Laboratory diagnosis and interpretation of tests for syphilis

Detection of Treponema pallidum DNA for diagnosis, resistance identification, and treatment outcome prediction in early syphilis among men who have sex with men

OBJECTIVES

We investigated the use of Treponema pallidum DNA (TP-DNA) for diagnosis, resistance identification, and treatment outcome prediction in early syphilis among men who have sex with men (MSM).

METHODS

MSM seeking care for sexually transmitted infections were prospectively enrolled from September 2021 to August 2024. Oral rinse, rectal swab, and urethral swab samples were tested for TP-DNA. Resistance-associated mutations (RAMs) to macrolides and tetracyclines were identified. Treatment responses were compared between syphilis cases with detected TP-DNA and those without.

RESULTS

Of 656 MSM enrolled, TP-DNA was most frequently detected in oral rinse samples (37.8% [193/510]), followed by rectal swab (20.2% [103/510]) and urethral swab samples (11.6%, 59/510) in clinic visits for early syphilis. TP-DNA was detected in 45.7% (233/510) of early syphilis cases and 0.7% (1/141) of cases without syphilis, resulting in a specificity of 99.3% (95% CI: 96.1-100%) and sensitivity of 45.7% (95% CI: 41.3-50.1%). Secondary syphilis cases had the highest yield of TP-DNA detection (67.6% [117/173]), followed by primary (48.7% [19/39]) and early latent syphilis cases (32.6% [97/298]). The Ct values of T. pallidum PCR in oral rinse samples were significantly lower in cases of higher rapid plasma reagin (RPR) titres (p < 0.001). The rate of T. pallidum harbouring RAMs to macrolides was 58.9% (139/236), increasing over 6-month intervals, from 32.4% (12/37) in 2021 to 77.8% (21/27) in 2023. Cases of detected TP-DNA had greater serological responses to treatments than those without: 80.3% (159/198) vs. 67.0% (156/233) at month 6 (p 0.002) and 84.1% (143/170) vs. 70.3% (137/195) at month 12 (p = 0.002).

DISCUSSION

T. pallidum PCR showed high specificity for the diagnosis of early syphilis, which correlated with RPR titres and treatment response, and lower Ct values in oral rinse samples correlated with higher RPR titres. The high prevalence of T. pallidum strains with RAMs to macrolides argues against using azithromycin to treat syphilis in Taiwan.

Epstein-Barr virus-associated infectious mononucleosis exhibits substantially higher non-treponemal test titers in biological false-positive reactions

OBJECTIVES

Biological false-positive (BFP) reactions in rapid plasma reagin (RPR) tests can complicate syphilis screening interpretation. Although Epstein-Barr virus-associated infectious mononucleosis (EBV-IM) is a known cause of BFP reactions, the characteristics of RPR titers in such cases remain unclear. This study aimed to compare the RPR titers in BFP reactions between patients with EBV-IM and those with other underlying conditions.

METHODS

We retrospectively analyzed the RPR and Treponema pallidum hemagglutination assay (TPLA) results of all tests performed at a community hospital in Japan between April 2016 and March 2024. BFP reactions were defined as positive RPR and negative TPLA results. Clinical characteristics and RPR titers were compared between EBV-IM and other causes of BFP reactions.

RESULTS

Among 154 confirmed BFP cases, EBV-IM cases (n = 7) showed significantly higher RPR titers than other underlying conditions (n = 147) (median 28.5 relative units [RU], interquartile range [IQR]: 11.2-31.2 vs. 1.9 RU, IQR: 1.2-4.3, p < 0.001), despite a significantly younger age (median age 18 years, IQR: 17.4-25 vs. 72 years, IQR, 44.5-82, p < 0.001). Among all BFP cases, neoplasms were the most common underlying condition (22.1 %), followed by digestive diseases (8.4 %) and infectious diseases (7.8 %).

CONCLUSIONS

EBV-IM is associated with distinctively high RPR titers in BFP reactions, in contrast to the typically low titers observed under other conditions. Clinicians should be aware that high RPR titers can occur during BFP reactions, particularly in young patients with suspected EBV infection.

Forensic Microbiology: Challenges in Detecting Sexually Transmitted Infections

Sexual assault crimes consist of acts committed without consent and represent a major global issue with serious implications for victims. These acts have both short- and long-term consequences on the physical, mental, and sexual health of victims, with sexually transmitted infections (STIs) being one of the direct outcomes of such crimes. Sexually transmitted infections constitute a serious global public health problem and can lead to severe consequences. These infections may be caused by bacteria, viruses, or parasites and are transmitted through sexual contact. Some of the most common STIs among the general population and victims of sexual crimes include gonorrhoea, chlamydia, trichomoniasis, and syphilis. In most carriers, these infections are asymptomatic, making their detection particularly challenging. Considering the importance of further research in this field, the primary objectives of this study are to review the existing literature on the incidence of major STIs in victims of sexual crimes, to identify the various risk factors associated with these infections, and to explore their public health implications. Additionally, this study aims to assess different STI detection techniques, analyzing their advantages and disadvantages. Studies on this topic are crucial for better understanding the role of sexually transmitted infections in the context of sexual crimes. However, throughout this work, it was verified that point-of-care methods are a good option to allow the diagnosis to be faster and more accurate, when compared to other methods of detecting sexually transmitted infections.

Advancing syphilis diagnosis: multi-phase study evaluation of a TpN17-based double-antigen sandwich ELISA for detecting Treponema pallidum specific antibodies

Syphilis, a sexually transmitted infection caused by the bacterium Treponema pallidum, has high incidence rates among adults, pregnant women, and newborns. Diagnostic procedures typically involve a treponemal test (such as ELISA, CMIA, and IFI), followed by a non-treponemal test (VDRL and RPR). This study aimed to assess the diagnostic performance of a double antigen sandwich ELISA (DAgS-ELISA) using the recombinant protein TpN17, analyzing serum samples from both infected and not infected with T. pallidum. A total of 712 samples were deemed eligible and recharacterized using VDRL, ELISA, and FTA-ABS, with 613 ultimately included in the evaluation: 180 T. pallidum-positive, 169 T. pallidum-negative, and 264 positive samples for other diseases. The assay was standardized using checkerboard titration and evaluated based on the area under the ROC curve (AUC), sensitivity, specificity, accuracy, likelihood values, diagnostic ratio, and Cohen's Kappa index (κ). In phase I, positive and negative samples showed statistical differences (p < 0.0001) for the TpN17 protein. The ROC curve (AUC) was 98.7% and Cohen's Kappa of 0.91, indicating almost perfect agreement with the reference tests. Phase II results demonstrated an AUC of 97.5%, specificity of 100%, sensitivity of 88.9%, accuracy of 94.3%, a positive likelihood ratio of 1.512, a negative likelihood ratio of 0.11, and a diagnostic odds ratio of 13,600, with a Cohen's Kappa of 0.89. Cross-reactivity was observed in samples positive for Chagas disease (11.5%), HBV (2.6%), HCV (6.4%), and HTLV-1/2 (6.8%). Overall, TpN17 exhibited high diagnostic performance across all clinical stages of syphilis. Future research should expand the sample panel and explore new proteins to enhance DAgS-ELISA's effectiveness and applicability for syphilis diagnosis across diverse clinical settings.

Syphilitic Cholangiopathy Mimicking Primary Sclerosing Cholangitis

INTRODUCTION

Syphilis is a sexually transmitted disease with variable symptoms, often imitating various other disorders. Syphilis progresses through primary, secondary, latent, and tertiary stages, each with distinct clinical manifestations. A sudden rise in serum hepatic enzyme levels and imaging findings that mimic sclerosing cholangitis, both associated with a positive response to targeted antibiotic treatment, may indicate a diagnosis of acute syphilitic hepatitis.

CASE PRESENTATION

We report a case of early syphilis in the secondary stage, manifesting as sclerosing-cholangitis-like changes shown on ultrasonography, MR, and CT. Narrow-spectrum antibiotic therapy with procaine benzylpenicillin led to a consistent decrease in and normalization of levels of serum bilirubin and other markers of hepatic injury. Repeated sonography and MR cholangiography showed minimal residual changes in the intrahepatic biliary tree.

CONCLUSIONS

Infection with Treponema pallidum is one of the rare causes of secondary cholangitis. As the incidence of syphilis is rising worldwide, it should be considered as a differential diagnosis, especially for patients with high-risk sexual behavior and for whom there are laboratory findings of cholestatic or mixed cytolytic and cholestatic hepatitis, particularly if associated with exanthema, pharyngitis, and lymphadenopathy.

Update on syphilis diagnostics

PURPOSE OF REVIEW

Syphilis is rising globally, with resultant increases in morbidity and mortality that disproportionately impact underserved populations. Appropriate screening and testing for syphilis with accurate, reliable, affordable, and timely assays is crucial for combating this epidemic. This review provides a brief overview of laboratory methods for syphilis diagnosis, with a focus on recent updates in diagnostics and directions for future research.

RECENT FINDINGS

Syphilis can be complex and time-consuming to diagnose and stage appropriately. The historic use of darkfield microscopy for diagnosis has been eclipsed by algorithms that include both nontreponemal and treponemal antibody tests for screening and confirmation of active Treponema pallidum infection. Newer diagnostic modalities include nucleic acid amplification assays (NAATs) and point-of-care testing (POCT), which hold promise for increasing identification of active syphilis but have notable limitations. More work is needed to develop accurate, reliable, affordable, and expeditious tests to optimize syphilis diagnosis.

SUMMARY

Algorithms utilizing a combination of serological treponemal and nontreponemal assays remain standard of care for the diagnosis of syphilis, but recently developed NAATs and POCT assays present opportunities to increase syphilis detection. Further research is warranted to improve upon these testing modalities and explore other markers that could aid in syphilis diagnosis.

Clinical Presentation of Early Syphilis and Genomic Sequences of Treponema pallidum Strains in Patient Specimens and Isolates Obtained by Rabbit Inoculation

BACKGROUND

The global resurgence of syphilis necessitates vaccine development.

METHODS

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

RESULTS

TPA DNA was detected in 15 of 17 ulcer exudates and 3 of 17 blood PS specimens. TPA DNA was detected in 50 of 51 SS skin biopsies and 27 of 51 blood specimens. TPA was isolated from 47 rabbits with success rates of 71% (12/17) and 69% (35/51), respectively, from ulcer exudates and SS bloods. We obtained paired genomic sequences from 24 clinical samples and corresponding rabbit isolates. Six SS14- and 2 Nichols-clade genome pairs contained rare discordances. Forty-one of the 51 unique TPA genomes clustered within SS14 subgroups largely from East Asia, while 10 fell into Nichols C and E subgroups.

CONCLUSIONS

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

Investigation of Gray Matter Changes Using Voxel-Based Morphometry in HIV-Negative Patients with General Paresis of the Insane

Purpose

To investigate whole-brain gray matter volume (GMV) changes in human immunodeficiency (HIV)-negative patients with general paresis of the insane (GPI) using voxel-based morphometry (VBM).

Patients and Methods

A total of 18 HIV-negative individuals with GPI and 24 healthy control volunteers matched for sex, age, and education were enrolled in this study. 3 D T1-weighted imaging (3D T1WI) structural images of GPI patients and healthy controls were preprocessed using VBM. The GMV was then segmented and compared between the two groups. In addition, the correlation between cortical/subcortical GMVs and neuropsychological/laboratory test results was analyzed.

Results

Compared to the normal control group, the GPI group showed a decrease in GMV in multiple regions, including the bilateral frontal cortices (superior frontal gyrus, middle frontal gyrus, orbital gyrus), bilateral temporal/occipital cortices (superior temporal, bilateral inferior temporal, bilateral parahippocampal, bilateral cingulate, left precentral, left fusiform, left posterior superior temporal sulcus, left lateral occipital, right middle temporal, right precuneus, right insular, and right medioventral occipital), and right parietal cortices (right superior parietal, right inferior parietal) (p<0.01, FDR corrected). Additionally, there was an increase in GMV in the bilateral basal ganglia, right hippocampus, and bilateral thalamus (p<0.01, FDR corrected). In the GPI group, GMVs of the right rostral hippocampus (r=-0.524, p=0.026), bilateral dorsal caudate nucleus (r=-0.604, p=0.008; r=-0.685, p=0.002), and the right rostral temporal thalamus (r=-0.560, p=0.016) were negatively correlated with MMSE score.

Conclusion

VBM showed that there are structural changes in brain GMV in HIV-negative GPI patients. The use of VBM has the potential to provide a valuable imaging basis for the diagnosis of GPI.

Neuropsychiatric Manifestations of Syphilis

Neurosyphilis is a condition characterized by insidious onset of encephalopathy and delirium. The infrequency with which it is encountered makes neurosyphilis a formidable diagnostic challenge. We present a rare case of a 71-year-old male with ischemic cardiomyopathy, chronic obstructive pulmonary disease (COPD), undifferentiated arthritis and alcohol use disorder who was brought to the emergency department after he was found altered, confused, and paranoid. His hospital stay was eventful for multiple episodes of agitation that were difficult to control despite benzodiazepines and high doses of antipsychotics. After an extensive workup, he was found to have neurosyphilis and his delirium resolved following a brief period of treatment. This case illustrates the importance of early suspicion for neurosyphilis as a cause of delirium, especially in endemic areas and in patients with focal neurologic findings.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

An Unusual Case of Syphilis With Pulmonary Involvement

Syphilis can affect multiple organs in the secondary or tertiary stages of the disease. Recent reports have suggested an increase in the incidence of the disease. Involvement of the lung has been rarely described in syphilis. In this report, we discuss the case of a 26-year-old female with past medical history significant for HIV who presented to the hospital with complaints of shortness of breath and underwent thoracentesis; she was found to have syphilis with pulmonary involvement.

An Exuberant Case of Ulceronodular-Rupioid (Malignant) Syphilis in an HIV Patient: A Proposal for New Diagnostic Criteria

We report the case of a 28-year-old male with uncontrolled human immunodeficiency virus (HIV) infection who presented with extensive ulcerated lesions with dark lamellated crusting on his face, torso, and limbs. The patient had a rapid plasma reagin (RPR) titer of 1:512, indicative of syphilis. A skin biopsy revealed granulomata surrounded by lymphocytes, histiocytes, and plasma cells, with spirochetes visible on immunohistochemical staining. The patient's rash resolved with hyperpigmented scarring after penicillin and doxycycline treatment. This severe form of secondary syphilis has been termed malignant syphilis, lues maligna, ulceronodular syphilis, or rupioid syphilis. We propose a single descriptive name for this entity, ulceronodular-rupioid syphilis. In 1969, Fisher proposed criteria for malignant syphilis based on lesion appearance, histopathologic findings, high RPR values, and rapid response to treatment. We found that the Fisher criteria were imprecise with respect to specific histopathologic findings, the quantitation of RPR values, and what constitutes rapid response to treatment. Thus, we examined an additional 74 cases from the literature and propose new diagnostic criteria based on rash appearance, histopathologic characteristics, non-treponemal and treponemal test positivity, and response to therapy. We also found that uncontrolled viremia, and not a low CD4 count, is a major risk factor for ulceronodular-rupioid syphilis in HIV patients.

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

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

HERPES SIMPLEX VIRUS-1 SUSCEPTIBILITY AS A RISK FACTOR FOR SEPSIS, WITH CYTOMEGALOVIRUS SUSCEPTIBILITY ELEVATING SEVERITY: INSIGHTS FROM A BIDIRECTIONAL MENDELIAN RANDOMIZATION STUDY

ABSTRACT

Objective: We conducted a two-sample bidirectional Mendelian randomization (MR) study to investigate the causal relationships between herpes viruses and sepsis. Methods: Publicly available genome-wide association study data were used. Four viruses, HSV-1, HSV-2, EBV, and CMV, were selected, with serum positivity and levels of antibody in serum as the herpes virus data. Results: In forward MR, susceptibility to HSV-1 was a risk factor for sepsis. The susceptibility to CMV showed a severity-dependent effect on sepsis and was a risk factor for the 28-day mortality from sepsis, and was also a risk factor for 28-day sepsis mortality in critical care admission. The EBV EA-D antibody level after EBV infection was a protective factor for 28-day sepsis mortality in critical care admission, and CMV pp28 antibody level was a risk factor for 28-day sepsis mortality in critical care admission. No statistically significant causal relationships between HSV-2 and sepsis were found. No exposures having statistically significant association with sepsis critical care admission as an outcome were found. In reverse MR, the sepsis critical care admission group manifested a decrease in CMV pp52 antibody levels. No causal relationships with statistical significance between sepsis exposure and other herpes virus outcomes were found. Conclusion: Our study identifies HSV-1 susceptibility as a sepsis risk, with CMV susceptibility elevating severity. Varied effects of EBV and CMV antibodies on sepsis severity are noted. Severe sepsis results in a decline in CMV antibody levels. Our results help prognostic and predictive enrichment and offer valuable information for precision sepsis treatment.

Retrospective comparison of false-positive result frequencies of 3 syphilis serology screening tests in pregnant and nonpregnant patients at an academic medical center in Appalachia

OBJECTIVE

This study retrospectively compared false-positive result frequencies of 3 syphilis serology screening tests and assessed whether false positivity was associated with pregnancy and age.

METHODS

Results for 3 screening tests were retrieved from the laboratory database, including rapid plasma reagin (RPR) assay between October 2016 and September 2019, BioPlex 2200 Syphilis Total immunoassay between May 2020 and January 2022, and Alinity i Syphilis TP assay between February 2022 and April 2023. The false-positive result frequencies were calculated based on testing algorithm criteria.

RESULTS

False-positive result frequency for BioPlex was 0.61% (90/14,707), significantly higher than 0.29% (50/17,447) for RPR and 0.38% (55/14,631) for Alinity (both P < .01). Patients with false-positive results were significantly older than patients with nonreactive results for RPR (median age: 36 vs 28, P < .001), but not for BioPlex or Alinity. For all 3 tests, the positive predictive values in pregnant women were lower than those in nonpregnant women or men. However, pregnant women did not exhibit a higher false-positive result frequency.

CONCLUSION

Although false-positive result frequencies were low overall for all 3 syphilis serology tests, there is a significant difference between different tests. Pregnancy was not associated with more false-positive results for all 3 tests.

Sculpting the Silent Intricacies: A Rare Triad of Syphilitic Aneurysms Unveiled

This case report revolves around a 73-year-old male patient who initially sought medical attention due to left lower extremity weakness. Suspicions of a potential vascular etiology arose during the initial clinical examination, prompting further investigation. Unexpectedly, computed tomography (CT) imaging of the abdomen and pelvis revealed the presence of three giant aneurysms. Concurrently, positive syphilis titers were identified. The patient's presentation, marked by focal neurological deficits, unveiled the incidental discovery of a triad of aneurysms involving the distal abdominal aorta, right common iliac, and left common iliac. The neurological symptoms observed in the patient were attributed to the compression within the left common iliac artery, leading to compromised blood flow to the lower extremity. Alternatively, the neurological deficits could be linked to neurosyphilis or a combination of both factors. This case underscores the critical role of considering syphilis in patients presenting with neurological symptoms. The unique discovery of extensive aortic abnormalities through imaging studies, specifically CT angiography, emphasized the importance of such diagnostic tools in unraveling complex and potentially life-threatening vascular pathologies. Recognizing the diverse manifestations of syphilis in patients with vast neurological symptoms is crucial for timely diagnosis and multidisciplinary management. This case emphasizes the need to keep a high index of suspicion for syphilis in individuals who have widespread aortic anomalies together with neurological symptoms, to sum up. The triad of aneurysms discovered incidentally in this 73-year-old patient underscores the intricate interplay between vascular and neurological manifestations. The timely diagnosis and multidisciplinary management of both the neurological and vascular aspects of this unique presentation are essential for ensuring optimal patient outcomes.

Evaluation of Serological Tests for the Diagnosis of Syphilis

Background Syphilis remains a significant public health concern in India. Ensuring the accuracy of diagnostic tests is crucial for effectively managing this disease. Objectives This study aims to assess the detectability of syphilis using commercially available non-treponemal and treponemal tests due to observed discrepancies in test results, which can lead to confusion and anxiety among healthcare providers and patients. Materials and methods We analyzed 2312 serum samples using the rapid plasma reagin (RPR), Treponema pallidum hemagglutination assay (TPHA), enzyme-linked immunosorbent assay (ELISA), and modified TPHA rapid test, interpreting the results according to the manufacturers' instructions. We evaluated the diagnostic accuracy of all four tests. Concordance between the traditional and reverse algorithms was determined by calculating the percentage of agreement and the kappa (κ) coefficient. Results Of the 2312 samples tested, 34 (1.5%) were positive, and 2098 (90.7%) were negative across all four tests. Comparing the test results with clinical diagnosis, TPHA and TP-ELISA showed the highest sensitivity at 96.08%, while RPR demonstrated the highest specificity at 100%. The agreement between the traditional and reverse algorithms was moderate, with a 97.3% agreement and a κ value of 0.53. Conclusion Reliance on a single serological test for syphilis screening presents limitations. A combined approach using both RPR and TPHA tests can more accurately diagnose and confirm syphilis. This combination strategy is cost-effective and relatively simple to implement.

Cerebrospinal Fluid Biomarkers of Symptomatic Neurosyphilis in People With HIV Compared with Uninfected Individuals

We evaluated the diagnostic clinical performance characteristics (DCPC) of cerebrospinal fluid (CSF) total protein (TP), white blood cell count (WBC), and lactate (LA) with different cutoff points as adjunct biomarkers of confirmed or presumptive symptomatic neurosyphilis (NS) and the impact of HIV infection. From 5,640 participants who underwent lumbar punctures, 236 participants were included, and classified as either people with HIV (PWH) or people without HIV (PWoH) according to the CDC criteria for confirmed NS (n = 42), presumptive NS (n = 74), systemic syphilis (SS) (n = 38), serological diagnosis of syphilis (n = 18), PWH without SS and NS (n = 10), and negative control (n = 72). In PWoH, for presumptive NS, the combination of CSF TP > 45 mg/dL and/or WBC > 5.0 cells/mm3 is valuable for screening, whereas in PWH, it is not recommended for either screening or case-finding NS, however the DCPC were better in the suppressed group. In PWoH, the value of CSF TP > 45 mg/dL is adequate for both screening and confirmation of presumptive NS, subject to prevalence. For WBC count > 20 cell/mm3, the positive predictive value (PPV) of the test is almost perfect, suggesting a confirmatory test. In PWH, CSF TP is an inadequate marker of NS. The WBC count, with cutoffs of > 10 or > 20 cells/mm3, was moderately applicable for screening.As conclusions: CSF WBC count and TP showed distinct DCPC in confirmed or presumptive NS, better in the former. These biomarkers could be included for presumptive NS diagnosis. DCPC of these biomarkers for the diagnosis of NS is greatly affected by HIV co-infection.

Evaluating the diagnostic accuracy of TpN17 and TmpA recombinant proteins in syphilis detection: a phase II study

Syphilis is a sexually transmitted infection (STI) caused by the spiral bacterium Treponema pallidum. Diagnosis is based on epidemiology, clinical and serology, but serodiagnosis is challenging because distinct clinical forms of the infection may influence serological performance. Several recombinant Treponema pallidum-proteins have already been tested for syphilis diagnosis and they are critical to achieve high accuracy in serological testing. A total of 647 samples were included in the study: 180 T. pallidum-positive samples, 191 T. pallidum-negative samples and 276 sera from individuals infected with unrelated diseases. The diagnostic potential was validated by analysis of ROC curves. For the indirect ELISA, TpN17 (100%) and TmpA (99%) showed excellent AUC values. Sensitivity values were 97.2% for TpN17 and 90.6% for TmpA, while specificity was 100% for both molecules. According to the clinical phase, TmpA ranged from 84% to 97%, with the highest value for secondary syphilis. TpN17 was 100% sensitive for the primary and secondary stages and 93.2% for recent latent syphilis. All clinical phases achieved 100% specificity. Accuracy values showed that TmpA (> 95%) and TpN17 (> 98%) presented high diagnostic accuracy for all clinical stages of syphilis. Cross-reactivity was only observed in one sample positive for Chagas disease (1.5%), when TpN17 was evaluated. On the other hand, TmpA showed reactivity for two samples positive for Chagas disease (3.1%), one sample positive for HBV (1.25%), two samples positive for HIV (9.5%) and one sample positive for HTLV (1.6%). The TmpA antigen's performance was evaluated in multiple studies for syphilis diagnosis, corroborating our findings. However, TpN17 sensitivity values have ranged in other studies. According to clinical stages of the infection, our findings obtained close performance values.

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.

A 4-fold or greater decrease in TPPA titers may indicate effective BPG treatment in primary syphilis

BACKGROUND

In the majority of clinical environments, the treponema pallidum particle agglutination (TPPA) test is known for its higher specificity compared to the rapid plasma reagin (RPR) test and is commonly employed for the diagnosis of syphilis, but their use for serological monitoring after syphilis therapy is controversial.

OBJECTIVES

We aim to evaluate whether the TPPA titers is suitable for monitoring syphilis treatment efficacy.

METHODS

At first, 232 patients with primary syphilis were recruited. Serological testing was performed at baseline (initial visit) and at 6 months (±1 month) after benzathine penicillin G (BPG) treatment. Second, New Zealand white male rabbits were infected with Treponema pallidum (T. pallidum) to evaluate the changes in TPPA titers after BPG therapy. Finally, we compared the TPPA titers in the culture supernatant of rabbit splenocytes stimulated with T. pallidum with or without BPG.

RESULTS

After 6 months of treatment, 150 (64.7%) of 232 primary syphilis patients achieved serological cure, and 82 (35.3%) had adverse outcomes. Among 110 patients with TPPA titers decreased by more than fourfold, 109 of them were serological cure patients (≥4-fold decrease in RPR titers) (P ＜ 0.0001). In the rabbit model of syphilis, the TPPA titers was significantly decreased in the treatment subgroup (P = 0.016) and remained constant (±2-fold) or increased (≥4-fold) in the nontreatment subgroup. In addition, T. pallidum resulted in a positive TPPA titers in the culture supernatant of splenocytes (median titers was 1: 80), while BPG could directly reduce the TPPA titers in the culture supernatant (median titers was 1: 40) (P = 0.032).

CONCLUSIONS

A 4-fold or greater decrease in TPPA titers may indicate effective treatment in primary syphilis. Combining TPPA titers with RPR titers results may potentially aid in the early diagnosis of syphilis.

Evaluation of chemiluminescence immunoassay as a screening test for syphilis on blood donor samples

BACKGROUND AND OBJECTIVE

Global re-emergence of syphilis among blood donors necessitates novel diagnostic and prevention approaches that encourage timely intervention. Thus, the present study was planned to evaluate the efficiency of Chemiluminescence immunoassay (CLIA) as a screening test for syphilis.

MATERIAL AND METHODS

This prospective cross-sectional observational study was conducted from October 2021 to September 2022. A total of 344 donors were enrolled by purposive sampling method, including additional 16 donors who were reactive by the Rapid plasma reagin test (RPR) during the study period. Data from three screening tests - RPR test, Treponema pallidum haemagglutination assay (TPHA) and CLIA for 360 blood donors were analysed. TPHA was considered the gold standard test.

RESULTS

Of the total 360 samples tested, 21 (5.8 %) were reactive by the RPR test. Of these 21 RPR reactive samples, 19 (90.5 %) were reactive by both TPHA and CLIA, while 2 (9.5 %) RPR reactive samples were non-reactive by both TPHA and CLIA. Of the remaining 339 RPR non-reactive samples, 1 (0.3 %) sample was reactive by both TPHA and CLIA, and 1 (0.3 %) was reactive by CLIA alone. CLIA was found to have sensitivity and specificity of 100 % and 99.7 % and positive predictive value (PPV) and negative predictive values (NPV) of 95.2 % and 100 % respectively, while it was 95 %, 99.4 %, 90 %, and 99.7 %, respectively, with the RPR test.

CONCLUSION

CLIA was found to have a higher sensitivity, specificity, PPV and NPV than the RPR test. Thus, CLIA can be an acceptable alternative for syphilis screening in blood donors.

Evaluation of between-assay consistency among laboratory testing methods for neurosyphilis: a systematic review

We conducted a systematic review to analyse the consistency of nontreponemal-specific tests of Treponema pallidum in cerebrospinal fluid. We searched the PubMed, EMBASE, Web of Science, CNKI, Wanfang and Chongqing VIP databases. The inclusion criteria were studies conducted on nontreponemal-specific tests in cerebrospinal fluid (CSF) within the same population. Exclusion criteria were studies with incomplete data or where we were unable to obtain the full text, duplicate reports, case reports and studies without sensitivity or specificity results. We used kappa value analysis and McNemar's test to analyse study consistency. We initially collected a total of 198 articles and ultimately included six articles that involved 429 patients with neurosyphilis. The performance between venereal disease research laboratory tests (VDRL) and the reactive plasma regain or toluidine red serum unheated test was similar. The kappa value for consistency between VDRL and reactive plasma regain was >0.8 in three articles, and was 0.892 for consistency between VDRL and toluidine red serum unheated test in one article. Our results suggested that CSF-reactive plasma regain or CSF-toluidine red serum unheated test may serve as alternative tests in the diagnosis of neurosyphilis with CSF-VDRL.

Penicillin Responsive Presumed Seronegative Ocular Syphilis in a Patient with Human Immunodeficiency Virus: A Case Report and Review of the Literature

Ocular and systemic syphilis are well known to mimic other clinical entities making them challenging to diagnose in many cases. Syphilis testing plays an important role in diagnosis and timely treatment. Here we describe a patient with untreated human immunodeficiency virus (HIV) infection who presented with bilateral panuveitis with repeatedly negative syphilis serologies. In light of worsening retinitis while on aggressive anti-viral treatment and in consideration of the clinical suspicion for syphilitic uveitis, intravenous penicillin was initiated empirically. The patient demonstrated significant improvement subjectively and objectively after treatment. We also review and discuss syphilis testing reliability generally and in HIV co-infected patients in particular. Empiric intravenous penicillin should be considered in patients with clinical features of ocular syphilis despite negative serologic testing, especially in those with HIV co-infection.

Presentation of Ocular Syphilis with Bilateral Optic Neuropathy

A 60-year-old otherwise healthy male presented with a 1 year history of bilateral progressive visual loss. His best-corrected visual acuity was counting fingers at 2 m with his right eye and counting fingers at 0.5 m with his left eye. Visual field testing revealed bilateral near-total loss of visual fields. Slit-lamp examination was unremarkable, apart from bilateral grade two nuclear sclerotic cataracts. Both optic discs were pale-looking with some retinal pigment epithelial alterations at the left papillomacular region. Enhanced depth imaging optical coherence tomography depicted punctate hyperreflective dots at the inner choroidal level corresponding to the retinal pigment epithelial changes in the left eye. Fundus autofluorescence imaging revealed patchy hyper-autofluorescent and hypo-autofluorescent areas, and there was mild staining in the early and late phases of the fluorescein angiogram at the papillomacular region in the left eye. A diagnosis of bilateral optic neuropathy was made. A full systemic work-up was carried out, and serological tests pointed out the presence of syphilis with normal cranial magnetic resonance imaging. He was treated accordingly. Our case clearly demonstrates the importance of a high clinical suspicion for syphilis in cases of optic neuropathy.

The optimum condition of the toluidine red unheated serum test for the replacement of the venereal disease research laboratory test in cerebrospinal fluid for neurosyphilis diagnosis

Background

The cerebrospinal fluid (CSF) venereal disease research laboratory (VDRL) test remains the standard for the laboratory diagnosis of neurosyphilis. The toluidine red unheated serum test (TRUST) is an alternative to the VDRL test as a serological test for syphilis, but it lacks guidelines for its use in CSF for neurosyphilis diagnosis.

Methods

A total of 210 suspected neurosyphilis patients were included, consisting of 124 neurosyphilis patients and 86 syphilis/non-neurosyphilis patients. The TRUST was modified into the CSF-TRUST-10 test with 10 μL of antigen by referring to the CSF-VDRL test, and the CSF-TRUST-17 test with 17 μL of antigen by referring to its procedures in serum. The diagnostic performance of the CSF-TRUST-10 and CSF-TRUST-17 tests and the concordance between them and the CSF-VDRL test were evaluated.

Results

The diagnostic performance of the CSF-TRUST-10 and CSF-TRUST-17 tests for diagnosing neurosyphilis were comparable to the CSF-VDRL test, as well as the positive rate. The agreement rate was 98.7% between the qualitative CSF-TRUST-10 and CSF-VDRL tests. A total of 91.4% of the quantitative CSF-TRUST-10 results were consistent with the CSF-VDRL test, and the discordant results were no more than two titres. The agreement rate was 98.1% between the qualitative CSF-TRUST-17 and CSF-VDRL tests and 87.6% between the quantitative CSF-TRUST-17 and CSF-VDRL tests.

Conclusions

The CSF-TRUST with 10 μL of antigen could be an alternative for the CSF-VDRL test for neurosyphilis diagnosis. Our results provide a basis for using the TRUST to guide the diagnosis of neurosyphilis.

Pulmonary syphilis with a cicatricial variant of organizing pneumonia: a case report

BACKGROUND

Syphilis is a chronic disease that progresses in the primary, secondary, latent, and tertiary stages. Pulmonary manifestations of syphilis are rare, and their histological features have not been well-described.

CASE PRESENTATION

A 78-year-old man was referred to our hospital because of a solitary nodular shadow in the right middle lung field on a chest radiograph. Five years prior, a rash appeared on both legs. He was tested for syphilis at a public health center, and the non-treponemal test result was negative. When he was approximately 35 years old, he had unspecified sexual intercourse. Chest computed tomography showed a 13-mm nodule with a cavity in S6 of the right lower lobe of the lung. Robot-assisted resection of the right lower lobe was performed because of suspected localized right lower lobe lung cancer. A cicatricial variant of organizing pneumonia (CiOP) was observed, and immunohistochemistry identified Treponema pallidum inside the macrophages in the nodule cavity. The rapid plasma regain (RPR) value was negative, and the Treponema pallidum hemagglutination assay was positive. The patient was diagnosed as having secondary syphilis with pulmonary involvement. Insidious progression of secondary syphilis may result in CiOP and a negative RPR test result.

CONCLUSIONS

We report the first case of pulmonary syphilis with a histological pattern of CiOP. It may be asymptomatic and difficult to diagnose because the RPR test may be negative for a long period of time. When either non-treponemal or treponemal test results are positive, the possibility of pulmonary syphilis should be considered along with appropriate medical treatment.

Global, regional, and national trends of syphilis from 1990 to 2019: the 2019 global burden of disease study

BACKGROUND

Syphilis is a sexually transmitted disease caused by Treponema pallidum, and the infection source is syphilis patients. This study aimed to estimate the incidence, mortality rate, and disability-adjusted life years (DALYs) of syphilis to improve the understanding of the current global situation of syphilis.

METHODS

This study collected data on syphilis incidence, mortality, and DALYs from the 2019 Global Burden of Disease database.

RESULTS

The global number of incident cases and age-standardized incidence rate (ASIR) increased from 8,845,220 (95% UI: 6,562,510-11,588,860) in 1990 to 14,114,110 (95% UI: 10,648,490-18,415,970) in 2019 and 160.03/100,000 persons (95% UI: 120.66-208.1) to 178.48/100,000 persons (95% UI: 134.94-232.34), respectively. The estimated annual percentage change (EAPC) in the ASIR was 0.16 (95% CI: 0.07-0.26). The EAPC in the ASIR associated with high and high-middle sociodemographic indices increased. The ASIR increased among males but decreased among females, and the incidence peaked among males and females between the ages of 20 and 30 years. The EAPCs in the age-standardized death rate and age-standardized DALY rate decreased.

CONCLUSIONS

The incidence and ASIR of syphilis increased worldwide from 1990 to 2019. Only the regions with high and high-middle sociodemographic indices showed an increase in the ASIR. Moreover, the ASIR increased among males but decreased among females. The age-standardized death rate and DALY rate both declined worldwide. The increase in the global ASIR of syphilis is a challenge.

An evaluation of a multiplex PCR assay for the detection of Treponema pallidum, HSV-1, and HSV-2

Multiplex PCR can utilize limited clinical material and is more cost-effective and expected to be used for the detection of Treponema pallidum, herpes simplex virus type 1 and 2 (HSV-1,2). We established a multiplex TP-HSV1-HSV2 Polymerase Chain Reaction (multiplex PCR) targeting the conserved regions of the PolA gene of TP and the UL42 gene of HSV1 and HSV2 to test skin lesions of 115 patients suspected of having TP and HSV1/2 infections. The laboratory sensitivities for all 3 pathogens were 300 copies/mL. The overall clinical sensitivity and specificity in secretion samples for TP were 91.7% and 100%, for HSV1 100% and 98%, and for HSV2 89.7% and 100%, respectively. The method appears superior in patients suspected of early TP infection but negative for nontreponemal antibody testing, and the method is also useful for the differential diagnosis of new skin lesions on genital, perianal, and oral sites of patients with a history of previous syphilis.

Syphilis

Syphilis is an important public health problem in the U.S. and many high-income nations. The rates of syphilis continue to increase and there is an urgent need for medical providers of a variety of backgrounds to recognize this disease. In this review, we cover the key clinical findings of syphilis and provide an overview of the diagnosis and management of this disease in adults.

Screening and diagnostic testing protocols for HIV and Syphilis infections in health care setting in Qatar: Evaluation and recommendations

BACKGROUND

HIV and Syphilis are common STIs, which have become a concern and burden on healthcare systems, as many infections go untreated and lead to potentially serious complications. HIV is usually diagnosed with Western blot, PCR, and p24 antigen testing. Whereas, Syphilis is mainly diagnosed through clinical findings and serologic testing. The Medical Commission Department (MC) under MOPH is responsible for screening all newcomers to Qatar, aiming to keep the country free from serious infectious diseases.

OBJECTIVE

We aimed to evaluate the diagnostic efficiency of the protocols used in the MC for screening HIV and Syphilis infections.

METHODS

We conducted a retrospective study of samples analyzed by 4th Generation ARCHITECT® HIV Ag/Ab Combo and Rapid Plasma Reagin (RPR) between January to December 2019. ARCHITECT® HIV Ag/Ab Combo positive samples were confirmed by INNO-LIA™ HIVI/II and RT-PCR. RPR-reactive samples were confirmed by ARCHITECT® Syphilis Treponema pallidium Antibody (Syphilis TPA) assay.

RESULTS

For HIV, data were collected from 585,587 individuals, of which 595 (0.1%) were positive by the ARCHITECT® HIV Ag/Ab Combo (Analyzer A). When all initially positive sera were re-tested on newly collected blood samples using different ARCHITECT® HIV Ag/Ab Combo analyzer (analyzer B), 99.8% (594/595) of samples were also positive, suggesting high reproducibility. The positive predictive value (PPV) between ARCHITECT® HIV Ag/Ab Combo and the INNO-LIA™ HIVI/II confirmatory assay was 31.8%. The PPV between ARCHITECT® HIV Ag/Ab Combo and HIV-PCR assay was 26.8%. Retrospective data for Syphilis were collected from a total of 97,298 individuals who visited the MC, of which 198 (0.20%) were initially positive by RPR. The PPV between RPR and Syphilis TPA confirmatory assay was 36.6%.

CONCLUSION

Despite the high rate of false positivity using ARCHITECT® HIV Ag/Ab Combo and RPR screening assays, both assays have proven to be highly effective as screening testing methods.

Syphilis, the Great Imitator-Clinical and Dermoscopic Features of a Rare Presentation of Secondary Syphilis

Syphilis is characterized by a wide range of variable clinical symptoms; therefore, it is often referred to as "The Great Imitator". Here, we report the case of a 69-year-old hepatitis-C-positive MSM patient, who was admitted to our clinic due to a solitary firm painless erythematous maculopapular lesion with a central crater-like crust on the upper right thigh that occurred two months prior. The dermoscopy showed an erythematous, copper-colored, oval lesion with diffuse monomorphic dotted and glomerular vessels, central crust, and circular scaling (Biett's sign). The histological findings ruled out neoplasia and described a plasma cell infiltrate and endothelial swelling. Finally, the combination of the dermoscopic image, histological findings and the additionally acquired knowledge about the sexual history of the patient at the second visit led to the diagnosis, which was then confirmed with serological tests. Dermoscopy may become a supportive tool to facilitate the recognition of secondary syphilis; however, the reporting of these atypical cases is crucial to highlight the many faces of the disease so that clinicians consider syphilis as part of the differential diagnosis of non-specific lesions.

Neurosyphilis with ocular involvement and normal magnetic resonance imaging results affirmed by metagenomic next-generation sequencing

The rapid and accurate identification of pathogenic agents is the key to guide clinicians on diagnosis and medication, especially for intractable diseases, such as neurosyphilis. It is extremely challenging for clinicians to diagnose neurosyphilis with no highly sensitive and specific test available. It is well known that the early transmission and immune evasion ability of Treponema pallidum have earned it the title of "stealth pathogen." Neurosyphilis has complex clinical manifestations, including ocular involvement, which is infrequent and often overlooked, but its neuroimaging results may be normal. Therefore, it is important to find a new test that can detect the presence or absence of Treponema pallidum immediately for the diagnosis of neurosyphilis. We reviewed all the patients admitted to the Sichuan Provincial People's Hospital between 2021 and 2022 who had ocular involvement and whose clinical samples were examined via metagenomic next-generation sequencing (mNGS), and we found 10 candidates for further analysis. The results of magnetic resonance imaging (MRI) were normal for four patients, and three of them met the diagnostic criteria for neurosyphilis confirmed by mNGS. In addition, the results of mNGS from the three patients were further validated using polymerase chain reaction (PCR). Five of the 10 patients had diplopia manifestations; two (20%) experienced abducens nerve palsies, two (20%) had eyelid drooping, and one (10%) had decreased vision. One of the 10 patients (10%) who was HIV positive and five patients had abnormal MRI results. To our knowledge, Treponema pallidum was detected by mNGS in patients with ocular involvement and normal MRI results for the first time. Given this situation, we recommend mNGS as a potential and supplementary tool for the diagnosis and differential diagnosis of neurosyphilis.

A suite of PCR-LwCas13a assays for detection and genotyping of Treponema pallidum in clinical samples

The performance of commonly used assays for diagnosis of syphilis varies considerably depending on stage of infection and sample type. In response to the need for improved syphilis diagnostics, we develop assays that pair PCR pre-amplification of the tpp47 gene of Treponema pallidum subsp. pallidum with CRISPR-LwCas13a. The PCR-LwCas13a assay achieves an order of magnitude better analytical sensitivity than real-time PCR with equivalent specificity. When applied to a panel of 216 biological specimens, including 135 clinically confirmed primary and secondary syphilis samples, the PCR-LwCas13a assay demonstrates 93.3% clinical sensitivity and 100% specificity, outperforming tpp47 real-time PCR and rabbit-infectivity testing. We further adapt this approach to distinguish Treponema pallidum subsp. pallidum lineages and identify genetic markers of macrolide resistance. Our study demonstrates the potential of CRISPR-based approaches to improve diagnosis and epidemiological surveillance of syphilis.

Assessment of recombinant antigens Tp0100 and Tp1016 of Treponema pallidum for serological diagnosis of syphilis

Objective

To discover novel serodiagnostic candidates for the serological diagnosis of syphilis.

Methods

Two recombinant Treponema pallidum proteins Tp0100 and Tp1016 were expressed, purified, and identified by Western Blotting. A total of 600 clinical serum samples were tested with the Tp0100‐based ELISA, the Tp1016‐based ELISA, and the commercial LICA Syphilis TP kit (ChIVD, Beijing, China). The sensitivities were determined by testing 340 samples from individuals with clinically diagnosed primary, secondary, latent, and tertiary syphilis. The specificities were determined by screening 260 samples from healthy controls and individuals with potentially cross‐reactive infections, including leptospirosis, Lyme disease, hepatitis B, tuberculosis, rheumatoid arthritis, systemic lupus erythematosus. Kappa (κ) values were applied to compare the agreement between clinical syphilis diagnosis and the Tp0100‐based ELISA, the Tp1016‐based ELISA, or the LICA Syphilis TP test.

Results

Using clinical syphilis diagnosis as the gold standard, Tp0100 exhibited an overall sensitivity of 95.6% and specificity of 98.1% for testing IgG antibody while Tp1016 demonstrated only an overall sensitivity of 75.0% and specificity of 79.6%. In contrast, the LICA Syphilis TP test revealed an overall sensitivity of 97.6% and specificity of 96.2%. In addition, the overall percent agreement and corresponding κ values were 96.7% (95% CI 95.6%–97.8%) and 0.93 for the Tp0100‐based ELISA, 77.0% (95% CI 74.3%–79.7%) and 0.54 for the Tp1016‐based ELISA, and 97.0% (95% CI 96.0%–98.0%) and 0.94 for the LICA Syphilis TP test, respectively.

Conclusion

The recombinant T. pallidum protein Tp0100 shows promise as a novel diagnostic antigen in the serological tests for syphilis.

Investigating latent syphilis in HIV treatment-experienced Ethiopians and response to therapy

Objectives

We investigated people with HIV (PWH) receiving combination antiretroviral therapy (cART) for latent syphilis infection prevalence, risk factors, treatment response, and neurosyphilis.

Methods

A prospective follow-up study was conducted on PWH and latent syphilis. The cases were randomly assigned to receive either benzathine penicillin G (BPG) or doxycycline (DOXY), and the posttreatment response was evaluated after 12 and 24 months. The traditional algorithm was used for serodiagnosis, and a semi-quantitative rapid plasma reagin (RPR) test monitored disease activity and treatment effectiveness.

Results

Of the 823 participants, 64.8% were women, and the mean age was 41.7±10 years. Thirty-one (3.8%) of the participants (22 males and nine females) had latent syphilis. The risk factors were male sex (aOR = 3.14), increasing age (aOR = 1.04 per year), and cART duration (aOR = 1.01 per month). Baseline RPR titers were: ≤1:4 in 19 (61.3%), between 1:8 and 1:32 in 10 (32.2%), and >1:32 in 2 (6.4%). None of the seven cerebrospinal fluid analyses supported a neurosyphilis diagnosis. In the 12^th month of treatment, 27 (87.1%) had adequate serological responses, three (9.7%) had serological nonresponse, and one (3.2%) had treatment failure. Syphilis treatment was repeated in the last four cases with the alternative drug. In terms of adequate serologic response, both therapies were comparable at the 12^th month, p = 0.37. All cases responded to treatment in the 24^th month.

Conclusion

In PWH receiving cART, latent syphilis occurred more in men than women, suggesting an investigation of sexual practices and the impact of antenatal syphilis screening. Syphilis disease activity reduces in the latent stage. Therefore, the routine cerebrospinal fluid analysis contributes little to the diagnosis of asymptomatic neurosyphilis and the treatment success of latent syphilis. DOXY is an alternative to BPG, and cART improves serologic response to latent syphilis treatment.

Performance of Molecular Tests in the Diagnosis of Syphilis From 2009 to 2019: A Systematic Review and Meta-Analysis

BACKGROUND

Syphilis continues to be a public health problem, and its diagnosis still has limitations. Molecular diagnosis provides an alternative for rapid and effective management. The objective is to determine the accuracy of tests in the molecular diagnosis of syphilis.

METHODS

We searched PubMed and Web of Sciences for articles related to molecular detection of syphilis from January 1, 2009, to December 31, 2019. The bivariate Reitsma model and the hierarchical receiver operating characteristic curve model were used to evaluate the diagnostic performance of molecular tests at a 95% confidence interval. A subgroup meta-analysis was performed to explore sources of heterogeneity.

RESULTS

Forty-seven articles were identified for qualitative synthesis, of which 23 met the inclusion criteria for meta-analysis. The pooled sensitivities in conventional polymerase chain reaction (PCR) and real-time PCR were 77.52 (59.50-89.01) and 68.43 (54.96-79.39), respectively. The pooled specificities were 98.00 (90.73-99.59) and 98.84 (97.55-99.46), respectively. Ulcer samples had a better performance (sensitivity of 79.88 [69.00-87.62] and specificity of 98.58 [97.25-99.27]), and the major target genes were the polymerase A gene and tpp47 gene.

CONCLUSIONS

Our work showed that conventional PCR was more widely used than real-time PCR in the diagnosis of syphilis, and ulcers were the best specimens. Sample types and target genes are factors that may influence the quality of the different tests. These results could provide evidence for further work in the direction of providing a more efficient diagnostic test.

Membrane location of cardiolipin antigen in Treponema pallidum: further study on the origin of nontreponemal antibodies

Aim: The present study examined the membrane location of cardiolipin antigen in treponemes. Materials & methods: The authors used different methods to disrupt the outer membrane of treponemes, detected the location of the cardiolipin antigen and analyzed the immune response in rabbits immunized with various antigens. Results: All organisms were labeled with nontreponemal antibodies on immunoelectron and fluorescence microscopy, except the citrate buffer-treated group, which is a method leading to relatively complete removal. Except for citrate buffer-treated spirochetes, all treponemes produced low-titer, nontreponemal antibodies in immunized rabbits. Conclusion: These findings indicated that the cardiolipin antigen was localized in the outer membrane of spirochetes. This study provided further evidence of the origin of nontreponemal antibodies during Treponema pallidum infection.

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.

A Case Report of Secondary Syphilis Co-Infected with Measles: A Diagnostic Dilemma with Fever and Rash

Fever and rash as manifestations of infection by microorganisms are collectively known as febrile exanthem. Since viruses are more frequently associated with fever and rash, these symptoms are thus impetuously termed viral exanthem. However, bacteria represent a frequently overlooked infectious etiology causing rash in humans. In addition, certain microbes may exhibit pathognomonic features that erupt during illness and facilitate clinical diagnosis. Conversely, coinfections often obscure the clinical characteristics of the primary disease and further challenge clinicians attempting to reach a diagnosis. We retrospectively looked at de-identified clinical data of a patient who presented to the Hospital for Tropical Diseases in Bangkok in July 2019 with complaints of fever and rash. The case involved a 35-year-old who presented with a 3-day history of fever, respiratory symptoms, myalgia, conjunctivitis, diarrhea, and a generalized maculopapular rash. On examination, the patient was febrile, tachycardic, and tachypneic, with a mean arterial pressure of 95 mmHg. A differential white blood cell count showed: leukocytes, 5800/µL; neutrophils, 4408/µL; lymphocytes, 406/µL; and platelets, 155,000/µL. Striking findings involving the integumentary system included Koplik’s spots and generalized maculopapular rash. Further serology revealed positive immunoglobulin (Ig)M and IgG for both measles and rubella virus, including reactive serology for Treponema pallidum. Here we describe the clinical course and management of this patient.

Development of a Bead-Based Multiplex Assay for Use in Multianalyte Screening and Surveillance of HIV, Viral Hepatitis, Syphilis, and Herpes

Diagnostic assays that can simultaneously determine the presence of infection with multiple pathogens are key for diagnosis and surveillance. Current multiplex diagnostic assays are complex and often have limited availability. We developed a simple, multianalyte, pathogen detection assay for screening and serosurveillance using the Luminex Magpix platform that is high throughput and can be helpful in monitoring multiple diseases. The Luminex bead-based 10-plex immunoassay for the detection of HIV-1, HIV-2, Treponema pallidum, hepatitis B virus (HBV), hepatitis C virus (HCV), herpes simplex virus 1 (HSV-1), and HSV-2 infections was accomplished by coupling beads with specific antigens to detect IgG antibodies in plasma or serum samples. Each coupled antigen was systematically optimized, and the performance was evaluated using a panel of well-characterized specimens (n = 417) that contained antibodies to HIV-1, HIV-2, T. pallidum, HBV, HCV, HSV-1, and HSV-2. The multiplex assay had a sensitivity of 92.2% (95% Clopper-Pearson confidence interval [CI], 90.2 to 94.0%) and a specificity of 98.1% (95% CI, 97.6 to 98.7%). The sensitivities and specificities for disease-specific biomarker detection ranged from 68.7 to 100% and 95.6 to 100%, respectively. The results showed that the 10-plex immunoassay had an overall agreement of 96.7% (95% CI, 96.7 to 97.3%) with reference tests and a corresponding kappa value of 0.91 (95% CI, 0.90 to 0.93). Kappa values for the individual pathogens ranged from 0.69 to 1.00. The assay is robust and allows the simultaneous detection of antibodies to multiple antigens using a small sample volume in a high-throughput format. This assay has the potential to simplify disease surveillance by providing an alternative to expensive and highly specialized individual tests.

Fetal and neonatal abnormalities due to congenital syphilis: a literature review

OBJECTIVE

The recent recrudescence of syphilis among women of childbearing age is associated with an increasing number of cases of congenital syphilis. We aimed to summarize the fetal and neonatal abnormalities due to congenital syphilis infection, particularly signs amenable to prenatal diagnosis.

METHODS

Eligible studies were retrieved from the PubMed collection database. Articles focusing on postnatal and antenatal abnormalities covered the periods from 1969 to 2019 and 1975 to 2019, respectively. This review included cohort studies, case series and case reports reporting findings regarding congenital syphilis infections described before and/or after birth. Articles were reviewed by three experts in prenatal diagnosis, and all findings were classified as amenable or not amenable to prenatal diagnosis.

RESULTS

A total of 432 cases of congenital syphilis infection were reported. Abnormalities were described antenatally in 161 cases, postnatally in 319 cases, and in both the antenatal and postnatal periods in 57 cases. The most frequently reported signs amenable to prenatal diagnosis were abdominal abnormalities (hepatomegaly, splenomegaly, and bowel abnormalities), fetal growth restriction, and elevated middle cerebral artery peak systolic velocity in the context of ascites or atypical hydrops. Brain abnormalities were rare and never isolated. In the neonatal period, the most common abnormalities were hepatosplenomegaly, bone damage and skin lesions.

CONCLUSION

We found that no individual sonographic sign or pattern of signs is pathognomonic for fetal syphilis. In fetuses with ultrasound abnormalities suggestive of congenital infection, syphilis must be considered as part of the work-up. This article is protected by copyright. All rights reserved.

Systematic Review: The Neovaginal Microbiome

OBJECTIVE

To review neovaginal colonization and inflammatory patterns, and factors that may impact this.

METHODS

A systematic review of the neovaginal microbiome was conducted in concordance with PRISMA guidelines through October 2021.

RESULTS

Thirteen articles were included, totaling 458 patients. Neovaginal constructions were most commonly performed with penile and scrotal skin grafts, sigmoid segments, and peritoneal grafts. The neovaginal microflora identified were generally polymicrobial and shared similarities with the native tissue. Nine studies identified Lactobacillus: 5/6 for penile skin, 1/3 for sigmoid, 1/1 for peritoneum, and 2/3 for other graft types, suggesting that the neovagina may support Lactobacillus either innately, via rectal migration or oral probiotic supplementation. A polymicrobial, bacterial vaginosis-like environment was found in nine studies. Inflammatory markers were also described: 2/6 for penile skin, 2/3 for sigmoid, 0/1 for peritoneum, and 1/3 for other graft types. Scant data were available on the impact of postsurgical duration, oral hormones, dilating, sexual practices, or douching on the neovaginal microbiome.

CONCLUSION

Understanding and optimizing the polymicrobial neovaginal microenvironment may improve surgical outcomes, specifically inflammatory, pain, and infectious. Future research should focus on standardizing testing and classification systems, and treating neovaginal dysbiosis.

Mucocutaneous Manifestations of People Living with HIV in Current Antiretroviral Therapy Era

OBJECTIVE

It has been reported that approximately 90% of patients who are infected with human immunodeficiency virus (HIV) have various cutaneous symptoms that are related to the virus. This study aims to describe the cutaneous disorders that have developed in HIV-infected patients and to investigate the factors that may be related, such as relationships to drug use and CD4 counts.

METHODS

This cross-sectional study included people who were living with HIV and being followed by our hospital's infectious diseases clinic after they had been referred to the dermatology clinic because of skin lesions. These patients had been diagnosed with HIV by enzyme-linked immunosorbent assay tests and were included in the study if they were older than 18 years and had agreed to participate. Findings from detailed dermatological examinations were recorded, along with the patients' CD4 counts, the durations of their illnesses, and the treatments they received.

RESULTS

144 patients were included in the study. The most common mucocutaneous manifestation was seborrheic dermatitis, at 28.5% (n = 41). The mean CD4 count was 607.1 (min-max = 10.6-1982).The CD4 counts were divided into three groups in the study as follows: 22 (15.3%) patients with <200, 35 (24.3%) patients between 200 and 500, and 87 (60.4%) patients with >500. There were no statistical differences between these groups in terms of dermatological findings. Nevertheless, the highest rate of patients with three or more dermatological conditions was found among those with CD4 counts <200 (n = 11.50%).

CONCLUSION

Skin manifestations are common in patients who are HIV-positive; however, many skin disorders can be seen in HIV/acquired immunodeficiency syndrome (AIDS) patients whatever CD4 cell counts of these patients are.

Thyroid gland involvement in secondary syphilis: a case report

BACKGROUND

Syphilis is a systemic, infectious disease caused by Treponema pallidum and is notorious for the variety of its clinical presentations.

OBJECTIVE

We report a case of secondary syphilis with thyroid gland and ocular involvement in a human immunodeficiency virus (HIV) negative patient.

METHODS

We present the patient's history, clinical findings, laboratory test results, imaging and management.

RESULTS

A 39-year-old Caucasian, HIV unaffected woman presented with acute midline neck swelling, dyspnea and difficulty to talk or swallow. Serologic tests for syphilis were positive. PCR performed on a thyroid fine needle aspiration cytology (FNAC) aspirate was positive for Treponema pallidum. Skin lesions and unilateral loss of vision were present. Treatment with intravenous benzyl-penicillin showed a good regression of symptoms.

CONCLUSION

We report an unusual case of thyroid swelling in a secondary syphilis infection. Awareness of syphilis as a differential diagnosis is important in a risk population.

'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.