Dark ground microscopy and treponemal serological tests in the diagnosis of early syphilis

BASHH UK guidelines for the management of syphilis 2024

The 2024 UK guidelines for the management of syphilis are in line with current evidence and practice within the UK. Key updates are detailed at the start of the article. These guidelines are accompanied by the first UK guidelines for the management of syphilis in pregnant people and children, 2024.

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

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

AEDV Expert Consensus for the Management of Syphilis

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

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 primary syphilis (PS) participants and skin biopsies and blood from 51 secondary syphilis (SS) participants in Guangzhou, China for Treponema pallidum subsp. pallidum (TPA) qPCR, 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 two 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 over two-thirds of samples. Our results support the use of WGS from rabbit isolates to inform vaccine development.

Early syphilis in Guangzhou, China: presentation, molecular detection of Treponema pallidum , and genomic sequences in clinical specimens and isolates obtained by rabbit infectivity testing

Background

The global resurgence of syphilis requires novel prevention strategies. Whole genome sequencing (WGS) of Treponema pallidum ( TPA ) using different specimen types is essential for vaccine development.

Methods

Patients with primary (PS) and secondary (SS) syphilis were recruited in Guangzhou, China. We collected ulcer exudates and blood from PS participants, and skin biopsies and blood from SS participants for TPA polA polymerase chain reaction (PCR); ulcer exudates and blood were also used to isolate TPA strains by rabbit infectivity testing (RIT). TPA WGS was performed on 52 ulcer exudates and biopsy specimens and 25 matched rabbit isolates.

Results

We enrolled 18 PS and 51 SS participants from December 2019 to March 2022. Among PS participants, TPA DNA was detected in 16 (89%) ulcer exudates and three (17%) blood specimens. Among SS participants, TPA DNA was detected in 50 (98%) skin biopsies and 27 (53%) blood specimens. TP A was isolated from 48 rabbits, with a 71% (12/17) success rate from ulcer exudates and 69% (36/52) from SS bloods. Twenty-three matched SS14 clade genomes were virtually identical, while two Nichols clade pairs had discordant tprK sequences. Forty-two of 52 unique TPA genomes clustered in an SS14 East Asia subgroup, while ten fell into two East Asian Nichols subgroups.

Conclusions

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

Summary

We performed Treponema pallidum molecular detection and genome sequencing from multiple specimens collected from early syphilis patients and isolates obtained by rabbit inoculation. Our results support the use of whole genome sequencing from rabbit isolates to inform syphilis vaccine development.

The role of legal medicine professionals in preventing pregnancy and sexually transmitted infections among female victims of sexual assault

Sexual violence can have an overwhelming impact on the victim's physical and mental health; the consequences include unintended pregnancy and sexually transmitted infections (STIs). Therefore, the examiners must assess victims for possible pregnancy and sexually transmitted infections as a part of the sexual assault examination. This article aims to orient the medico-legal examiners towards their role in preventing unintended pregnancy and sexually transmitted infections among victims of sexual assault. Prompt detection of pregnancy or STIs is critical, as any delay would adversely affect the successful administration of emergency contraception and post-exposure prophylaxis (PEP) against human immunodeficiency virus (HIV) and other sexually transmitted infections.

Is dark-field microscopy still useful for the primary syphilis diagnosis in the 21ST century?

INTRODUCTION

Serological test for primary syphilis could be negative the first 5-15 days. The aim of this study was to evaluate the benefit of including dark field microscopy (DFM) in the diagnosis algorythm for primary syphilis.

MATERIALS/METHODS

Patients attended to a sexual transmission diseases clinic of Madrid, from 2015 to 2019, for a genital ulcer with clinical suspicion of primary syphilis. They were tested for DMF and serological test (EIA/TPPA/RPR).

RESULTS

Over the total amount of samples (806), 53.2% (429) were positive for DFM. Thus, the 48% of the 429 patients had negative serological test (EIA/RPR) of which the 77.6% were positive at TPPA.

CONCLUSIONS

DFM allows primary syphilis early diagnosis, even without serological test. If no direct detection methods are available, for patients without history of syphilis, TPPA could help to diagnose primary syphilis.

Classic bedside diagnostic techniques

Correctly performing bedside diagnostic tests is an important fundamental skill for practicing dermatologists. Even with new technologies, bedside diagnostic tests have been useful in contemporary practice. When properly implemented, bedside diagnostic techniques can efficiently and economically aid in diagnosis and treatment. We have reviewed the most commonly used diagnostic procedures while considering them in their historical context, outlined the procedures for performing the tests, and discussed the relevance and regulatory requirements of the tests.

Bioactive Compounds as Potential Agents for Sexually Transmitted Diseases Management: A Review to Explore Molecular Mechanisms of Action

Sexually transmitted diseases (STDs) are produced by pathogens like bacteria, fungi, parasites, and viruses, and may generate severe health problems such as cancer, ulcers, and even problems in the newborn. This narrative review aims to present updated information about the use of natural bioactive compounds for the prevention and treatment of sexually transmitted infections. A search of the literature was performed using databases and search engines such as PubMed, Scopus, Google Scholar and Science Direct. From the pharmacotherapeutic management point of view, any strategies for prevention should contain medical approaches. The bioactive compounds obtained from natural products have shown biological effects against different microorganisms for the treatment of these diseases. The main results showed antimicrobial, antiprotozoal, antifungal and antiviral effects such as HIV. Also, the molecular mechanisms, signalling pathways and action targets of natural compounds were highlighted, thus justifying bacterial and antifungal inhibition, apoptosis or reduction of viral replication. From the data of our study, we can conclude that natural compounds may be a significant source for adjuvant drugs / complementary therapies in the treatment of STDs. With all these benefits, the future must conduct extensive clinical trials and the development of pharmaceutical nanotechnologies for a greater therapeutic effect.

A Longitudinal Case Study of Concurrent Infection with Syphilis and Human Immunodeficiency Virus During the Early Phase

Due to the low incidence of concurrent human immunodeficiency virus (HIV) and syphilis infection identified during the early phase, such as window period (WP), little is known about the clinical manifestations, diagnosis, and treatment efficacy at very early stages. One longitudinal study was conducted in a 42-year-old blood donor who was concurrently infected with syphilis and HIV. This blood donor was treated with a penicillin-based regimen and early antiretroviral therapy (ART). Sequential serological and nucleic acid tests were performed and the results were comparatively analyzed. A regular male donor who had two occasions of high-risk sexual behaviors 41 and 35 days before donation donated whole blood at the Shenzhen Blood Center. ART was initiated at the 28th day after donation (DAD), and syphilis treatment was received at the 49th DAD. Microbiological analysis using a fourth-generation anti-HIV enzyme-linked immunosorbent assay (ELISA) (4th GAHE) and electro-chemiluminesent immunoassay indicated a positive signal at the 6th DAD, while a third-generation anti-HIV ELISA (3rd GAHE) showed positive at the 26th DAD. All nucleic acid testing (NAT) for HIV RNA were reactive except the minipool NAT of 6 pooled samples at 117th DAD. The HIV viral load declined more than 4-log in copies per milliliter over 3 months, until reaching nondetectable levels at 246th DAD. Nevertheless, HIV-1 DNA was still detectable at 403rd DAD. Among all methods utilized, anti-treponema pallidum ELISA detected syphilis infection at the earliest time. A successful serological response to syphilis treatment was reached around the 80th DAD. Concurrent infection with syphilis and HIV during early phases did not significantly change the sensitivity of reagents in detection nor alter the therapeutic efficacy for the treatment of both pathogens, but might result in delayed HIV serological WP.

Is dark-field microscopy still useful for the primary syphilis diagnosis in the 21ST century?

INTRODUCTION

Serological test for primary syphilis could be negative the first 5-15 days. The aim of this study was to evaluate the benefit of including dark field microscopy (DFM) in the diagnosis algorythm for primary syphilis.

MATERIALS/METHODS

Patients attended to a sexual transmission diseases clinic of Madrid, from 2015 to 2019, for a genital ulcer with clinical suspicion of primary syphilis. They were tested for DMF and serological test (EIA/TPPA/RPR).

RESULTS

Over the total amount of samples (806), 53.2% (429) were positive for DFM. Thus, the 48% of the 429 patients had negative serological test (EIA/RPR) of which the 77.6% were positive at TPPA.

CONCLUSIONS

DFM allows primary syphilis early diagnosis, even without serological test. If no direct detection methods are available, for patients without history of syphilis, TPPA could help to diagnose primary syphilis.

2020 European guideline on the management of syphilis

The 2020 edition of the European guideline on the management of syphilis is an update of the 2014 edition. Main modifications and updates include: -The ongoing epidemics of early syphilis in Europe, particularly in men who have sex with men (MSM) -The development of dual treponemal and non-treponemal point-of-care (POC) tests -The progress in non-treponemal test (NTT) automatization -The regular episodic shortage of benzathine penicillin G (BPG) in some European countries -The exclusion of azithromycin as an alternative treatment at any stage of syphilis -The pre-exposure or immediate post-exposure prophylaxis with doxycycline in populations at high risk of acquiring syphilis.

The outer membrane protein Tp92 of Treponema pallidum induces human mononuclear cell death and IL-8 secretion

Treponema pallidum is the pathogen that causes syphilis, a sexually transmitted disease; however, the pathogenic mechanism of this organism remains unclear. Tp92 is the only T. pallidum outer membrane protein that has structural features similar to the outer membrane proteins of other Gram-negative bacteria, but the exact functions of this protein remain unknown. In the present study, we demonstrated that the recombinant Tp92 protein can induce human mononuclear cell death. Tp92 mediated the human monocytic cell line derived from an acute monicytic leukemia patient (THP-1) cell death by recognizing CD14 and/or TLR2 on cell surfaces. After the stimulation of THP-1 cells by the Tp92 protein, Tp92 may induce atypical pyroptosis of THP-1 cells via the pro-caspase-1 pathway. Meanwhile, this protein caused the apoptosis of THP-1 cells via the receptor-interacting protein kinase 1/caspase-8/aspase-3 pathway. Tp92 reduced the number of monocytes among peripheral blood mononuclear cells. Interestingly, further research showed that Tp92 failed to increase the tumour necrosis factor-α, interleukin (IL)-1β, IL-6, IL-10, IL-18 and monocyte chemotactic protein 1 (MCP)-1 levels but slightly elevated the IL-8 levels via the Nuclear Factor (NF)-κB pathway in THP-1 cells. The data suggest that Tp92 recognizes CD14 and TLR2, transfers the signal to a downstream pathway, and activates NF-κB to mediate the production of IL-8. This mechanism may help T. pallidum escape recognition and elimination by the host innate immune system.

Centers for Disease Control and Prevention Syphilis Summit-Diagnostics and Laboratory Issues

Syphilis, caused by the bacterium Treponema pallidum, is on the rise in the United States particularly among men who have sex with men. The disease is complex with varied clinical manifestations and challenges remain in the laboratory diagnostic setting because T. pallidum is noncultivable and no single test can accurately diagnose all stages of the disease. There are missed opportunities for the use of direct detection tests in primary and secondary syphilis. The increasing use of different reverse sequence algorithms for serology testing without validation in populations with varying risks for syphilis makes the interpretation of test results difficult; this has led to concerns about diagnostic errors or overtreatment. On the other hand, the traditional algorithm may miss some early primary syphilis cases, which is of concern in high-risk populations. The potential utility of rapid syphilis serology tests in different settings or populations remains to be determined. The implementation of better tests and appropriate testing algorithms together with laboratory guidelines for test use in general will lead to better diagnostic options for syphilis.

Syphilis: presentations in general medicine

Syphilis is caused by the spirochete bacteriumTreponema pallidumand can be transmitted both sexually and from mother to child.T pallidumcan infect any organ and produces a clinical disease with a relapsing and remitting course. It is not hard to see, therefore, why it is often described as the great mimic. In this review, we provide an update of modern syphilis epidemiology, clinical presentations, and testing and treatment strategies.

A novel ELISA using a recombinant outer membrane protein, rTp0663, as the antigen for serological diagnosis of syphilis

BACKGROUND

The lack of Treponema pallidum-specific antigens with highly accurate diagnosis makes the diagnosis of syphilis challenging.

METHODS

A soluble recombinant version of a new diagnostic protein Tp0663 has been produced. The serodiagnostic potential of this protein was assessed by screening 3326 serum samples simultaneously evaluated by rapid plasma reagin and T. pallidum particle agglutination tests. Kappa (κ) coefficients were used to compare the concordance between clinical diagnosis and the Tp0663-based ELISA or the ARCHITECT Syphilis TP chemiluminescent immunoassay (Abbott GmbH and Co. KG).

RESULTS

Using the results of clinical diagnosis as the gold standard, the sensitivity and specificity of Tp0663 were found to be 98.83% (95% confidence interval (CI) 96.61-99.60%) and 100% (95% CI 99.88-100%), respectively. In comparison, the ARCHITECT Syphilis TP assay was found to have a lower sensitivity (97.27%, 95% CI 94.46-98.67%) and specificity (99.61%, 95% CI 99.32-99.78%). In particular, the ARCHITECT Syphilis TP exhibited a false-positive rate of 0.39%. Moreover, the ELISA was in perfect agreement with the gold standard, with a κ value of 0.99, comparable to that of ARCHITECT Syphilis TP (0.96).

CONCLUSION

These results identified Tp0663 as a novel serodiagnostic candidate with great potential for developing novel tests for the diagnosis of syphilis.

UK national guidelines on the management of syphilis 2015

These guidelines are an update for 2015 of the 2008 UK guidelines for the management of syphilis. The writing group have piloted the new BASHH guideline methodology, notably using the GRADE system for assessing evidence and making recommendations. We have made significant changes to the recommendations for screening infants born to mothers with positive syphilis serology and to facilitate accurate and timely communication between the teams caring for mother and baby we have developed a birth plan. Procaine penicillin is now an alternative, not preferred treatment, for all stages of syphilis except neurosyphilis, but the length of treatment for this is shortened. Other changes are summarised at the start of the guideline.

Current standards for diagnosis of syphilis: comparing the russian and foreign guidelines (part I)

Despite the abundance of existing laboratory methods the diagnosis of syphilis still faces many challenges. Though direct detection of T. pallidum plays an important role in early manifest forms of the disease, serological tests remain the mainstay of diagnosis. Traditional syphilis screening algorithm based on nontreponemal tests with subsequent confirmation using treponemal tests is a standard worldwide. Recently, the ability to automate the treponemal tests promotes the increasingly widespread implementation of reverse algorithm when these tests are used for syphilis screening. None of the current serological algorithms are able to reliably differentiate between active and previously treated syphilis, which causes uncertainty in the management of patients. There is no «gold standard» for the diagnosis of neurosyphilis, ocular, auricular and visceral syphilis. The interpretation of serological tests in children born to seropositive mothers is also complicated. Diagnosis of congenital syphilis in newborns and, consequently, the prescription of antibiotic therapy often depends on assessment of the adequacy of maternal treatment during pregnancy, which leads to subjective decisions. This article provides a comparative analysis of the «Federal guidelines for the management of patients with syphilis» and their foreign analogues, discusses significant peculiarities of these guidelines and reviews current concerns and controversies in syphilis diagnosis.

Canadian Public Health Laboratory Network laboratory guidelines for the use of direct tests to detect syphilis in Canada

Treponema pallidum subsp. pallidum and/or its nucleic acid can be detected by various methods such as microscopy, rabbit infectivity test or polymerase chain reaction (PCR) tests. The rabbit infectivity test for T. pallidum, although very sensitive, has been discontinued from most laboratories due to ethical issues related to the need for animal inoculation with live T. pallidum, the technically demanding procedure and long turnaround time for results, thus making it impractical for routine diagnostic use. Dark-field and phase-contrast microscopy are still useful at clinic- or hospital-based laboratories for near-bedside detection of T. pallidum in genital, skin or mucous lesions although their availability is decreasing. The lack of reliable and specific anti-T. pallidum antibodies and its inferior sensitivity to PCR may explain why the direct fluorescent antibody test for T. pallidum is not widely available for clinical use. Immunohistochemical staining for T. pallidum also depends on the availability of specific antibodies, and the method is only applicable for histopathological examination of biopsy and autopsy specimens necessitating an invasive specimen collection approach. With recent advances in molecular diagnostics, PCR is considered to be the most reliable, versatile and practical for laboratories to implement. In addition to being an objective and sensitive test for direct detection of Treponema pallidum subsp. pallidum DNA in skin and mucous membrane lesions, the resulting PCR amplicons from selected gene targets can be further characterized for antimicrobial (macrolide) susceptibility testing, strain typing and identification of T. pallidum subspecies.

Molecular methods in the laboratory diagnosis of sexually transmitted infections

Sexually transmitted infections (STIs) are a public health problem, and their prevalence is rising even in developed nations, in the era of HIV/AIDS. While the consequences of STIs can be serious, the good news is that many of these complications are preventable if appropriate screening is done in high-risk individuals, when infection is strongly suspected. The diagnostic tests for STIs serve many purposes. Apart from aiding in the diagnosis of typical cases, they help diagnose atypical cases, asymptomatic infections and also multiple infections. But, the test methods used must fulfill the criteria of accuracy, affordability, accessibility, efficiency, sensitivity, specificity and ease of handling. The results must be rapid, cost-effective and reliable. Most importantly, they have to be less dependent on collection techniques. The existing diagnostic methods for STIs are fraught with several challenges, including delay in results, lack of sensitivity and specificity. With the rise of the machines in diagnostic microbiology, molecular methods offer increased sensitivity, specificity and speed. They are especially useful for microorganisms that cannot be, or are difficult to cultivate. With the newer diagnostic technologies, we are on the verge of a major change in the approach to STI control. When diagnostic methods are faster and results more accurate, they are bound to improve patient care. As automation and standardization increase and human error decreases, more laboratories will adopt molecular testing methods. An overview of these methods is given here, including a note on the point-of-care tests and their usefulness in the era of rapid diagnostic tests.

Evaluation of the recombinant protein TpF1 of Treponema pallidum for serodiagnosis of syphilis

Syphilis is a chronic infection caused by Treponema pallidum subsp. pallidum, and diagnosis with sensitive and specific methods is a challenging process that is important for its prevention and treatment. In the present study, we established a recombinant protein TpF1-based indirect immunoglobulin G (IgG) enzyme-linked immunosorbent assay (ELISA) and a Western blot assay for human and rabbit sera. The 20-kDa recombinant protein TpF1 was detected by Western blotting performed with sera from rabbits immunized with recombinant TpF1 and infected with the T. pallidum Nichols strain and T. pallidum clinical isolates but was not detected by Western blotting with sera from uninfected rabbits. The sensitivity of the recombinant protein was determined by screening sera from individuals with primary, secondary, latent, and congenital syphilis (n = 82). The specificity of the recombinant protein was determined by screening sera from uninfected controls (n = 30) and individuals with potentially cross-reactive infections, including Lyme disease (n = 30) and leptospirosis (n = 5). The sensitivities of TpF1-based ELISAs were 93.3%, 100%, 100%, and 100% for primary, secondary, latent, and congenital syphilis, respectively, and the specificities were all 100% for sera from uninfected controls and individuals with potentially cross-reactive infections. In Western blot assays, the sensitivities and specificities of TpF1 for human sera were all 100%. The reactivities of TpF1 with syphilitic sera were proportional to the titers of the T. pallidum particle agglutination (TPPA) assay. These data indicate that the recombinant protein TpF1 is a highly immunogenic protein in human and rabbit infections and a promising marker for the screening of syphilis.

An Outbreak of Early Syphilis in Patients Registered at the City Institute for Skin and Venereal Diseases in Belgrade from 2010 to 2012: a Case Series of 86 Patients

The purpose of this study was to analyze the characteristics of an outbreak of early syphilis registered at the City Institute for Skin and Venereal Diseases in Belgrade, during the period from 2010 to 2012. The study was designed as a case-note review. In a three-year-long period, a total of 86 patients with early syphilis were registered: 33 cases of primary, 31 of secondary and 22 cases of early latent syphilis. Sixty-five (76.5%) of all patients were men who have sex with men, 15 were heterosexual men and 6 were women. The majority of patients were infected in Belgrade, and in 51/86 cases oral sex was the only risk factor. There were 13 HIV-positive patients, all men who have sex with men. Thus, 20% of men who had sex with men in this study were co-infected with HIV. In conclusion, this outbreak of early syphilis in Belgrade, in which more than two thirds of all patients were men who have sex with men, of whom 20% were HIV-infected, shows the need for: 1) enhanced prevention efforts targeting this group more important than ever, with education and condom use for oral sex as an important part of patient counseling; 2) coordinated and expeditious surveillance, partner services, screening among population at-risk, as well as early diagnosis and treatment.

Using the Line Blot Syphilis test system for diagnosingsyphilis by the linear immunoblotting method

ZAO ECOlab (Russia) developed Line Blot Syphilis, a new test system on the basis of the linear immunoblotting method using Treponema рallidum recombinant antigens. The article assessed the diagnostic value of the Line Blot Syphilis test system in the form of a confirmatory test. As a part of the conducted study, the test system demonstrated its absolute sensitivity and specificity to serum-positive (n = 237) and serum-negative (n = 114) samples, in which the presence or absence of Т.pallidum antibodies was confirmed by two treponemal tests. As a result of examining 14 samples attributed to doubtful analytes based on two test results (passive hemagglutination test and immunofluorescence test with absorption), the data compliance between the Line Blot Syphilis test system and data from INNO-LIA Syphilis Score amounted to 100% (14/14) or 93% (13/14) for the immune-enzyme assay and 57% (8/14) for the immunofluorescence test with absorption. It is recommended to use the Line Blot Syphilis test system (ZAO ECOlab) as a confirmatory syphilis test.

Qualitative and quantitative aspects of the serological diagnosis of early syphilis

Summary:

The aim of the present study was to evaluate the use of various serological tests in the diagnosis of early syphilis. The Murex enzyme immunoassay (EIA) test was used for screening; the Venereal Diseases Research Laboratory (VDRL) test, the Treponema pallidum particle agglutination assay (TPPA) and the Mercia antitreponemal IgM EIA were used in all the patients with a positive screening test and in those with suspected syphilis or in known contacts. In 89 cases of primary syphilis, the Murex EIA screening test was positive in 67 (75%) patients, the Mercia IgM EIA in 80 (90%) cases, the VDRL in 60 (67%) cases and the TPPA in 85 (96%) cases. All the tests were positive in 68 patients with secondary syphilis. In 72 cases of early latent syphilis, the Murex EIA screening test was positive in 68 (94%) patients, the Mercia IgM EIA in 50 (69%) cases, the VDRL in 61 (85%) cases and the TPPA in 68 (94%) cases. The Mercia IgM EIA was the only test positive in four (6%) of these cases; these four patients were known contacts. Antibody titres in the VDRL and TPPA increased as the infection progressed.

Primary syphilis

Cases of syphilis have been increasing in the UK and it remains an important public health problem. Here, we provide an overview of syphilis, its presentation, diagnosis and management.

Cutaneous manifestations of syphilis : recognition and management

After a marked decline in the number of syphilis cases in the context of AIDS prevention campaigns, a significant increase has been observed in states of the former Soviet Union since 1994. In recent years, outbreaks have also been reported in the US, Canada, and several European countries. The current epidemic in the US and in different parts of Europe has largely involved men who have sex with men, many of whom are infected with HIV. Since a misdiagnosis of syphilis can have serious consequences for the patient and also for pregnancies and newborns, clinicians should be aware of the many manifestations of syphilis and difficulties in the diagnosis and management of the disease. Younger clinicians in particular are no longer familiar with the diverse clinical symptoms and the complex diagnostics of syphilis. Patients co-infected with HIV may present with atypical clinical manifestations and laboratory test results. Furthermore, through its association with an increased risk of HIV infection, syphilis has acquired a new potential for morbidity and mortality, and the diagnosis of syphilis should be routinely considered in patients with uveitis, sudden deafness, aortic thoracic aneurysm, or pregnancy. Only a minority of syphilis infections are detected in the primary stage. This may be because of atypical locations and, occasionally, atypical morphology of the lesions; however, it may also be because of the difficulty of detecting the pathogen. In the secondary stage, which is clinically extremely diverse, the diagnosis is confirmed serologically. There is a need for increased awareness of the symptoms and signs of acute infections, together with a willingness to consider the diagnosis of syphilis in patients with vague symptoms. An increasing number of diagnostic tests (both specific and nonspecific) are now available. However, in the absence of clinical symptoms or in cases with a low titer or inconsistent test results, diagnosis of syphilis can be difficult or even impossible. Treatment and follow-up should follow current guidelines designed for the involved area. In this article, the cutaneous manifestations of syphilis and their diagnostic and therapeutic management are described in detail.

Application of a noninvasive oral fluid test for detection of treponemal IgG in a predominantly HIV-infected population

The performance of a time-resolved fluorescence immunoassay (TRFIA) for detection of treponemal IgG from oral fluid specimens has been assessed in a predominantly HIV-infected population. Serological investigation is the method of choice for confirming clinical suspicion of syphilis; however, in the primary stage of disease, direct detection of treponemes in lesion fluid or Treponema pallidum DNA is recommended because of the reduced sensitivity of serological tests. There may be occasions when blood for serological investigation is difficult to obtain due to individual patient preference or logistical necessity to improve participation in screening initiatives, particularly in outreach situations. Collection of oral fluid for detection of treponemal antibody may prove an attractive alternative and, with this in mind, an oral fluid assay for detection of treponemal IgG was developed. Time-resolved fluorescence was used to detect treponemal IgG extracted from commercially available oral fluid collection devices. Paired serum and saliva samples were obtained from 210 individuals, 101 of whom were diagnosed with syphilis on the grounds of medical examination confirmed by serological testing. Oral fluid specimens from 14 subjects were rejected because they contained insufficient control antibody or were inhibitory. The population tested was predominantly men who have sex with men, many of whom were HIV infected. The overall sensitivity and specificity of the oral fluid assay was 95.8 and 86.1%, respectively, based on the 5th percentile of the positive results, and 93.7 and 91.1%, respectively, based on a cutoff derived by mixture model analysis. For individuals with primary syphilis, the optimum sensitivity of the oral fluid assay was 87.5%, whereas in those with disease classified as secondary syphilis and early latent syphilis, the sensitivity of the oral fluid assay was 100 and 94.7%, respectively. The oral fluid assay is a useful alternative to serological testing in certain situations, and further development of this technology to enable detection of treponemal IgM should increase its sensitivity for detecting cases of primary syphilis.

Syphilis in adults

Syphilis is a sexually transmitted disease with protean manifestations resulting from infection by Treponema pallidum. It is systemic early from the outset, the primary pathology being vasculitis. Acquired syphilis can be divided into primary, secondary, latent, and tertiary stages. The infection can also be transmitted vertically resulting in congenital syphilis, and occasionally by blood transfusion and non-sexual contact. Diagnosis is mainly by dark field microscopy in early syphilis and by serological tests. The management in the tropics depends on the diagnostic facilities available: in resource poor countries, primary syphilis is managed syndromically as for anogenital ulcer. The introduction of rapid "desktop" serological tests may simplify and promote widespread screening for syphilis. The mainstay of treatment is with long acting penicillin. Syphilis promotes the transmission of HIV and both infections can simulate and interact with each other. Treponemes may persist despite effective treatment and may have a role in reactivation in immunosuppressed patients. Partner notification, health education, and screening in high risk populations and pregnant women to prevent congenital syphilis are essential aspects in controlling the infection.