Syphilis in China: results of a national surveillance programme

Spatial heterogeneity analysis for the transmission of syphilis disease in China via a data-validated reaction-diffusion model

Based on the distinctive spatial diffusion characteristics observed in syphilis transmission patterns, this paper introduces a novel reaction-diffusion model for syphilis disease dynamics, incorporating general incidence functions within a heterogeneous environment. We derive the basic reproduction number essential for threshold dynamics and investigate the uniform persistence of the model. We validate the model and estimate its parameters by employing the multi-objective Markov Chain Monte Carlo (MCMC) method, using real syphilis data from the years 2004 to 2018 in China. Furthermore, we explore the impact of spatial heterogeneity and intervention measures on syphilis transmission. Our findings reveal several key insights: (1) In addition to the original high-incidence areas of syphilis, Xinjiang, Guizhou, Hunan and Northeast China have also emerged as high-incidence regions for syphilis in China. (2) The latent syphilis cases represent the highest proportion of newly reported cases, highlighting the critical importance of considering their role in transmission dynamics to avoid underestimation of syphilis outbreaks. (3) Neglecting spatial heterogeneity results in an underestimation of disease prevalence and the number of syphilis-infected individuals, undermining effective disease prevention and control strategies. (4) The initial conditions have minimal impact on the long-term spatial distribution of syphilis-infected individuals in scenarios of varying diffusion rates. This study underscores the significance of spatial dynamics and intervention measures in assessing and managing syphilis transmission, which offers insights for public health policymakers.

An observational prospective study based on a large cohort of HIV-negative neurosyphilis patients with particular reference to the Jarisch-Herxheimer reaction

PURPOSE

The purpose of this study is to outline a complete picture of Jarisch-Herxheimer reaction (JHR) in the central nervous system among HIV-negative neurosyphilis patients.

METHODS

A prospective study cohort of 772 cases with almost all stages of neurosyphilis depicted the features of JHR including occurrence rate, risk profiles, clinical manifestations, medical management and prognosis.

RESULTS

The total occurrence rate of JHR was 9.3% (95% CI, 7.3-11.4%), including 4.1% (95% CI, 2.7-5.6%) with severe JHR. The reaction started 5 h after treatment initiation, peaked after 8 h, and subsided after 18 h. Patients with severe JHR experienced a longer recovery time (26 h). Patients with general paresis (OR = 6.825), ocular syphilis (OR = 3.974), pleocytosis (OR = 2.426), or a high CSF-VDRL titre (per log2 titre increase, OR = 2.235) were more likely to experience JHR. Patients with general paresis had an 11.759-fold increased risk of severe JHR. Worsening symptoms included cognitive impairment, mania, nonsense speech, and dysphoria, while symptoms of hallucination, urination disorder, seizures, myoclonus, or aphasia appeared as new-onset symptoms. Neurosyphilis treatment did not need to be interrupted in most patients with JHR and could be reinstated in patients with seizures under supportive medication when JHR subsided.

CONCLUSION

Severe JHR displayed a 4.1% occurrence rate and clinicians should pay particular attention to patients at a higher risk of JHR. The neurosyphilis treatment regime can be restarted under intensive observation for patients with severe JHR and, if necessary, supportive medication should be initiated and continued until the end of therapy.

Vulnerable newborn phenotypes in Peru: a population-based study of 3,841,531 births at national and subnational levels from 2012 to 2021

Background

We aimed to examine the national and subnational prevalence of vulnerable newborn phenotypes in Peru, 2012-2021.

Methods

Newborn phenotypes were defined using gestational age (preterm [PT], term [T]), birthweight for gestational age using INTERGROWTH-21st standards (small for gestational age [SGA], appropriate for gestational age [AGA] or large for gestational age [LGA]), and birthweight (low birthweight [LBW], non-LBW) using the Peruvian National Birth Registry as six (by excluding birthweight) and ten newborn phenotypes (using all three outcomes). Small phenotypes (with at least one classification of PT, SGA, or LBW) were further considered. Using individual-level data, we stratified the phenotypes by maternal educational level, maternal age, healthcare insurance, altitude of residence, and geographic region (Coast, Andes, and Amazon).

Findings

The prevalence of the five vulnerable newborn phenotypes for the study period was LGA+T (15.2%), AGA+PT (5.2%), SGA+T (4.6%), LGA+PT (0.8%), and SGA+PT (0.7%). The Coast had a higher prevalence of newborns with large phenotypes (19.4%) and the Highlands a higher prevalence of newborns with small phenotypes (12.5%). Mothers with poor socioeconomic status, extreme ages and living at high altitude had a higher prevalence of newborns with small phenotypes, and mothers who were wealthier, more educated, and older had a higher prevalence of infants with large phenotypes.

Interpretation

Our findings cautiously suggest that socioeconomic and geographic disparities may play a crucial role in shaping vulnerable newborn phenotypes at national and subnational level in Peru. Further studies using longitudinal data are needed to corroborate our findings and to identify individual-level risk factors.

Funding

Ter Meulen Grant from the KNAW Medical Sciences Fund of the Royal Netherlands Academy of Arts and Sciences (KNAWWF/1085/TMB406, KNAWWF/1327/TMB202116), Fogarty Program (D43TW011502).

Cholestatic Hepatitis with Concomitant Nephrotic Syndrome due to Secondary Syphilis in a Young Man

Introduction

Syphilis, an ancient sexually transmitted disease, is recognized as a systemic infection disease manifesting with diverse symptoms and variations. Secondary syphilis characterized by systemic symptoms resulted from hematogenous and lymphatic dissemination of the infection, may include manifestations such as hepatitis and nephrotic syndrome. However, the simultaneous occurrence of hepatitis and nephrotic syndrome in secondary syphilis is rare.

Case Presentation

A young man presented with fatigue, abnormal liver function tests, and hyperbilirubinemia and had history of men who have sex with men (MSM). Serological tests confirmed the diagnosis of secondary syphilis, and kidney biopsy indicated membranous nephritis. After antibiotic treatment, the patient experienced resolution of proteinuria, and liver enzyme levels returned to normal.

Conclusion

Syphilis should be considered in the differential diagnosis of simultaneous liver and kidney dysfunction, particularly in patients engaging in high-risk sexual behavior. This case highlights the importance of considering syphilis in young patients with MSM and presenting with unexplained nephrotic syndrome and liver abnormalities.

An Incognito Standardized Patient Approach for Measuring and Reducing Intersectional Healthcare Stigma

Background

Consistent evidence highlights the role of stigma in impairing healthcare access in people living with HIV (PLWH), men who have sex with men (MSM), and people with both identities. We developed an incognito standardized patient (SP) approach to obtain observations of providers to inform a tailored, relevant, and culturally appropriate stigma reduction training. Our pilot cluster randomized control trial assessed the feasibility, acceptability, and preliminary effects of an intervention to reduce HIV stigma, anti-gay stigma, and intersectional stigma.

Methods

Design of the intervention was informed by the results of a baseline round of incognito visits in which SPs presented standardized cases to consenting doctors. The HIV status and sexual orientation of each case was randomly varied, and stigma was quantified as differences in care across scenarios. Care quality was measured in terms of diagnostic testing, diagnostic effort, and patient-centered care. Impact of the training, which consisted of didactic, experiential, and discussion-based modules, was assessed by analyzing results of a follow-up round of SP visits using linear fixed effects regression models.

Results

Feasibility and acceptability among the 55 provider participants was high. We had a 87.3% recruitment rate and 74.5% completion rate of planned visits (N=238) with no adverse events. Every participant found the training content "highly useful" or "useful." Preliminary effects suggest that, relative to the referent case (HIV negative straight man), the intervention positively impacted testing for HIV negative MSM (0.05 percentage points [PP], 95% CI,-0.24, 0.33) and diagnostic effort in HIV positive MSM (0.23 standard deviation [SD] improvement, 95% CI, -0.92, 1.37). Patient-centered care only improved for HIV positive straight cases post-training relative to the referent group (SD, 0.57; 95% CI, -0.39, 1.53). All estimates lacked statistical precision, an expected outcome of a pilot RCT.

Conclusions

Our pilot RCT demonstrated high feasibility, acceptability, and several areas of impact for an intervention to reduce enacted healthcare stigma in a low-/middle-income country setting. The relatively lower impact of our intervention on care outcomes for PLWH suggests that future trainings should include more clinical content to boost provider confidence in the safe and respectful management of patients with HIV.

Identification of a Potential Vaccine against Treponema pallidum Using Subtractive Proteomics and Reverse-Vaccinology Approaches

Syphilis, a sexually transmitted infection, is a deadly disease caused by Treponema pallidum. It is a Gram-negative spirochete that can infect nearly every organ of the human body. It can be transmitted both sexually and perinatally. Since syphilis is the second most fatal sexually transmitted disease after AIDS, an efficient vaccine candidate is needed to establish long-term protection against infections by T. pallidum. This study used reverse-vaccinology-based immunoinformatic pathway subtractive proteomics to find the best antigenic proteins for multi-epitope vaccine production. Six essential virulent and antigenic proteins were identified, including the membrane lipoprotein TpN32 (UniProt ID: O07950), DNA translocase FtsK (UniProt ID: O83964), Protein Soj homolog (UniProt ID: O83296), site-determining protein (UniProt ID: F7IVD2), ABC transporter, ATP-binding protein (UniProt ID: O83930), and Sugar ABC superfamily ATP-binding cassette transporter, ABC protein (UniProt ID: O83782). We found that the multiepitope subunit vaccine consisting of 4 CTL, 4 HTL, and 11 B-cell epitopes mixed with the adjuvant TLR-2 agonist ESAT6 has potent antigenic characteristics and does not induce an allergic response. Before being docked at Toll-like receptors 2 and 4, the developed vaccine was modeled, improved, and validated. Docking studies revealed significant binding interactions, whereas molecular dynamics simulations demonstrated its stability. Furthermore, the immune system simulation indicated significant and long-lasting immunological responses. The vaccine was then reverse-transcribed into a DNA sequence and cloned into the pET28a (+) vector to validate translational activity as well as the microbial production process. The vaccine developed in this study requires further scientific consensus before it can be used against T. pallidum to confirm its safety and efficacy.

Prevalence of Syphilis Infections Among Volunteer Blood Donors in Jinan Blood Center, China: A 15-Year Retrospective Study

BACKGROUND

Syphilis infections among volunteer blood donors increased rapidly in recent years. It is important to analyze the demographics of seropositive donor groups and help to recruit donors from low-risk population.

OBJECTIVE

The aim of this study was to analyze the syphilis prevalence among volunteer blood donors in Jinan Blood Center and give direction to blood recruitment.

METHODS AND MATERIALS

A cross-sectional study was conducted among blood donors in Jinan, China. Socio-demographic data and blood donation testing data from January 2007 to December 2021 were extracted from the database of blood management software of Jinan Blood Center for analysis. All blood samples were screened by ELISA, and those anti-TP-positive samples were counted and analyzed by sex, age, educational background, occupation and blood donation times. Logistic regression was used to explore risk factors associated with syphilis infection.

RESULTS

Totally 700,757 blood samples were collected in the study during 2007 to 2021, 2290 cases were detected anti-TP positive with a positive rate of 0.33%. Female, 35-44 years old, with a lower education degree, farmers and first-time donors were the high-risk subgroups.

CONCLUSION

Consultation and identification of high-risk population groups should be improved. Measures should be taken to make the donor recruitment more professional and detailed.

Spatial Heterogeneity and Its Influencing Factors of Syphilis in Ningxia, Northwest China, from 2004 to 2017: A Spatial Analysis

Syphilis remains a growing and resurging infectious disease in China. However, exploring the influence of environmental factors on the spatiotemporal distribution of syphilis remains under explore. This study aims to analyze the spatiotemporal distribution characteristics of syphilis in Ningxia, Northwest China, and its potential environmental influencing factors. Based on the standardized incidence ratio of syphilis for 22 administrative areas in Ningxia from 2004 to 2017, spatiotemporal autocorrelation and scan analyses were employed to analyze the spatial and temporal distribution characteristics of syphilis incidence, while a fixed-effect spatial panel regression model identified the potential factors affecting syphilis incidence. Syphilis incidence increased from 3.78/100,000 in 2004 to 54.69/100,000 in 2017 with significant spatial clustering in 2007 and 2009-2013. The "high-high" and "low-low" clusters were mainly distributed in northern and southern Ningxia, respectively. The spatial error panel model demonstrated that the syphilis incidence may be positively correlated with the per capita GDP and tertiary industry GDP and negatively correlated with the number of health facilities and healthcare personnel. Sex ratio and meteorological factors were not significantly associated with syphilis incidence. These results show that the syphilis incidence in Ningxia is still increasing and has significant spatial distribution differences and clustering. Socio-economic and health-resource factors could affect the incidence; therefore, strengthening syphilis surveillance of migrants in the economically developed region and allocating health resources to economically underdeveloped areas may effectively help prevent and control syphilis outbreaks in high-risk cluster areas of Ningxia.

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.

Prevalence of Treponema Pallidum Antibody among Volunteer Blood Donors in China

Background

Infection with syphilis is still a major public health problem. The precise data for syphilis seroprevalence in the populations will help to develop a strategy for prevention and treatment of it. However, the data for syphilis prevalence in continuous years among volunteer blood donors in China is rare.

Methods

A retrospective study for Treponema pallidum (TP) antibody in blood donors was conducted from January 2010 to December 2019 at the Blood Center of Zhejiang Province, China. TP antibody was detected with two different reagents using enzyme-linked immunosorbent assay and the only sample which was reactive in the two reagents was defined as seropositive.

Results

A total of 992,646 volunteer blood donors were analyzed and the positive rate of TP antibody in the blood donors was 0.43%. From 2010 to 2019, the positive rates of TP antibody were 0.53%, 0.51%, 0.51%, 0.43%, 0.36%, 0.18%, 0.11%, 0.12%, 0.11%, and 0.10%, respectively. The positive rates of TP antibody were significantly different among blood donor age group (p < 0.001), with the highest positive rate in 45–54-years-old group (0.93%). The positive rates of TP antibody in male and female blood donors were 0.44% and 0.41%, respectively. The positive rate was 0.57% among the first-time blood donors, which was significantly higher than that of the repeat blood donors (0.17%). The positive rate of TP antibody in blood donors decreased gradually with the increase of educational level.

Conclusion

The syphilis seroprevalence is low in the blood donors of the Hangzhou area, and the positive rate of blood donors is associated with age, educational level, and times of blood donation. Increasing the number of repeat blood donations is helpful to improve blood safety.

Spatial-temporal analysis of HIV/AIDS and syphilis in mainland China from 2007 to 2017

Human immune deficiency virus (HIV)/acquired immune deficiency syndrome (AIDS) and syphilis are the most common sexually transmitted diseases (STDs) worldwide, as well as in China. The objective of this study is to describe the trend of spatial and temporal variation of HIV/AIDS and syphilis in mainland China from 2007 to 2017. Stratified analysis was conducted according to age and the GDP per capita. Estimated Annual Percentage Change (EAPC) was calculated and spatial autocorrelation analysis was used to evaluate the epidemiology and identify clusters. The morbidity of new HIV infection increased from 2.5034/100 000 in 2007 to 6.9247/100 000 in 2017, with an EAPC of 9.84 (95% confidence interval [CI]: 9.07-10.60). From 2007 to 2017, the morbidity of syphilis presented a significant upward trend from 15.8834/100 000 to 34.4867/100 000 (EAPC = 6.48, 95% CI: 4.23-8.73). The number of new HIV infections (205 084) and syphilis (921 279) were highest in the 20-30 years old group, where the incidence decreased with age over 20 years. In general, HIV and syphilis infection had the same incidence trend according to age and time stratification. The morbidity of new HIV infection was mainly reported from Xinjiang and southwestern China. As for syphilis, the highest was found in Zhejiang in Xinjiang and southeast coastal areas. Both HIV and syphilis infection showed a nonrandom positive correlation by Moran's I value. The High-High cluster areas of HIV infection were concentrated in southwestern and eastern China due to syphilis. A highly significant positive correlation was found between gross domestic product per capita and syphilis infection (p < 0.05) but was not associated with HIV infection. The incidence of AIDS/HIV and syphilis is increasing year by year, and a higher prevalence is found in younger individuals. More attention should be paid to HIV infection in the southwest, syphilis in southeast coastal areas, and both the two diseases in Xinjiang.

A Markov based model to estimate the number of syphilis cases among floating population

Syphilis is a sexually transmitted disease that spreads widely around the world, infecting tens of millions of people every year. In China, syphilis not only causes more than 1 million infections every year, but also has its own characteristics in spreading pattern: this disease always spreads with the migration of floating population. There have been many related investigations and studies on the transmission of syphilis with the floating population in China, but the study of quantitative modeling in this field is very limited. In this paper, based on the Markov process model and datasets collected in Zhejiang Province, China, we construct a new model to analyze the transmission and immigration process of syphilis. The results show that immigrant patients are one of the sources of infection of syphilis in Zhejiang province, and the infection rate is remarkable which should not be ignored. By using the PRCC method to analyze the relationship between parameters and infected cases, we also find two main effective measures that can control the spread of syphilis and reduce the infection rate: the self-attention of infected persons, and the use of sexual protection measures. With the increasing frequent exchanges of people among different countries and regions, studying the transmission of diseases with the floating populations has become more and more important. The method we use in this paper gives a new insight studying this issue, providing a quantitative research method using the data of diagnosed cases. All the methods and models in this paper can be extendly used in the studies of other diseases where immigrant patients should be considered.

New Syphilis Cases in Older Adults, 2004-2019: An Analysis of Surveillance Data From South China

Background: Sexual health among older adults is a major public health concern globally. The syphilis burden is increasing in older adults in China. This study aimed to describe factors associated with syphilis infection and diagnosis among older adults in China during a 16 year period. Methods: Using 16 years of data (2004-2019) from the syphilis case report system of Guangdong, China, we compared data from older adults (aged ≥50 years) with those from younger people (aged 15-49 years). We compared the two age group with the Chi-square test for difference, and Joinpoint regression models to assess the temporal trends. Results: During the study period, 242,115 new syphilis diagnoses were reported in older adults. The mean notification rate of new diagnoses was 64.1 per 100,000 population across the entire 16-year period, which significantly increased over time (average annual percent change [AAPC] 16.2%, 95% CI 13.7-18.7). Syphilis diagnoses increased significantly over time among less developed cities and older women. In 2019, compared with younger adults, newly diagnosed older adults were more likely to be male, native to reporting city, had unknown transmission routes, and were diagnosed late. Conclusion: Our findings call for an urgent need to deliver more targeted prevention interventions for older adults, such as strengthen awareness among health care providers, and integration of syphilis services and primary health care for older adults.

Predictors of Seronegative Conversion After Centralized Management of Syphilis Patients in Shenzhen, China

Objective: The aim of this study was to explore the seronegative conversion status of syphilis patients after centralized management and to analyze potential determinants.

Materials and Methods: A retrospective population-based cohort study was conducted, and data for individuals who had been diagnosed with syphilis between 2011 and 2019 were retrieved from the Shenzhen Nanshan Center for Chronic Disease Control. Seroconversion statuses were summarized as percentages. Univariable and multiple Cox proportional hazard regression models were used to analyze the factors associated with seronegative conversion among syphilis patients.

Results: During the study period, 1,545 patients with syphilis participated in the syphilis convergence case management program on a voluntary basis, of whom 290 were excluded due to missing follow-up data. A total of 27.6% (346/1255) of patients with syphilis showed seronegative conversion. Multivariable analysis revealed that the following significantly determined syphilis seroconversion from positive to negative: younger age (15–19 years vs. ≥30 years: HR = 2.18), male gender (HR = 1.45), lower baseline toluidine red unheated serum test (TRUST) titer of ≤ 1:8 (HR = 2.23), and different disease stages, including latent syphilis (HR = 1.98), primary syphilis (HR = 7.67), and secondary syphilis (HR = 4.83).

Conclusions: Few patients with syphilis tested negative after treatment at the end of the study. Seronegative conversion in the patients was associated with age, sex, baseline TRUST titer, and syphilis stage.

The effect of public health awareness and behaviors on the transmission dynamics of syphilis in Northwest China, 2006-2018, based on a multiple-stages mathematical model

Syphilis, a sexually transmitted infectious disease caused by the bacterium treponema pallidum, has re-emerged as a global public health issue with an estimated 12 million people infected each year. Understanding the impacts of health awareness and behaviors on transmission dynamics of syphilis can help to establish optimal control strategy in different regions. In this paper, we develop a multiple-stage SIRS epidemic model taking into account the public health awareness and behaviors of syphilis. First, the basic reproduction number R0 is obtained, which determines the global dynamics behaviors of the model. We derive the necessary conditions for implementing optimal control and the corresponding optimal solution for mitigation syphilis by using Pontryagin's Maximum Principle. Based on the data of syphilis in Ningxia from 2006 to 2018, the parameterizations and model calibration are carried out. The fitting results are in good agreement with the data. Moreover, sensitivity analysis shows that the public awareness induced protective behaviors C_e, compliance of condom-induced preventability ε and treatment for the primary syphilis m₁ play an important role in mitigating the risk of syphilis outbreaks. These results can help us gain insights into the epidemiology of syphilis and provide guidance for the public health authorities to implement health education programs.

The associations of increased cerebral small vessel disease with cognitive impairment in neurosyphilis presenting with ischemic stroke

BACKGROUND AND PURPOSE

Ischemic stroke is a common clinical feature of neurosyphilis, but its accompanying cognitive decline is often overlooked. The mechanisms of cognitive impairment in neurosyphilis presenting with ischemic stroke are not fully understood. Cerebral small vessel disease (CSVD) was recently shown to predict post-stroke cognitive decline. Therefore, this study aims to validate the correlation between CSVD and cognitive impairment in neurosyphilis presenting with ischemic stroke.

METHODS

We enrolled 179 neurosyphilis patients diagnosed as acute ischemic stroke and performed a 12-month cognitive assessment follow-up. CSVD burden was evaluated by neuroimaging markers, including white matter hyperintensities (WMHs), lacunes, cerebral microbleeds (CMBs), and perivascular spaces (PVS). We performed multivariate logistic regression analysis to determine the association between cognitive decline and total CSVD burden score in neurosyphilis patients.

RESULTS

The neurosyphilis participants had a significantly higher total CSVD score and lower cognitive function score compared with the syphilis-uninfected patients. Acute cognitive impairment was associated with total CSVD score, extensive microbleeds, and Grade 3 WMHs. After 12-month follow-up, the poor prognosis of post-stroke cognitive impairment was associated with a higher burden of CSVD and extensive microbleeds.

CONCLUSIONS

Cerebral small vessel disease loads in neurosyphilis patients presenting with ischemic stroke are independently associated with acute cognitive impairment and have a prospective value for post-stroke cognitive outcomes.

Evolution of syphilis incidence in Sibiu county (Romania) over a period of 10 years (2009-2018)

Syphilis is the most common sexually transmitted disease that mainly affects socially active people, with a fluctuating worldwide incidence over the years. A retrospective study was conducted over a period of 10 years (2009-2018) that included 396 patients with syphilis diagnosed and monitored by Sibiu County Emergency Clinical Hospital, Romania. During this period (2009-2018), we observed a decrease in the new cases of syphilis by 35.90%, and the average syphilis incidence was 9.90 new cases per 100,000 inhabitants. Syphilis was diagnosed more frequently in men with an average age of 35.39 years, from urban areas, with and educational level of grades 9-12, unmarried, workers, or without occupation. Out of the 396 patients with syphilis, about 6% were HIV coinfected. Over half of the HIV coinfected cases were declared MSM (men who have sex with men), and 40% of these cases were registered in 2018. The most common clinical stage of syphilis was the latent form (67.93%). Regarding the syphilis treatment regimen, we noted the transition from the classic regimen with benzathine-penicillin G (100% in 2009) to alternative therapies (mainly with cephalosporins) in 2018 (56.86%). Our findings showed that in the last 10 years in our county, the incidence of syphilis had a downward trend, but with an increase in syphilis-HIV co-infection and neurosyphilis cases.

Prevalence and Predictors of Syphilis in Female Sex Workers in Eastern China: Findings from Six Consecutive Cross-Sectional Surveys

Purpose

Female sex workers play an important role in transmitting HIV and syphilis from high-risk groups to the general population. However, epidemic trends and risk factors for syphilis in Chinese female sex workers (FSWs) remain unclear.

Methods

Using convenient sampling methods, 2482 FSWs were interviewed and tested for syphilis from 2014 to 2019, all of them were divided into two groups of high-grade FSWs and low-grade FSWs according to service solicited and clients price there were. Demographic data were collected and logistic regression analysis was used to identify risk factors for syphilis.

Results

43.67% of participants have received free condoms, 76.15% of them engaged in peer education of the 2482 FSWs tested for syphilis, 107 (4.31%) were positive. The prevalence of syphilis in high-grade FSWs was significantly lower than that in low-grade FSWs (3.14% and 5.62%, respectively).The overall prevalence of syphilis increased from 3.19% to4.47%. The percentage of FSWs received free condoms and engaged in peer education increased significantly. With upgraded awareness of syphilis, the number of FSWs having protected sex also increased significantly. It is also found that low-grade female sex workers are at greater risk of syphilis than those high-grade ones (odds ratio (OR) = 1.76, 95% CI 1.18–2.63, p < 0.05).

Conclusion

Great awareness of syphilis and the increased utilization of condom did not reduce the prevalence of syphilis, especially in low-grade FSWs group. More effective integrated interventions should be developed for such populations.

Ocular syphilis

Syphilis is a sexually transmitted, systemic, inflammatory disease caused by the spirochaete, Treponema pallidum. The natural history of untreated syphilis progresses through four distinct stages: primary, secondary, latent, and tertiary syphilis. Ocular involvement can occur at any stage of syphilis and any part of the eye can be affected. With the exception of syphilitic posterior placoid chorioretinitis, the diverse manifestations of ocular syphilis have few distinct features that can be used to assist in clinical diagnosis. Therefore, ocular syphilis should always be a part of the differential diagnosis of most, if not all, ocular infectious and inflammatory presentations. Specifically, uveitis presentations, high-risk sexual history, illicit drug use history, treatment failure, prior history of syphilis should prompt further diagnostic workup for ocular syphilis. A presumptive diagnosis of ocular syphilis relies on serological testing, both treponemal and nontreponemal tests. All patients with ocular syphilis should have their cerebrospinal fluids tested for the co-existence of neurosyphilis and their blood tested for human immunodeficiency virus co-infection. In the United States, Centers for Disease Control and Prevention recommend that ocular syphilis be managed according to its treatment guidelines for neurosyphilis, with parenteral aqueous crystalline penicillin G the drug of choice. With the timely diagnosis and appropriate treatment, ocular syphilis is curable. However, delayed diagnosis of ocular syphilis may result in long-term visual impairment. Delayed diagnosis occurs because of its diverse presentations mimicking other ocular diseases, and failure of the clinician to order serological testing. With the recent worldwide resurgence of ocular syphilis, clinicians should be familiar with the manifestation, diagnosis, and treatment of ocular syphilis.

Detection-Based Monetary Incentives to Improve Syphilis Screening Uptake: Results of a Pilot Intervention in a High Transmission Setting in Southern China

BACKGROUND

Underscreening of syphilis in clinical settings is a pervasive problem in resource-constrained settings where heavy patient loads and competing health priorities inhibit health providers' ability to meet screening coverage targets. A "detection-based" pay-for-performance (P4P) strategy can incentivize more targeted testing by rewarding providers with a monetary bonus for every confirmed case.

METHODS

Five clinics in a high transmission setting of China participated in the 6-month pilot intervention. Seropositive proportions during the P4P intervention were compared with those during the preintervention phase using multilevel logistic regression models adjusted for age and sex of clinic attendees.

RESULTS

There were 8423 patients that sought care at 1 of the 6 clinics over the course of the study. Adjusted odds of a positive syphilis screen were greater during the intervention period compared to the preintervention interval (odds ratio, 1.33; 95% confidence interval, 1.14-1.56). Variability in clinic-level effects was substantial given the small number of sites of this pilot study.

CONCLUSIONS

Results of this detection-based P4P pilot study demonstrate the feasibility and preliminary effectiveness of this approach for improving syphilis case detection in resource-constrained clinical settings. A fully powered randomized trial is needed to inform the full utility of this approach for improving sexually transmitted disease detection globally.

Positive syphilis serology contributes to intracranial stenosis in ischemic stroke patients

BACKGROUND AND PURPOSE

The risk of ischemic stroke is increased among people living with syphilis infection; however, whether syphilis is an independently risk for stenosis is unclear. We investigated the clinical, laboratory, and vascular stenosis features of ischemic stroke patients living with positive syphilis serology to evaluate the role of syphilis in cerebral artery stenosis.

METHODS

The demographic, clinical characteristics, and the distribution of cerebral artery stenosis were compared between 668 syphilis-positive and 785 syphilis-negative ischemic stroke patients. Multivariate logistic regression analysis was performed to determine the degree and distribution of stenosis associated with positive syphilis serology and estimate the factors related to artery stenosis in the syphilis-positive ischemic stroke patients.

RESULTS

Syphilis-positive ischemic stroke patients were distinct from the nonsyphilis population, with a younger age, fewer women, and a different risk factor profile. Positive syphilis serology was independently associated with moderate stenosis (OR, 2.31; 95% CI 2.02-2.69; p = .003) and severe stenosis (OR, 6.15; 95% CI, 2.85-8.94; p < .001), mainly intracranial stenosis (OR, 1.49; 95% CI, 1.15-1.92; p = .002) rather than extracranial stenosis. Among stroke patients with positive syphilis serology, the higher RPR titer (OR, 1.18, 95% CI, 1.07-1.89 for RPR titer 1:16; OR, 5.16, 95% CI 2.99-8.89 for RPR titer > 1:32) and previous unknown or untreated syphilis (OR, 3.63; 95% CI, 2.72-4.03; p < .001) were the factors related to stenosis.

CONCLUSIONS

Syphilis infection, especially when less well controlled, may play an important role in intracranial stenosis of ischemic stroke patients.

The importance of proper and prompt treatment of ocular syphilis: a lesson from permanent vision loss in 52 eyes

BACKGROUND

Ocular involvement can occur at any stage of syphilis. Prompt diagnosis and proper treatment of ocular syphilis are vital to avoid long-term consequences.

OBJECTIVES

To describe the risk factors for ocular syphilis and clinical features of blindness caused by syphilis.

METHODS

We report risk factors for ocular syphilis amongst patients seen at the Shanghai Skin Disease Hospital between October 2009 and October 2017. We identify patients with ocular syphilis resulting in blindness and report the clinical characteristics, laboratory findings and treatment outcomes of these patients.

RESULTS

A total of 8310 new cases of syphilis were seen, of which 213 patients had ocular disease and 50 patients had blindness due to syphilis. Increasing age and higher RPR titres were associated with ocular involvement but there was no association with HIV status. Blindness in syphilis was restricted predominantly to patients with optic nerve involvement and not patients with isolated uveitis. Fifty patients (and a total of 67 eyes) met the WHO definition of blindness prior to treatment for syphilis. At the end of follow-up, vision had improved in 24 of 67 eyes (35.8%) after treatment. Successful treatment of uveitis was associated with the best improvement in visual acuity, whilst patient with underlying optic atrophy prior to treatment had the worst visual outcome.

CONCLUSIONS

Ocular involvement is an important manifestation of syphilis which may result in blindness. Our data demonstrate outcomes for ocular syphilis are poor if detected late; early recognition and diagnosis is therefore vital to avoid permanent visual loss.

Prevalence and trends of transfusion-transmittable infections among blood donors in Southwest China

BACKGROUND

The high prevalence of transfusion-transmitted infections (TTIs) is causing serious harm to human health worldwide. The aim of this research was to assess the prevalence and influencing factors of TTIs in Southwest China.

METHODS

A retrospective study of blood donor records from January 2008 to December 2015 was conducted. All samples were screened for HBV, HCV, HIV and syphilis. The donor's data was recorded and analyzed statistically using SPSS software.

RESULTS

We revealed that the prevalence of TTIs showed a decreasing trend from 2.39 to 1.98%, and this was slightly lower than that in other regions of China. Syphilis infection was the most serious issue among blood donors in Southwest China, which demonstrated a significantly higher rate than that in other areas of China. The high infection rate of the female and farmer groups in rural regions is worth noting. The logistic regression model showed that age, occupation and donor category was the influential factors for TTIs.

CONCLUSIONS

The overall prevalence of TTIs demonstrated a decreasing trend from 2008 to 2015 in Southwest China, but there is still a sufficient threat to blood safety, and more efforts are needed to further guarantee blood safety in China.

Prevalence and associated factors of Treponema pallidum infection in a rural area of southwestern China

Background

Epidemiological data on Treponema pallidum infection are scarce from the southwestern region of China. The purpose of this study was to determine the distribution and determinants of T. pallidum infection in the region.

Methods

A community-based cross-sectional study of 2608 participants aged ≥14 years was conducted in a rural area of southwestern China in 2014–15. A pretested questionnaire was used to collect sociodemographic characteristics and other factors associated with T. pallidum infection. The diagnoses of T. pallidum, human immunodeficiency virus (HIV), hepatitis B virus (HBV) and hepatitis C virus (HCV) infections were determined by commercial test kits. Logistic regression analysis was used to determine the correlates for T. pallidum infection, and adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were calculated.

Results

The prevalence of T. pallidum infection was 1.2% (95% CI 0.8 to 1.7%). Risk factors varied by gender. In the male group, T. pallidum infection was significantly associated with ever injection drug use (aOR = 9.42, 95% CI 2.47 to 35.87) and HCV infection (aOR = 13.28, 95% CI 3.20 to 51.70). In the female group, correlates for T. pallidum infection included spouse having syphilis (aOR = 126.66, 95% CI 7.58 to 2122.94), ever having blood transfusion (aOR = 10.51, 95% CI 1.58 to 41.21) and HBV infection (aOR = 4.19, 95% CI 1.35 to 10.93).

Conclusions

The prevalence of T. pallidum infection was high in the rural area of southwestern China. Correlates for T. pallidum infection varied with sex specific. Intervention should be developed for the prevention and control of T. pallidum infection.

Increased CCL24 and CXCL7 levels in the cerebrospinal fluid of patients with neurosyphilis

Background

Monocytes are recruited into the cerebrospinal fluid (CSF) of patients with neurosyphilis, suggesting abnormal chemokine expression. We aimed to investigate the aberrant expression of chemokines in the CSF of these patients.

Methods

CSF and serum samples were collected from patients with neurosyphilis between July 2017 and June 2019 in the Dermatology Department, Second Affiliated Hospital of Zhejiang University. Differences in the expression of 38 chemokines between patients with and without neurosyphilis were detected using RayBio^® Human Chemokine Antibody Array C1. CCL24 and CXCL7 levels in the patients’ CSF and serum were further measured using RayBio^® CCL24 and CXCL7 ELISA kits.

Results

Ninety‐three CSF and serum samples of patients with syphilis were collected. Antibody array analysis showed that the CSF levels of CCL24 (P = .0185), CXCL7 (P < .0001), CXCL13 (P < .0001), CXCL10 (P < .0001), and CXCL8 (P < .0001) were significantly higher in patients with than without neurosyphilis. ELISA confirmed significantly higher CCL24 and CXCL7 levels in the CSF of patients with than without neurosyphilis (CCL24: 6.082 ± 1.137 pg/mL vs 1.773 ± 0.4565 pg/mL, P = .0037; CXCL7: 664.3 ± 73.19 pg/mL vs 431.1 ± 90.54 pg/mL, P = .0118). Increased CCL24 and CXCL7 expression was seen throughout all neurosyphilis stages, had moderate diagnostic efficiency for neurosyphilis, and correlated poorly with CSF cell count and Venereal Disease Research Laboratory titer. CSF CCL24 levels also correlated poorly with CSF protein concentration.

Conclusion

Abnormally high CSF chemokines levels may play a role in the pathogenesis of neurosyphilis.

Prevalence and predictors of bacterial vaginosis in HIV-infected women in Maharashtra, India

We evaluated the prevalence and determinants of bacterial vaginosis (BV) in HIV-infected women from Maharashtra, India. Among 912 HIV-infected women enrolled, BV was diagnosed in 191 (20.9%) and intermediate BV was diagnosed in 258 (28.3%) women. Women with more than two pregnancies had 1.6 times increased risk of BV (95% CI 1.0, 2.5, p-value 0.038), women who were menopausal had 6.2 times increased risk of BV (95% CI 2.4, 15.6, p-value <0.001) and women who were human papillomavirus (HPV) positive had 2.3 times increased risk of BV (95% CI 1.4, 3.9, p-value 0.001). Although we observed significantly increased risk of BV among women diagnosed with cervical intraepithelial neoplasia or worse disease in the univariate analysis (odds ratio 3.5, 95% CI 1.5, 8.1, p-value 0.004), it did not reach statistical significance in the multivariate analysis. Women who had the first sexual intercourse after the age of 18 had significantly lower risk of BV. To conclude, we observed high prevalence of BV in HIV-infected women and increased risk of BV in HPV positive, HIV-infected women.

Comparison of "Lumipulse anti-Treponema pallidum" and "Architect Syphilis TP" and further examination

Background

Syphilis is a sexually transmitted disease caused by Treponema pallidum (TP) infection. In recent years, diagnostic reagents with fully automated immunoassay instruments have become mainstream. However, these positive screening tests with high sensitivity, which are performed with full automation, need confirmation by Treponema pallidum particle agglutination (TPPA) to be judged as positive.

Methods

We evaluated the diagnostic performance of Lumipulse G TP‐N assay (Lumi‐TP, Fujirebio Inc) in 223 preselected TP‐positive samples and 1041 TP‐negative samples, compared it with that of the TP gold standard test (TPPA) and Architect Syphilis TP test (Archi‐TP, Abbott).

Results

The concordance rates for the results for the positive and negative samples between Lumi‐TP and TPPA were 100%. On the other hand, the rates for the results between Archi‐TP and TPPA were 100% for positive samples and 99.14% (1032/1041) for negative samples. Correlation tendency and rate between Archi‐TP and Lumi‐TP were 2.549 and 0.841 in positive specimens up to 160 detected values in Lumi‐TP. However, the detection value of Archi‐TP reached a plateau when it exceeded about 40. Furthermore, according to the comparison of each value obtained from Archi‐TP and Lumi‐TP with the strength of the staining of each line in the immune‐chromatography assay kit, ESPLINE TP (Fujirebio Inc) for TP major antigens, Tp15‐17 and TpN47, it was found that Lumi‐TP obtained higher values than Archi‐TP, particularly for TpN 47.

Conclusions

Lumi‐TP has high specificity and is useful not only for screening but also for determining the amount of anti‐TP antibodies.

The epidemic of major sexually transmitted diseases in Shanghai, China, 2009-2018

Acquired immune deficiency syndrome (AIDS), hepatitis B virus (HBV), hepatitis C virus (HCV), gonorrhea and syphilis are the major sexually transmitted diseases (STDs) in the world, which are the focus of epidemic prevention and control in China. The epidemiological trend analysis of STDs in Shanghai could reflect the epidemic situation of these diseases in high-income areas of China, providing a reference for how to control their epidemic. Although the overall incidence rate of infectious diseases levelled off after 2009, Shanghai still faces many new obstacles in the fight against STDs. Without effective prevention and control strategies for high-risk behaviors, such as active sexual activity without protection, for key susceptible populations, there may be a more serious epidemic of STDs in the future. Given these situations, strategies for controlling STDs in Shanghai should be more targeted with the development of epidemics, focusing on the following key areas for future work: i) attaching importance to health education; ii) strengthening epidemic surveillance; and iii) developing Community Health Service Centers (CHSC) as intervention subjects.

Epidemiology of Treponema pallidum, Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, and herpes simplex virus type 2 among female sex workers in the Middle East and North Africa: systematic review and meta-analytics

BACKGROUND

The epidemiology of sexually transmitted infections (STIs) and the role of commercial heterosexual sex networks in driving STI transmission in the Middle East and North Africa (MENA) region remain largely unknown.

OBJECTIVE

To characterize the epidemiology of Treponema pallidum (syphilis), Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, and herpes simplex virus type 2 (HSV-2) among female sex workers (FSWs) in MENA using an in-depth quantitative assessment.

METHODS

A systematic review on ten international, regional, and country-level databases was conducted, and reported following PRISMA guidelines. Pooled prevalences of current and/or ever infection for each STI were estimated using random-effects meta-analyses. Sources of between-study heterogeneity were investigated through random-effects meta-regressions.

RESULTS

One T. pallidum incidence study and 144 STI prevalence studies were identified for 45 812 FSWs in 13 MENA countries. The pooled prevalence of current infection was 12.7% (95% confidence interval (CI) = 8.5%-17.7%) for T. pallidum, 14.4% (95% CI = 8.2%-22.0%) for C. trachomatis, 5.7% (95% CI = 3.5%-8.4%) for N. gonorrhoeae, and 7.1% (95% CI = 4.3%-10.5%) for T. vaginalis. The pooled prevalence of ever infection (seropositivity using antibody testing) was 12.8% (95% CI = 9.4%-16.6%) for T. pallidum, 80.3% (95% CI = 53.2%-97.6%) for C. trachomatis, and 23.7% (95% CI = 10.2%-40.4%) for HSV-2. The multivariable meta-regression for T. pallidum infection demonstrated strong subregional differences, with the Horn of Africa and North Africa showing, respectively 6-fold (adjusted odds ratio (AOR): 6.4; 95% CI = 2.5-16.7) and 5-fold (AOR = 5.0; 95% CI = 2.5-10.6) higher odds of infection than Eastern MENA. There was also strong evidence for declining T. pallidum odds of infection at 7% per year (AOR = 0.93; 95% CI = 0.88-0.98). Study-specific factors including diagnostic method, sample size, sampling methodology, and response rate, were not associated with syphilis infection. The multivariable model explained 48.5% of the variation in T. pallidum prevalence.

CONCLUSIONS

STI infection levels among FSWs in MENA are considerable, supporting a key role for commercial heterosexual sex networks in transmission dynamics, and highlighting the health needs of this neglected and vulnerable population. Syphilis prevalence in FSWs appears to have been declining for at least three decades. Gaps in evidence persist for multiple countries.

Post-treatment serological changes in some patients with early syphilis exhibit a parabolic trend

Early syphilis accounts for a large proportion of patients with syphilis. Non- Treponema pallidum tests are commonly used to assess treatment effectiveness by analyzing the serological titer before treatment and six months after treatment. However, serological changes during the first three months after completion of treatment have not been completely understood. This prompted us to investigate whether serum titers of patients exhibit a continuous decrease post-treatment and to assess the trend of change in serological titer during this period. One hundred and seventy-three eligible patients with early syphilis were included in the analysis. Pre-treatment serological titers and those at three and six months post-treatment were compared and analyzed. Serological recovery was defined as a 4-fold or greater decrease in titer from pre-treatment level. Forty patients (23.1%) were found to have an increased serum titer at three months after treatment. Among the 40 patients, 13 patients had primary syphilis, 5 patients had secondary syphilis, and 22 patients had early latent syphilis. The proportion of patients with primary syphilis was higher, and their initial titers were significantly lower. No significant differences were observed with respect to age, gender, or initial treatment. The assessment results of 17 patients (9.8% of the total patients) change. Serological changes in some patients exhibit a parabolic pattern that may affect the clinician’s assessment of patient recovery. Therefore, more frequent assessment of serological titer might be required within the first six months post-treatment.

Is repeated retreatment necessary for HIV-negative serofast early syphilis patients?

A persistent non-treponemal serological response can be observed in patients with syphilis after treatment and is referred to as serofast. This status makes it difficult for clinicians to judge the curative effect of treatment, particularly in patients with early syphilis. In the present study, a total of 114 eligible serofast patients treated between January 2009 and June 2016 were retrospectively analyzed. All patients were subjected to rapid plasma reagin (RPR) serological tests and followed up for 24 months. The patients who remained serofast after initial therapy were given the first retreatment, and at 12 months, those who were still serofast received a second retreatment. After the first retreatment (6 months), 33.3% of the subjects (38/114) were serologically cured (≥4-fold decline in RPR titer). At 24 months, the patients that had achieved serological cure accounted for 23.7% (18/76) of the patients that received the second retreatment. Furthermore, 26.3% of subjects that achieved serological cure (10/38) and had not been further treated after the first retreatment spontaneously presented with a ≥4-fold decline in RPR titer or negative status. In conclusion, the present study indicated that in patients with early syphilis and serofast status after initial treatment, retreatments may not provide any significant benefit. The second retreatment did not significantly improve the patient's serological cure rate. There is no evidence that patients with early syphilis and serofast should receive multiple retreatments, in spite of this being commonly performed in clinical practice.

High HbA1c level is correlated with blood-brain barrier disruption in syphilis patients

Diabetes mellitus (DM) and neurosyphilis (NS) may both damage the blood-brain barrier (BBB). It seems that non-neurosyphilis (non-NS) patients with high HbA_1c levels are likely to develop into NS. However, the correlation of HbA_1c level with BBB disruption in syphilis (non-NS) patients is unclear. In this study, we used dynamic contrast-enhanced (DCE) MRI to quantify regional BBB permeability in syphilis (non-NS) patients and detected several molecular biomarkers of cerebrospinal fluid (CSF). We found that BBB permeability values in the hippocampus, white matter, and cortex inferior temporal gyrus were correlated with albumin quotient (Qalb), CSF concentrations of interleukin IL-6 and IL-10. Moreover, BBB breakdown in white matter was correlated with CSF concentrations of sICAM-1 and sVCAM-1. In conclusion, our data suggest that BBB integrity may be liable to be disrupted in syphilis (non-NS) patients, patients with high HbA_1c levels, as well as syphilis (non-NS) patients with high HbA_1c levels, and it is particularly important to control blood glucose in these patients.

Serological response to therapy following retreatment of serofast early syphilis patients with benzathine penicillin

Background

Some syphilitic patients remain in a serologically positive state after the recommended therapy. Although we often retreat patients in clinical practice, the optimal treatment protocol remains uncertain due to the paucity of data regarding serological response to retreatment and long-term outcomes.

Methods

We examined rapid plasma reagin serological test results of 70 serofast early syphilis cases who were retreated with 2.4 million units of benzathine penicillin weekly for 3 weeks. Serological retreatment success was defined as a minimum 4-fold decrease in baseline rapid plasma reagin test antibody titre within 6 months.

Results

Thirty-four (48.6%) of the patients who failed to achieve serological cure at 6 months after initial therapy achieved serological cure at 12 months. Patients who had higher non-treponemal titres at baseline and at 6 months were more likely to exhibit serological cure after retreatment than those with lower titres.

Conclusions

Our results suggest that the incremental benefit of retreating serofast patients with early syphilis is moderate, considering the almost 1:1 ratio of serological response to serofast state at follow-up.

Prevent Mother-to-Child Transmission (PMTCT) Programs and Enhancement of Maternal Healthcare Infrastructure to Improve Early Detection of Maternal Syphilis in Shanghai, China

This study aimed to compare the screening and diagnosis of maternal syphilis in Shanghai between the national and municipal prevent mother-to-child transmission (PMTCT) of syphilis policies, and then to assess whether PMTCT programs and enhancing healthcare infrastructure could bring about an early detection of maternal syphilis. Detection of maternal syphilis was initiated in 2001 and then scaled-up in 2011 along with the enhancement of antenatal healthcare infrastructure. The initial five-year periods of municipal and national PMTCT policies were defined as the “exploring period” (2002–2006) and the “comprehensive period” (2011–2015). The demographic and gestational weeks (GW) of syphilis screening and diagnosis were analyzed to identify the factors affecting early detection. During the study period, maternal syphilis screening increased from 83,718 in 2002 to 243,432 in 2015. Of the 1,894,062 pregnant women screened, 1526 and 2714 participants were diagnosed with maternal syphilis in 2002–2006 and 2011–2015, respectively. The average age of diagnosis was 28.36 years and non-residents accounted for 71.1%. In the comprehensive period, more women received early syphilis screening (14.0% vs. 10.8%) and diagnosis (13.3% vs. 7.3%) within 12 GWs compared with the exploring period. Significantly, early detection grew during 2011–2015, which was not seen in the exploring period. Multivariate analysis revealed a greater possibility for infected women to be diagnosed within 16 GWs (OR = 2.76) in the comprehensive period, but those who were non-residents and unemployed were less likely to receive early detection. In conclusion, early detection of maternal syphilis has been remarkably improved. More emphasis is required on the development of pro-vulnerable policies and the implementation of tailored health education to improve the accessibility of routine antenatal care and awareness of syphilis prevention.

Risk Factors for Congenital Syphilis Transmitted from Mother to Infant - Suzhou, China, 2011-2014

Mother-to-child transmission of syphilis remains a major global public health issue, and elimination of congenital syphilis is one of the millennium development goals of the World Health Organization (1). In 2012, an estimated 930,000 maternal syphilis infections caused 350,000 adverse pregnancy outcomes, including 143,000 early fetal deaths and stillbirths, 62,000 neonatal deaths, 44,000 preterm or low-weight births, and 102,000 infected infants worldwide (2). In China, the number of congenital syphilis cases reported annually increased from 468 in 2000 to 10,032 in 2013; the corresponding national congenital syphilis incidence rate increased nearly 26-fold, from 2.6 cases per 100,000 live births in 2000 to 69.9 in 2013 (3,4). To examine risk factors for mother-to-child transmission of syphilis, a cohort of pregnant women with a new syphilis diagnosis and their live-born infants was recruited during July 2011-July 2014 in Suzhou, in eastern China. Multivariable logistic regression results demonstrated that gestational age >36 weeks at the time of maternal syphilis diagnosis, higher maternal titers of rapid plasma reagin (RPR) and higher Treponema pallidum particle agglutination assay (TPPA) titers are risk factors for congenital syphilis. Among women with syphilis diagnosed at >36 weeks' gestational age, three quarters were migrant women. Recommendations for strengthening community and provider education about mother-to-child transmission of syphilis, early diagnosis and timely treatment of syphilis in pregnancy, and improving and providing access to prenatal care and screening migrant pregnant women with temporary residence status might reduce the incidence of congenital syphilis in China.

Urea-mediated dissociation alleviate the false-positive Treponema pallidum-specific antibodies detected by ELISA

The serological detection of antibodies to Treponema pallidum is essential to the diagnosis of syphilis. However, for the presence of cross-reaction, the specific antibody tests [e.g., enzyme-linked immunosorbent assay (ELISA)] always have false-positive results. In this study, we derived and validated the dissociation of urea in an attempt to alleviate the situation of false-positive antibodies to T. pallidum detected by ELISA. Six serum samples that were false-positive antibodies to T. pallidum detected by ELISA, and 16 control serum samples (8 sera positive for both specific IgG and IgM, and 8 IgG-positive and IgM-negative sera) were collected to select the appropriate dissociated concentration and time of urea. Our goal was to establish improved an ELISA method based on the original detection system of ELISA. The sensitivity of the improved ELISA was evaluated by 275 serum samples with class IgM-positive antibodies to T. pallidum. At 6 mol/L with 10 minutes dissociation of urea, 6 samples with false-positive antibodies to T. pallidum were converted to negative, and compared with true-positive antibodies to T. pallidum. The sensitivity of the improved ELISA was 100% by detecting the class IgM-positive antibodies to T. pallidum in sera of patients with syphilis. Considering the importance at the diagnosis of syphilis, antibodies to T. pallidum in serum samples should be retested by the improved ELISA method to avoid false-positive results.

Mathematical Assessment of the Role of Early Latent Infections and Targeted Control Strategies on Syphilis Transmission Dynamics

A new multi-stage deterministic model for the transmission dynamics of syphilis, which incorporates disease transmission by individuals in the early latent stage of syphilis infection and the reversions of early latent syphilis to the primary and secondary stages, is formulated and rigorously analysed. The model is used to assess the population-level impact of preventive (condom use) and therapeutic measures (treatment using antibiotics) against the spread of the disease in a community. It is shown that the disease-free equilibrium of the model is globally-asymptotically stable whenever the associated control reproduction number (denoted by [Formula: see text]) is less than unity. A special case of the model is shown to have a unique and globally-asymptotically stable endemic equilibrium whenever the associated reproduction number (denoted by [Formula: see text]) exceeds unity. Uncertainty and sensitivity analysis of the model, using parameter values and ranges relevant to syphilis transmission dynamics in Nigeria, show that the top three parameters that drive the syphilis infection (with respect to [Formula: see text]) are the disease transmission rate ([Formula: see text]), compliance in condom use (c) and efficacy of condom ([Formula: see text]). Numerical simulations of the model show that the targeted treatment of secondary syphilis cases is more effective than the targeted treatment of individuals in the primary or early latent stage of syphilis infection.

A spatiotemporal meta-analysis of HIV/syphilis epidemic among men who have sex with men living in mainland China

Background

Geographic differences in HIV, syphilis and condomless sex among men who have sex with men in China remained unknown. We aimed to elucidate these spatiotemporal changing patterns in China.

Methods

We conducted a spatiotemporal meta-analysis. We searched four databases for studies conducted between 2001 and 2015. We included studies that reported original data of HIV/syphilis prevalence in China, the study’s area/province, and period of data collection. We grouped studies into six regions and four time periods. We examined the changing patterns of national and regional prevalence of HIV, syphilis and condomless sex.

Results

Search results yielded 2119 papers, and 272 were included in the meta-analysis. The sample sizes of the studies ranged from 19 to 47,231. National HIV prevalence increased from 3.8% (95% CI 3.0–4.8) in 2001–07 to 6.6% (5.6–7.7) in 2013–15. In most regions, the rise occurred before 2010 and the HIV prevalence remained relatively stable afterwards, except for the Northwest which showed a considerable increase since 2008. National syphilis prevalence decreased from 12.3% (10.2–14.9) in 2001–07 to 7.1% (5.6–8.9) in 2013–15.

Conclusions

The trends of HIV and syphilis infections have been effectively curbed in MSM in most regions of China. Continuous efforts, particularly promotion of condom use, are needed to further reduce these infections.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3532-8) contains supplementary material, which is available to authorized users.

Mother-to-child transmission prevention of human immunodeficiency virus, syphilis and hepatitis B virus

BACKGROUND

China is the first country to initiate a nationwide program for prevention of mother-to-child transmission of human immunodeficiency virus, syphilis and hepatitis B virus by an integrated approach. However, the progress of this program remains unreported at national or local level for China. Therefore, we performed a hospital-based longitudinal study to assess the integrated prevention effect in Hunan, South-central China.

METHODS

This study was conducted at 123 counties in Hunan and covered all local hospitals providing midwifery and antenatal care services from 2010 to 2016. We used the Cochran-Armitage test to examine the temporal changes of the indicators related with prevention of mother-to-child transmission. Besides, we used Spearman rank correlation analysis to assess the association between mother-to-child transmission rates and the process indicators related with prevention of mother-to-child transmission.

RESULTS

After implementation of integrated prevention program, the indicators related with prevention of mother-to-child transmission are moving in the right direction. From 2010 to 2016, mother-to-child transmission rates significantly decreased from 19.4% to 9.6% for human immunodeficiency virus, and from 116.3 to 13.6 cases per 100,000 live births for syphilis. The proportion of children receiving hepatitis B immunoglobulin injection within 24h after birth increased from 95.2% to 98.9% among exposed neonates. Mother-to-child transmission rates were negatively associated with the process indicators related with prevention of mother-to-child transmission (all P<0.05).

CONCLUSIONS

Our prevention program of mother-to-child transmission for three diseases by an integrated approach proved to be viable and effective. Our model may be of interest to other countries.

Screening for syphilis with dual algorithms: analysis of discordant and concordant serology results in a population with a low prevalence of syphilis

BACKGROUND

Currently, many laboratories have switched the traditional screening algorithm (TSA) to reverse screening algorithm (RSA) for the efficiencies in high-volume syphilis screening. However, confusions have been arisen regarding this paradigm shift.

OBJECTIVE

To compare the performance of two algorithms with head-to-head mode.

METHODS

Sera screening for syphilis were tested in parallel with chemiluminescence immunoassay (CIA) and toluidine red unheated serum test (TRUST). CIA-reactive sera from the RSA were reflexively tested with TRUST and confirmed with Treponema pallidum particle agglutination assay (TPPA), while the TRUST-reactive serology from the TSA were afterwards tested with TPPA.

RESULTS

A total of 110 663 serum samples were screened. The RSA identified 2259 (2.0%) CIA-reactive results, of which 377 (16.7%) showed TPPA nonreactive results, while the TSA identified 934 (0.8%) TRUST-reactive results, of which 67 (7.2%) showed TPPA-nonreactive results. Among the 2259 CIA-reactive results, 1392 (61.6%) were TRUST-nonreactive, of which 350 (25.1%) were TPPA-nonreactive. A total of 182 sera from the 350 TPPA-nonreactive sera were further tested by a second CIA (VITROS Syphilis TPA, VITROS TPA), of which 155 (85.2%) were nonreactive and 27 (14.8%) were reactive. The 27 VITROS TPA-reactive sera were further tested with a treponemal Western blot assay (Euroimmun IgG Western Blot, EuroWB), of which 11 (41%) were indeterminate, 6 (22%) were nonreactive and 10 (37%) were reactive. Among the 10 EuroWB-reactive sera, two seroconverted to TPPA 1:80+/- after 1-year follow-up. Of 867 CIA-reactive/TRUST-reactive results, 27 (3.1%) were TPPA-nonreactive.

CONCLUSIONS

The RSA identified more patients with reactive treponemal serology. However, it also yielded an increased likely false-reactive rate compared with the TSA, especially those results with low index values and TRUST-nonreactive serology, were necessary to retest with a second treponemal test. Further testing results with TPPA, VITROS TPA and EuroWB suggested the false-reactive CIA screening results and the likely false-nonreactive TPPA results when the reactive treponemal results screened with RSA were to be identified.

Evaluating the progress to eliminate mother-to-child transmission (MTCT) of syphilis in Hunan Province, China: A study based on a health service delivery model

To prevent mother-to-child transmission (MTCT) of syphilis, Hunan Province launched a free syphilis screening and treatment programme in 2011. Thus far, the programme has been implemented for 6 years. This study aimed to assess progress toward the elimination of MTCT of syphilis in Hunan Province from 2011-2016. Estimates of syphilis-related adverse pregnancy outcomes (APOs) were based on the health service delivery model developed by the WHO, which were then translated into disability-adjusted life years (DALYs). Default values in the model were replaced by a Chinese version. The progress of this programme was assessed through the reduction of estimated DALYs with and without screening and treatment services. The results showed that the estimated number of syphilis-related APOs in Hunan Province from 2011 to 2016 was 3,840, more than 70% of which occurred among women who had at least one antenatal care visit but were not screened or treated for syphilis during pregnancy. The public health burden resulting from maternal syphilis-related APOs was 192,528 DALYs over six years, and with the current screening and treatment coverage, approximately 163,794 expected DALYs (46%) were averted. Our estimates indicate that in Hunan Province, syphilis in pregnancy continues to be an important cause of APOs, which can lead to substantial perinatal morbidity and mortality. Approximately half of the expected public health burden resulting from syphilis-related APOs was averted by the current screening and treatment services, which suggests progress toward the elimination of MTCT of syphilis in Hunan Province.

Trends and Predictors of Syphilis Prevalence in the General Population: Global Pooled Analyses of 1103 Prevalence Measures Including 136 Million Syphilis Tests

Background

This study assessed levels, trends, and associations of observed syphilis prevalence in the general adult population using global pooled analyses.

Methods

A standardized database of syphilis prevalence was compiled by pooling systematically gathered data. Random-effects meta-analyses and meta-regressions were conducted using data from the period 1990-2016 to estimate pooled measures and assess predictors and trends. Countries were classified by World Health Organization region. Sensitivity analyses were conducted.

Results

The database included 1103 prevalence measures from 136 million syphilis tests across 154 countries (85% from women in antenatal care). Global pooled mean prevalence (weighted by region population size) was 1.11% (95% confidence interval [CI], .99-1.22). Prevalence predictors were region, diagnostic assay, sample size, and calendar year interacting with region. Compared to the African Region, the adjusted odds ratio (AOR) was 0.42 (95% CI, .33-.54) for the Region of the Americas, 0.13 (95% CI, .09-.19) for the Eastern Mediterranean Region, 0.05 (95% CI, .03-.07) for the European Region, 0.21 (95% CI, .16-.28) for the South-East Asia Region, and 0.41 (95% CI, .32-.53) for the Western Pacific Region. Treponema pallidum hemagglutination assay (TPHA) only or rapid plasma reagin (RPR) only, compared with dual RPR/TPHA diagnosis, produced higher prevalence (AOR >1.26), as did smaller sample-size studies (<500 persons) (AOR >2.16). Prevalence declined in all regions; the annual AORs ranged from 0.84 (95% CI, .79-.90) in the Eastern Mediterranean to 0.97 (95% CI, .97-1.01) in the Western Pacific. The pooled mean male-to-female prevalence ratio was 1.00 (95% CI, .89-1.13). Sensitivity analyses confirmed robustness of results.

Conclusions

Syphilis prevalence has declined globally over the past 3 decades. Large differences in prevalence persist among regions, with the African Region consistently the most affected.

Prevalence of hepatitis B virus, hepatitis C virus, human immunodeficiency virus and Treponema pallidum infections in hospitalized patients before transfusion in Xiangya hospital Central South University, China from 2011 to 2016

Background

Human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV) and Treponema pallidum (TP) infections are considered classic transfusion-transmissible infections (TTIs). Few data are available about the prevalence of TTIs in patients before blood transfusion in China. This study aimed to investigate the seroprevalence of four TTIs among patients before blood transfusion in Xiangya Hospital Central South University, China.

Methods

From 2011 to 2016, 442,121 hospitalized patients before possible blood transfusion were tested for hepatitis B surface antigen (HBsAg), anti-HCV, syphilis antibody (anti-TP) and anti-HIV.

Results

Of the 442,121 patients, the overall positivity of the four TTI serum markers was 15.35%. The positive rates of HBsAg, anti-HCV, anti-HIV and anti-TP were 10.98, 1.43, 0.16 and 2.78%, respectively. TTI serum markers showed a significant difference by gender, with positive rates of 17.98% for males and 12.79% for females. The prevalence of TTI serum markers varied significantly by age. The overall co-infection rate was 0.63%, and the top three multiple infections were HBV-TP, HBV-HCV, and HCV-TP. The co-infection rates of HBV-TP and HBV-HCV showed a significant decrease from 2011 to 2016, while the rates of other co-infections remained stable.

Conclusions

The prevalence of TTIs in patients before blood transfusion is much higher compared to that in blood donors in the region. The infection rates of HIV and TP increased, and the infection rate of HBsAg decreased in recent years.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3051-7) contains supplementary material, which is available to authorized users.

HIV epidemics in Shenzhen and Chongqing, China

OBJECTIVE

Men who have sex with men (MSM) and heterosexuals are the populations with the fastest growing HIV infection rates in China. We characterize the epidemic growth and age patterns between these two routes from 2004 to 2015 in Chongqing and Shenzhen, China.

DESIGN AND METHODS

Data were downloaded from the National HIV/ AIDS Comprehensive Response Information Management System. For the new HIV diagnoses of heterosexuals and MSM in both cities, we estimated the growth rates by fitting different sub-exponential models. Heat maps are used to show their age patterns. We used histograms to compare these patterns by birth cohort.

RESULTS

The MSM epidemics grew significantly in both cities. Chongqing experienced quadratic growth in HIV reported cases with an estimated growth rate of 0.086 per week and a "deceleration rate" of 0.673. HIV reported cases of MSM in Shenzhen grew even more drastically with a growth rate of 0.033 per week and "deceleration rate" of 0.794. The new infections are mainly affecting the ages of 18 to 30 in Chongqing and ages of 20 to 35 in Shenzhen. They peaked in early 1990's and mid-1990's birth cohorts in Chongqing and Shenzhen respectively. The HIV epidemic among heterosexuals grew rapidly in both cities. The growth rates were estimated as 0.02 and 0.028 in Chongqing and Shenzhen respectively whereas the "deceleration rates" were 0.878 and 0.790 in these two places. It affected mostly aged 18 to 75 in males and 18 to 65 in females in Chongqing and aged 18 to 45 in males and 18 to 50 in females in Shenzhen in 2015. In Chongqing, the heterosexual female epidemics display two peaks in HIV diagnoses in the birth cohorts of early 1950's and early 1980's, with heterosexual male epidemics peaked in early 1940's and early 1960's. The heterosexual male and female epidemics display higher rates in the birth cohort 1940-1960, than the birth cohort 1960-1990. It peaked in birth cohorts of 1950's and 1980's in Shenzhen.

CONCLUSIONS

We revealed striking differences in epidemic growth and age patterns of the HIV epidemics in these two cities. Our results may be used to inform age-targeted public health policies to curb their epidemic growth.

Landscape of emerging and re-emerging infectious diseases in China: impact of ecology, climate, and behavior

For the past several decades, the infectious disease profile in China has been shifting with rapid developments in social and economic aspects, environment, quality of food, water, housing, and public health infrastructure. Notably, 5 notifiable infectious diseases have been almost eradicated, and the incidence of 18 additional notifiable infectious diseases has been significantly reduced. Unexpectedly, the incidence of over 10 notifiable infectious diseases, including HIV, brucellosis, syphilis, and dengue fever, has been increasing. Nevertheless, frequent infectious disease outbreaks/events have been reported almost every year, and imported infectious diseases have increased since 2015. New pathogens and over 100 new genotypes or serotypes of known pathogens have been identified. Some infectious diseases seem to be exacerbated by various factors, including rapid urbanization, large numbers of migrant workers, changes in climate, ecology, and policies, such as returning farmland to forests. This review summarizes the current experiences and lessons from China in managing emerging and re-emerging infectious diseases, especially the effects of ecology, climate, and behavior, which should have merits in helping other countries to control and prevent infectious diseases.

Tracing the origin of Treponema pallidum in China using next-generation sequencing

Syphilis is a systemic sexually transmitted disease caused by Treponema pallidum ssp. pallidum (TPA). The origin and genetic background of Chinese TPA strains remain unclear. We identified a total of 329 single-nucleotide variants (SNVs) in eight Chinese TPA strains using next-generation sequencing. All of the TPA strains were clustered into three lineages, and Chinese TPA strains were grouped in Lineage 2 based on phylogenetic analysis. The phylogeographical data showed that TPA strains originated earlier than did T. pallidum ssp. pertenue (TPE) and T. pallidum ssp. endemicum (TPN) strains and that Chinese TPA strains might be derived from recombination between Lineage 1 and Lineage 3. Moreover, we found through a homology modeling analysis that a nonsynonymous substitution (I415F) in the PBP3 protein might affect the structural flexibility of PBP3 and the binding constant for substrates based on its possible association with penicillin resistance in T. pallidum. Our findings provide new insight into the molecular foundation of the evolutionary origin of TPA and support the development of novel diagnostic/therapeutic technology for syphilis.

Molecular Subtyping and Surveillance of Resistance Genes In Treponema pallidum DNA From Patients With Secondary and Latent Syphilis in Hunan, China

BACKGROUND

Over the past decade, the incidence of syphilis and widespread macrolide resistance in its etiological agent, Treponema pallidum subsp. pallidum, have become a major health concern across countries, including China. Regional trends in subtypes and antibiotic resistance can be monitored effectively by molecular surveillance programs. In this study, whole blood samples were used to assess circulating T. pallidum strains collected from various regions of Hunan, China, between 2013 and 2015.

METHODS

Traditional polymerase chain reaction, targeting polA, tpp47, bmp, and tp0319 genes, was used as preliminary screening assay. About 455 polymerase chain reaction-positive specimens were obtained from 2253 whole blood samples of patients with secondary or latent syphilis. Molecular subtyping was performed using a Centers for Disease Control and Prevention-based typing method combined with an analysis of the variable region of tp0548 gene. Resistance to macrolides was analyzed by examining point mutations in 23S rRNA, and the presence of the G1058C point mutation within 16S rRNA associated with decreased susceptibility to doxycycline was assessed.

RESULTS

Circulating T. pallidum strains were resolved into 32 subtypes, among which subtype 14d/f was predominant. A2059G mutation in 23S rRNA, and the G1058C mutation in 16S rRNA was absent, but the prevalence of A2058G mutation in 23S rRNA was 97.5%.

CONCLUSIONS

We found that it is possible to use whole blood to evaluate molecular subtypes and monitor antibiotic resistance in circulating T. pallidum strains, especially when chancres are absent. High frequency of macrolide-resistant T. pallidum indicates that macrolide antibiotics, such as azithromycin, should be avoided as a treatment option for syphilis in Hunan, China.