had also developed numbness in her left extremities. An ophthalmological examination revealed inflammatory changes in the eye. Cerebrospinal fluid analysis showed increased cell counts, protein, and interleukin-6 levels. Brain magnetic resonance imaging revealed multiple high signal intensities on T2-weighted (T2W)/fluid-attenuated inversion recovery (FLAIR) images of the pons and occipital and parietal lobes. The T2W/FLAIR high-signal-intensity lesion in the pons was hyperintense on diffusion-weighted imaging (DWI) and hypointense on apparent diffusion coefficient mapping (ADC), suggesting cytotoxic edema. Another high-signal-intensity lesion on T2W/FLAIR was isointense to hyperintense on DWI and hyperintense on ADC, indicating vasogenic edema. The vasogenic edema in the left occipital lobe contained a small core that was hyperintense on DWI and hypointense on ADC, suggesting cytotoxic edema. The patient was diagnosed with acute neuro-Behçet's disease (neuro-BD) and responded well to high-dose glucocorticoid and colchicine treatment. The present report emphasizes that patients with acute neuro-BD may present with cytotoxic edema in the pons and cerebral spheres. Further reports of similar cases would contribute to a better understanding of the role of cytotoxic edema in the pathophysiology of neuro-BD and help elucidate the mechanisms underlying a unique presentation characterized by a central cytotoxic edema core within vasogenic edema. (233 words).

A case of syphilitic balanitis of Follman in a circumcised patient-Don't be fooled! A case report

Syphilis is known as the great masquarader. We describe a case of a young patient with an atypical chancre.

Epidemiological characteristics of syphilis in mainland China, 2004 to 2019

OBJECTIVES

Syphilis is a globally prevalent sexually transmitted infection. This study aimed to elucidate the epidemiological characteristics of syphilis in China from 2004 to 2019.

METHODS

Incidence data for syphilis across 31 provinces in mainland China were obtained from the Data Center of China Public Health Science for the period from 2004 to 2019. Epidemiological methods and the Chi-squared test were used to analyze the temporal, regional, and disease stage distributions of syphilis.

RESULTS

In total, 5,527,399 syphilis cases were reported in China from 2004 to 2019, with an average annual prevalence of 25.7063 per 100,000 population and overall increasing trend. In terms of regional distribution, high-incidence provinces included Shanghai, Zhejiang, Fujian, Guangxi, Guangdong, Xinjiang, Ningxia, and Qinghai. The proportion of latent syphilis increased from 20.41% in 2004 to 82.95% in 2019, with an upward trend each year.

CONCLUSIONS

Syphilis incidence exhibited an overall increasing trend in China, and latent syphilis was predominant. Syphilis incidences considerably varied among regions, and syphilis was detected from coastal to inland provinces. Thus, syphilis prevention and control programs should be tailored according to the specific epidemiological characteristics of each region.

Sudden hearing loss secondary to syphilis

BACKGROUND

Syphilis is a sexually transmitted disease caused by the spirochete Treponema pallidum, whose incidence has increased significantly in recent years. Some patients may develop sudden hearing loss (SHL) against the background of otosyphilis.

OBJECTIVES

The objective of our study was to determine whether routine lues serology is useful in patients presenting with sudden hearing loss.

METHODS

For this purpose, all cases of SHL treated in our hospital during a period of 6 years were propectively collected. The frequency of positivity for syphilis in these patients, the treatment received, and their evolution were determined.

RESULTS

Of the total number of patients evaluated during that period, 71 underwent serological screening for syphilis, of whom 2 (2.8 %) presented positive screening antibodies. In one of them, the RPR was normal and had been treated with lues a few years before. After treatment there was no improvement. The other patient, diagnosed with otosyphilis with unconfirmed suspected neurological disease, showed normalization of hearing after specific treatment.

CONCLUSIONS

Since it is a potentially curable disease, despite the low overall frequency of syphilis in patients with SHL it is advisable to perform serological screening for syphilis in high risk patients (e.g., incarceration, multiple recent sexual partners, men who have sex with men) or atypical clinical presentation (e.g., concurrent neuropathies).

Syphilitic scleritis and episcleritis: A review

Scleritis and episcleritis are rare, but potentially sight-threatening forms of syphilis. To provide a full description of this neglected subset of ocular syphilis, we evaluated the English literature for reports of syphilitic scleritis and episcleritis, recording the demographics, clinical characteristics, serological data, management practices, treatment responses, and visual outcomes. Previously published descriptions of 44 patients with syphilitic scleritis (50 eyes) and 9 patients with syphilitic episcleritis (14 eyes) were identified. The predominant type of scleritis was anterior scleritis, accounting for 92.9% of cases, with nodular anterior scleritis being the most frequent subtype at 58.1%. Almost one-quarter of patients were co-infected with human immunodeficiency virus (HIV). Initial misdiagnosis was common and led to delays in initiating treatment with appropriate antibiotics. Visual outcomes were often good in both scleritis and episcleritis, irrespective of HIV infection status, although complications including scleral thinning, keratitis, and uveitis, along with permanent visual loss and an association with neurosyphilis, were reported. Response to antibiotic treatment was typically rapid, often within 1 week. With the rising global incidence of syphilis, testing patients with scleritis or episcleritis for this infectious disease is important to ensure prompt diagnosis and treatment for best ocular and systemic outcomes.

A Potential Screening Strategy to Identify Probable Syphilis Infections in the Urban Emergency Department Setting

Background

Syphilis diagnosis in the emergency department (ED) setting is often missed due to the lack of ED-specific testing strategies. We characterized ED patients with high-titer syphilis infections (HTSIs) with the goal of defining a screening strategy that most parsimoniously identifies undiagnosed, untreated syphilis infections.

Methods

Unlinked, de-identified remnant serum samples from patients attending an urban ED, between 10 January and 9 February 2022, were tested using a three-tier testing algorithm, and sociodemographic variables were extracted from ED administrative database prior to testing. Patients who tested positive for treponemal antibodies in the first tier and positive at high titer (≥1:8) for nontreponemal antibodies in the second tier were classified as HTSI. Human immunodeficiency virus (HIV) status was determined with Bio-Rad enzyme-linked immunosorbent assay and confirmatory assays. Exact logistic regression and classification and regression tree (CART) analyses were performed to determine factors associated with HTSI and derive screening strategies.

Results

Among 1951 unique patients tested, 23 (1.2% [95% confidence interval, .8%-1.8%]) had HTSI. Of those, 18 (78%) lacked a primary care physician, 5 (22%) were HIV positive, and 8 (35%) were women of reproductive age (18-49 years). CART analysis (area under the curve of 0.67) showed that using a screening strategy that measured syphilis antibodies in patients with HIV, without a primary care physician, and women of reproductive age would have identified most patients with HTSI (21/23 [91%]).

Conclusions

We show a high prevalence of HTSI in an urban ED and propose a feasible, novel screening strategy to curtail community transmission and prevent long-term complications.

Immunophenotypic variations in syphilis: insights from Mendelian randomization analysis

Background

Infection with Treponema pallidum instigates complex immune responses. Prior research has suggested that persistent Treponema pallidum infection can manipulate host immune responses and circumvent host defenses. However, the precise role of immune cells in Treponema pallidum infection across different stages remains a contentious issue.

Methods

Utilizing summary data from genome-wide association studies, we employed a two-sample Mendelian randomization method to investigate the association between 731 immunophenotypes and syphilis. Syphilis was categorized into early and late stages in this study to establish a more robust correlation and minimize bias in database sources.

Results

Our findings revealed that 33, 36, and 27 immunophenotypes of peripheral blood were associated with syphilis (regardless of disease stage), early syphilis and late syphilis, respectively. Subsequent analysis demonstrated significant variations between early and late syphilis in terms of immunophenotypes. Specifically, early syphilis showcased activated, secreting, and resting regulatory T cells, whereas late syphilis was characterized by resting Treg cells. More B cells subtypes emerged in late syphilis. Monocytes in early syphilis exhibited an intermediate and non-classical phenotype, transitioning to classical in late syphilis. Early syphilis featured naive T cells, effector memory T cells, and terminally differentiated T cells, while late syphilis predominantly presented terminally differentiated T cells. Immature myeloid-derived suppressor cells were evident in early syphilis, whereas the dendritic cell immunophenotype was exclusive to late syphilis.

Conclusion

Multiple immunophenotypes demonstrated associations with syphilis, showcasing substantial disparities between the early and late stages of the disease. These findings hold promise for informing immunologically oriented treatment strategies, paving the way for more effective and efficient syphilis interventions.

Neutrophil CD64 index as a potential blood biomarker for the diagnosis of neurosyphilis in secondary and tertiary syphilis: A retrospective study

Objective

To examine the correlation of neutrophil CD64 (nCD64) index with neurosyphilis (NS) across different stages of syphilis.

Methods

A total of 1243 syphilis patients at different stages (344 of primary, 385 of secondary, and 514 of tertiary) included in this study were divided into NS and non-NS (NNS). Correlations of nCD64 index with currently used syphilis biomarkers were explored using Spearman correlation test. Relationships between nCD64 index and NS at different stages were investigated by stratified analysis and restricted cubic spline model. The diagnostic performance of nCD64 index for NS was assessed by receiver operating characteristic (ROC) curve.

Results

Significant statistical correlations of nCD64 index with cerebrospinal fluid (CSF) NS indicators were found in secondary and tertiary syphilis. Increased nCD64 index was associated with increased risk of NS in secondary and tertiary syphilis. ROC analysis values further confirmed the diagnostic potential of nCD64 index for NS. Marked decrease of nCD64 index was observed in NS patients after effective antisyphilitic treatments.

Conclusions

The nCD64 index may help to the diagnosis of NS in secondary and tertiary syphilis.

Syphilis seroprevalence and associated factors: A cross-sectional study in formal female sex workers in a province of Peru

Syphilis is a sexually transmitted infection (STI) considered a public health problem that affects vulnerable and at-risk populations, such as sex workers. We designed a retrospective cross-sectional study based on the review of health evaluation records of sex workers who attended consultations to obtain comprehensive health cards at a Health Center in the Province of San Vicente de Cañete in Peru during the year 2020. We obtained sociodemographic and employment information and the RPR (rapid plasma reagin) test results to diagnose syphilis. We evaluated 220 records of sex workers with a mean age of 27.9 ± 6.9 years and the initiation of sexual relations of 16.0 ± 1.6 years, while the accumulated time they had as sex workers was 2.9 ± 2.4 years. 85.9% of those evaluated reported being heterosexual. The prevalence of syphilis was 7.3% (CI95: 4.2%-11.5%). Being a homosexual sex worker was significantly associated with syphilis (OR: 19.6; 95% CI: 4.8-80.0) compared to heterosexuals. The prevalence of syphilis presented a value similar to that reported in other Latin American and national studies, and it is evident that it is a health problem among sex workers.

Atypical Manifestations of Syphilis: A 10-Year Retrospective Study

Background: The incidence of syphilis has increased in high-income countries in the past few decades, especially among men who have sex with men. In the present study, we aimed to analyze the correlations between atypical syphilis manifestations and the demographic, clinical, and laboratory features of patients and to review unusual presentations of syphilis reported in the literature. Methods: We conducted a retrospective analysis of 307 patients with syphilis diagnosed between 1 January 2013 and 31 October 2023 at the sexually transmitted infection (STI) centers of the University of Genoa and University of Foggia with both typical and atypical manifestations of disease. Results: In our series, atypical manifestations were detected in 25.8% of the patients, especially in the secondary stage of the disease. Lesions with annular morphology and lesions presenting as itchy erythematous scaly plaques with a psoriasiform appearance were the most common atypical presentations of secondary syphilis. A statistical analysis revealed that homosexual orientation, syphilis reinfection, and venereal disease research laboratory (VDRL) titers > 1:32 were correlated with atypical manifestations. Conclusions: Our study demonstrates that the spectrum of syphilis manifestations, in all the stages of the disease, is wide; atypical manifestations often pose diagnostic challenges, may delay the provision of appropriate treatment, and facilitate the spread of the infection.

Comprehensive Overview of Treponema pallidum Outer Membrane Proteins

Treponema pallidum, the causative agent of syphilis, is a sexually transmitted microorganism that exhibits remarkable motility capabilities, allowing it to affect various systems. Despite its structural resemblance to gram-negative bacteria due to its dual-membrane, T. pallidum possesses a lower abundance of outer membrane proteins (OMPs), which enables it to effectively conceal itself. This review presents a comprehensive analysis of the clinical diagnostic potential associated with the OMPs of T. pallidum. Furthermore, the known OMPs in T. pallidum that are responsible for mediating host interactions have been progressively elucidated. This review aims to shed light on the pathogenesis of syphilis, encompassing aspects such as vascular inflammation, chancre self-healing, neuroinvasion, and reinfection. Additionally, this review offers a detailed overview of the current state and prospects of development in the field of syphilis vaccines, with the ultimate goal of establishing a foundation for understanding the pathogenesis and implementing effective prevention strategies against syphilis.

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.