Cerebrospinal Fluid Treponema pallidum Particle Agglutination Assay for Neurosyphilis Diagnosis

State-of-the-Art Review: Neurosyphilis

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

Cerebrospinal fluid CXCL13 concentration for diagnosis and monitoring of neurosyphilis in people with HIV

OBJECTIVES

The study aimed to assess and compare cerebrospinal fluid (CSF)-CXCL13 levels in People with HIV (PWH) with suspected neurosyphilis (NS), those with syphilis but without NS, and patients without treponema infection. Additionally, it aimed to evaluate changes in CSF-CXCL13 concentrations before and after antibiotic treatment.

DESIGN

This was a prospective cohort study involving 93 PWH suspected of NS. All participants underwent lumbar puncture, with CSF-CXCL13 levels measured at baseline and during follow-up in patients diagnosed with NS.

METHODS

CSF-CXCL13 levels were quantified using ELISA. The Mann-Whitney U test was used to analyze differences between groups, while the Wilcoxon test assessed within subject changes. ROC curve analysis determined the diagnostic efficacy of CSF-CXCL13 for NS.

RESULTS

Significantly higher CSF-CXCL13 levels were observed in patients with NS compared to those with syphilis without NS and non-syphilis patients. Posttreatment, a decline in CSF-CXCL13 levels was noted in all NS cases. A CSF-CXCL13 threshold exceeding 60.0 pg/ml, in conjunction with reactive CSF-FTA-ABS, yielded a sensitivity of 88.9% and a specificity of 97.6% for NS diagnosis.

CONCLUSIONS

CSF-CXCL13 emerges as a valuable adjunctive biomarker for detecting NS in PWH, especially in cases with nonreactive CSF-VDRL. Monitoring CSF-CXCL13 levels also appears effective in evaluating therapeutic response in PWH undergoing NS treatment.

Syphilis for dermatologists: Current concepts

Dermatologists are familiar with the classic aspects of syphilis. Our objective in this update is to display novel features of sexually acquired syphilis, its pathophysiology, natural history, atypical clinical variants, skin of color, clinical pearls, and prospects. Textbook knowledge, congenital syphilis, epidemiology, and historical data are excluded.

Multicentric evaluation of a specific intrathecal anti-Treponema pallidum IgG index as a diagnostic biomarker of neurosyphilis: results from a retro-prospective case-control study

BACKGROUND AND OBJECTIVES

The diagnosis of neurosyphilis (NS) lacks a true 'gold standard', making the diagnosis challenging while consequences of a misdiagnosis are potentially severe. The aim of this study was to evaluate the diagnostic performance of measuring an antibody index (AI) for the intrathecal synthesis of specific anti-Treponema pallidum (T. pallidum) IgG for the diagnosis of NS.

METHODS

Specific anti-T. pallidum IgG were measured simultaneously in paired cerebrospinal fluid (CSF)-serum samples collected retrospectively and prospectively between 2007 and 2022, from patients suspected of NS, in Switzerland. An AI was calculated to account for blood-brain barrier integrity. Area under the receiver operating characteristic curve, sensitivity/specificity and positive/negative predictive values of AI test were estimated. Two NS definitions were used: NS1 included patients with NS suspicion presenting with neurological symptoms and/or acute neurosensory signs, and positive T. Pallidum Hemagglutinations Assay (TPHA)/T. pallidum particle agglutination assay (TPPA) serology and CSF-TPHA/TPPA ≥320, and either CSF-leucocytes >5 cells/mm3 and/or CSF-protein >0.45 g/L and/or a reactive CSF-venereal disease research laboratory (VDRL)/rapid plasma reagin (RPR) test. NS2 included patients with suspected NS presenting with acute ocular and/or otologic symptoms, and positive TPHA/TPPA serology, and a favourable response to NS treatment. Controls were patients diagnosed with any other central nervous system (CNS) pathologies and with positive TPHA/TPPA serology.

RESULTS

The study included 71 NS (43 NS1 and 28 NS2) and 110 controls. With a threshold of ≥1.7, sensitivity and specificity of the specific AI test were 90.7% (CI 77.7 to 97.4) and 100% (CI 96.7 to 100.0), respectively, for NS1 and 14.3% (CI 4 to 32.7) and 100% (CI 96.7 to 100.0) for NS2. In patients suspected of NS with a CNS involvement (NS1 group), NS could be confirmed by the positivity of this specific AI.

CONCLUSIONS

Measurement of an intrathecal synthesis index of specific anti-T. pallidum IgG in patients with CSF inflammatory signs appears to be a valuable diagnostic test. However, in otic or ocular syphilis, presenting few CSF abnormalities, AI is not sufficient alone to confirm NS diagnosis.

TRIAL REGISTRATION

Swiss Association of Research Ethics Committees number 2019-00232.

CDC Laboratory Recommendations for Syphilis Testing, United States, 2024

This report provides new CDC recommendations for tests that can support a diagnosis of syphilis, including serologic testing and methods for the identification of the causative agent Treponema pallidum. These comprehensive recommendations are the first published by CDC on laboratory testing for syphilis, which has traditionally been based on serologic algorithms to detect a humoral immune response to T. pallidum. These tests can be divided into nontreponemal and treponemal tests depending on whether they detect antibodies that are broadly reactive to lipoidal antigens shared by both host and T. pallidum or antibodies specific to T. pallidum, respectively. Both types of tests must be used in conjunction to help distinguish between an untreated infection or a past infection that has been successfully treated. Newer serologic tests allow for laboratory automation but must be used in an algorithm, which also can involve older manual serologic tests. Direct detection of T. pallidum continues to evolve from microscopic examination of material from lesions for visualization of T. pallidum to molecular detection of the organism. Limited point-of-care tests for syphilis are available in the United States; increased availability of point-of-care tests that are sensitive and specific could facilitate expansion of screening programs and reduce the time from test result to treatment. These recommendations are intended for use by clinical laboratory directors, laboratory staff, clinicians, and disease control personnel who must choose among the multiple available testing methods, establish standard operating procedures for collecting and processing specimens, interpret test results for laboratory reporting, and counsel and treat patients. Future revisions to these recommendations will be based on new research or technologic advancements for syphilis clinical laboratory science.

Neurosyphilis: insights into its pathogenesis, susceptibility, diagnosis, treatment, and prevention

Background and aim

Invasion of the central nervous system by Treponema pallidum can occur at any stage of syphilis. In the event that T. pallidum is not cleared promptly, certain individuals may experience progression to neurosyphilis, which manifests as cognitive and behavioral abnormalities, limb paralysis, and potentially fatal outcomes. Early identification or prevention of neurosyphilis is therefore crucial. The aim of this paper is to conduct a critical and narrative review of the latest information focusing exclusively to the pathogenesis and clinical management of neurosyphilis.

Methodology

To compile this review, we have conducted electronic literature searches from the PubMed database relating to neurosyphilis. Priority was given to studies published from the past 10 years (from 2013 to 2023) and other studies if they were of significant importance (from 1985 to 2012), including whole genome sequencing results, cell structure of T. pallidum, history of genotyping, and other related topics. These studies are classic or reflect a developmental process.

Results

Neurosyphilis has garnered global attention, yet susceptibility to and the pathogenesis of this condition remain under investigation. Cerebrospinal fluid examination plays an important role in the diagnosis of neurosyphilis, but lacks the gold standard. Intravenous aqueous crystalline penicillin G continues to be the recommended therapeutic approach for neurosyphilis. Considering its sustained prominence, it is imperative to develop novel public health tactics in order to manage the resurgence of neurosyphilis.

Conclusion

This review gives an updated narrative description of neurosyphilis with special emphasis on its pathogenesis, susceptibility, diagnosis, treatment, and prevention.

Comparison of Treponema-specific immunoglobulin G (IgG) index with Treponema pallidum particle agglutination (TPPA) index for detection of intrathecal Treponema-specific antibody synthesis for serological diagnosis of neurosyphilis

The determination of Treponema-specific intrathecal immunoglobulin synthesis with the Treponema pallidum particle agglutination (TPPA) index is a well-established method recommended in German guidelines for the diagnosis of neurosyphilis. However, the TPPA test is no longer available. The aim of this study was to evaluate whether the determination of a Treponema-specific immunoglobulin G (IgG) index can substitute the TPPA index. Serum and cerebrospinal fluid (CSF) samples from patients with confirmed (n=6) and probable (n=3) neurosyphilis as well as patients with adequately treated syphilis without neurosyphilis (n=4) were investigated. In addition to index calculation further CSF parameters were determined. The results of the Treponema IgG and the TPPA index were consistent in all patients with confirmed neurosyphilis and non-neurosyphilis patients. In two patients with probable neurosyphilis the IgG index appeared more plausible than the TPPA index when taking into account all available laboratory and clinical data of the patients. In conclusion, the determination of Treponema-specific intrathecal immunoglobulin synthesis with the IgG index appears to be a suitable alternative to the TPPA index.

Advantages and limitations of current diagnostic laboratory approaches in syphilis and congenital syphilis

INTRODUCTION

The reemergence of syphilis, especially congenital syphilis, presents a significant public health threat. Accurate diagnosis of syphilis depends on recognition of a constellation of symptoms, review of medical and sexual history, and multiple laboratory tests. While reliable, current tests for syphilis can be difficult to interpret, which can lead to delays in treatment.

AREA COVERED

This review summarizes the major advantages and limitations of available diagnostic laboratory methods for syphilis, provides an update on recent advances in laboratory tools, and highlights the urgent need for coordinated efforts to create new tools to halt the resurgence of syphilis.

EXPERT OPINION

In syphilis, the wide variety of short-lived signs and symptoms followed by periods of latency create diagnostic challenges. Currently available laboratory tests, when positive, require additional information to interpret (prior testing, treatment, and sexual history). Point-of-care tests that can rapidly and accurately detect both treponemal and non-treponemal antibodies would be a huge step toward reducing test turnaround time and time to treatment. Incorporating biological insights and technology innovations to advance the development of direct detection assays is urgently needed. A comprehensive coordinated effort is critical to stem the tide of rising syphilis in the United States and globally.

Analysis of Treponema pallidum DNA and CXCL13 in Cerebrospinal Fluid in HIV-Negative Syphilis Patients

Purpose

Neurosyphilis (NS) is a chronic infectious disease associated with Treponema pallidum subsp. pallidum (TP) infection of the central nervous system. The purpose of this study was to offer evidence for the diagnosis and treatment of NS by revealing the detection of TP DNA and CXCL13 concentration in the cerebrospinal fluid (CSF) of HIV-negative syphilis patients.

Patients and Methods

This study included 75 syphilis patients. The frequency of TP invasion into the CSF was detected by nested PCR. ELISA was performed to detect CSF CXCL13 concentrations, and ROC analysis was performed to assess diagnostic accuracy. Sociodemographic data, clinical symptoms, and laboratory indices of patients were collected. CSF CXCL13 levels and clinical characteristics of syphilis patients were investigated retrospectively.

Results

The detection rate of CSF DNA of TP by nested PCR was 5.3% and 16.7% in HIV-negative syphilis patients and NS patients, respectively. There was a significant difference between the NS and non-NS groups in terms of neurological symptoms, CSF TPPA, CSF TRUST, CSF nucleated cells, CSF protein, and CSF CXCL13 levels (P<0.05). ROC curve analysis showed that the AUC for CSF CXCL13 levels was 0.906 (95% CI 0.832-0.981, P <0.0001), with an optimal critical value of 57.85 pg/mL and sensitivity and specificity of 88.89% and 78.95%, respectively.

Conclusion

Nested PCR can be used as an auxiliary diagnosis of NS, and CSF CXCL13 >60 pg/mL has high sensitivity and specificity for NS patients and non-NS patients. CXCL13 may be a useful marker to distinguish NS from non-NS syphilis in HIV-negative patients.

Aberrant gray matter structure in neurosyphilis without conventional MRI abnormality: a pilot study with voxel and surface-based morphology

Background

The underlying mechanism of neurosyphilis was not fully understood.

Purpose

To assess gray matter (GM) microstructure in patients with early-stage neurosyphilis without overt conventional magnetic resonance imaging (MRI) abnormality using voxel-based morphometry (VBM) and surface-based morphometry (SBM) analyses.

Material and Methods

Three-dimensional high-resolution T1-weighted imaging data from 19 individuals with neurosyphilis and 19 healthy controls were analyzed. A battery of neuropsychological tests was performed before each MRI examination. The differences of GM volume and cerebral cortical morphological data between the two groups were compared. The correlations between MRI metrics and neuropsychology/laboratory tests in the patient group were investigated.

Results

Regional decreased GM volumes in patients with neurosyphilis were found in the left frontal cortices (Rolandic operculum, middle frontal, and precentral) and bilateral temporal/occipital cortices (bilateral middle temporal, left lingual, and right middle occipital) ( P < 0.05, FDR correction). SBM analysis showed significant cortical thickness reduction in the right medial orbitofrontal lobe, and reduced gyrification index in the left insula in patients with neurosyphilis ( P < 0.05, FDR correction). Additionally, in the patient group, the GM volume in the middle frontal gyrus, the cortical thickness of right medial orbitofrontal lobe, and the gyrification index in the left insula were negatively correlated to the number connection test-A scores. The gyrification index was also negatively correlated to cerebrospinal fluid white blood cell count.

Conclusion

Early-stage neurosyphilis without conventional MRI abnormality presented regional GM volume reduction and cortical morphological changes, which might be related to cognitive impairment and intra-cranial infection. VBM and SBM analyses might be useful for understanding the underlying neural trait of neurosyphilis.

Advances in laboratory diagnostic methods for cerebrospinal fluid testing for neurosyphilis

Neurosyphilis is a chronic infectious disease caused by the invasion of Treponema pallidum into the central nervous system. In recent years, with the increase in the latent syphilis infection rate, the incidence of neurosyphilis has gradually increased, the typical symptoms of neurosyphilis have decreased, atypical manifestations have increased, and the clinical manifestations have become increasingly diverse. Cerebrospinal fluid testing plays an important role in the diagnosis of neurosyphilis. In recent years, there have been many advances in cerebrospinal fluid testing. This review focuses on the current and potential laboratory indicators of neurosyphilis in cerebrospinal fluid, aiming to provide a reference for clinical application and ideas for future experimental research of neurosyphilis.

Intrathecal immunoglobin synthesis and its role in patients with neurosyphilis

Background

Intrathecal protein synthesis (ITS) occurs in various central nervous system disorders, but few quantitative studies have focused on ITS for neurosyphilis (NS) in southwestern China. We made a study to quantitatively assess the ITS in patients with NS and to investigate the association between ITS and the stages of NS.

Methods

CSF-serum specimen pairs from 142 patients (66 NS and 76 non-NS/syphilis) were collected for routine CSF and serum tests. The NS group was divided into slight and severe subgroups according to the NS stages. Three formulas for the quantitative determination of the intrathecal synthesis were calculated to characterize the specimens, including the Ig index (Q_Ig/Q_alb), Ig extended index (Ig_EI), and intrathecally synthesized fraction (IgIF) using the hyperbolic function. The role of QTPPA/QIgG as an antibody index (AI = Q specific Ig/QIgG) was also explored.

Results

Sero_TRUST titres (1:16, 1:1-1:256), sero_TPPA titres (1:163840, 1:1280-1:1310720), total protein (MTP), and CSF_Igs (p < 0.05) were found to be significantly elevated in the NS group. Intrathecal Ig synthesis can be identified using all three formulas in the NS group. The pattern of Ig intrathecal synthesis was IgIF-G (48.62%) > IgIF-A = IgIF-M (p < 0.05), with the dominant intrathecal fraction being IgG (median, 48.62%), which was also verified by Q_IgG> Q_alb> Q_IgM = Q_IgA. In the slight NS group, the intrathecal fractions of IgM (>0 in 4 out of 20 cases) and IgG (>0 in 16 out of 20) were lower than the intrathecal fractions of IgM (>0 in 19 out of 35 cases) and IgG (>0 in 33 out of 38) in the severe group (p < 0.05). The area under the curve (AUC) of the CSF_TPPA antibody index was 0.867 (0.792, 0.922), with an optimal cutoff point of 0.81, providing a sensitivity of 88.91% and specificity of 84.62%.

Conclusion

Although the intrathecal synthesis pattern is IgG dominant in patients with NS, brain-derived IgM and IgA can also be found. Moreover, intrathecal IgM and IgG were associated with a parenchymatous type of neurosyphilis. Syphilis-specific antibodies are a new potential tool for NS diagnosis.

Point-of-care SARS-CoV-2 sensing using lens-free imaging and a deep learning-assisted quantitative agglutination assay

The persistence of the global COVID-19 pandemic caused by the SARS-CoV-2 virus has continued to emphasize the need for point-of-care (POC) diagnostic tests for viral diagnosis. The most widely used tests, lateral flow assays used in rapid antigen tests, and reverse-transcriptase real-time polymerase chain reaction (RT-PCR), have been instrumental in mitigating the impact of new waves of the pandemic, but fail to provide both sensitive and rapid readout to patients. Here, we present a portable lens-free imaging system coupled with a particle agglutination assay as a novel biosensor for SARS-CoV-2. This sensor images and quantifies individual microbeads undergoing agglutination through a combination of computational imaging and deep learning as a way to detect levels of SARS-CoV-2 in a complex sample. SARS-CoV-2 pseudovirus in solution is incubated with acetyl cholinesterase 2 (ACE2)-functionalized microbeads then loaded into an inexpensive imaging chip. The sample is imaged in a portable in-line lens-free holographic microscope and an image is reconstructed from a pixel superresolved hologram. Images are analyzed by a deep-learning algorithm that distinguishes microbead agglutination from cell debris and viral particle aggregates, and agglutination is quantified based on the network output. We propose an assay procedure using two images which results in the accurate determination of viral concentrations greater than the limit of detection (LOD) of 1.27 × 103 copies per mL, with a tested dynamic range of 3 orders of magnitude, without yet reaching the upper limit. This biosensor can be used for fast SARS-CoV-2 diagnosis in low-resource POC settings and has the potential to mitigate the spread of future waves of the pandemic.

Clinical and laboratory features in patients with positive syphilis serology presenting with acute ischemic stroke or transient ischemic attack: a prospective cohort study

Background

Neurosyphilis (NS) can lead to acute ischemic stroke (AIS) or transient ischemic attack (TIA). We compared the clinical characteristics and laboratory features among AIS and TIA patients who were syphilis-seronegative (control group) or had latent syphilis (LS) or NS to evaluate their stroke outcome.

Methods

This prospective cohort study was conducted on patients who had recently suffered AIS or TIA. After serological syphilis screening, clinical and laboratory data were collected, and brain imaging and spinal tap (serologically syphilis-positive patients only) were performed. Stroke outcome was re-evaluated approximately three months later.

Results

The 344 enrolled patients were divided into three groups: control group (83.7%), LS (13.1%), and NS (3.2%). A multivariate analysis revealed: 1) age of ≥ 70 years, generalized brain atrophy via imaging, and alopecia (adjusted odds ratio [AOR] = 2.635, 2.415, and 13.264, respectively) were significantly associated with LS vs controls; 2) age of ≥ 70 years (AOR = 14.633) was significantly associated with NS vs controls; and 3) the proportion of patients with dysarthria was significantly lower (AOR = 0.154) in the NS group than in the LS group. Regarding the NS patient cerebrospinal fluid (CSF) profile, only 2/11 cases had positive CSF-Venereal Disease Research Laboratory (VDRL) test results; the other nine cases were diagnosed from elevated white blood cell counts or protein levels combined with positive CSF fluorescent treponemal antibody absorption (FTA-ABS) test results. Regarding disability, the initial modified Rankin scale (mRS) score was lower in the control group than in the NS group (p = 0.022). At 3 months post-stroke, the mRS score had significantly decreased in the control (p < 0.001) and LS (p = 0.001) groups. Regarding activities of daily living, the 3-month Barthel Index (BI) score was significantly higher in control patients than in LS (p = 0.030) or NS (p = 0.002) patients. Additionally, the 3-month BI score was significantly increased in the control (p < 0.001) and LS (p = 0.001) groups.

Conclusions

Because syphilis was detected in many AIS and TIA patients, especially those aged ≥ 70 years, routine serological syphilis screening may be warranted in this population. Patients with syphilitic infection had worse stroke outcomes compared with NS patients.

Neurosyphilis in China: A Systematic Review of Cases From 2009-2021

Considered the increased threaten of neurosyphilis in China, a review on cases reported in the literature to describe the clinical epidemiological characteristics of neurosyphilis cases, may be beneficial to the early detection and management strategies of neurosyphilis for clinicians. We searched the literature on Chinese neurosyphilis cases published from January 1, 2009 to December 31, 2021, described their clinical epidemiological characteristics and calculated the prevalence of neurosyphilis amongst other associated diseases, according to the individual study criteria. A total of 284 studies including 7,486 neurosyphilis cases were included. No meta-analysis was performed due to the heterogeneity of the data. Among 149 case reports and 93 retrospective case series studies, the main clinical manifestation of 3,507 neurosyphilis cases was cerebral parenchymal syphilis (57.3%), followed by asymptomatic neurosyphilis (16.7%), meningovascular syphilis (13.6%), meningitis syphilis (7.7%) and ocular syphilis (2.8%), etc. In addition, the initial diagnosis was incorrect in 53.2% patients, and the most frequent misdiagnoses were mental disorders (31.0%), stroke (15.9%), cognitive impairment (9.0%), etc. The positive or abnormal rates of cerebrospinal fluid non-treponemal and treponemal tests, white blood cell counts and protein concentrations were 74.2%, 96.2%, 61.5%, and 60.9%, respectively. Aqueous penicillin was the first choice for treatment in 88.3% cases, and 81.7% and 50.0% patients had response in the improvement of symptoms and serological effective in CSF, respectively. Among 26 studies on neurosyphilis patients amongst other associated diseases, the prevalence of neurosyphilis amongst central nervous system infectious diseases, syphilis-associated neurological symptoms, serofast status, coinfected with human immunodeficiency virus were 10.6%-30.1%, 23.2%-35.5%, 9.8%-56.1%, and 8.9%, respectively. In summary, the lack of early detection of neurosyphilis cases remains a clinical challenge. The high rate of misdiagnosis and high prevalence of neurosyphilis amongst associated diseases strongly remind clinicians to focus on the early detection among suspected cases. Besides, the standard treatment regimen and long-term follow-up, which complied with guideline should be provided. Further prospective studies are urgent to better delineate the clinical epidemiological characteristics of neurosyphilis in China.

Management of Adult Syphilis: Key Questions to Inform the 2021 Centers for Disease Control and Prevention Sexually Transmitted Infections Treatment Guidelines

A panel of experts generated 5 "key questions" in the management of adult syphilis. A systematic literature review was conducted and tables of evidence were constructed to answer these questions. Available data suggest no clinical benefit to >1 dose of benzathine penicillin G for early syphilis in human immunodeficiency virus (HIV)-infected patients. While penicillin remains the drug of choice to treat syphilis, doxycycline to treat early and late latent syphilis is an acceptable alternate option if penicillin cannot be used. There are very limited data regarding the impact of additional antibiotic doses on serologic responses in serofast patients and no data on the impact of additional antibiotic courses on long-term clinical outcomes. In patients with isolated ocular or otic signs and symptoms, reactive syphilis serologic results, and confirmed ocular/otic abnormalities at examination, a diagnostic cerebrospinal fluid (CSF) examination is not necessary, because up to 40% and 90% of patients, respectively, would have no CSF abnormalities. Based on the results of 2 studies, repeated CSF examinations are not necessary for HIV-uninfected patients or HIV-infected patients on antiretroviral therapy who exhibit appropriate serologic and clinical responses after treatment for neurosyphilis. Finally, several important gaps were identified and should be a priority for future research.

Disparity in Availability of Laboratory Testing for Syphilis Among Different Hospitals in Shandong Province, Eastern China

The aim of this study was to understand the availability of laboratory testing for syphilis among hospitals in Shandong province. Basic information on hospitals that provide clinical health service for sexually transmitted infections (STIs) and the type of laboratory tests for syphilis provided was collected and analyzed using the chi-square test. A total of 410 and 456 hospitals that provided clinical services for STI were surveyed in 2012 and 2018. Significant differences in the availability of nontreponemal tests were observed among different levels (χ² = 6.624, P = .010) and types (χ² = 17.752, P = .001) of hospitals in 2012, but not in 2018. A significant difference in the availability of treponemal tests was observed among different levels of hospitals in 2012 (χ² = 9.937, P = .002) but not in 2018. Significant differences in the availability of nontreponemal tests, titer of nontreponemal tests, and treponemal tests were observed among hospitals with different affiliations in 2018 (P = 0.000; χ² = 15.274, P = .000; P = .021) but not in 2012. The availability of nontreponemal and treponemal tests for syphilis among hospitals in 2018 was higher than that in 2012 (90.13% vs. 57.56%, χ² = 121.219, P = .000). The availability of laboratory testing has been much improved. Further efforts are needed to reduce the disparity in the availability among different hospitals.

Intrathecal Synthesis Index of Specific Anti-Treponema IgG: a New Tool for the Diagnosis of Neurosyphilis

Neurosyphilis (NS) diagnosis is challenging because clinical signs are diverse and unspecific, and a sensitive and specific laboratory test is lacking. We tested the performance of an antibody index (AI) for intrathecal synthesis of specific anti-Treponema IgG by enzyme-linked immunosorbent assay (ELISA) for NS diagnosis. We conducted a retroprospective monocentric study including adults with neurological symptoms who had serum and cerebral spinal fluid (CSF) samples collected between 2006 and 2021. Two NS definitions were used. NS1 included patients with neurological symptoms, positive Treponema pallidum particle agglutination (TPPA) serology, and CSF-TPPA of ≥320, as well as CSF-leukocytes of >5 cells/mm³ and/or CSF-protein of >0.45 g/L and/or a reactive CSF-VDRL/RPR test. NS2 included patients with acute ocular and/or otologic symptoms, positive TPPA serology, and a response to NS treatment. Controls were patients with central nervous system disorders other than neurosyphilis. Anti-Treponema pallidum IgG were measured simultaneously in serum and CSF, and AI was calculated according to Reiber diagram. We assessed the AI test area under the curve (AUC), sensitivity/specificity, and estimated positive and negative predictive values. In total, 16 NS1 patients, 11 NS2 patients, and 71 controls were included. With an AI of ≥1.7 as a positive test for NS diagnostic, specificity was 98.6% (95% confidence interval [CI 95%] of 92.4 to 100.0) and sensitivity was 81.3% (CI 95% of 54.4 to 96.0) for NS1 and 98.6% (CI 95% 92.4 to 100.0) and 27.3% (CI 95% 6.0 to 61.0), respectively, for NS2. Positive and negative predictive values were >95% for NS1 and >85% for NS2, for prevalence above and below 20%. Measuring an AI for intrathecal synthesis of specific anti-Treponema pallidum IgG is a new promising tool highly specific for NS diagnosis.

IMPORTANCE In the context of a lack of a gold standard for the diagnosis of neurosyphilis due to either nonspecific or nonsensitive tests, we present in this article a new promising tool highly specific for NS diagnosis. This new test involves measuring an intrathecal synthesis index of specific anti-Treponema IgG by ELISA.

'Neurosyphilis in the Northern Territory of Australia: a clinical guideline'

BACKGROUND

The Northern Territory (NT) of Australia is currently experiencing a syphilis epidemic. Neurosyphilis is commonly considered in the differential diagnosis for patients presenting with neurologic conditions such as dementia and stroke in the NT.

AIMS

To explore the local epidemiologic, diagnostic and treatment complexities of neurosyphilis in the NT and produce a guideline for clinical practice.

METHODS

A database search was undertaken and local and global neurosyphilis guidelines were analysed. A guideline was created based on findings of the critical review and consultation with local multi-disciplinary experts.

RESULTS

Neurosyphilis is frequently encountered in the NT but studies suggest it is often under-treated. Dementia is the most common clinical presentation locally. Establishing a diagnosis of neurosyphilis is complex and requires stepwise evaluation of clinical, laboratory and radiological findings.

CONCLUSIONS

A clinical guideline and algorithm have been developed for the diagnosis and management of patients with neurosyphilis. This article is protected by copyright. All rights reserved.

Alternatives to the Cerebrospinal Fluid Venereal Disease Research Laboratory Test for Neurosyphilis Diagnosis

BACKGROUND

The diagnosis of neurosyphilis relies in large part on the cerebrospinal fluid (CSF) Venereal Disease Research Laboratory (VDRL) test, which is diagnostically specific but not sensitive.

METHODS

We determined the sensitivity and specificity of 3 CSF tests in addition to the CSF-VDRL in participants with syphilis enrolled in a research study: detection of Treponema pallidum ribosomal RNA, T. pallidum particle agglutination titer, and chemokine (C-X-C motif) ligand 13 (CXCL13) concentration. Neurosyphilis was defined as asymptomatic or symptomatic meningitis: CSF white blood cells >10/μL without or with neurological symptoms, including new vision or hearing loss.

RESULTS

Cerebrospinal fluid-VDRL, CSF T. pallidum ribosomal RNA detection, and CSF T. pallidum particle agglutination titer ≥1:640 were specific (89%-96%) but not sensitive (12%-48%). In contrast, diagnostic sensitivity of CSF-CXCL13 thresholds established from receiver operating characteristic curves using the Youden index was 78% to 83% and specificity was 76% to 81%. In individuals with nonreactive CSF-VDRL, neurosyphilis diagnosis could be confirmed by CSF-CXCL13 concentration in 69% to 75%.

CONCLUSIONS

Further studies of CSF-CXCL13 should include CSF samples from multiple cohorts and countries and should use standard neurosyphilis definitions to establish uniform thresholds for diagnosis.

Neurosyphilis

PURPOSE OF REVIEW

This article focuses on the epidemiology, clinical presentation, diagnosis, and management of neurosyphilis, with an emphasis on clinically relevant issues faced by the practicing neurologist.

RECENT FINDINGS

The incidence of primary and secondary syphilis, the sexually transmissible stages of infection, has been on the rise for the past 2 decades. A concerning recent trend is the surge in cases of syphilis in women and of congenital syphilis. Neurosyphilis remains a relatively common complication that can occur at any stage of syphilis. Along with meningitis, meningovascular syphilis, which has been historically described as a late presentation of neurosyphilis, now frequently occurs as a manifestation of early infection. Late forms of neurosyphilis, including tabes dorsalis and general paresis, are less prevalent in the era of widespread penicillin use. As more laboratories adopt the reverse-sequence algorithm for syphilis testing, patients with serodiscordant results (ie, a reactive serum treponemal test with a nonreactive nontreponemal test) may present an increasingly encountered diagnostic challenge for neurologists. Although the CSF Venereal Disease Research Laboratory (VDRL) remains a mainstay of diagnostic testing for neurosyphilis, using a higher titer cutoff (greater than 1:320) for the Treponema pallidum particle agglutination assay (TPPA) from the CSF may improve the utility of the TPPA as a supporting criterion for the diagnosis of neurosyphilis. Penicillin G is the treatment of choice for neurosyphilis, although ceftriaxone may be a reasonable alternative therapy.

SUMMARY

A high index of suspicion and awareness of the variable clinical presentations of neurosyphilis are essential to the approach to this treatable infection. Neurologists should be mindful of the limitations of serologic testing in the diagnosis of neurosyphilis and exercise clinical judgment to determine the likelihood of the diagnosis.

Strategies for the diagnosis and management of meningitis in HIV-infected adults in resource limited settings

INTRODUCTION

The incidence of human immunodeficiency virus-1 (HIV-1) associated meningitis has been declining in the post-combination antiretroviral treatment (ART) era, although survival rates remain low for the common causes like tuberculosis and cryptococcal disease. Diagnosis and treatment of meningitis in HIV-1 is complicated by atypical clinical presentations, limited accuracy of diagnostic tests, access to diagnostic tests, and therapeutic agents in low- and middle-income countries (LMIC) and immune reconstitution inflammatory syndrome (IRIS).

AREAS COVERED

We provide an overview of the common etiologies of meningitis in HIV-1-infected adults, suggest a diagnostic approach based on readily available tests, and review specific chemotherapeutic agents, host-directed therapies, supportive care, timing of ART initiation, and considerations in the management of IRIS with a focus on resource-limited settings. They identify key knowledge gaps and suggest areas for future research.

EXPERT OPINION

Evidence-based management of HIV-1-associated meningitis is sparse for common etiologies. More readily available and sensitive diagnostic tests as well as standardized investigation strategies are required in LMIC. There is a lack of availability of recommended drugs in areas of high HIV-1 prevalence and a limited pipeline of novel chemotherapeutic agents. Host-directed therapies have been inadequately studied.

Diagnostic tools for neurosyphilis: a systematic review

Purpose

Increasing incidences of syphilis highlight the preoccupation with the occurrence of neurosyphilis. This study aimed to understand the current diagnostic tools and their performance to detect neurosyphilis, including new technologies and the variety of existing methods.

Methods

We searched databases to select articles that reported neurosyphilis diagnostic methods and assessed their accuracy, presenting sensitivity and specificity values. Information was synthesized in tables. The risk of bias was examined using the Cochrane Handbook for Systematic Reviews of Diagnostic Test Accuracy recommendations.

Results

Fourteen studies were included. The main finding was a remarkable diversity of tests, which had varied purposes, techniques, and evaluation methodologies. There was no uniform criterion or gold standard to define neurosyphilis. The current basis for its diagnosis is clinical suspicion and cerebrospinal fluid analysis. There are new promising tests such as PCR tests and chemokine measurement assays.

Conclusions

The diagnosis of neurosyphilis is still a challenge, despite the variety of existing and developing tests. We believe that the multiplicity of reference standards adopted as criteria for diagnosis reveals the imprecision of the current definitions of neurosyphilis. An important next step for the scientific community is to create a universally accepted diagnostic definition for this disease.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06264-8.

Divergent and self-reactive immune responses in the CNS of COVID-19 patients with neurological symptoms

Individuals with coronavirus disease 2019 (COVID-19) frequently develop neurological symptoms, but the biological underpinnings of these phenomena are unknown. Through single-cell RNA sequencing (scRNA-seq) and cytokine analyses of cerebrospinal fluid (CSF) and blood from individuals with COVID-19 with neurological symptoms, we find compartmentalized, CNS-specific T cell activation and B cell responses. All affected individuals had CSF anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies whose target epitopes diverged from serum antibodies. In an animal model, we find that intrathecal SARS-CoV-2 antibodies are present only during brain infection and not elicited by pulmonary infection. We produced CSF-derived monoclonal antibodies from an individual with COVID-19 and found that these monoclonal antibodies (mAbs) target antiviral and antineural antigens, including one mAb that reacted to spike protein and neural tissue. CSF immunoglobulin G (IgG) from 5 of 7 patients showed antineural reactivity. This immune survey reveals evidence of a compartmentalized immune response in the CNS of individuals with COVID-19 and suggests a role of autoimmunity in neurologic sequelae of COVID-19.

Brazilian Protocol for Sexually Transmitted Infections 2020: acquired syphilis

The Clinical Protocol and Therapeutic Guidelines for Comprehensive Care of People with Sexually Transmitted Infections, published by the Brazilian Ministry of Health in 2020, includes updates concerning acquired syphilis. The document comprises rapid test use, safety and efficacy of benzathine benzylpenicillin, case follow-up, neurosyphilis clinical and laboratory management, approaching sex partners, assistance and monitoring of diagnosed pregnant women, and syphilis and HIV co-infection specificities, as well as a case notification summary. Health managers and professionals must be continuously trained so as to integrate care and surveillance, to strengthen actions for efficient control of syphilis, to broaden the search for sex partners, and to expand access of most vulnerable populations to health services. Most people with syphilis are asymptomatic; this contributes to the maintenance of the transmission chain. Without adequate treatment of pregnant women with syphilis, severe consequences can occur, such as miscarriage, prematurity, low birth weight, natimortality, and congenital syphilis.

Brazilian Protocol for Sexually Transmitted Infections 2020: syphilis diagnostic tests

The recommendations for diagnostic tests for investigating syphilis are part of the Clinical Protocol and Therapeutic Guidelines for Comprehensive Care for People with Sexually Transmitted Infections and the Technical Manual for Syphilis Diagnosis, published by the Brazilian Ministry of Health. These recommendations were developed based on scientific evidence and discussions with a panel of experts. This article presents direct tests to detect Treponema pallidum in lesions and algorithms that combine treponemal and non-treponemal antibody tests to assist in syphilis diagnosis, with the aim of contributing to the efforts of health service managers and health professionals in qualifying health care. The article also covers the use of non-treponemal tests to investigate neurosyphilis and guidelines for interpreting non-treponemal antibody titers in monitoring the treatment and diagnosis of congenital syphilis, as well as prospects for innovations in diagnosis. The critical role of rapid immunochromatographic treponemal tests for public health and for addressing syphilis is also highlighted.

Highlighted excerpt: During the natural evolution of syphilis, activity periods with distinct clinical, immunological, and histopathological characteristics are interspersed with latent periods when there are no signs or symptoms, making access to tests critical for early diagnosis.

Neurosyphilis: a series of 178 cases at the 3rd-level hospital of Marrakesh (Morocco)

Neurosyphilis (NS) is an infection of the central nervous system (CNS), caused by Treponema pallidum. Up to 4-10% of patients with untreated syphilis may develop NS which still constitutes a health challenge. The aim of this study is to analyze epidemiological, clinical, paraclinical, therapeutic, and progression profiles of NS in the south of Morocco. Authors analyzed retrospectively 178 files of patients with neurosyphilis, collected in the Neurology Department of Marrakesh over 25 years from January 1994 to March 2019. In our study, the mean age was 46 years (17-75 years). The number of males was dominant (87.6%). The most common presentation was meningoencephalitis. Four cases were atypical (late congenital syphilis, amyotrophic lateral sclerosis, neurosyphilis associated with neuro-Behcet's disease, and acute polyradiculoneuropathy). All patients had positive TPHA and VDRL serologies in blood; CSF-TPHA was positive in all patients, and CSF-VDRL was positive in 64.0% of patients. CT scan and brain MRI showed cortical atrophy in the majority of cases. One hundred seventy-seven patients were treated with intravenous injection of aqueous penicillin G. Neurosyphilis is still a significant medical problem in developing countries, and its occurrence in HIV infection is the reason for a growing number of new cases in developed countries. Given the frequent atypical manifestations of the disease, screening for neurosyphilis should be considered in all patients with neurological or psychiatric symptoms.

A Dual-Platform Point-of-Care Test for Neurosyphilis Diagnosis

BACKGROUND

The diagnosis of neurosyphilis relies on cerebrospinal fluid (CSF) abnormalities (pleocytosis, elevated protein) and CSF-Venereal Disease Research Laboratory (VDRL) test. In resource-limited settings, the CSF-VDRL test may not be widely available.

METHODS

We optimized a commercial immunochromatographic strip test, the DPP Chembio syphilis assay, for performance with CSF and tested centrifuged CSF samples of 71 patients with syphilis (35 with neurosyphilis and 36 without neurosyphilis). A CSF dilution of 1:4 was chosen based on agreement with CSF pools with documented results from the CSF-VDRL test and fluorescent treponemal antibody absorption test on CSF. Using an electronic reader, we obtained unit values of treponemal and nontreponemal antibodies for all study samples and generated a receiver operating characteristic curve; using the Youden index, we established diagnostic cutoffs with optimal sensitivity and specificity.

RESULTS

Diagnostic sensitivity of the nontreponemal test was 80% (95% confidence interval, 63%-92%) and specificity was 97% (95% confidence interval, 85%-100%) for neurosyphilis diagnosis using a reactive CSF-VDRL that improved after neurosyphilis therapy as a criterion standard.

CONCLUSIONS

In this small study, the DPP Chembio test showed promising results for neurosyphilis diagnosis. Further studies are needed to assess its performance in resource-limited settings.

Sensitivity and Specificity of Treponemal-specific Tests for the Diagnosis of Syphilis

We conducted a systematic review of relevant syphilis diagnostic literature to address the question, “What is the sensitivity and specificity of the treponemal tests currently approved by the Food and Drug Administration (FDA) for the diagnosis of syphilis (by stage)?” There were 16 treponemal assays evaluated: 13 immunoassays and 3 manual assays (fluorescent treponemal antibody absorbed test [FTA-ABS], microhemagglutination assay for Treponema pallidum antibodies [MHA-TP], Treponema pallidum particle agglutination assay [TP-PA]). MHA-TP and FTA-ABS were less sensitive in primary and secondary syphilis than TP-PA; TP-PA is the most specific manual treponemal assay. There is insufficient evidence to recommend one particular treponemal immunoassay (eg, enzyme immunoassays, chemiluminescence immunoassays, microbead immunoassays) over another based on published performance data. For diagnosis of neurosyphilis, cerebrospinal fluid (CSF) TP-PA has similar performance to CSF FTA-ABS in studies with patients with definitive or presumptive neurosyphilis. However, CSF treponemal testing has limitations in its sensitivity and specificity and should be interpreted within the context of the clinical scenario, additional CSF test results and syphilis prevalence.

Syphilis Laboratory Guidelines: Performance Characteristics of Nontreponemal Antibody Tests

We reviewed the relevant syphilis diagnostic literature to address the following question: what are the performance characteristics, stratified by the stage of syphilis, for nontreponemal serologic tests? The database search included key terms related to syphilis and nontreponemal tests from 1960–2017, and for data related to the venereal disease research laboratory test from 1940–1960. Based on this review, we report the sensitivity and specificity for each stage of syphilis (primary, secondary, early latent, late latent, or unknown duration; tertiary as well as neurosyphilis, ocular syphilis, and otic syphilis). We also report on reactive nontreponemal tests in conditions other than syphilis, false negatives, and automated nontreponemal tests. Overall, many studies were limited by their sample size, lack of clearly documented clinical staging, and lack of well-defined gold standards. There is a need to better define the performance characteristics of nontreponemal tests, particularly in the late stages of syphilis, with clinically well-characterized samples. Published data are needed on automated nontreponemal tests. Evidence-based guidelines are needed for optimal prozone titrations. Finally, improved criteria and diagnostics for neurosyphilis (as well as ocular and otic syphilis) are needed.

[Brazilian Protocol for Sexually Transmitted Infections 2020: syphilis diagnostic tests]

The recommendations for diagnostic tests for investigating syphilis are part of the Clinical Protocol and Therapeutic Guidelines for Comprehensive Care for People with Sexually Transmitted Infections and the Technical Manual for Syphilis Diagnosis, published by the Brazilian Ministry of Health. These recommendations were developed based on scientific evidence and discussions with a panel of experts. Aiming to contribute to the efforts of health service managers and health professionals in qualifying health care, this article presents the use of direct tests to detect Treponema pallidum in lesions, as well as algorithms that combine treponemal and non-treponemal antibody tests to assist in the diagnosis of syphilis. The article also covers use of non-treponemal tests to investigate neurosyphilis and guidelines for interpreting non-treponemal antibody titers in monitoring treatment and diagnosis of congenital syphilis, as well as prospects for innovations in diagnosis. The important role of rapid immunochromatographic treponemal tests for public health and for addressing syphilis is also highlighted.

[Brazilian Protocol for Sexually Transmitted Infections 2020: acquired syphilis]

The Clinical Protocol and Therapeutic Guidelines for Comprehensive Care for People with Sexually Transmitted Infections, published by the Ministry of Health of Brazil in 2020, includes the update on acquired syphilis. The document comprises rapid tests use, safety and efficacy of the administration of benzathine benzylpenicillin, follow-up of cases, clinical and laboratory management of neurosyphilis, approach to sexual partnerships, assistance and monitoring of diagnosed pregnant women, and specificities of syphilis and HIV co-infection, as well as a summary of the notification of cases. It is necessary to train health managers and professionals on a continuous basis, with a view to integrating care and surveillance, strengthening effective syphilis control actions, increasing the search for sexual partnerships, and expanding the access of the most vulnerable populations to health services.

Neurosyphilis and Lyme neuroborreliosis

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Laboratory Diagnostic Tools for Syphilis: Current Status and Future Prospects

With the increasing number of patients infected with syphilis in the past 20 years, early diagnosis and early treatment are essential to decline syphilis prevalence. Owing to its diverse manifestations, which may occur in other infections, the disease often makes clinicians confused. Therefore, a sensitive method for detecting T. pallidum is fundamental for the prompt diagnosis of syphilis. Morphological observation, immunohistochemical assay, rabbit infectivity test, serologic tests, and nucleic acid amplification assays have been applied to the diagnosis of syphilis. Morphological observation, including dark-field microscopy, silver-staining, and direct fluorescent antibody staining for T. pallidum, can be used as a direct detection method for chancre specimens in primary syphilis. Immunohistochemistry is a highly sensitive and specific assay, especially in the lesion biopsies from secondary syphilis. Rabbit infectivity test is considered as a sensitive and reliable method for detecting T. pallidum in clinical samples and used as a historical standard for the diagnosis of syphilis. Serologic tests for syphilis are widely adopted using non-treponemal or treponemal tests by either the traditional or reverse algorithm and remain the gold standard in the diagnosis of syphilis patients. In addition, nucleic acid amplification assay is capable of detecting T. pallidum DNA in the samples from patients with syphilis. Notably, PCR is probably a promising method but remains to be further improved. All of the methods mentioned above play important roles in various stages of syphilis. This review aims to provide a summary of the performance characteristics of detection methods for syphilis.

Exploratory neuroimmune profiling identifies CNS-specific alterations in COVID-19 patients with neurological involvement

One third of COVID-19 patients develop significant neurological symptoms, yet SARS-CoV-2 is rarely detected in central nervous system (CNS) tissue, suggesting a potential role for parainfectious processes, including neuroimmune responses. We therefore examined immune parameters in cerebrospinal fluid (CSF) and blood samples from a cohort of patients with COVID-19 and significant neurological complications. We found divergent immunological responses in the CNS compartment, including increased levels of IL-12 and IL-12-associated innate and adaptive immune cell activation. Moreover, we found increased proportions of B cells in the CSF relative to the periphery and evidence of clonal expansion of CSF B cells, suggesting a divergent intrathecal humoral response to SARS-CoV-2. Indeed, all COVID-19 cases examined had anti-SARS-CoV-2 IgG antibodies in the CSF whose target epitopes diverged from serum antibodies. We directly examined whether CSF resident antibodies target self-antigens and found a significant burden of CNS autoimmunity, with the CSF from most patients recognizing neural self-antigens. Finally, we produced a panel of monoclonal antibodies from patients' CSF and show that these target both anti-viral and anti-neural antigens-including one mAb specific for the spike protein that also recognizes neural tissue. This exploratory immune survey reveals evidence of a compartmentalized and self-reactive immune response in the CNS meriting a more systematic evaluation of neurologically impaired COVID-19 patients.

German guidelines on the diagnosis and treatment of neurosyphilis

Introduction

In view of the importance of neurosyphilis and the difficulties encountered in diagnosing it, the S1 guideline "Neurosyphilis" has been published by the German Society for Neurology (DGN) in accordance with the stipulations of the Association of the Scientific Medical Societies in Germany (AWMF). The present article is an abridged translation of that German guideline.

Main recommendations

(a) Neurosyphilis can manifest as early neurosyphilis (meningitis, meningovascular neurosyphilis or syphilitic gummas) or late neurosyphilis (tabes dorsalis, general paresis). (b) The following diagnostic criteria help to establish the presence of probable neurosyphilis (always point iv, accompanied by any two of points i to iii): (i) subacute or chronic neuro-psychiatric symptoms; (ii) increased cerebrospinal fluid (CSF) cell count or signs of blood-CSF barrier disruption; (iii) positive effect of anti-neurosyphilis antibiotic therapy on clinical course and CSF findings; (iv) positive TPHA/TPPA or FTA test in serum. (c) The diagnosis of neurosyphilis is confirmed by the subsequent detection of intrathecal production of antibodies against Treponema pallidum. (d) In neurosyphilis, treatment with intravenous penicillin or ceftriaxone for 14 days is recommended. (e) The following parameters can be used to assess a therapeutic effect: clinical findings, serum VDRL, and CSF cell count.

Conclusion

The German guideline on the diagnosis and treatment of neurosyphilis is a practical tool to support clinicians in diagnosing and treating patients with neurosyphilis. This article is an abridged translation of this guideline (Klein MW, J.; Angstwurm, K.; Esser, S.; Hahn, K.; Matschke, M.; Scheithauer, S.; Schoefer, H.; Sturzenegger, M.; Wildemann, B. Neurosyphilis, S1-Leitlinie. Deutsche Gesellschaft für Neurologie, Leitlinien für Diagnostik und Thearpie in der Neurologie 2020).

More than meets the eye: Papilledema from syphilis posing as idiopathic intracranial hypertension

Idiopathic intracranial hypertension (IIH), or pseudotumor cerebri, is a diagnosis of exclusion. Elevated intracranial pressure (ICP) can result from a variety of inflammatory and structural causes affecting cerebrospinal fluid production and absorption. First described in 1935, syphilis is a well-established cause of elevated ICP, referred to as syphilitic hydrocephalus. We report a case of a 49-year-old man presenting with vision changes and headache who was treated for IIH without resolution of symptoms, and eventually diagnosed with syphilitic hydrocephalus. Syphilis should be considered as a cause of elevated ICP prior to a diagnosis of IIH.

A Novel Nested Real-time Polymerase Chain Reaction for Treponema pallidum DNA in Syphilis Biospecimens

BACKGROUND

Early diagnosis of Treponema pallidum infection is helpful for disease management, and conventional PCR is suitable for lesion swabs of patients with probable early syphilis. We thus tested nested and real-time PCR (NR-PCR) in various biosamples from syphilitic patients.

METHODS

Samples were collected from syphilis patients before treatment. Specific primer sequences targeting the T. pallidum gene polA were designed for NR-PCR.

RESULTS

Across syphilis types, most samples assayed with NR-PCR returned a positive result, including earlobe blood (92.0%), cerebrospinal fluid (CSF) (90.2%), lesion swabs (74.3%), serum (66.9%), and whole blood (64.2%). No significant differences were observed in positive samples for whole blood, serum, and lesion swabs between primary and secondary syphilis (P > 0.05 for all comparisons). However, more whole-blood samples from patients with secondary syphilis were positive for NR-PCR than whole blood samples from patients with tertiary and latent syphilis (P < 0.05 for all comparisons). For neurosyphilis patients, significantly more earlobe blood samples tested positive than did whole-blood samples (P < 0.05), but there was no difference in positive results for earlobe blood and whole blood in latent syphilis. Significantly more serum samples tested positive in latent syphilis patients with rapid plasma regain (RPR) titers of 1:8 or greater, compared to those with RPR of 1:4 or less.

CONCLUSIONS

Nested and real-time PCR can be used to identify T. pallidum DNA in biosamples from syphilitic patients, especially earlobe blood.

Diagnostic Testing in Central Nervous System Infection

Patients with central nervous system (CNS) infection experience very high levels of morbidity and mortality, in part because of the many challenges inherent to the diagnosis of CNS infection and identification of a causative pathogen. The clinical presentation of CNS infection is nonspecific, so clinicians must often order and interpret many diagnostic tests in parallel. This can be a daunting task given the large number of potential pathogens and the availability of different testing modalities. Here, we review traditional diagnostic techniques including Gram stain and culture, serology, and polymerase chain reaction (PCR). We highlight which of these are recommended for the pathogens most commonly tested among U.S. patients with suspected CNS infection. Finally, we describe the newer broad-range diagnostic approaches, multiplex PCR and metagenomic sequencing, which are increasingly used in clinical practice.

Medullary involvement in neurosyphilis: a report of 12 cases and a review of the literature

Study design

Retrospective case series.

Objectives

To describe the epidemiological, clinical, MRI and therapeutic features and the outcomes of patients with syphilitic myelitis in a third-level hospital in Marrakesh in southern Morocco.

Setting

The Neurology Department, University Hospital Mohamed VI Marrakesh, Morocco.

Methods

Twelve charts of persons with syphilitic myelitis over a period of 17 years were reviewed to determine demographics, presenting symptoms, clinical and radiological findings, biological features, treatment received and outcomes.

Results

There were 120 reports of neurosyphilis. Twelve patients (10%) had syphilitic myelitis. Eleven patients (92%) were male with mean age of 44 at presentation. Tabes dorsalis was the most common clinical form. Cerebrospinal fluid analysis showed lymphocytic meningitis in nine patients (75%). Spine MRI was abnormal in four patients (33%). All patients were treated with 30 million units of aqueous penicillin G IV per day for 10 days, every 3 months. In follow-up, two patients (17%) with clinical syphilitic meningomyelitis improved significantly, eight patients (66%) with tabes dorsalis and subacute transverse myelitis showed partial improvement but clinical status was stationary for two patients (17%) with Erb paraplegia.

Conclusions

All patients with myelopathy should undergo syphilitic serology because of nonspecific manifestations and curability of this disease.

Diagnostic performance of PCR assays for the diagnosis of neurosyphilis: a systematic review

INTRODUCTION

Syphilis continues to be a major public health problem and the recent resurgence in syphilis in high-income settings has seen an accompanying increase in cases of neurosyphilis. While the introduction of PCR has had a significant impact on the diagnosis of early syphilis, cerebrospinal fluid (CSF) serological assays remain the most commonly used tests to diagnosis neurosyphilis. We reviewed data on the performance of CSF-PCR for the diagnosis of neurosyphilis.

METHODS

We searched Pubmed, Medline, EMBASE and the grey literature for references on PCR in neurosyphilis. We calculated the sensitivity and specificity of PCR compared with reference testing for the diagnosis of neurosyphilis.

RESULTS

We identified 66 articles of which seven met the study inclusion criteria. The sensitivity of PCR for definite neurosyphilis varied between 40% and 70% and specificity between 60% and 100% across the studies. The most commonly used PCR assay targeted Tp47 which had an overall sensitivity of 68% and a specificity of 91.9%.

DISCUSSION

The sensitivity of PCR was low compared with CSF-serological assays but the challenges of evaluating a diagnostic test in the absence of a clear gold standard make definitive interpretation challenging. Most studies were small and not adequately powered highlighting the need for multicentre, multicountry trials to provide adequate statistical power in evaluations of new tests the diagnosis of neurosyphilis.

Syphilis

Treponema pallidum subspecies pallidum (T. pallidum) causes syphilis via sexual exposure or via vertical transmission during pregnancy. T. pallidum is renowned for its invasiveness and immune-evasiveness; its clinical manifestations result from local inflammatory responses to replicating spirochaetes and often imitate those of other diseases. The spirochaete has a long latent period during which individuals have no signs or symptoms but can remain infectious. Despite the availability of simple diagnostic tests and the effectiveness of treatment with a single dose of long-acting penicillin, syphilis is re-emerging as a global public health problem, particularly among men who have sex with men (MSM) in high-income and middle-income countries. Syphilis also causes several hundred thousand stillbirths and neonatal deaths every year in developing nations. Although several low-income countries have achieved WHO targets for the elimination of congenital syphilis, an alarming increase in the prevalence of syphilis in HIV-infected MSM serves as a strong reminder of the tenacity of T. pallidum as a pathogen. Strong advocacy and community involvement are needed to ensure that syphilis is given a high priority on the global health agenda. More investment is needed in research on the interaction between HIV and syphilis in MSM as well as into improved diagnostics, a better test of cure, intensified public health measures and, ultimately, a vaccine.

Neurosyphilis in Africa: A systematic review

Introduction

Neurological involvement is one of the most important clinical manifestations of syphilis and neurological disease occurs in both early and late syphilis. The impact of HIV co-infection on clinical neurosyphilis remains unclear. The highest prevalence of both syphilis and HIV is in Africa. Therefore it might be expected that neurosyphilis would be an important and not uncommon manifestation of syphilis in Africa and frequently occur in association with HIV co-infection; yet few data are available on neurosyphilis in Africa. The aim of this study is to review data on neurosyphilis in Africa since the onset of the HIV epidemic.

Methods

We searched the literature for references on neurosyphilis in Africa for studies published between the 1^st of January 1990 and 15^th February 2017. We included case reports, case series, and retrospective and prospective cohort and case-control studies. We did not limit inclusion based on the diagnostic criteria used for neurosyphilis. For retrospective and prospective cohorts, we calculated the proportion of study participants who were diagnosed with neurosyphilis according to the individual study criteria. Depending on the study, we assessed the proportion of patients with syphilis found to have neurosyphilis, and the proportion of patients with neurological syndromes who had neurosyphilis. Due to heterogeneity of data no formal pooling of the data or meta-analysis was undertaken.

Results

Amongst patients presenting with a neurological syndrome, three studies of patients with meningitis were identified; neurosyphilis was consistently reported to cause approximately 3% of all cases. Three studies on stroke reported mixed findings but were limited due to the small number of patients undergoing CSF examination, whilst neurosyphilis continued to be reported as a common cause of dementia in studies from North Africa. Ten studies reported on cases of neurosyphilis amongst patients known to have syphilis. Studies from both North and Southern Africa continue to report cases of late stage syphilis, including tabes dorsalis and neurosyphilis, in association with ocular disease.

Discussion

This is the first systematic review of the literature on neurosyphilis in Africa since the beginning of the HIV epidemic. Neurosyphilis continues to be reported as a manifestation of both early and late syphilis, but the methodological quality of the majority of the included studies was poor. Future well-designed prospective studies are needed to better delineate the incidence and clinical spectrum of neurosyphilis in Africa and to better define interactions with HIV in this setting.

Involvement of the central nervous system is an important manifestation of syphilis which may be more common in patients co-infected with HIV. As most cases of syphilis and HIV are seen in Africa it might be anticipated that neurosyphilis was common there. We reviewed all published material on neurosyphilis in Africa since 1990. There were few well designed studies of neurosyphilis. A small number of studies suggested that syphilis remains a cause of meningitis in Africa. Our data suggest that neuosyphilis remains an important disease in Africa but better prospective studies are needed to understand its epidemiology.