Syphilis

Clinical characteristics and cause analysis of false-positive results in treponemal testing among patients

BACKGROUND

Currently, there is a dearth of systematic research data on the phenomenon of false-positive reactions in treponemal tests. The aim of this study is to analyze the clinical characteristics and influencing factors associated with false-positive treponemal tests in patients, so as to enhance the diagnostic accuracy of syphilis and mitigate misdiagnosis-induced incorrect treatment.

METHODS

From January 2017 to December 2023, a total of 759 cases with false-positive results for treponema were screened for blood transfusion, surgery, or other medical interventions at Jinling hospital. The demographic, clinical, and laboratory characteristics of patients were retrospectively analyzed to identify the risk factors associated with false-positive reactions in treponemal antibody screening.

RESULTS

The results indicated that individuals under 18 years old, over 45 years old and males exhibited a higher false-positive rate for treponemal tests (p < 0.001). The false-positive rates of treponema were found to be higher in the fields of pediatrics, nephrology, and internal medicine (p < 0.05). There was no difference observed in ABO blood group distribution (p > 0.05). .Furthermore, the levels of treponema antibody and coagulation function were found to be associated with the occurrence of false-positive syphilis test results.  Multivariate logistic regression analysis indicated that ≤18 years, ≥45 years, male were independent risk factors (p < 0.01).

CONCLUSION

This study demonstrates that the false-positive rate of treponemal tests can be increased by factors such as age, gender, immune diseases, and coagulation disorders. The treponemal antibodies titer level is a valuable reference for assessing false-positive results. To enhance the accuracy of syphilis diagnosis, multiple risk factors should be considered when interpreting results from treponemal tests.

Spatio-Temporal Distribution Characteristics of Syphilis: on the Scale of Towns (Streets) in Nantong City, Jiangsu Province, China

Objectives

To investigate the spatio-temporal distribution characteristics and changing trends of syphilis in Nantong city.

Methods

Joinpoint regression model, spatial autocorrelation and SaTScan spatio-temporal scanning were used to analyze the trend of syphilis reported incidence and spatio-temporal distribution characteristics in Nantong City.

Results

From 2013 to 2022, the reported incidence of syphilis in Nantong City increased at an average annual rate of 6.60%, of which the increase rate of latent syphilis was 13.45%. The high-high clustering areas were mainly distributed in 15 streets of Chongchuan District and all streets of Nantong Development Zone. SaTScan spatio-temporal scanning detected a total of two clustering areas, all from 2021 to 2022. The first cluster includes 24 streets with a radius of 16.27 km, and the second cluster includes 18 streets within a radius of 34.90 km.

Conclusion

The reported incidence of syphilis in Nantong City showed an increasing trend, mainly manifested as an increase in latent syphilis, and the reported incidence of syphilis in various towns (streets) showed obvious spatial clustering, and attention should be paid to key areas and targeted interventions should be formulated.

Comparison of ARIMA and Bayesian Structural Time Series Models for Predicting the Trend of Syphilis Epidemic in Jiangsu Province

Purpose

This study sets out to explore the forecasting value in syphilis incidence of the Bayesian structural time series (BSTS) model in Jiangsu Province.

Methods

The seasonal autoregressive integrated moving average (ARIMA) and BSTS models were constructed using the series from January 2017 to December 2021, and the prediction accuracy of both models was tested using the series from January 2022 to November 2022.

Results

From January 2017 to November 2022, the total number of syphilis cases in Jiangsu Province was 170629, with an average monthly notification cases of 2403. The optimal model was ARIMA (1,0,0) (0,1,1) 12 (AIC = 663.12, AICc = 664.05, and BIC = 670.60). The model coefficients were further tested: AR1 = 0.48 (t = 3.46, P < 0.001), and SMA1 =-0.48 (t =-2.32, P = 0.01). The mean absolute deviation, mean absolute percentage error, root mean square error, and root mean square percentage error from the BSTS model were smaller than those from the ARIMA model. The total number of syphilis cases predicted by the BSTS model from December 2022 to December 2023 in Jiangsu Province was 29902 (95% CI: 16553 ~ 42,401), with a monthly average of 2300 (95% CI: 1273 ~ 3262) cases.

Conclusion

Syphilis is a seasonal disease in Jiangsu Province, and its incidence is still at a high level. The BSTS model is superior to the ARIMA model in dynamically predicting the incidence trend of syphilis in Jiangsu Province and has better application value.

[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.

Atypical Presentation of Tertiary Syphilis

Syphilis is a sexually transmitted infection characterized by multiple stages. Cardiovascular involvement is a manifestation of tertiary syphilis, occurring between 10 and 40 years after the primary infection. The authors present a case of atypical presentation of tertiary syphilis in a 49-year-old male patient who was admitted to the hospital with bilateral transient loss of vision. Contrast-enhanced CT imaging revealed thoracic aortitis with carotid occlusion, coronary artery stenosis, ischemic stroke, myocardial infarction, and multiple intracardiac thrombi. A postmortem autopsy revealed positive laboratory results for syphilis, which was corroborated by medical autopsy findings of syphilitic aortitis. Keywords: CT-Angiography, Aorta, Cardiac, Vascular, Tertiary Syphilis © RSNA, 2024.

Endocarditis and ascending aortic aneurysm with aortic valve insufficiency secondary to late syphilis: Case report

Venereal syphilis, caused by Treponema pallidum, is a major global health problem. Untreated latent syphilis can progress to tertiary syphilis, often leading to severe complications such as cardiac involvement, particularly syphilitic aortitis, which may manifest decades after the initial infection. We present a case of a 46-year-old woman who developed an ascending aortic aneurysm and severe aortic valve insufficiency due to late-stage syphilis. She presented with bilateral lower limb edema, intermittent chest pain, decreased functional capacity, and dyspnea, ultimately requiring hospitalization for cardiogenic shock. Diagnostic imaging revealed significant aortic valve damage and aneurysmal dilation of the ascending aorta, while serological tests confirmed tertiary cardiovascular syphilis. Surgical intervention involved the reconstruction of the ascending aorta and replacement of the aortic valve with a bioprosthetic valve. Histopathological analysis indicated chronic endocarditis. Postoperative management included intensive care support and antibiotic treatment. The patient demonstrated satisfactory recovery, with no further complications reported at the 3-month follow-up.

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.

Global, regional, and national burden of syphilis, 1990-2021 and predictions by Bayesian age-period-cohort analysis: a systematic analysis for the global burden of disease study 2021

Objective

To comprehensively assess the global burden of syphilis and related risk factors over 1990-2021, forecast future disease trends, and understand the impact of syphilis on global health.

Methods

Global Burden of Disease Study 2021 (GBD 2021) data were used for age-, sex-, and region-stratified analysis of the numbers and age-standardized rates (per 100,000 population) of syphilis incidence, prevalence, deaths, and disability-adjusted life years (DALYs). Next, a differential analysis of syphilis risk factors was performed. Finally, trends for years after 2021 were predicted using Bayesian age-period-cohort (BAPC) prediction models.

Results

In 2021, the total number of syphilis prevalence globally was 70,541,482.80 (95% uncertainty interval: 54,910,897.66-88,207,651.97), with the highest numbers noted in Central Sub-Saharan Africa [4,622.60 (95% uncertainty interval: 3,591.97-5,753.45)]. Over 1990-2021, the global age-standardized prevalence and incidence rates increased, whereas the age-standardized death and DALY rates decreased. Among all groups, infants aged <5 years demonstrated the highest age-standardized DALY rates. Moreover, the lower the sociodemographic index (SDI), the higher was the age-standardized rate. The primary factor contributing to syphilis disease burden was identified to be unsafe sex. BAPC analysis revealed an overall increase in age-standardized prevalence rate in the <5-year age group over 1990-2035, and the highest age-standardized prevalence rate occurred in the 25-34-year age group.

Conclusion

Between 1990 and 2021, syphilis occurrence and prevalence increased consistently. Projections indicated a continual increase in syphilis incidence in children aged <5 years, and age-standardized prevalence rates were the highest in adults aged 25-34 years. Our results regarding the epidemiological trends of syphilis and its variations across regions, age groups, and sexes may aid policymakers in addressing the global impact of the disease effectively.

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.

Evaluating the effect of the plan of national syphilis control in controlling the syphilis epidemic in Jiangsu, China 2010-2020

Background

Starting in 2010, the Chinese government initiated a 10-year syphilis control plan, called the national syphilis control plan (NSCP), to address the emerging threat of syphilis. We aimed to evaluate the effect of the NSCP plan on syphilis control in Jiangsu, China.

Methods

The temporal trends of syphilis incidence, prevalence and rate of condom use were estimated by Joinpoint regression with average annual percent change (APC) and average annual percentage (APPC). A Chi-square test was conducted to analyze the outcomes in different subgroups. ArcGIS was used to analyze the spatiotemporal distribution of syphilis incidence.

Results

Geographically, early and congenital syphilis incidence decreased significantly in all areas of the province during the period of NSCP. Early syphilis incidence decreased from 21.1 to 8.8 (APC: -7.5, 95%CI: -8.6, -6.5, p < 0.001) per 100,000 people, and congenital syphilis decreased from 63.6 to 4.1 (APC: -14.8, 95%CI: -20.8, -8.4, p < 0.01) per 100,000 newborns from 2010 to 2020. Also, syphilis prevalence reduced from 13.4 to 3.8% (APC: -8.7, 95%CI: -12.1, -5.0, p = 0.001) among men who have sex with men, from 5.3 to 1.7% (APC: -7.9, 95%CI: -11.7, -3.8, p = 0.002) among female sex workers and remained under 1.0% with slight variations among pregnant women (APC: 0.3, 95%CI: -4.3, 5.1, p = 0.877) from 2010 to 2020. 0.2% (2,436) of pregnant women who received free syphilis testing during pregnancy were diagnosed with current syphilis infection, and 97.0% (2,555) of newborns in the province were delivered to women diagnosed with syphilis. 91.8% (2,346) of live babies and about 90% of diagnosed patients received complete standard syphilis diagnosis and treatment services.

Conclusion

Trends of early syphilis incidence and syphilis prevalence show a considerable decreasing trend among almost all the key populations after implementing NSCP. Congenital syphilis has significantly decreased as well and hence, the NSCP program should be sustained and strengthened to control the syphilis epidemic in China further.

Immunization with Tp0954, an adhesin of Treponema pallidum, provides protective efficacy in the rabbit model of experimental syphilis

Syphilis, a chronic multisystemic disease caused by spirochete Treponema pallidum subspecies pallidum infection, continues to be a serious global health problem and congenital syphilis remains a major cause of adverse outcomes in pregnancy in developing countries. The development of an effective vaccine is the most cost-effective way to eliminate syphilis, but so far has been elusive. Here, we evaluated the immunogenicity and protective efficacy of Tp0954, a T. pallidum placental adhesin, as a potential vaccine candidate in a New Zealand White rabbit model of experimental syphilis. Animals immunized with recombinant Tp0954 (rTp0954) produced high titers of Tp0954-specific serum IgG, high levels of IFN-γ from splenocytes and specific splenocyte proliferation response when compared to control animals immunized with PBS and Freund’s adjuvant (FA). Furthermore, rTp0954 immunization significantly delayed the development of cutaneous lesions, promoted inflammatory cellular infiltration at the primary lesion sites, as well as inhibited T. pallidum dissemination to distal tissues or organs when compared with that of the control animals. In addition, the naïve rabbits receiving popliteal lymph nodes from Tp0954-immunized, T. pallidum-challenged animals were not infected by T. pallidum, confirming sterile immunity. These findings suggest that Tp0954 is a potential vaccine candidate against syphilis.

A Case of Neurosyphilis With Penicillin Failure

Neurosyphilis is any involvement of the central nervous system (CNS) by Treponema pallidum. The CNS may be involved at any stage of infection.

A 54-year-old previously healthy African American male was hospitalized due to a two-year history of progressive cognitive decline. One year after symptoms began, he developed, over a four-month period, gait disturbance resulting in frequent falls, speech impairment, worsening memory loss, psychosis, and an inability to perform activities of daily living.

A diagnosis of neurosyphilis was established upon cerebrospinal fluid (CSF) positive results and new changes in his mental status. The CSF showed predominant lymphocytic pleocytosis (17), elevated protein (111), and IgG index (4.25). Other viral and bacterial panels were negative. Intravenous penicillin G, 24 million units daily for 14 days, was given. Two months later, the patient was transferred to the hospital for altered behavior and mental status changes from the cognitive baseline. The repeat CSF rapid plasma reagin (RPR) titer (1:4) was the same as at initial diagnosis, despite appropriate treatment. Brain MRI showed progressive volume loss in both temporal lobes, thalamus, and cerebellum, consistent with evolving encephalitis. Treatment with intravenous penicillin G, 24 million units, was repeated. The patient improved clinically.

Hence, in emerging cases of syphilis, this patient has been diagnosed with a neurosyphilis flare, unresponsive to the usual dose and duration of penicillin. We recommended a repeat CSF examination every six months and having a lower threshold for CSF examination for possible flare or resistance. Our case showed a failure to respond to the usual course of penicillin, requiring a second course of IV Penicillin G, although no resistance to penicillin has been reported.

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.

Acquired Syphilis by Nonsexual Contact in Childhood

BACKGROUND

Children may acquire syphilis by nonsexual contact as a consequence of close and repetitive contact with mucosal or skin lesions of people with active syphilis.

METHODS

Prospective cohort study of pediatric patients with acquired syphilis by nonsexual contact. Demographics, clinical findings, posttreatment serology development and general laboratory data were collected. Sexual transmission was ruled out after a careful medical and psychosocial evaluation of the patient and his/her family.

RESULTS

Twenty-four patients were included in the study. Mean age at diagnosis was 4.2 years old. All of them came from overcrowded households with poor hygiene conditions. The most frequent reason for consultations was secondary syphilis skin lesions (79.2%). The psychosocial evaluation of children and their families did not reveal signs of sexual abuse in any of the cases. Seventy-eight families and their cohabitants were evaluated, 23 (29.5%) resulted positive for rapid plasma reagin and treponemal test of hemagglutination; 60.9% of the cases were asymptomatic. The symptomatic relatives showed lesions of secondary syphilis. A sustained fall on nontreponemal antibodies titer (rapid plasma reagin) was observed after treatment, becoming negative in 6/24 (25%) cases within 12 months posttreatment.

DISCUSSION

Following evaluation, it was considered that sexual abuse was unlikely. However, if examination and psychosocial evaluation do not support it, other ways of transmission must be considered. Overcrowded and poor household conditions boost the risks for nonsexual treponema transmission. An infected member of the family or a caretaker are a particular risk to an infant due to common practices such as using saliva to moisten the rubber nipples of the milk bottles or trying the food temperature using the lips before feeding the infants.

Molecular diagnostic of syphilis

Syphilis is a sexually transmitted infection caused by Treponema pallidum subsp. pallidum with an increasing incidence in Spain and in the rest of the world. Diagnosis is based mainly on serology, since direct diagnosis by dark field microscopy presents difficulties that limit its widespread use. Molecular biology techniques can be a useful tool for diagnosis in primary and secondary syphilis, although not all types of samples show the same behaviour. These techniques are also useful for the diagnosis of congenital syphilis. They are not recommended, however, for neurosyphilis, due to the low sensitivity of polymerase chain reaction in cerebrospinal fluid. These techniques have been used to study the controversial origin of syphilis, and, through the enhanced Centers for Disease Control method, to perform typing, which helps to elucidate the epidemiology of this infection. Finally, molecular techniques can detect mutations related to macrolide resistance, which are present in a very high percentage of infections.

Brazilian Protocol for Sexually Transmitted Infections 2020: acquired syphilis

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

Syphilis Diagnosis and Treatment: State of The Art

The present review summarises the current knowledge in the field of syphilis diagnosis and treatment, along with epidemiologic and historical data. A literature search was conducted in PubMed and Google Scholar, using the search terms “syphilis”, “diagnosis”, “dermoscopy”, “management AND treatment”, “laboratory tests AND syphilis”, and “primary OR secondary OR tertiary OR congenital syphilis”. A total of 55 out of 100 papers were included in this review. An overview of the different clinical presentation of primary, secondary, tertiary, and congenital syphilis, with particular attention to dermatologic signs and dermoscopic examination, is provided. The panorama diagnostic procedures are illustrated, along with their accuracy and recommendation. Treatment and management options of patients at different syphilis stages are provided and discussed according to the referring guidelines. The dermatologist can play a key role in providing the early and correct diagnosis and setting up in the proper management of patients with syphilis infection.

Acquired Syphilis: epidemiological profile of cases in state of Pará from 2017 to 2019

Objective: To quantify patients diagnosed with acquired syphilis and the prevalence of the disease in the state of Pará, Brazil, from January 2017 to June 2019, in addition to characterizing the demographic aspects of patients included in the sample. Methods: observational, descriptive and cross-sectional study, conducted by reviewing the database of the Notifiable Diseases Information System made available by the State Health Department of Pará, of reported cases of acquired syphilis, in the defined period. This study included patients of both sexes, aged 18 years or older, who had acquired syphilis and were notified. Results: 5,620 cases of acquired syphilis were reported, of which the majority were male (n = 3,229; 57.45%), mixed race (n = 4,058; 72.2%), low education (n = 2,250; 40%) and in the young adult range (18–30 years; n = 2,514; 44.74%). The highest concentration of cases was observed in the metropolitan mesoregion of Belém and the Lower Amazon. Conclusions: Acquired syphilis is still prevalent and is characterized as a public health problem. Epidemiological surveillance needs to be constant, and more efficient public policies need to be employed in primary care to reduce the number of cases and make early diagnoses with appropriate treatment.

Identification of the factors associated with post-treatment asymptomatic neurosyphilis in HIV-negative patients with serological non-response syphilis: a retrospective study

Some syphilis patients do not exhibit an appropriate serological response after treatment despite the absence of any clinical evidence of treatment failure or reinfection. This condition is called "serofast syphilis" or "serological non-response syphilis." This study explored the incidence of asymptomatic neurosyphilis (ANS) and related factors in 324 asymptomatic patients with serological non-response syphilis. We analyzed descriptive statistics stratified by the presence of asymptomatic neurosyphilis for the basic characteristics of samples. Bivariate analysis was conducted to assess correlations between outcomes and potential predictors. Variables significant in the bivariate analysis (p<0.1) were entered into multivariable logistic regression models. All p-values were two-sided with a significance threshold of p<0.05. The results indicated that 89 of 324 patients had ANS (incidence of 27.5%), and the greatest risk factors were a < fourfold decrease in serum rapid plasma reagin (RPR) titers after treatment and current serum RPR titers >1:32. Our findings suggest that ANS is common among syphilis patients, and patients with a fourfold decrease in serum RPR titers after treatment and current serum RPR titers >1:32 are more likely to develop ANS.

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.

Epidemiological Features and Risk Factors for Acquiring Hepatitis B, Hepatitis C, and Syphilis in HIV-Infected Patients in Shaanxi Province, Northwest China

Human immunodeficiency virus (HIV)-infected patients are at a higher risk for co-infection with Hepatitis B virus (HBV), Hepatitis C virus (HCV), and Treponema pallidum (TP; the agent causing syphilis) than the general population. The prevalence of HBV, HCV, and syphilis has geographic differences and varies from region to region among HIV-positive individuals. A retrospective study was carried out on HIV-positive individuals between June 2011 and June 2016 in Shaanxi Province. Univariate and multivariate logistic regression analyses using stepwise regression analysis regarding risk factors for HIV–HBV, HIV–HCV, and HIV–syphilis co-infection. HBV–HCV, HCV–syphilis, HBV–syphilis, and HBV–HCV–syphilis co-infection rates were 1.7%, 2.2%, 2.6%, and 0.1%, respectively. The rate of ineffective hepatitis B vaccine immunization was as high as 30.2% among HIV-positive individuals. Ethnicity (OR = 31.030, 95% CI: 11.643–82.694) and HIV transmission routes (OR = 134.024, 95% CI: 14.328–1253.653) were the risk factors for HCV infection in HIV-positive individuals. Among the HIV-positive individuals with the antibodies of TP, the rate of homosexual transmission was also higher, but heterosexual transmission was lower (OR = 0.549 95% CI: 0.382–0.789) The HIV-infected patients in Shaanxi Province had the characteristics of low active detection rate and late diagnosis. The high rate of ineffective vaccination against HBV suggests a need for improved vaccination services.

Enhanced molecular typing and macrolide and tetracycline-resistance mutations of Treponema pallidum in Barcelona

Aim: To describe the molecular types of Treponema pallidum and the proportion of macrolide and tetracycline resistance mutations in Barcelona. Materials & methods: Molecular type was determined using the Enhanced-CDC Typing system and antibiotic resistance was determined by sequencing the 23S and 16S rRNA genes. Results: A total of 183 patients were enrolled and 213 specimens (99 ulcers, 114 bloods) were collected. Sixty-two (70.5%) of 88 ulcers and 0 (0%) of bloods T. pallidum-DNA containing samples were fully typed. Up to 21 different strain types were identified (14d/g in 27.4%; 14f/g in 14.5%). Macrolide resistance mutations were present in 95% and tetracycline in 0%. Conclusion: Several different strains co-exist in Barcelona with a high proportion of macrolide resistance and absence of tetracycline resistance.