Syphilis

Looks Like Neurosyphilis, Feels Like Guillain-Barre: At the Confluence of Infection and Immunology

We present a 51-year-old male, with a past medical history of type 2 insulin-dependent diabetes mellitus (T2IDDM) without neuropathy, coronavirus disease 2019 (COVID-19) in April 2020 without residual symptoms, Raynaud's, and recent occupational outdoor exposure to insects as a construction manager who came to the emergency room complaining of a three-week history of bilateral progressive numbness and weakness beginning in his lower extremities and ascending toward his pelvis. Notably, he received the second dose of his Moderna COVID-19 vaccine one week prior to symptom onset and four weeks prior to admission. He also reported a recent appearance of a maculopapular rash on his upper extremities and flanks. Physical exam was remarkable for bilateral distal motor weakness in the upper and lower extremities with associated paresthesia and decreased reflexes in the lower extremities. The patient had slight ataxia and difficulty with heel walk and toe walk. Notably, the cranial nerve exam was normal, and the patient was afebrile. Intravenous immune globulin (IVIG) was started empirically for the treatment of Guillain-Barre syndrome (GBS), and doxycycline 100mg intravenous twice a day and ceftriaxone 2g intravenous daily were started for possible tick-borne disease. Subsequently, rapid plasma reagin (RPR) returned reactive at 1:64, and cerebral spinal fluid (CSF) venereal disease research laboratory (VDRL) test was reactive at 1:2 with markedly elevated protein and pleocytosis. Human immunodeficiency virus (HIV) testing was negative. Lyme disease testing was negative. Nerve conduction studies (NCS) and electromyography (EMG) showed a sensorimotor polyneuropathy with mixed demyelinating and axonal features. IVIG was continued for a total of five days, and antibiotics were changed to penicillin G (PCN G) for a total of 14 days for definitive treatment of early neurosyphilis (NS). While both clinical and laboratory findings confirm a positive diagnosis of NS, the patient’s CSF composition showed very elevated total protein levels and pleocytosis. Additionally, his early peripheral neuropathy and EMG findings are not characteristics of a single disease and, instead, suggested a mixed pathology. We postulate that this patient had confirmed secondary syphilis with early NS associated with, and possibly correlated with, a simultaneous episode of acute inflammatory demyelinating polyneuropathy (AIDP) and/or a vaccine-related phenomenon.

Patterns of Sexually Transmitted Co-infections and Associated Factors Among Men Who Have Sex With Men: A Cross-Sectional Study in Shenyang, China

Background

Men who have sex with men (MSM) are disproportionately affected by sexually transmitted infections (STIs). We sought to describe patterns of sexually transmitted co-infections and explore factors associated with increased acquisition of STIs among MSM.

Methods

We enrolled MSM in Shenyang, China, between July and December 2020 to test for four STIs, including human papillomavirus (HPV), Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), and Treponema pallidum (TP). Data regarding demographic and behavioral characteristics of participants were collected through a self-administered digital questionnaire. We adopted the ordinal logistic regression model to identify factors associated with acquiring more STIs.

Results

Overall, 177 participants with completed test results for all four STIs were analyzed. These participants had a median age of 29.0 (interquartile range: 23.0-38.0) years. The prevalence of STI co-infections was 23.7% [42/177; 95% confidence interval (CI), 17.8%-30.8%], among which HPV/CT (47.1%) and HPV/CT/NG (50.0%) co-infection were the predominant types among participants with dual and multiple infections, respectively. Participants who had a higher educational background [adjusted odds ratio (aOR), 0.46; 95% CI, 0.24-0.85; P = 0.014] and had a history of STIs (aOR, 2.53; 95% CI, 1.24-5.18; P = 0.011) were positively associated with acquiring more STIs.

Conclusions

MSM in Shenyang suffer a substantial burden of sexually transmitted co-infections. An optimized multi-STI integration strategy targeting prevention, surveillance, screening, and treatment is warranted to reduce the prevalence of sexually transmitted co-infections, especially in less-educated MSM.

British Columbia's Experience after Implementation of the Treponema pallidum Reverse Algorithm and PCR Detection, 2015 to 2020

British Columbia (BC) implemented the syphilis reverse screening algorithm and Treponema pallidum PCR testing in 2014. We summarize the performance characteristics of the algorithm, together with PCR direct detection, and report on syphilis cases identified from 2015 to 2020. Prior to 2015, samples for syphilis diagnosis were first screened by rapid plasma reagin (RPR). As of 2015, sera were screened by the Siemens Advia Centaur syphilis assay (enzyme immunoassay [EIA]). Positive and equivocal samples were reflex tested by a T. pallidum passive particle agglutination assay (TPPA) and RPR. We used T. pallidum DNA PCR on clinical samples and restriction fragment length polymorphism analysis to identify azithromycin resistance mutations. Case/epidemiological data were obtained from the BC surveillance system. Of 1,631,519 samples screened by the EIA, 72,492 (4.4%) were positive and 187 (<0.1%) were equivocal. Of EIA-positive/equivocal samples, 10.6% were false positive, and false positivity was higher at lower EIA indices. The reverse algorithm detected 4,693 late latent syphilis cases that likely would have been missed by RPR screening. PCR had a very high sensitivity of 100% versus 52.9% and 52.4% for dark-field (DF) and immunofluorescence (IF) microscopy, respectively. The azithromycin resistance mutation A2058G was identified in 96% of PCR-positive samples, and A2059G was identified in 4%. Annually, there were 944 to 1,467 syphilis cases, with 62% in men who reported male sexual partners. The reverse algorithm had a low false-positive rate and very few equivocal screening results but did identify previously undiagnosed late latent syphilis cases. PCR was more sensitive than both DF and IF microscopy for direct diagnosis and enabled monitoring for azithromycin resistance. IMPORTANCE In this study, we summarize the performance characteristics of the algorithm, together with PCR direct detection and epidemiological analysis, and report on syphilis cases identified from 2015 to 2020. This allowed us to paint a complete picture of the outcome of the utilization of the reverse algorithm for diagnosing syphilis cases. The study clearly showed that the reverse algorithm had a low false-positive rate and very few equivocal screening results but did identify previously undiagnosed late latent syphilis cases. PCR was more sensitive than both DF and IF microscopy for direct diagnosis and enabled monitoring for azithromycin resistance.

Correlation of Treponemal Chemiluminescent Microparticle Immunoassay Screening Test Signal Strength Values With Reactivity of Confirmatory Testing

BACKGROUND

Automated chemiluminescent microparticle immunoassays (CMIAs) are the most common first step at high-volume laboratories for syphilis screening. If the initial screening test is reactive, 1 more treponemal test is required, resulting in increased cost. In this multicenter study, we aimed to determine the correlation between the CMIA signal-to-cutoff ratio (S/Co) and the confirmatory tests to reduce unnecessary confirmatory testing.

METHODS

Eight hospitals from 5 provinces participated in this study. All laboratories used Architect Syphilis TP CMIA (Abbott Diagnostics, Abbott Park, IL) for initial screening. Treponema pallidum hemagglutination (TPHA), rapid plasma reagin (RPR), and fluorescent treponemal antibody absorption (FTA-ABS) were used as confirmatory tests according to the reverse or European Centre for Disease Prevention and Control algorithms. A receiver operating characteristic analysis was used to determine the optimal S/Co ratio to predict the confirmation results.

RESULTS

We evaluated 129,346 serum samples screened by CMIA between January 2018 and December 2020. A total of 2468 samples were reactive; 2247 (91%) of them were confirmed to be positive and 221 (9%) were negative. Of the 2468 reactive specimens, 1747 (70.8%) had an S/Co ratio ≥10.4. When the S/Co ratios were ≥7.2 and ≥10.4, the specificity values were determined to be 95% and 100%, respectively. In a subgroup of 75 CMIA-positive patients, FTA-ABS was performed and 62 were positive. Among these FTA-ABS-positive patients, 24 had an S/Co ratio <10.4, and negative TPHA and RPR.

CONCLUSIONS

We propose a potentially cost-effective reverse screening algorithm with a treponemal CMIA S/Co ratio ≥10.4, obviating the need for secondary treponemal testing in about 71% of the screening-reactive samples. This would substantially reduce the confirmatory testing volume and laboratory expenses. However, in high-risk group patients with CMIA positive results, S/Co ratio <10.4, and negative TPHA and RPR, FTA-ABS may be used for confirmation.

Assessment of the appropriate management of syphilis patients in primary health care in different regions of Brazil from 2012 to 2018

This study aimed to analyze the presence of adequate infrastructure and work process in primary health care for the diagnosis, management, and treatment of syphilis in Brazil in 2012, 2014, and 2018. This is a cross-sectional, nationwide study with data from the three cycles of the Program for Improvement of Access and Quality of Basic Healthcare (PMAQ-AB): 2012 (Cycle I), 2014 (Cycle II), and 2018 (Cycle III). Two outcomes were assessed: adequate infrastructure and work process. The independent variables were macroregion, municipality size, Municipal Human Development Index (HDI-M), and coverage of the Family Health Strategy (FHS). Variance-weighted least squares regression was used to estimate annual changes in percentage. In total, 13,842 primary basic health units (UBS) and 17,202 professional health care teams were assessed in Cycle I; 24,055 UBS and 29,778 teams in Cycle II, and 28,939 UBS and 37,350 teams in Cycle III. About 1.4% of UBS had adequate infrastructure in Cycle I; 17.5% had in Cycle II; and 42.7% had in Cycle III. Adequate work process also increased in the three cycles, ranging from 47.3% in Cycle I to 45.5% in Cycle II and 75.4% in Cycle III. However, inequities are observed, considering that richer regions and larger municipalities, with higher HDI-M and lower FHS coverage improved the most. The low prevalence of adequate infrastructure and work process for the care of patients with syphilis in Brazil reflects a significant weakness in the Brazilian health system.

Treponema pallidum delays the apoptosis of human polymorphonuclear neutrophils through the intrinsic and extrinsic pathways

Treponema pallidum is a "stealth pathogen" responsible for infectious sexually transmitted diseases. Although neutrophils are usually present in skin lesions of early syphilis, the role of these cells in T. pallidum infection has barely been investigated. Neutrophils are short-lived cells that undergo constitutive apoptosis, and phagocytosis usually accelerates this process. Here, we demonstrated that human polymorphonuclear neutrophils (hPMNs) could phagocytose T. pallidum in vitro. An unexpected discovery was that T. pallidum inhibited hPMNs apoptosis markedly in an opsonin-independent manner. Furthermore, this phenomenon was not affected by bacterial viability, as detected by annexin V, morphology studies, and TUNEL staining. Exploration of the underlying mechanism showed that expression of the cleaved forms of caspase-3, -8, and -9 and effector caspase activity were diminished significantly in T. pallidum-infected hPMNs. T. pallidum also impaired staurosporine- and anti-Fas-induced signaling for neutrophil apoptosis. Of note, these effects were accompanied by inducing the autocrine production of the anti-apoptotic cytokine IL-8. Taken together, our data revealed that T. pallidum could inhibit the apoptosis of hPMNs through intrinsic and extrinsic pathways and provide new insights for understanding the pathogenicity mechanisms of T. pallidum.

A peculiar case of syphilis infection: The great imitator is on the rise

The incidence of syphilis is on the rise worldwide and can pose many diagnostic and therapeutic difficulties for doctors. Given the wide variety of presenting symptoms, syphilis is also known as the great imitator, which in turn frequently leads to a pronounced diagnostic- and therapeutic delay for patients. Here we present a case report of syphilitic uveitis and papillitis accompanied by acute vision loss, a rare presentation of a tertiary syphilis infection that clinically mimicked a giant cell arteritis (GCA) or arteritic anterior ischemic optic neuropathy (AAION). The patient was treated with high-dose intravenous benzyl penicillin after which full vision was restored. By presenting this case, we hope to raise awareness for the increasing incidence of syphilis infections and stress the importance of syphilis testing in patients with otherwise unexplained uveitis.

A Case of Syphilitic Hepatitis in an Adolescent

The incidence of syphilis is rising among adolescents necessitating improved provider awareness and screening practices. We present a case of an adolescent with acute hepatitis ultimately diagnosed with secondary syphilitic hepatitis. Clinical presentation, laboratory abnormalities, and histologic features of syphilitic hepatitis are nonspecific, with diagnosis relying on clinical suspicion and targeted testing. This case highlights the importance of screening for syphilis in sexually active adolescents with acute hepatitis. The rising incidence of syphilis among adolescents, and the variety of clinical manifestations including those commonly seen by pediatric gastroenterologists, makes elevated clinical suspicion essential to prompt diagnosis and treatment. With improved provider awareness across general pediatric and subspecialty providers, the transmission of syphilis among adolescent patients can be reduced.

Epidemiology, Management, Quality of Testing and Cost of Syphilis in Germany: A Retrospective Model Analysis

Background

A multi-dimensional model can be a useful tool for estimating the general impact of disease on the different sectors of the healthcare system. We chose the sexually transmitted disease syphilis for our model due to the good quality of reported data in Germany.

Methods

The model included gender- and age-stratified incident cases of syphilis (in- and outpatients) provided by a German statutory health insurance company, as well as seroprevalence data on syphilis in first-time blood donors. Age standardized rates were calculated based on the standard German population. The test quality was assessed by extrapolating the number of false-positive and false-negative results based on data from Europe-wide external quality assessment (EQA) schemes. The model analysis was validated with the reported cases and diagnosis-related group (DRG)-statistics from 2010 to 2012. The annual direct and indirect economic burden was estimated based on the outcomes of our model.

Results

The standardized results were slightly higher than the results reported between 2010 and 2012. This could be due to an underassessment of cases in Germany or due to limitations of the dataset. The number of estimated inpatients was predicted with an accuracy of 89.8 %. Results from EQA schemes indicated an average sensitivity of 92.8 % and an average specificity of 99.9 % for the recommended sequential testing for syphilis. Based on our model, we estimated a total average minimal annual burden of €20,292,110 for syphilis on the German healthcare system between 2010 and 2012.

Conclusions

The linking of claims data, results from EQA schemes, and blood donor surveillance can be a useful tool for assessing the burden of disease on the healthcare system. It can help raise awareness in populations potentially at risk for infectious diseases, demonstrate the need to educate potential risk groups, and may help with predictive cost calculations and planning.

The dark art of syphilis serology - an analysis of testing algorithms at a UK reference laboratory

Introduction. Due to the complex nature of treponemal serology interpretation, testing algorithms vary across the UK.Gap statement. There is currently no gold standard method for interpretation of discordant serology results.Aim. To analyse serological response in early infection and to determine the best approach for discordant total antibody EIA and TPPA samples.Methodology. National reference laboratory serology and PCR (genital ulcer swabs) results from 2010 to 2017 were extracted from an electronic laboratory database.Results. A total of 24149 sera underwent analysis. Of syphilis PCR positive cases with contemporaneous sera, 33% (17/52) were IgM positive/equivocal, whilst all were EIA and TPPA positive. No sera with isolated IgM positivity (0/90) demonstrated seroconversion consistent with early treponemal infection, in contrast to 17% (2/12) of sera with isolated TPPA positivity. Isolated EIA positivity was observed in 6.2% (1499/24149) samples with the same result on repeat testing in 73% (154/211). In 100 samples with discordant EIA/TPPA results, IgG Immunoblot was more commonly positive (12/41, 29%) or equivocal (24/41, 59%), in those with a higher EIA antibody index, compared to those with a low antibody index, of which none tested positive and 2/3 (67 %) were equivocal.Conclusion. Isolated IgM positivity was not helpful in identifying early infection; isolated total antibody EIA positivity is unlikely to be a significant finding. IgG immunoblot testing was unable to determine clear treponemal antibody status in nearly half of all EIA/TPPA discordant samples.

YTHDF1 Negatively Regulates Treponema pallidum-Induced Inflammation in THP-1 Macrophages by Promoting SOCS3 Translation in an m6A-Dependent Manner

Background

Previous studies have confirmed that the bacterium Treponema pallidum (TP) or its proteins provide signals to macrophages that induce an inflammatory response; however, little is known about the negative regulation of this macrophage-mediated inflammatory response during syphilis infection or the underlying mechanism. Recent evidence suggests the role of the RNA modification, N⁶-adenosine methylation (m6A), in regulating the inflammatory response and pathogen-host cell interactions. Therefore, we hypothesized that m6A plays a role in the regulation of the inflammatory response in macrophages exposed to TP.

Methods

We first assessed m6A levels in TP-infected macrophages differentiated from the human monocyte cell line THP-1. The binding and interaction between the m6A "writer" methyltransferase-like 3 (METTL3) or the m6A "reader" YT521-B homology (YTH) domain-containing protein YTHDF1 and the suppressor of cytokine signaling 3 (SOCS3), as a major regulator of the inflammatory response, were explored in differentiated TP-infected THP-1 cells as well as in secondary syphilitic lesions from patients. The mechanisms by which YTHDF1 and SOCS3 regulate the inflammatory response in macrophages were assessed.

Results and Conclusion

After macrophages were stimulated by TP, YTHDF1 was upregulated in the cells. YTHDF1 was also upregulated in the syphilitic lesions compared to adjacent tissue in patients. YTHDF1 recognizes and binds to the m6A methylation site of SOCS3 mRNA, consequently promoting its translation, thereby inhibiting the JAK2/STAT3 pathway, and reducing the secretion of inflammatory factors, which results in anti-inflammatory regulation. This study provides the first demonstration of the role of m6A methylation in the pathological process of syphilis and further offers new insight into the pathogenesis of TP infection.

Immune Privilege Furnishes a Niche for Latent Infection

The microenvironment of the CNS (eye and brain) is fertile ground for infection if the barriers are breached. The result of pathogen invasion is often devastating destruction of tissues. In the eye, inflammation is broadly classified either as "infectious" (i.e. caused by infection) or "non-infectious". However, increasingly, forms of intraocular inflammation (IOI), which clinically appear to be "non-infectious" turn out to be initiated by infectious agents, suggesting that pathogens have been retained in latent or persistent form within ocular tissues and have reactivated to cause overt disease. A similar pathogenesis applies to latent infections in the brain. Not all CNS tissues provide an equally protective niche while different pathogens escape detection using different strategies. This review summarises how immune privilege (IP) in the CNS may be permissive for latent infection and allow the eye and the brain to act as a reservoir of pathogens which often remain undetected for the lifetime of the host but in states of immune deficiency may be activated to cause sight- and life-threatening inflammation.

Optic Disc Edema in Syphilis

BACKGROUND

Syphilis is an uncommon cause of optic nerve head edema; however, differentiating syphilis from other etiologies of optic nerve head swelling may be challenging. We describe 4 cases of ocular syphilis presenting with swollen optic nerve head(s) without overt signs of intraocular inflammation to better define the phenotypic presentation of this condition to allow its early recognition and treatment and discuss potential pathophysiological mechanisms of syphilitic optic neuropathy.

METHODS

Retrospective case series of patients presenting to a tertiary neuro-ophthalmology practice with a swollen optic nerve head(s) but no overt signs of intraocular inflammation, which was eventually determined to be secondary to syphilis.

RESULTS

Four patients were included in the study. The mean age was 43 years, 2 were women and 2 had bilateral involvement. Two patients had a recent history of skin rash, and one patient was investigated for abdominal pain and elevated liver enzymes. Two patients presented with photopsias and preserved visual function, whereas 2 presented with vision loss. Although chorioretinitis was present in all cases, it was very subtle in all and was only appreciated on fundus autofluorescence (FA) in 3 of 4 cases. Three patients demonstrated evidence of optic perineuritis on neuro-imaging. All patients were treated with a course of intravenous penicillin with a variable degree of visual recovery.

CONCLUSIONS

Systemic symptoms are common in patients with syphilic optic neuropathy. Optic disc edema as a manifestation of syphilis is usually accompanied by subtle chorioretinitis, which is best appreciated on FA. Optic perineuritis is common in patients with syphilitic optic neuropathy, with its pathophysiology likely similar to meningitis seen in neurosyphilis.

The Outer Membrane Lipoprotein Tp0136 Stimulates Human Platelet Activation and Aggregation Through PAR1 to Enhance Gq/Gi Signaling

Background

Chancre self-healing, a typical clinical phenomenon of primary syphilis, is essentially wound healing. The first response to a wound is constriction of the injured blood vessels and activation of platelets to form a fibrin clot. However, the role of Treponema pallidum in platelet activation and clot formation remains unclear.

Objectives

We aimed to elucidate the role of the outer membrane Treponema pallidum lipoprotein Tp0136 in human platelet activation and aggregation and explore the related mechanism.

Methods

A series of experiments were performed to assess the effects of Tp0136 on human platelet activation and aggregation in vitro. The effect of Tp0136 on platelet receptors was studied by detecting PAR1 protein levels and studying related receptor sites. The involvement of the G_q/G_i signaling pathway downstream of PAR1 was explored.

Results

Tp0136 significantly accelerated the formation of human platelet clots as well as platelet adhesion to and diffusion on fibrinogen to promote platelet aggregation. Tp0136 also potentiated P-selectin expression and PF4 release to promote platelet activation and downregulated PAR1 expression. The activation and aggregation induced by Tp0136 were reverted by the specific PAR1 antagonist RWJ56110 and the human PAR1 antibody. In addition, Tp0136 significantly enhanced G_q and G_i signaling activation, thereby triggering p38 phosphorylation and Akt-PI3K activation, increasing the release of intraplatelet Ca²⁺ and attenuating the release of cytosolic cAMP. Furthermore, the specific PAR1 antagonist RWJ56110 significantly suppressed G_q and G_i signaling activation.

Conclusions

Our results showed that the Treponema pallidum Tp0136 protein stimulated human platelet activation and aggregation by downregulating PAR1 and triggered PAR1-dependent G_q and G_i pathway activation. These findings may contribute to our understanding of the self-healing of chancroid in early syphilis.

Ocular Syphilis as a Cause of Chronic Postoperative Uveitis Followed by a Localized Ocular Jarisch-Herxheimer-like Reaction

OBJECTIVE

The case draws attention to syphilis as a cause of chronic postoperative uveitis following cataract surgery and is the first to document transient worsening of ocular inflammation without systemic symptoms after initiation of treatment, suggesting a localized Jarisch-Herxheimer-like reaction.

DESIGN

Case report.

RESULTS

The average thickness of the retinal nerve fiber layer was used as an objective measure of intraocular inflammation. The patient's nerve edema worsened during a standard neurosyphilis treatment course and returned to normal several weeks after completion of therapy.

CONCLUSION

Syphilis serologic testing should be strongly considered in the work-up for chronic postoperative uveitis. A localized ocular Jarisch-Herxheimer-like reaction may occur and should not detract from completion of neurosyphilis treatment.

Otosyphilis with Clinical and Serologic Responses with Weekly Intramuscular Penicillin: A Case Report and Literature Review

With the increasing prevalence of syphilis in different parts of the world, it is important to be cognizant of serious forms of syphilis. Otosyphilis is a rare form of syphilis with an extremely high rate of complications. Early diagnosis is essential to prevent a complete loss of hearing and decrease mortality. We present a unique case of otosyphilis who presented with left hearing loss, tinnitus, and vertigo, with audiometric findings confirming the hearing loss. An MRI brain showed asymmetric enhancement of the left cochlea and vestibular apparatus. She initially received oral steroids and trans-tympanic steroid injections with transient improvement of symptoms. She was diagnosed with syphilis through contact tracing after her ex-boyfriend tested positive. She received three weekly doses of intramuscular penicillin. Interestingly, her symptoms, rapid plasma regain (RPR) titer, and audiometry findings markedly improved. Once a diagnosis of otosyphilis was established, she received 14 days of intravenous penicillin.

Syphilis and Ischemic Stroke: Old Question Revisited by a Nationwide Cohort Study

BACKGROUND AND PURPOSE

In the era of easily available antibiotic use, this study provides epidemiological evidence for a re-examination of the relationship between syphilis and IS.

METHODS

Patients aged 18 years and older with newly diagnosed syphilis were included (N=1,585) from 2000, to 2012, and participants without syphilis in the control group (N=6,340) were matched by propensity score (age, sex, index year, insured amount, urbanization, seasons, and comorbidities). The Cox proportional hazard model was used to estimate the hazard ratio (HR) and 95% confidence interval (CI) of IS. Five different Cox regression models, sensitivity analyses, and negative control were conducted to test our findings.

RESULTS

1,585 patients (1,055 [66.56%] men; mean [SD] age, 49.59 [20.32] years) had syphilis, and 3.8% had new-onset IS. The syphilis group had a higher risk of IS than the controls (adjusted HR, 1.35; 95% CI, 1.01-1.80; P-value<0.05) after full adjustment. Serial sensitivity analyses yielded consistent results.

CONCLUSIONS

Syphilis patients have higher risk of IS, and our data raise the question of implementation of prophylactic treatment for IS.

Calvarial Lytic Lesions in Neurosyphilis with Ocular Involvement

We report a case of calvarial lytic lesions in neurosyphilis with ocular involvement. A 42-year-old woman with a past medical history of polysubstance abuse presented with recent bilateral vision loss. CT revealed numerous calvarial lytic lesions and multiple myeloma was initially suspected. Syphilis screening with RPR and confirmative CSF studies were positive for active infection. The patient was treated with Penicillin G and demonstrated clinical improvement. The objective of this study was to provide insight into a rare manifestation of syphilis with osseous involvement and encourage further discourse into establishment of standards of care for syphilitic osteomyelitis. There exist no evidence-based guidelines regarding optimal treatment route and duration, role of bone biopsy, determination of therapeutic impact, and threshold for surgical intervention in the management of syphilitic osteomyelitis.

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A patient with neurosyphilis was found to have numerous calvarial lytic lesions.

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Syphilis should be considered in the differential diagnosis for lytic lesions.

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Expedited treatment with Penicillin resulted in clinical improvement.

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Guidelines for management of syphilitic osteomyelitis need to be established.

OUP accepted manuscript

Syphilis is a sexually transmitted infection caused by the bacterium Treponema pallidum. Tertiary syphilis, a late-stage multi-visceral complication of the disease is characterized by its diversity of clinical manifestations. Here, we present the first documented case of tertiary syphilis that clinically and radiologically mimicked primary rectal cancer with hepatic metastasis.

Leukocytoclastic vasculitis in a patient with syphilis and HIV coinfection

Leukocytoclastic vasculitis (LCV) is a small vessel vasculitis characterized by an inflammatory infiltrate composed of neutrophils with fibrinoid necrosis and “leukocytoclasia”, a term that refers to nuclei disintegration into fragments. LCV is related to multiple conditions including ANCA-associated vasculitis, cryoglobulinemia, IgA vasculitis, infectious and systemic diseases such as rheumatoid arthritis and systemic erythematous lupus (SLE) as well as infections and malignancy. We describe the clinical case of severe systemic vasculitis in a young male patient with secondary syphilis and HIV coinfection manifested by cutaneous and neurological involvement, as well as peripheral necrosis that requires bilateral lower limb amputation. The skin biopsy revealed histopathological changes compatible with endarteritis obliterans and LCV related to treponemal infection. This case highlights the plethora of clinical manifestations of treponemal infection and the diagnostic challenge this poses in current clinical practice.

Traditional Neurosyphilis in 21st Century - Tabes Dorsalis, Dementia Paralytica, Aseptic Meningitis and Unilateral Oculomotor Nerve Palsy in an HIV-Negative Man

Syphilis is potentially a multisystem chronic infection caused by Treponema pallidum. Late symptomatic neurosyphilis has been less reported in developed countries, most often seen in untreated patients or in patients with HIV coinfection. We present a case of complicated neurosyphilis with widespread neurological involvement (dementia paralytica, tabes dorsalis, leptomeningitis and left oculomotor nerve involvement) presenting in the 21st century in an urban area of a well-developed European country in an HIV-negative patient.

Gene-Specific Sex Effects on Susceptibility to Infectious Diseases

Inflammation is an integral part of defense against most infectious diseases. These pathogen-induced immune responses are in very many instances strongly influenced by host’s sex. As a consequence, sexual dimorphisms were observed in susceptibility to many infectious diseases. They are pathogen dose-dependent, and their outcomes depend on pathogen and even on its species or subspecies. Sex may differentially affect pathology of various organs and its influence is modified by interaction of host’s hormonal status and genotype: sex chromosomes X and Y, as well as autosomal genes. In this Mini Review we summarize the major influences of sex in human infections and subsequently focus on 22 autosomal genes/loci that modify in a sex-dependent way the response to infectious diseases in mouse models. These genes have been observed to influence susceptibility to viruses, bacteria, parasites, fungi and worms. Some sex-dependent genes/loci affect susceptibility only in females or only in males, affect both sexes, but have stronger effect in one sex; still other genes were shown to affect the disease in both sexes, but with opposite direction of effect in females and males. The understanding of mechanisms of sex-dependent differences in the course of infectious diseases may be relevant for their personalized management.

The Great Imitator: Latent Neurosyphilis Revealed After Initiation of the Immunosuppressive Drug Secukinumab

Syphilis is a multi-organ system bacterial infection caused by the bacterium Treponema pallidum. Syphilis can advance through four clinical stages: primary, secondary, latent, and tertiary. Once in the tertiary stage, mortality is seen in up to 58% of individuals. Here, we present a case of latent neurosyphilis manifesting after initiation of the immunosuppressive medication secukinumab, a monoclonal antibody that antagonizes interleukin-17A. A 66-year-old male with type II diabetes mellitus, hyperlipidemia, and rheumatoid arthritis presented to the emergency department for a right lower quadrant abdominal cellulitis at the site of his insulin pump. On examination, a non-blanching papular rash on the palms and soles with several scaling papules was discovered. No visible pustules, oral lesions, or perirectal lesions were seen. Neurological examination was noncontributory. His past medical history revealed initiation of secukinumab for the management of rheumatoid arthritis two months prior to presentation. The rash developed six weeks after starting secukinumab. Basic laboratory tests, including a complete blood count, thyroid panel, renal function panel, fasting blood glucose, electrolytes, and C-reactive protein, were within normal limits. A hepatic panel revealed mildly elevated alkaline phosphatase, alanine transaminase, and erythrocyte sedimentation rate Westergren level. Laboratory tests for hepatitis B, hepatitis C, HIV-1, Chlamydia trachomatis, and Neisseria gonorrhoeae all returned negative. A rapid plasma reagin (RPR) titer returned positive at 1:128, and a serum Treponema pallidum Ab returned reactive. Lumbar puncture serologies demonstrated a positive Venereal Disease Research Laboratory (VDRL) test. The patient was diagnosed with latent neurosyphilis and started on intravenous crystalline penicillin G for three weeks. A thorough history, comprehensive physical examination, and basic workup should be performed in any individual prior to immunosuppressive medication initiation. On initial presentation, our patient had an isolated rash on the palms and soles, which is classical for secondary syphilis. The specific manifestations seen in syphilis depend upon the timing, site, and immune status of the individual. Due to its ability to have a variety of presentations, syphilis should always remain on the differential for any physician caring for immunocompromised individuals. Again, initiation of immunosuppressive medications, such as the monoclonal antibody secukinumab, can result in the reactivation of previously dormant infections. As physicians, we must carefully screen our patients prior to initiating immunosuppressive agents to prevent disease reactivation.

The Impact of Early-Life Exposures on Women's Reproductive Health in Adulthood

Purpose of Review

To review the effects of early-life, preconception, and prior-generation exposures on reproductive health in women.

Recent Findings

Women’s early-life factors can affect reproductive health by contributing to health status or exposure level on entering pregnancy. Alternately, they can have permanent effects, regardless of later-life experience. Nutrition, social class, parental smoking, other adverse childhood experiences, environmental pollutants, infectious agents, and racism and discrimination all affect reproductive health, even if experienced in childhood or in utero. Possible transgenerational effects are now being investigated through three- or more-generation studies. These effects occur with mechanisms that may include direct exposure, behavioral, endocrine, inflammatory, and epigenetic pathways.

Summary

Pregnancy is increasingly understood in a life course perspective, but rigorously testing hypotheses on early-life effects is still difficult. In order to improve the health outcomes of all women, we need to expand our toolkit of methods and theory.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40471-021-00279-0.

Treponema pallidum (syphilis) antigen TpF1 induces activation of macrophages and accelerates P2X7R-induced NLRP3-dependent release of IL-1β

BACKGROUND

Syphilis is a chronic infectious disease caused by Treponema pallidum (Tp) infection, which causes local inflammation in the host. TpF1 is an oligomeric protein expressed by the Tp-infected host that can induce the host immune response. There are few studies regarding the role of TpF1 in macrophage activation and the subsequent release of cytokines.

OBJECTIVE

To elucidate the effects of TpF1 on the pathological process of Syphilis. In addition, we explored how purinergic 2X7 (P2X7R) induced NOD-like receptor family protein 3 (NLRP3) -dependent release of interleukin-1β (IL-1β) and the underlying mechanisms.

METHODS

We explored the influence of TpF1 on cytokine release by macrophages using qRT-PCR and ELISA. The specific phenotype of activated macrophages was determined by flow cytometry.

RESULTS

TpF1 was able to activate macrophages and induce the M1 macrophage phenotype. Moreover, TpF1 activated the NLRP3 inflammasome in macrophages, which was mediated by P2X7R.

CONCLUSIONS

The Tp-induced protein TpF1 is able to induce macrophage activation and P2X7R-induced NLRP3-dependent release of IL-1β. Our findings provide a theoretical basis for clarifying the clinical symptoms and pathogenesis of syphilis.

Evaluation of the nontreponemal IgM antibodies in syphilis serofast patients: A new serologic marker for active syphilis

BACKGROUND

Serofast status is challenging to interpret in clinical work, and distinguishing active syphilis in serofast patients can provide a reference for clinical diagnosis and treatment. However, effective serologic markers for active syphilis are still lacking.

OBJECTIVES

We aimed to explore the possibility of nontreponemal IgM antibodies in distinguishing active syphilis in serofast patients.

METHODS

A total of 1501 clinical serum samples were collected from 301 serofast patients, and nontreponemal IgM antibodies were detected by chemiluminescence immunoassay.

RESULTS

The results showed that a total of 29 samples (9.63%) of 301 serofast patients were positive for nontreponemal IgM antibodies, and our limited follow-up data showed that 66.67% (2/3) of the serofast patients progressed to neurosyphilis and cardiovascular syphilis.

CONCLUSION

These findings demonstrate that most serofast patients with positive nontreponemal IgM antibodies have evidence of progressive syphilis, and nontreponemal IgM antibodies can be used as a new serologic marker for the activity of syphilis. Nontreponemal IgM antibodies may play a role in the management of serofast patients.

Sífilis adquirida na população de 50 anos ou mais

Objetivo: avaliar a prevalência de sífilis adquirida na população ≥50 anos residente em Santa Catarina, sua distribuição geográfica e tendência no período 2013-2018.Métodos: estudo ecológico exploratório, analisando dados na plataforma virtual da Diretoria de Vigilância Epidemiológica, relativos às notificações de sífilis na população catarinense com ≥50 anos, sendo a faixa etária dividida em quatro grupos: 50-59 anos, 60-69 anos, 70-79 anos e ≥80 anos.Resultados: a taxa de ocorrência de sífilis na população estudada aumentou de 18,2 para 110,7 casos /100.000 habitantes no período. O incremento foi observado em todas as faixas etárias a partir dos 50 anos e sexos, destacando-se a população de 50-59 anos. As maiores incidências foram verificadas nas macrorregiões Grande Florianópolis e Planalto Norte/Nordeste.Conclusão: houve crescimento exponencial do agravo no período 2013-2018, na população referida, para ambos os sexos, ocorrendo de forma diferenciada segundo macrorregião de saúde. Os resultados obtidos preocupam e merecem atenção da gestão pública.

Re-emergence of syphilis in women of reproductive age and its association with the increase in congenital syphilis in Mexico during 2010-2019: an ecological study

Background

Syphilis is a sexually transmitted infection that is re-emerging in different parts of the world. This infection can be transmitted during pregnancy, causing neonatal syphilis. The objective of this study was to examine trend in syphilis, congenital syphilis, and neonatal deaths among the Mexican population during 2010–2019.

Methods

An ecological study was carried out to collect information about the incidence of syphilis, the incidence of congenital syphilis, and the incidence of neonatal death from congenital syphilis. The variables were described considering age, sex, Mexican state, and year. Trends across time (calendar year) were analyzed using linear regression, increases were estimated with 95% confidence intervals, and p < 0.05 was considered statistically significant.

Results

The incidence of syphilis increased by an average of 0.336 cases/100,000 per year and was higher among women aged 15–19 years (0.693 cases). Cases of congenital syphilis increased from 62 cases in 2010 to 372 cases in 2019; furthermore, the increase in syphilis cases among women aged 20 to 24 years was associated with an increase in cases of congenital syphilis. In 2010, 50% of Mexican states did not report cases of congenital syphilis, but in 2018, only 10% did not report cases of congenital syphilis. Between 2010 and 2018, 83 neonatal deaths were reported, with the highest incidence in 2018 (0.88 deaths/100,000 newborns).

Conclusion

The incidence of congenital syphilis is increasing in Mexico. As a consequence of the reemergence of syphilis among the population of reproductive age, it is necessary to address and treat syphilis in various population groups.

Effect of storage on survival of infectious Treponema pallidum spiked in whole blood and platelets

BACKGROUND

Blood donations must be tested for evidence of syphilis, a transfusion-transmitted infection. Screening blood for syphilis-related antibodies greatly reduced the risk of transfusion-transmitted syphilis (TTS). It is commonly believed that Treponema pallidum (Tp), the bacterium causing syphilis, does not survive in blood during cold storage-suggested as one reason why no cases of TTS have been recognized in the United States for many years. Some have suggested that routine syphilis screening of blood donations is no longer needed. To address the effect of storage, we investigated the survival of Tp experimentally spiked into blood and platelets stored under conventional conditions.

STUDY DESIGN AND METHODS

We spiked fresh human blood products with high concentrations of Tp and inoculated samples at intervals into rabbits, a sensitive assay detecting infectious Tp. We tested whole blood (WB) stored refrigerated (1-6°C) for 9 days and platelets stored at room temperature for 7 days or refrigerated for 14 days. We assayed sera of the rabbits collected at intervals for seroconversion using two different tests and assessed orchitis. Rabbits were considered infected if one or both serological test results became positive.

RESULTS

Viable Tp survived 7 days in WB and 6 days in platelets stored at both ambient and cold temperatures.

DISCUSSION

Tp at concentrations much higher than those possibly present in an infected blood unit survived in cold blood products longer than previously reported and, thus, storage conditions cannot be relied upon to eliminate T. pallidum from blood or platelets. TTS remains a topic of concern for public health.

King Charles VIII of France's Death: From an Unsubstantiated Traumatic Brain Injury to More Realistic Hypotheses

On April 7, 1498, Charles VIII, King of France, attended a game of palm in the ditches of the Château d'Amboise. The 27-year-old King suddenly collapsed and became comatose. He laid down, almost on his own, on a straw mat that was hastily arranged, and he died 9 hours later. His contemporaries perceived his death as a perfect reminder of fatality: a king could die alone in a miserable gallery. All who looked into this curious death had dwelled on the frontal blow to head that the king had sustained right before his demise and had not considered alternative scenarios. The present study, still with limited available evidence, aimed to reexamine the historical account of his death in light of modern medical knowledge. It is virtually impossible that a minor bump with low kinetic energy could kill a 27-year-old man. Many historical accounts of Charles VIII's life and death, including Italian ambassadors' letters, led us to reconsider the commonly held version and to propose an alternative hypothesis. We have concluded that Charles VIII had experienced an acute consciousness disorder with language impairment that could have been related to an epileptic condition secondary to neurosyphilis. We have discussed whether a more accurate diagnosis for the cause of death could be obtained by a pathological analysis of the King's remains.

[Syphilis in young Brazilian military recruits in 2016: sociodemographic, behavioral, and clinical aspects]

The objective was to characterize sociodemographic, behavioral, and clinical aspects in young Brazilian military recruits according to prevalence of syphilis. This was a descriptive study based on a nationwide population-based survey in 2016 with a probabilistic sample of military recruits 17 to 22 years of age. A confidential self-applied questionnaire was used. Blood samples were drawn from participants for treponemal and non-treponemal syphilis tests. Descriptive statistical techniques were used to estimate syphilis prevalence rates and distribution of frequencies between the target variables, considering 95% confidence intervals (95%CI), after weighting the data. Of the total of 37,282 participants, 73.7% were sexually initiated. Prevalence rates for lifetime and confirmed syphilis were 1.6% and 1.1%, respectively. The following population variables showed higher prevalence of syphilis: lack of Internet access at home; initiation of sexual activity before 14 years of age; men who have sex with men; more than five sexual partners; having received presents, drugs, or other incentives in exchange for sex; and prior history of symptoms of sexually transmissible infections. An increase was observed in syphilis in Brazilian military recruits when compared to previous surveys. This increase emphasizes the importance of this sentinel population for performing active surveillance in order to support healthcare strategies for youth, including in the school system.

Intra-urban differentials of congenital and acquired syphilis and syphilis in pregnant women in an urban area in northeastern Brazil

BACKGROUND

Currently syphilis is considered an epidemic disease worldwide. The objective of this study was to identify intra-urban differentials in the occurrence of congenital and acquired syphilis and syphilis in pregnant women in the city of Natal, in northeast Brazil.

METHODS

Cases of syphilis recorded by the municipal surveillance system from 1 January 2011 to 30 December 2018 were analysed. Spatial statistical analyses were performed using the kernel density estimator of the quadratic smoothing function (weighted). SaTScan software was applied for the calculation of risk based on a discrete Poisson model.

RESULTS

There were 2163 cases of acquired syphilis, 738 cases of syphilis in pregnant women and 1279 cases of congenital syphilis. Kernel density maps showed that the occurrence of cases is more prevalent in peripheral areas and in areas with more precarious urban infrastructure. In 2011-2014 and 2015-2018, seven statistically significant clusters of acquired syphilis were identified. From 2011 to 2014, the most likely cluster had a relative risk of 3.54 (log likelihood ratio [LLR] 38 895; p<0.001) and from 2015 to 2018 the relative risk was 0.54 (LLR 69 955; p<0.001).

CONCLUSIONS

In the municipality of Natal, there was a clustered pattern of spatial distribution of syphilis, with some areas presenting greater risk for the occurrence of new cases.

Potential for Phages in the Treatment of Bacterial Sexually Transmitted Infections

Bacterial sexually transmitted infections (BSTIs) are becoming increasingly significant with the approach of a post-antibiotic era. While treatment options dwindle, the transmission of many notable BSTIs, including Neisseria gonorrhoeae, Chlamydia trachomatis, and Treponema pallidum, continues to increase. Bacteriophage therapy has been utilized in Poland, Russia and Georgia in the treatment of bacterial illnesses, but not in the treatment of bacterial sexually transmitted infections. With the ever-increasing likelihood of antibiotic resistance prevailing and the continuous transmission of BSTIs, alternative treatments must be explored. This paper discusses the potentiality and practicality of phage therapy to treat BSTIs, including Neisseria gonorrhoeae, Chlamydia trachomatis, Treponema pallidum, Streptococcus agalactiae, Haemophilus ducreyi, Calymmatobacterium granulomatis, Mycoplasma genitalium, Ureaplasma parvum, Ureaplasma urealyticum, Shigella flexneri and Shigella sonnei. The challenges associated with the potential for phage in treatments vary for each bacterial sexually transmitted infection. Phage availability, bacterial structure and bacterial growth may impact the potential success of future phage treatments. Additional research is needed before BSTIs can be successfully clinically treated with phage therapy or phage-derived enzymes.

Detection of Treponema pallidum by immunocytochemistry of cervical smear: A case report

Syphilis is an infectious disease caused by Treponema pallidum (T. pallidum). A cervical smear is useful when screening for sexually transmitted diseases; however, T. pallidum is not detected in the usual Papanicolaou smear. We report the detection of T. pallidum by immunocytological examination of a cervical smear. A 22-year-old woman presented with nephrotic syndrome. On admission, we performed screening tests for infections, and her serology was positive for syphilis. A Papanicolaou cervical smear (Thin-Prep) showed slight nuclear enlargement, nuclear irregularity, and mild hyperchromasia in the superficial cells, but no organism was detected. T. pallidum was detected in the remaining specimen using immunocytochemistry. We also detected the T. pallidum DNA in a cervical biopsy specimen by polymerase chain reaction (PCR). Our findings suggest that immunocytological examination and PCR assay examination are useful tests for syphilis diagnosis.

The Immunoglobulin M-Shed Acute Phase Antigen (SAPA)-test for the Early Diagnosis of Congenital Chagas Disease in the Time of the Elimination Goal of Mother-to-Child Transmission

BACKGROUND

Diagnosis of congenital Chagas disease (CChD) in most endemic areas is based on low-sensitive microscopy at birth and 9-month immunoglobulin G (IgG), which has poor adherence. We aim to evaluate the accuracy of the Immunoglobulin M (IgM)-Shed Acute Phase Antigen (SAPA) test in the diagnosis of CChD at birth.

METHODS

Two cohort studies (training and validation cohorts) were conducted in 3 hospitals in the department of Santa Cruz, Bolivia. Pregnant women were screened for Chagas disease, and all infants born to seropositive mothers were followed for up to 9 months to diagnose CChD. A composite reference standard was used to determine congenital infection and was based on the parallel use of microscopy, quantitative polymerase chain reaction (qPCR), and IgM-trypomastigote excreted-secreted antigen (TESA) blot at birth and/or 1 month, and/or the detection of anti-Trypanosoma cruzi IgG at 6 or 9 months. The diagnostic accuracy of the IgM-SAPA test was calculated at birth against the composite reference standard.

RESULTS

Adherence to the 6- or 9-month follow-up ranged from 25.3% to 59.7%. Most cases of CChD (training and validation cohort: 76.5% and 83.7%, respectively) were detected during the first month of life using the combination of microscopy, qPCR, and/or IgM-TESA blot. Results from the validation cohort showed that when only 1 infant sample obtained at birth was evaluated, the qPCR and the IgM-SAPA test have similar accuracy (sensitivity: range, 79.1%-97.1% and 76.7%-94.3%, respectively, and specificity: 99.5% and 92.6%, respectively).

CONCLUSIONS

The IgM-SAPA test has the potential to be implemented as an early diagnostic tool in areas that currently rely only on microscopy.

Unexpected Reason for Non-healing Oral Ulcers: Syphilis

Syphilis is a sexually transmitted infectious disease caused by Treponema pallidum and characterized by a complex and variable clinical presentation. Cases of unexpected oral syphilis presenting as non-healing ulcers are uncommonly reported. We report 3 cases (one female and two males, aged 35, 35, and 56 years, respectively) in which patients presented with non-healing oral ulcers. Biopsies revealed surface ulceration and a significant neutrophilic infiltrate rather than the more conventional plasma cell infiltrate seen with most reported syphilis infections, potentially leading to an inaccurate diagnosis. Treponema pallidum immunohistochemistry highlighted spirochetes within the epithelium, with additional diagnostic confirmation by serum T. pallidum particle agglutination assay. Sexual history documentation by the clinician with nonspecific oral ulcers is paramount to aiding diagnosis and leading to proper management. Further, it is important to perform immunohistochemistry for T. pallidum in oral biopsies from non-healing ulcers, especially when clinical history raises the differential diagnosis or when other clinical manifestations may support this consideration.

Syphilis: then and now

Getting to know the history of syphilis should begin with an attempt to establish the original source of its spread throughout the world. The dispute about the origin of syphilis, a sexually transmitted infection caused by Treponema pallidum (subspecies pallidum), had not been resolved even as late as in the twenty-first century, and to this day the supporters and opponents of the thesis that syphilis was brought to Europe by Christopher Columbus' sailors have been fighting without solid and sustainable foundations. The French named syphilis "the Neapolitan disease", while the Italians called it "the French disease".

Treponema pallidum among Female Sex Workers: A Cross-Sectional Study Conducted in Three Major Cities in Northern Brazil

Female sex workers (FSWs) are an important group of people vulnerable to sexually transmitted infections. Northern Brazil is a rural and socioeconomically underdeveloped region, with lack of epidemiological information on syphilis in key populations. This study investigated the prevalence and factors associated with exposure to Treponema pallidum among FSWs in three major cities in northern Brazil. This cross-sectional study was conducted with a convenience sample of 415 FSWs from the cities of Belém, Macapá, and Rio Branco. Blood samples and personal data were collected from January 2009 to August 2010. Rapid plasma reagin and immunoenzymatic assays were used to detect antibodies against T. pallidum. Logistic regression models were used to determine factors associated with exposure to T. pallidum. In total, 36.1% were exposed to T. pallidum, and 15.7% had active syphilis. Sexual risk behaviors, use of illicit drugs, low education, and reduced monthly income were associated with exposure to T. pallidum. The high rate of exposure to T. pallidum indicates the urgent need for measures to identify, treat, and prevent syphilis and an education program for the valuation, care, and social inclusion of FSWs in northern Brazil.

[A clinical suspected case of cerebral syphilitic gumma showing spontaneous regression]

A 46-years-old man who complained of headache for 4 months was transported our hospital due to vertigo and nausea. Gadolinium-enhanced T₁WI showed ring-like enhancements in the right pedunculus cerebellaris medius and left frontal lobe on the brain surface. Additionally, FLAIR images showed high intensity area indicating perilesional edema. We diagnosed the patient as neurosyphilis with his serum and cerebrospinal fluid findings, and considered him as cerebral syphilitic gumma because of brain MRI findings. An HIV test was negative. Follow-up MRI before treatment demonstrated spontaneous regression of these lesions, and after intravenous treatment with penicillin G for 14 days complete regression. Since then, he has had no sign of recurrence. Although there are some characteristic brain MRI findings of cerebral syphilitic gumma, spontaneous regression of these lesions in this case was an unusual finding.

Structural Modeling of the Treponema pallidum Outer Membrane Protein Repertoire: a Road Map for Deconvolution of Syphilis Pathogenesis and Development of a Syphilis Vaccine

Treponema pallidum, an obligate human pathogen, has an outer membrane (OM) whose physical properties, ultrastructure, and composition differ markedly from those of phylogenetically distant Gram-negative bacteria. We developed structural models for the outer membrane protein (OMP) repertoire (OMPeome) of T. pallidum Nichols using solved Gram-negative structures, computational tools, and small-angle X-ray scattering (SAXS) of selected recombinant periplasmic domains. The T. pallidum "OMPeome" harbors two "stand-alone" proteins (BamA and LptD) involved in OM biogenesis and four paralogous families involved in the influx/efflux of small molecules: 8-stranded β-barrels, long-chain-fatty-acid transporters (FadLs), OM factors (OMFs) for efflux pumps, and T. pallidum repeat proteins (Tprs). BamA (TP0326), the central component of a β-barrel assembly machine (BAM)/translocation and assembly module (TAM) hybrid, possesses a highly flexible polypeptide-transport-associated (POTRA) 1-5 arm predicted to interact with TamB (TP0325). TP0515, an LptD ortholog, contains a novel, unstructured C-terminal domain that models inside the β-barrel. T. pallidum has four 8-stranded β-barrels, each containing positively charged extracellular loops that could contribute to pathogenesis. Three of five FadL-like orthologs have a novel α-helical, presumptively periplasmic C-terminal extension. SAXS and structural modeling further supported the bipartite membrane topology and tridomain architecture of full-length members of the Tpr family. T. pallidum's two efflux pumps presumably extrude noxious small molecules via four coexpressed OMFs with variably charged tunnels. For BamA, LptD, and OMFs, we modeled the molecular machines that deliver their substrates into the OM or external milieu. The spirochete's extended families of OM transporters collectively confer a broad capacity for nutrient uptake. The models also furnish a structural road map for vaccine development. IMPORTANCE The unusual outer membrane (OM) of T. pallidum, the syphilis spirochete, is the ultrastructural basis for its well-recognized capacity for invasiveness, immune evasion, and persistence. In recent years, we have made considerable progress in identifying T. pallidum's repertoire of OMPs. Here, we developed three-dimensional (3D) models for the T. pallidum Nichols OMPeome using structural modeling, bioinformatics, and solution scattering. The OM contains three families of OMP transporters, an OMP family involved in the extrusion of noxious molecules, and two "stand-alone" proteins involved in OM biogenesis. This work represents a major advance toward elucidating host-pathogen interactions during syphilis; understanding how T. pallidum, an extreme auxotroph, obtains a wide array of biomolecules from its obligate human host; and developing a vaccine with global efficacy.

Ocular Syphilis Presenting As Non-arteritic Anterior Ischemic Optic Neuropathy

Syphilis is a sexually transmitted disease caused by the spirochetal bacteria Treponema pallidum. It can cross the blood-brain barrier within days of the infection, causing neurosyphilis and ocular syphilis at any stage of the disease. Ocular syphilis can manifest in any part of the eye but usually as posterior uveitis and pan-uveitis or various types of inflammatory or immune-mediated optic neuritis. Misdiagnosing ocular syphilis as a non-infectious disease has been reported even when seen by ophthalmologists due to the wide variety of possible presentations. In this case report, we describe a case of ocular syphilis that presented with a non-arteritic anterior ischemic optic neuropathy (NA-AION), which to our knowledge, has not been described before in the literature.