Syphilis

Gut Microbiota Alternation in Disease Progression of Neurosyphilis

Background

The gut microbiota plays an important role in the development of neurological disorders such as Parkinson's disease and Alzheimer's disease. However, studies on the gut microbiota of patients with neurosyphilis (NS) were rarely reported.

Methods

In this study, we collected fecal samples from 62 syphilis patients, including 39 with NS and 23 with non-NS. Among the NS patients, 18 were general paresis (GP). The white blood cell counts, protein concentrations, and Venereal Disease Research Laboratory test positive rates of cerebrospinal fluid from patients in NS or GP group were significantly higher than those from patients in non-NS group. 16S ribosomal RNA sequencing results revealed that the alpha and beta diversities of the gut microbiota were similar between NS and non-NS patients or GP and non-NS patients.

Results

Linear discriminant analysis with effect size (LEfSe) analysis showed that some taxa, such as Coprobacter, were increased in both NS group and GP group, compared with non-NS group. Besides, the clade of Akkermansia was also overrepresented in GP Patients. Meanwhile, some taxa such as Clostridia_UCG-014 and SC-I-84 were underrepresented in NS patients. The abundances of class Bacilli and genus Alloprevotella were decreased in GP patients. Among them, the abundances of some taxa such as Coprobacter and Akkermansia have been reported to be associated with other neuropsychiatric disorders.

Conclusion

Our findings suggest that the alternation of the gut microbiota in NS patients may contribute to the course of NS, which will deepen our understanding of NS.

Gestational and congenital syphilis across the international border in Brazil

BACKGROUND

Brazil lacks data from syphilis in its border areas. We aimed to describe the spatial and temporal distribution of acquired syphilis (AS), in pregnancy (SP) and congenital syphilis (CS) in Brazilian municipalities in the arches border contexts.

METHODS

An ecological, cross-sectional study was conducted from 2010 to 2020. The study was based on the cases of syphilis available in the Notifiable Diseases Information System (SINAN), and on the Primary Health Care Information System. The detection rates of AS and SP, and the incidence of CS were estimated, and the time series was analyzed. Data between the border arches were compared.

RESULTS

In 2020, data showed 7,603 cases of AS (detection rate 64.8/100,000 inhabitants), 3,960 cases of SP (detection rate of 21.6/1,000 live births) and 836 cases of CS (incidence of 4.6/1,000 live births) in the border region. Between 2010 and 2020, the mean annual increase of detection rate of SP was 53.4% in Brazil, 48.0% in the border region, 59.6% in the North Arch, 28.8% in the Central and 67.2% in the South. Annual variation on the incidence of CS for the same period was 31.0% in Brazil 38.4% at the border, in the North and South Arcs 18.3% and 65.7% respectively. The Central Arch showed an increase only between 2010 and 2018 (62.7%). A total of 427 (72.6%) municipalities has primary health care coverage ≥ 95% of the population. In 2019, 538 (91.8%) municipalities reported using rapid tests for syphilis, which decreased to 492 (84%) in 2020. In 2019, 441 (75.3%) municipalities reported administering penicillin, and 422 (72%) in 2020.

CONCLUSION

Our data show syphilis reman problem at the Brazilian border, rates in pregnant are high. It was observed a reduction in the detection rates, SP and the incidence of CS between 2018 and 2020. Syphilis should be included on the agenda of all management levels, aiming at expanding access and quality care.

Investigation of the immune escape mechanism of Treponema pallidum

BACKGROUND

Syphilis is a chronic sexually transmitted disease caused by Treponema pallidum subspecies pallidum (T. pallidum), which is a public health problem that seriously affects human health worldwide. T. pallidum is characterized by early transmission and immune escape and is therefore termed an "invisible pathogen".

METHODS

This review systematically summarizes the host's innate and adaptive immune responses to T. pallidum infection as well as the escape mechanisms of T. pallidum.

PURPOSE

To lay the foundation for assessing the pathogenic mechanism and the systematic prevention and treatment of syphilis.

CONCLUSION

The immune escape mechanism of T. pallidum plays an important role in its survival. Exploring the occurrence and development of these mechanisms has laid the foundation for the development of syphilis vaccine.

Couple-level determinants of syphilis infection among heterosexual married couples of reproductive age in Guangdong Province, China: A population-based cross-sectional study

Background

Syphilis remains a major public health problem worldwide, and its prevention requires knowledge of factors that go beyond the individual-level. However, most syphilis-related studies have focused on individual-level and regional-level factors, neglecting couple-level factors. Thus, this study aimed to explore couple-level determinants of syphilis infection among heterosexual married couples.

Methods

This population-based cross-sectional study used data from heterosexual married couples who participated in the National Free Preconception Health Examination Project in Guangdong Province, China during 2014-2019. The syphilis infection was tested by the rapid plasma reagin test. Couple-level data were obtained by combining information provided by the man and woman living in the same household. Multivariate logistic models were employed to explore the couple-level determinants of syphilis infection by gender after adjusting for potential confounders.

Results

A total of 1,755,156 couples were recruited in this analysis. The seroprevalence was 0.25% (95%CI: 0.24-0.25%) and 0.26% (95%CI: 0.25-0.27%) among men and women, respectively. The median age was 28.0 (interquartile range, IQR: 25.0-31.0) years, and the median duration of marriage was 0.2 (IQR: 0.0-2.5) years. After adjusting for individual and regional-level variables, duration of marriage was a protective factor for syphilis infection in men (adjusted odds ratios, AOR: 0.97; 95% CI: 0.96-0.98) and women (AOR: 0.95, 95% CI: 0.94-0.96). The age gap and the difference in education level between the husband and wife were associated with syphilis infection, but these associations were somewhat different between men and women. Condom use was negatively associated with syphilis infection in men (AOR: 0.77; 95% CI: 0.70-0.84) and women (AOR: 0.77, 95% CI: 0.71-0.84). Our results also showed that couple mobility and the number of children were not statistically significant determinants of syphilis infection among heterosexual married couples.

Conclusion

This study contributes to a more comprehensive understanding of syphilis outcomes in individuals in the context of marriage in China. Several couple-level factors are indeed associated with syphilis infection, but these associations differ between men and women. Couple-based strategies that engage both women and men and efforts to promote condom use among heterosexual married couples need to be developed and further evaluated for syphilis prevention.

Prevalence of arboviruses and other infectious causes of skin rash in patients treated at a tertiary health unit in the Brazilian Amazon

BACKGROUND

In the clinical course of diseases such as arboviruses, skin rashes may appear, as is often seen in other infectious diseases. The aim of this study was to estimate the prevalence of arboviruses and other infectious causes of skin rash in a tertiary health unit in Manaus, Amazonas state, Western Brazilian Amazon.

METHODOLOGY/PRINCIPAL FINDINGS

This was a cross-sectional study of patients presenting with rash who sought care at Fundação de Medicina Tropical Dr. Heitor Vieira Dourado (FMT-HVD) from February 2018 to May 2019. Individuals of either gender, aged over 18 years, were invited to participate voluntarily. Infection by Zika virus (ZIKV), dengue virus (DENV), chikungunya virus (CHIKV), Mayaro virus (MAYV), Oropouche virus (OROV) and measles was evaluated using RT-qPCR (real-time polymerase chain reaction). Immunodiagnostic tests for EBV, CMV, HIV, syphilis, rubella and measles were also performed. A total of 340 participants were included, most were female (228, 67.1%) with an average age of 36.5 years (SD ± 12.2 years). The highest prevalence was of ZIKV monoinfections (65.3%, 222/340), followed by DENV (0.9%, 3/340) and CHIKV infection (0.3%, 1/340). No cases of MAYV, OROV or rubella were found. Other causes of skin rash were detected: measles (2.9%, 10/340), parvovirus B19 (0.9% 3/340), HIV (0.3%, 1/340) and syphilis 0.6% (2/340). The co-infections identified were ZIKV+HIV (0.3%, 1/340), ZIKV+measles (0.3%, 1/340), ZIKV+parvovirus B19 (0.3%, 1/340), ZIKV+EBV (0.3%, 1/340), EBV+parvovirus B19 (0.3%, 1/340), CMV+parvovirus B19 (0.6%, 2/340), CMV+syphilis (0.3%, 1/340), ZIKV+EBV+parvovirus B19 (0.3%, 1/340) and CMV+EBV+parvovirus B19 (0.9%, 3/340). Approximately one quarter of patients had no defined cause for their skin rash (25.3%, 86/340).

CONCLUSIONS

Despite the benign clinical evolution of most of the diseases diagnosed in this series of cases, syndromic surveillance of diseases such as syphilis and HIV are of utmost importance. Periodic serosurveillance might also aid in evaluating the trends of endemic diseases and eventual outbreaks.

Spatiotemporal distribution analysis of syphilis in Brazil: Cases of congenital and syphilis in pregnant women from 2001-2017

In Brazil, the notification of congenital (CS) and syphilis in pregnant women (SiP) is compulsory. Notification data provided by the Ministry of Health in combination with the mapping of vulnerable geographic areas is essential to forecasting possible outbreaks and more effectively combating infection through monitoring. We aim to evaluate the spatiotemporal distribution and epidemiological aspects of reported cases of CS and SiP in Brazil. A retrospective ecological study was carried out using secondary surveillance data obtained from the Brazilian National Notifiable Diseases Information System (SINAN) database, considering all reported cases of CS and SiP between 2001 to 2017. Epidemiological characteristics and time trends were analyzed using joinpoint regression models and spatial distribution, considering microregions or states/macroregions as units of analysis. A total of 188,630 (359/100,000 birth lives) CS and 235,895 of SiP (6.3/100,000 inhabitants) were reported during the period studied. In general, the epidemiologic profile of Brazil indicates most reported CS cases occurred in "mixed-race" newborns who were diagnosed within seven days of birth and whose mothers had received prenatal care, but the epidemiologic profile varies by Brazilian macroregion. Regarding SiP, most cases were among women who self-reported 'mixed-race', were aged 20-39 years, had up to eight years of formal education and were diagnosed with primary or latent syphilis. Approximately 549 (98.4%) and 558 (100%) microregions reported at least one case of CS and SiP, respectively. From 2012 to 2016, CS cases increased significantly in almost all Brazilian states, most notably in the South, Southeast, and Central-West macroregions, from 2001-2017 and the relative risk (RR) of SiP increased around 400% (RR: 1,00 to 445,50). Considering the epidemiological scenario of the infection in Brazil, it is necessary to enhance preventive, control and eradication measures.

High frequency of Nichols-like strains and increased levels of macrolide resistance in Treponema pallidum in clinical samples from Buenos Aires, Argentina

Globally, 94% of Treponema pallidum subsp. pallidum (TPA) clinical strains belong to the SS14-like group and 6% to the Nichols-like group, with a prevalence of macrolide resistance of 90%. Our goal was to determine whether local TPA strain distribution and macrolide resistance frequency have changed significantly since our last report, which revealed that Buenos Aires had a high frequency of Nichols-like strains (27%) and low levels of macrolide resistance (14%). Swab samples from patients with suspected syphilis were collected during 2015–2019 and loci TP0136, TP0548, TP0705 were sequenced in order to perform multilocus sequence typing. Strains were classified as Nichols-like or SS14-like. The presence of macrolide resistance-associated mutations was determined by examination of the 23S rDNA gene sequence. Of 46 typeable samples, 37% were classified as Nichols-like and 63% as SS14-like. Macrolide resistance prevalence was 45.7%. Seven allelic profiles were found, five were SS14-like and two were Nichols-like. The frequency of Nichols-like strains increased between studies (26.8% vs. 37%, p = 0.36). A dramatic increase was found in the frequency of macrolide resistant strains between studies (14.3% vs. 45.7%, p = 0.005). Our results are in agreement with international trends and underscore the need to pursue further TPA molecular typing studies in South America.

Multilocus sequence typing of Treponema pallidum pallidum in children with acquired syphilis by nonsexual contact

Background: There are scarce data of Treponema pallidum subsp. pallidum (TPA) characterization in children with syphilis. Nonsexually acquired transmission (NSAT) of TPA is possible in infants through close contact. Methods: A descriptive study in five families with NSAT of syphilis was conducted. Polymerase chain reaction detection of TPA in pediatric index cases (n = 6) and their relatives (n = 44) were conducted followed by multilocus sequence typing (MLST). Results: TPA was detected in swab samples in 16 cases and 12 were characterized by MLST. Nichols lineage was identified in two of five families and SS14-lineage in three of five. In four families, MLST profiles linked index cases to relatives. Conclusion: This is the first report of TPA characterization in children infected by NSAT.

Tertiary Syphilis Masquerading as Oropharyngeal Cancer

Syphilis is re-emerging in the United States. Treponema pallidum, the spirochete bacterium responsible for syphilis, has immunoevasive properties that facilitate pathogenesis and widespread tissue involvement. Host immune status, particularly the presence of HIV/AIDS, can influence the presentation and severity of the disease. Patients co-infected with HIV and syphilis may develop atypical lesions, including those involving the oropharynx. Any immunocompromised patient with tongue lesions and lymphadenopathy is presumed to have a wide differential diagnosis, and tissue sampling with histopathologic analysis is indicated. We present a patient with gumma of the tongue as the initial manifestation of tertiary syphilis.

Tp0684, Tp0750, and Tp0792 Recombinant Proteins as Antigens for the Serodiagnosis of Syphilis

The incidence of syphilis has increased alarmingly over the years. Its diagnosis continues to be a challenge, leading to the search for new alternative and effective methods. The objective of this study was to select and evaluate three Treponema pallidum recombinant proteins for potential use in syphilis serodiagnosis. Bioinformatics analysis was performed with three T. pallidum antigens (Tp0684, Tp0750, and Tp0792) to assess their physical, antigenic, and structural characteristics. The antigens were chemically synthesized, recombinant plasmids were expressed in Escherichia coli BL21 Star™ (DE3), and the recombinant proteins were purified by nickel affinity chromatography. The antigenicity of the recombinant proteins was evaluated by western blotting and enzyme-linked immunosorbent assay (ELISA), using the sera from patients with primary and latent syphilis. In silico analysis indicated the antigenic potential once the exposed B cell epitopes were detected in the evaluated proteins. Sera from patients with primary and latent syphilis specifically recognized rTp0684, rTp0750, and rTp0792 recombinant antigens. Moreover, the rTp0684-ELISA receiver operating characteristic (ROC) analysis showed an area under the ROC curve of 0.99, indicating high diagnostic efficacy with 97.62% specificity and 95% sensitivity. In conclusion, rTp0684 showed better potential as an antigen for the development of syphilis serodiagnosis. Thus, bioinformatic analysis can be an important tool to guide the selection of antigens for serological diagnosis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12088-022-01017-w.

Genital ulcers caused by sexually transmitted agents

Genital ulcers (GUs) represent a diagnostic challenge and can be secondary to neoplastic and inflammatory processes of different causes. Among those of infectious etiology, there are sexually transmitted infections (STIs), a very frequent reason for seeking the health service. The most common agents are herpes simplex virus and Treponema pallidum and, more rarely, Haemophilus ducreyi, Klebsiella granulomatis and Chlamydia trachomatis. A careful dermatological examination offers important diagnostic elements; however, atypical manifestations are very common. Distinctive characteristics of ulcers to look out for include their margin, edge, bottom, and base. Regional lymph node chain alterations should be evaluated regarding their number, size, mobility, consistency, inflammation, and pain on palpation. Diagnostic tests have variable sensitivity and specificity, and molecular tests are currently considered the reference exams. The rapid immunochromatographic tests represented a significant advance, as they can be performed with blood obtained from the digital pulp, offer results in up to 30 minutes, and do not require a laboratory structure. The treatment of persons affected by GU/STIs must be immediate, as it aims to prevent complications, as well as reduce transmission. It is not always considered that people with GUs/STIs have varying degrees of depression, anxiety, and self-reproach, with an impact on relationships. Establishing a bond and trusting the professional is essential for adherence to treatment and preventive measures that must be discussed individually.

Spatio-temporal variation on syphilis from 2005 to 2018 in Zhejiang Province, China

Background

Syphilis has spread throughout China, especially in Zhejiang Province which endangers the health and lives of people. However, the spatial and temporal epidemiological studies of syphilis in Zhejiang are not thorough enough. The temporal and spatial variation and the relevant factors of syphilis incidence should be analyzed for more effective prevention and control in Zhejiang, China.

Methods

Data on confirmed cases of syphilis in Zhejiang Province from 2005 to 2018 was used and the spatio-temporal distributions were described. The spatial autocorrelation analysis and SaTScan analysis were performed to identify spatio-temporal clusters. A Bayesian spatial Conditional Autoregression (CAR) model was constructed to explore the relationships between syphilis incidence and common social and natural indicators.

Results

474,980 confirmed cases of syphilis were reported between 2005 and 2018 with a large peak in 2010. Farmers and unemployed people accounted for the largest proportion of confirmed cases. And the significant spatial clusters of syphilis were concentrated in the north of Zhejiang Province, especially in more economically developed regions. Seven spatio-temporal clusters were identified and the main three high-risk areas were located in Hangzhou (RR = 1.62, P < 0.05), Zhoushan and Ningbo (RR = 1.99, P < 0.05), and Lishui (RR = 1.68, P < 0.05). The findings showed that the morbidity of syphilis was positively correlated with the Gross Domestic Product (GDP) per capita, the number of health technicians per 10,000 people, the proportion of the elderly and air temperature were negatively correlated with the proportion of the urban population, the proportion of men and precipitation.

Conclusions

The spatio-temporal analysis revealed that the prevalence of syphilis was still serious in Zhejiang Province. Syphilis high-risk areas were mainly located in the more developed coastal regions where more targeted intervention measures were required to be implemented. The study highlighted the need to strengthen Sexually Transmitted Diseases (STD) screening and health education for high-risk groups and improve the coverage of syphilis testing to reduce hidden syphilis cases.

Characteristics of HIV/sexually transmitted infections among men who have sex with men and women in Bangkok, Thailand

BACKGROUND

Men who have sex with men (MSM) are a key HIV target population in Thailand. An important subgroup is men who have sex with men and women (MSMW) as they can sexually transmit infections between individuals with different gender identities. This study compared the sexually transmitted infection risk behavior of different types of men in Thailand.

METHODS

We retrospectively reviewed the medical records of 839 consecutive male patients who visited an STI clinic in Bangkok, Thailand, between 2014 and 2020.

RESULTS

Men who have sex with women only (MSWO) predominated (58.0%), followed by men who have sex with men only (MSMO, 32.2%) and MSMW (9.8%). MSMW and MSMO shared similar sexual risk behaviors, such as significantly higher median numbers of sex partners (10 and 8, respectively) than MSWO (5; Kruskal-Wallis, p < 0.001). MSMW had the highest prevalence of concurrent sexual partnerships (91.4%), significantly different from MSWO (61.2%) and MSMO (76.7%; chi-squared, p < 0.001). HIV and syphilis prevalence was significantly higher for MSMO (48.9% and 51.1%) and MSMW (42.7% and 48.8%) than MSWO (12.3% and 20.9%; chi-squared, p < 0.001).

CONCLUSIONS

MSMW exhibited similar sexual risk behavior and high HIV/STI prevalence comparable to MSMO.

Prioritizing syphilis control: Now is the time for action

Syphilis control programs and research received fewer resources and attention compared to HIV and other sexually transmitted infections (STIs) in the pre-pandemic era. The neglect of syphilis within comprehensive STI control efforts may be related to diagnostic (poor diagnostics), historical (legacies of racism in research), public health (limited partner services), and social problems (limited public engagement). At the same time, there are increasingly compelling reasons to prioritize syphilis control programs and research by harnessing lessons learned and advances during COVID-19. The closure of many STI facilities has accelerated new syphilis diagnostic pathways (e.g., syphilis self-testing), providing new ways for people to be screened outside of clinics. COVID-19 has underlined health inequities that fuel syphilis transmission, providing an opportunity to reckon with the historical legacy of racism that is linked to syphilis research. COVID-19 partner tracing efforts have also contributed to additional resources for partner services which may enhance syphilis control efforts. Finally, COVID-19 has demonstrated the importance of public engagement, making the case for greater public involvement in syphilis control and prevention programs. Urgent action is needed to prioritize syphilis control in a wide range of settings.

A Rare Presentation of Undiagnosed Systemic Syphilis: A Case Report and Review of Literature

Within the specialties of infectious diseases and dermatology, few rashes involve the palms and soles. The syphilitic rash has a pathognomonic association with these body surfaces and signals physicians to investigate this disease. However, the distinct presentations and symptoms associated with syphilis and the various stages of the disease make it diagnostically challenging. We herein report a rather intricate and unusual case of a patient who presented with a new-onset headache and blurred vision and a two-month history of diffuse pruritic maculopapular rash sparing the palms and soles. Several physicians had not established a diagnosis in the outpatient setting. Inpatient workup eventually revealed that the patient was suffering from secondary syphilis with neurological and ocular involvement. Management included a prolonged course of intravenous penicillin G leading to a complete recovery. We share images of the skin findings and the details of the intricate workup and hospital course, as well as a review of the literature.

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.

The Mydriatic Red Eye as the Initial Presentation of Syphilis

BACKGROUND

Syphilis is a sexually transmitted infection that has been increasing in prevalence since the early 2000s. Ocular involvement occurs in a minority of patients and must be in the differential diagnosis for patients who present with red eye and uveitis.

CASE REPORT

A 29-year-old woman presented to the emergency department with a painful, mydriatic red eye. Review of systems revealed a rash as well as a recent genital lesion and, on further questioning, she admitted to a history of intravenous drug use and high-risk sexual activity. Ophthalmology was consulted and the patient was diagnosed with bilateral uveitis. Serologic testing was positive for syphilis, and she was admitted and treated with intravenous penicillin, with resolution of her uveitis. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Red eye is a common ocular symptom in patients presenting to the emergency department. The differential diagnosis of the red eye is broad and can range from benign etiologies, such as conjunctivitis, to life- and sight-threatening conditions, such as endogenous endophthalmitis. Systemic diseases such as syphilis may present with primarily ocular symptoms, and ocular syphilis must be identified and managed appropriately to prevent devastating sequelae.

Sexually transmitted infections and female reproductive health

Women are disproportionately affected by sexually transmitted infections (STIs) throughout life. In addition to their high prevalence in women, STIs have debilitating effects on female reproductive health due to female urogenital anatomy, socio-cultural and economic factors. In this Review, we discuss the prevalence and impact of non-HIV bacterial, viral and parasitic STIs on the reproductive and sexual health of cisgender women worldwide. We analyse factors affecting STI prevalence among transgender women and women in low-income settings, and describe the specific challenges and barriers to improved sexual health faced by these population groups. We also synthesize the latest advances in diagnosis, treatment and prevention of STIs.

Women are more affected by sexually transmitted infections than men. This Review examines the impact of non-HIV STIs on women’s health, and discusses recent advances and current challenges in the treatment and prevention of STIs.

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.

Congenital Syphilis Presenting with Brain Abnormalities at Neuroscan: A Case Report and a Brief Literature Review

A case of vertical transmission in a 35-year-old pregnant woman, gravida 4, para 2 with an unknown medical history of carrying primary syphilis is described. A routine 3rd trimester scan was performed at 30 + 5 weeks of pregnancy, which revealed fetal growth restriction (FGR) associated with absent fetal movement, a pathologic neuroscan characterized by cortical calcifications and ominous Doppler waveform analysis of the umbilical artery and ductus venosus. Computerized electronic fetal monitoring (EFM) showed a Class III tracing, according to the American College of Obstetricians and Gynecologists (ACOG) guidelines. An emergency C-section was performed and a female newborn weighing 1470 g was delivered. The Apgar scores were 5 and 8 at the first and fifth min, respectively. Besides the prompted obstetrical and neonatal interventions, the neonate died after 7 days. A histologic examination of the placenta revealed a chorioamnionitis at stage 1/2 and grade 2/3. The parenchyma showed diffuse delayed villous maturation, focal infarcts, and intraparenchymal hemorrhages. The decidua presented with chronic deciduitis with plasma cells. The parents declined the autopsy. Congenital syphilis is an emerging worldwide phenomenon and the multidisciplinary management of the mother and the fetus should be mandatory.

Annular rupioid secondary syphilis confined to the face

Syphilis is a sexually transmitted infection (STI) caused by treponema pallidum. Its rash usually affects the trunk and limbs extensively, including the palms and soles of the feet. Secondary syphilis confined to the face is extremely rare. We report a case of annular rupioid secondary syphilis, which was misdiagnosed as verruca vulgaris. The patient's lesions were confined to the face and resembled oyster shells. According to epidemiological history, clinical presentation, non-treponemal tests, treponemal tests, and effective benzathine penicillin G treatment, confirmed secondary syphilis.

Point-of-Care Diagnostics for Diagnosis of Active Syphilis Infection: Needs, Challenges and the Way Forward

Syphilis, a curable sexually transmitted infection, has re-emerged as a global public health threat with an estimated 5.6 million new cases every year. Pregnant women and men who have sex with men are key target populations for syphilis control and prevention programs. Frequent syphilis testing for timely and accurate diagnosis of active infections for appropriate clinical management is a key strategy to effectively prevent disease transmission. However, there are persistent challenges in the diagnostic landscape and service delivery/testing models that hinder global syphilis control efforts. In this commentary, we summarise the current trends and challenges in diagnosis of active syphilis infection and identify the data gaps and key areas for research and development of novel point-of-care diagnostics which could help to overcome the present technological, individual and structural barriers in access to syphilis testing. We present expert opinion on future research which will be required to accelerate the validation and implementation of new point-of-care diagnostics in real-world settings.

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.

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

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

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

Background

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

Methods

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

Results

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

Conclusions

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

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

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

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

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

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

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

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

Simultaneous ocular and osseous syphilis: a case report

Syphilis is a reemerging and potentially serious disease. Owing to its ubiquity and pleomorphism, it is called "the great imitator". We report the case of a young woman with secondary syphilis who presented with bilateral acute syphilitic posterior placoid chorioretinopathy along with a syphilitic skull periostitis. A pachymeningeal enhancement was observed on magnetic resonance imaging, but we believe it was an extension of the bone process rather than a meningitis itself on the basis of the normal cerebrospinal fluid analysis results. Treatment with intravenous crystalline penicillin resulted in complete resolution of the signs, symptoms, and imaging findings. Secondary syphilis is the stage with the highest bacteremia and the highest transmissibility, presenting mainly with mucocutaneous disorders and, less frequently, with involvement of other organs. High suspicion and a pragmatic approach are essential to the diagnosis because this disease can affect several organs, as in the present case, in which the eyes, bones, and skin were affected.

A Case of Syphilitic Hepatitis in an Adolescent

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

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

Background

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

Methods

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

Results

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

Conclusions

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

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

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

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

Background

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

Methods

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

Results and Conclusion

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

Immune Privilege Furnishes a Niche for Latent Infection

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

Optic Disc Edema in Syphilis

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

Background

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

Objectives

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

Methods

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

Results

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

Conclusions

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

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

OBJECTIVE

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

DESIGN

Case report.

RESULTS

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

CONCLUSION

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

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

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

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

BACKGROUND AND PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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