Global burden of maternal and congenital syphilis and associated adverse birth outcomes-Estimates for 2016 and progress since 2012

Syphilis vaccine development: Aligning vaccine design with manufacturing requirements

Syphilis, caused by Treponema pallidum subsp. pallidum, is a global health concern with increasing rates worldwide. Current prevention strategies, including screen-and-treat approaches, are not sufficient to resolve rising infection rates, emphasizing the need for a vaccine. Developing a syphilis vaccine necessitates a range of cross-disciplinary considerations, including essential disease-specific protection, technical requirements, economic feasibility, manufacturing constraints, public acceptance, equitable vaccine access, alignment with global public vaccination programs, and identification of essential populations to be vaccinated to achieve herd immunity. Central to syphilis vaccine development is prioritization of global vaccine availability, including access in low- to middle-income settings. Various vaccine platforms, including subunit, virus-like particle (VLP), mRNA, and outer membrane vesicle (OMV) vaccines, present both advantages and challenges. The proactive consideration of both manufacturing feasibility and efficacy throughout the pre-clinical research and development stages is essential for producing an efficacious, inexpensive, and scalable syphilis vaccine to address the growing global health burden caused by this disease.

Syphilis and pregnancy

•Although congenital syphilis has a known etiological agent, accessible diagnosis and low-cost, effective treatment with low fetal toxicity, it continues to challenge obstetric and antenatal care services. •The increasing rates of syphilis in the general population have direct repercussions on the increase in cases of congenital syphilis, a situation of objective interest for public health. •Although transforming the recording of syphilis and congenital syphilis into notifiable diseases improved the records and has made it possible to measure the occurrence of these diseases and create solutions, no effects on reducing their frequency have been reached yet. •The failure to control syphilis/congenital syphilis is multifactorial, and associates variables that range from the deficiency in teaching about these diseases in schools and in the training system of the various health professional segments, as well as the lack of rigid policies for quality control from antenatal care until the clinical follow-up of children exposed to Treponema pallidum during pregnancy. •To date, benzathine penicillin is the only antimicrobial accepted as effective by the main health authorities on the planet for the treatment of syphilis in pregnant women. •The fear of anaphylaxis in response to the treatment of syphilis with benzathine penicillin is an important factor hindering the prompt and correct treatment of pregnant women with syphilis, even though health authorities have made efforts to face the problem with solid arguments, still insufficient to resolve the question. •Although specific protocols are published, the failure to control the treatment of syphilis in pregnant women is still observed with high frequency, indicating and reinforcing a failure in the quality control of these care principles. The National Specialized Commission on Infectious Diseases of the Brazilian Federation of Gynecology and Obstetrics Associations (Febrasgo) endorses this document. Content production is based on scientific evidence on the proposed topic and the results presented contribute to clinical practice.

The relationship between selected sexually transmitted pathogens, HPV and HIV infection status in women presenting with gynaecological symptoms in Maputo City, Mozambique

Sexually transmitted infections (STIs) have a profound impact on sexual and reproductive health worldwide. Syphilis, gonorrhea, chlamydia, and trichomoniasis are four currently curable STIs. However, most STI cases are asymptomatic and not detected without laboratory diagnostics. Hepatitis B virus, herpes simplex virus, human immunodeficiency virus (HIV), and human papillomavirus (HPV) are four viral and incurable infections, but they can be mitigated by treatment. We investigated the prevalence of selected sexually transmitted pathogens and their relationship with HPV and HIV infection in women from Maputo, the capital of Mozambique. A cross-sectional study was conducted on 233 non-pregnant women seeking health care relating to gynecological symptoms in Mavalane Health facilities in Maputo, between the 1st of February 2018 and the 30th of July 2019. Cervical brush samples were collected and DNA was extracted. Selected STIs including HPV were detected using multiplex STD and HPV Direct Flow Chip Kits through a manual Hybrispot platform (Vitro, Master Diagnostica, Sevilla, Spain). HIV testing was performed using rapid tests: Determine HIV 1/2 test (Alere Abbott Laboratories, Tokyo, Japan) for screening, and UniGold HIV (Trinity Biotech, Ireland) for confirmation. All women (n = 233) were negative for Haemophilus ducreyi and Herpes Simplex Virus-1 (HSV-1). Among the 233 women, a high prevalence of STIs was found (89%), 63% of the women were positive for HPV and 24% were HIV positive. Treponema pallidum (TP), Trichomonas vaginalis (TV), Herpes Simplex Virus-2 (HSV-2), and Chlamydia trachomatis (CT) were detected in 17%, 14%, 8%, and 8% of the women, respectively. As a common phenomenon, vaginal discharge (90%) was the lower genital tract symptom reported by the majority of the women. Co-infection with any STI and HPV was detected in 56% (130/233) while 45% (59/130) of the co-infections were with high-risk HPV (hrHPV) genotypes. Among the HPV-positive participants, infection by TP was the most prevalent (27%). In total, 28% (66/233) of the participants were positive for any hrHPV genotypes. Co-infection with any STI and HIV was found in 15% (34/233) of the study participants. There was a significant association between HPV infection and TP (p = 0.039) and HSV-2 (p = 0.005). TV, TP, and CT-S1-CT-S2 positivity were significantly more prevalent in HIV-positive participants. Pathobionts Ureaplasma urealyticum/parvum and Mycoplasma hominis were detected in 84.0% (195/233) and 45% (105/233), respectively. This present study describes a high prevalence of STIs. Co-infection between HPV and STIs was found in the majority of the study subjects. The high prevalence of HPV emphasizes the need for HPV vaccination to prevent cervical cancer in this population. Management of STIs is also important in women presenting with gynecological symptoms.

Predicting adverse birth outcome among childbearing women in Sub-Saharan Africa: employing innovative machine learning techniques

BACKGROUND

Adverse birth outcomes, including preterm birth, low birth weight, and stillbirth, remain a major global health challenge, particularly in developing regions. Understanding the possible risk factors is crucial for designing effective interventions for birth outcomes. Accordingly, this study aimed to develop a predictive model for adverse birth outcomes among childbearing women in Sub-Saharan Africa using advanced machine learning techniques. Additionally, this study aimed to employ a novel data science interpretability techniques to identify the key risk factors and quantify the impact of each feature on the model prediction.

METHODS

The study population involved women of childbearing age from 26 Sub-Saharan African countries who had given birth within five years before the data collection, totaling 139,659 participants. Our data source was a recent Demographic Health Survey (DHS). We utilized various data balancing techniques. Ten advanced machine learning algorithms were employed, with the dataset split into 80% training and 20% testing sets. Model evaluation was conducted using various performance metrics, along with hyperparameter optimization. Association rule mining and SHAP analysis were employed to enhance model interpretability.

RESULTS

Based on our findings, about 28.59% (95% CI: 28.36, 28.83) of childbearing women in Sub-Saharan Africa experienced adverse birth outcomes. After repeated experimentation and evaluation, the random forest model emerged as the top-performing machine learning algorithm, with an AUC of 0.95 and an accuracy of 88.0%. The key risk factors identified were home deliveries, lack of prenatal iron supplementation, fewer than four antenatal care (ANC) visits, short and long delivery intervals, unwanted pregnancy, primiparous mothers, and geographic location in the West African region.

CONCLUSION

The region continues to face persistent adverse birth outcomes, emphasizing the urgent need for increased attention and action. Encouragingly, advanced machine learning methods, particularly the random forest algorithm, have uncovered crucial insights that can guide targeted actions. Specifically, the analysis identifies risky groups, including first-time mothers, women with short or long birth intervals, and those with unwanted pregnancies. To address the needs of these high-risk women, the researchers recommend immediately providing iron supplements, scheduling comprehensive prenatal care, and strongly encouraging facility-based deliveries or skilled birth attendance.

Increase in congenital syphilis in a tertiary-care centre from Madrid, Spain: Back to the classics

Globally, an increase in sexually transmitted diseases worldwide has been reported, including acquired Treponema pallidum infection. Congenital syphilis is the mother-to-child transmission syphilis infection, experiencing an increase in cases returning to incidence rates of years ago. We report three cases of symptomatic congenital syphilis occurring in a tertiary-care hospital in Madrid (Spain). Cases were diagnosed by serology and molecular biology methods. The use of molecular techniques in specimens such as skin lesion, subplacental exudate swabs, bronchoalveolar aspirate, or cerebrospinal fluid could favour the diagnosis of this clinical entity, especially in symptomatic newborns with systemic involvement.

Associations between maternal syphilis infection during pregnancy and low birth weight and preterm birth: a prospective cohort study

BACKGROUND

In recent years, syphilis is still the most common sexually transmitted disease worldwide. Pregnant women infected with syphilis can transmit it to the fetus in utero through mother-to-child transmission, which can directly lead to adverse pregnancy outcomes. The aim of this study was to investigate the associations between maternal syphilis infection and low birth weight and preterm birth in offspring.

METHODS

Multinomial logistic regression model was used to analyze the associations between maternal syphilis infection and low birth weight and preterm birth, and to explore its stability through subgroup analysis.

RESULTS

A total of 34,074 subjects were included in the study. After adjusting for potential confounders, maternal syphilis infection during pregnancy was associated with a 2.60-fold (95% CI 1.83-3.69) increased risk of low birth weight and a 1.91-fold (95% CI 1.35-2.69) increased risk of preterm birth. Subgroup analysis showed that the association was stable.

CONCLUSION

We found that maternal syphilis infection during pregnancy was significantly associated with an increased risk of low birth weight and preterm birth. The implementation of reasonable syphilis screening and standardized treatment and follow-up of pregnant syphilis may have important practical significance in reducing the low birth weight and preterm birth rate in offspring.

Syphilis in pregnancy and adverse birth outcomes: A nationwide longitudinal study in Brazil

OBJECTIVE

The present study aimed to evaluate the association between syphilis in pregnancy and low birth weight, small for gestational age, and preterm birth.

METHODS

This longitudinal study used Brazilian National Information System for livebirths (SINASC) linked to the gestational syphilis cases from Notifiable Diseases Information System (SINAN) from 2011 to 2017. Descriptive statistics and logistic regression were used to compare the birth outcomes of pregnant women with and without syphilis. The study protocol was approved by the Research Ethics Committee of the Institute of Collective Health of the Federal University of Bahia (CAAE: registration no. 18022319.4.0000.5030).

RESULTS

A total of 17 930 817 live births were included in the study. Of these, 155 214 (8.7/1000) were exposed to syphilis during pregnancy. Maternal syphilis increased the odds of low birth weight (aOR 1.88, 95% CI: 1.85-1.91), small for gestational age (aOR 1.53, 95% CI: 1.51-1.56), and preterm birth (aOR 1.35, 95% CI: 1.33-1.37). Higher odds were observed for pregnant women with VDRL titer ≥64 and untreated maternal syphilis when compared to mothers without syphilis. Analysis stratified by prenatal care showed higher odds for all adverse birth outcomes for mothers attending ≤6 prenatal appointments.

CONCLUSION

Our findings showed a strong association between gestational syphilis and adverse birth outcomes with increased odds observed among women with higher VDRL titers, lack of treatment, and fewer prenatal appointments. These results highlight the need for adequate screening and treatment for gestational syphilis during pregnancy to mitigate the risk of adverse birth outcomes.

Rapid systematic review of interventions to improve antenatal screening rates for syphilis, hepatitis B, and HIV in low- and middle-income countries

BACKGROUND

Infectious diseases including syphilis, HIV, and hepatitis B are major contributors to maternal and neonatal morbidity and mortality worldwide, especially in low- and middle-income countries (LMICs). The World Health Organization has prioritized elimination of vertical transmission of these three diseases.

OBJECTIVES

To rapidly assess the impact of interventions designed to improve antenatal screening rates for syphilis, HIV, and hepatitis B in LMICs and to identify areas for future implementation research.

SEARCH STRATEGY

A comprehensive search was conducted across PubMed, Embase, and EconLit, targeting articles published between January 1, 2013, and June 27, 2023.

SELECTION CRITERIA

We included quantitative interventional studies in English, involving pregnant adults (15 years or older) from LMICs. Exclusions were studies based in high-income countries, qualitative studies, or those investigating accuracy of diagnostic methods.

DATA COLLECTION AND ANALYSIS

From an initial 5549 potential studies, 27 were finalized for review after various screening stages. Data extraction covered aspects such as study design, intervention details, and outcomes. Findings were qualitatively synthesized within a systems thinking framework.

MAIN RESULTS

The interventions assessed varied in terms of geographic locations, health care system levels, and modalities. The review highlighted the effectiveness of interventions such as community health interventions, service quality improvements, and financial incentives.

CONCLUSIONS

The study underscores the potential of specific interventions in enhancing antenatal screening rates in LMICs. However, there is a discernible research gap concerning hepatitis B. The findings emphasize the importance of capacity building and health systems strengthening in public health interventions.

Doubts about the diagnosis and treatment of syphilis in pregnancy among primary care professionals in a telehealth service

This cross-sectional study aims to describe doubts regarding the diagnosis and treatment of syphilis in pregnancy among primary care professionals in a telehealth service. All teleconsultations (TCs) offered through TelessaúdeRS-UFRGS to primary health care (PHC) services in the state of Rio Grande do Sul between 2018 and 2021 involving syphilis in pregnancy were included. A total of 356 (TCs) were analyzed. The main doubts about syphilis during pregnancy raised by primary care professionals were related to the need for retreatment (35%), diagnostic definition (23%) and initial treatment (16%). In addition, 95% of TCs were suitable for diagnosing and treating syphilis based on the 2020 Brazilian Ministry of Health guideline. This study suggests that TCs can identify failures in the diagnosis and treatment of public health problems and support decision making in PHC involving syphilis in pregnancy.

Clinic-based evaluation of point-of-care dual HIV/syphilis rapid diagnostic tests at primary healthcare antenatal facilities in South Africa and Zambia

BACKGROUND

Southern African countries have the largest global burden of HIV and syphilis, with a high prevalence among women of reproductive age. Although antenatal screening is standard of care, syphilis screening has generally lagged behind HIV screening. We aimed to evaluate the performance and operational characteristics of two commercial dual HIV/syphilis point-of-care tests (POCTs) for simultaneous maternal HIV/syphilis screening.

METHODS

A clinic-based evaluation of dual HIV/syphilis POCTs (SD Bioline and Chembio) was conducted at five primary healthcare centres (PHCs) in South Africa and Zambia. POCT results using capillary fingerprick blood were compared to reference laboratory syphilis and HIV serological assays.

RESULTS

Three thousand four hundred twelve consenting pregnant women aged ≥ 18 years were enrolled. The prevalence of treponemal antibody seropositivity and HIV infection ranged from 3.7 to 9.9% (n = 253) and 17.8 to 21.3% (n = 643), respectively. Pooled sensitivity for syphilis compared to the reference assay was 66.0% (95%CI 57.7-73.4) with SD Bioline and 67.9% (95%CI 58.2-76.3) with Chembio. Pooled specificity for syphilis was above 98% with both POCTs. The sensitivities of SD Bioline and Chembio assays were 78.0% (95%CI 68.6-85.7) and 81.0% (95%CI 71.9-88.2), respectively compared to an active syphilis case definition of treponemal test positive with a rapid plasma reagin titre of ≥ 8. The negative predictive values (NPVs) based on various prevalence estimates for syphilis with both assays ranged from 97 to 99%. The pooled sensitivity for HIV was 92.1% (95%CI 89.4-94.2) with SD Bioline; and 91.5% (95%CI 88.2-93.9) with Chembio. The pooled specificities for HIV were 97.2% (95%CI 94.8-98.5) with SD Bioline and 96.7% (95%CI 95.1-97.8) with Chembio. The NPV based on various prevalence estimates for HIV with both assays was approximately 98%. Most participating women (91%) preferred dual POCTs over two single POCTs for HIV and syphilis, and healthcare providers gave favourable feedback on the utility of both assays at PHC level.

CONCLUSIONS

Based on the need to improve antenatal screening coverage for syphilis, dual HIV/syphilis POCTs could be effectively incorporated into antenatal testing algorithms to enhance efforts towards elimination of mother-to-child transmission of these infections.

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

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

Sociodemographic and clinical characteristics associated with maternal and congenital syphilis - A prospective study in Peru

OBJECTIVES

The objective of this study was to explore the factors and outcomes associated with gestational syphilis in Peru.

METHODS

Women from the miscarriage, vaginal delivery, and C-section wards from a large maternity hospital in Lima with or without syphilis diagnosis were enrolled and their pregnancy outcomes compared. Maternal syphilis status using maternal blood and child serostatus using cord blood were determined by rapid plasma reagin (RPR) and rapid syphilis tests. The newborns' clinical records were used to determine congenital syphilis.

RESULTS

A total of 340 women were enrolled, 197 were positive and 143 were negative for RPR/rapid syphilis tests. Antibody titers in sera from cord and maternal blood were comparable with RPR titers and were highly correlated (rho = 0.82, P <0.001). Young age (P = 0.009) and lower birth weight (P = 0.029) were associated with gestational syphilis. Of the women with gestational syphilis, 76% had received proper treatment. Mothers of all newborns with congenital syphilis also received appropriate treatment. Treatment of their sexual partners was not documented.

CONCLUSIONS

Syphilis during pregnancy remains a major cause of the fetal loss and devastating effects of congenital syphilis in newborns.

In-Depth Proteome Coverage of In Vitro-Cultured Treponema pallidum and Quantitative Comparison Analyses with In Vivo-Grown Treponemes

Previous mass spectrometry (MS)-based global proteomics studies have detected a combined total of 86% of all Treponema pallidum proteins under infection conditions (in vivo-grown T. pallidum). Recently, a method was developed for the long-term culture of T. pallidum under in vitro conditions (in vitro-cultured T. pallidum). Herein, we used our previously reported optimized MS-based proteomics approach to characterize the T. pallidum global protein expression profile under in vitro culture conditions. These analyses provided a proteome coverage of 94%, which extends the combined T. pallidum proteome coverage from the previously reported 86% to a new combined total of 95%. This study provides a more complete understanding of the protein repertoire of T. pallidum. Further, comparison of the in vitro-expressed proteome with the previously determined in vivo-expressed proteome identifies only a few proteomic changes between the two growth conditions, reinforcing the suitability of in vitro-cultured T. pallidum as an alternative to rabbit-based treponemal growth. The MS proteomics data have been deposited in the MassIVE repository with the data set identifier MSV000093603 (ProteomeXchange identifier PXD047625).

Congenital Syphilis Prevention Challenges, Pacific Coast of Colombia, 2018-2022

High incidences of congenital syphilis have been reported in areas along the Pacific coast of Colombia. In this retrospective study, conducted during 2018-2022 at a public hospital in Buenaventura, Colombia, we analyzed data from 3,378 pregnant women. The opportunity to prevent congenital syphilis was missed in 53.1% of mothers because of the lack of syphilis screening. Characteristics of higher maternal social vulnerability and late access to prenatal care decreased the probability of having >1 syphilis screening test, thereby increasing the probability of having newborns with congenital syphilis. In addition, the opportunity to prevent congenital syphilis was missed in 41.5% of patients with syphilis because of the lack of treatment, which also increased the probability of having newborns with congenital syphilis. We demonstrate the urgent need to improve screening and treatment capabilities for maternal syphilis, particularly among pregnant women who are more socially vulnerable.

Retrospective Cohort Study of Syphilis-Related Stillbirths in Winnipeg, Manitoba From 2017-2020

OBJECTIVE

Syphilis-related stillbirths (SRSBs) disproportionately affect marginalized women with 11% of all local stillbirths having maternal syphilis as a contributory factor in 2020. This study describes the incidence and perinatal factors associated with SRSB.

METHODS

This was a retrospective cohort study of all stillbirths occurring from 1 January 2017 to 31 December 2020, at a single tertiary-level referral hospital in Winnipeg, Manitoba. Cases that met criteria for SRSB were identified from hospital records and included in the final analysis. Maternal demographics, comorbidities, prenatal care attendance, sexually transmitted infection testing, treatment, and diagnostic investigations at time of stillbirth were collected from hospital charts using a standardized data collection form. Descriptive statistics were performed to present the results.

RESULTS

The proportion of SRSB increased over the period of study from 0%-11%. Eleven cases were identified as SRSB, with diagnosis occurring intrapartum in 7 cases and antenatally in 4 cases. Of the 4 antenatal cases, only 2 had identifiable treatment responses indicated by microbiological and pathology workup. Commonly identified risk factors for SRSB were homelessness, mental illness, substance use, sexually transmitted co-infections, and lack of prenatal care.

CONCLUSIONS

Cases of SRSB are rising in Winnipeg with 11% of all stillbirths having maternal syphilis as a contributory factor by 2020. SRSBs disproportionately affect marginalized women. The dramatic and rapid changes in the epidemiology of syphilis in Winnipeg are likely shared by other Canadian regions and warrant increased prevention strategies to improve outcomes.

Securing the supply of benzathine penicillin: a global perspective on risks and mitigation strategies to prevent future shortages

Benzathine benzylpenicillin is a globally indispensable medicine. As a long-lasting injectable penicillin, it serves as the primary treatment for syphilis, group A streptococcal infections, rheumatic fever and rheumatic heart disease. A competitive market and low profit margins, compounded by limited visibility of demand, have resulted in a decreased number of active pharmaceutical ingredient (API) manufacturers. By 2016, only three Chinese API manufacturers remained, continuing to supply to the global market today. Recurring global shortages, a consequence of supply and demand imbalances, indicate underlying market risks. Therefore, the need for mitigation strategies is imperative.

The cost-effectiveness of syphilis screening in pregnant women: a systematic literature review

Introduction

The cost-effectiveness study of syphilis screening in pregnant women has not been synthesized. This study aimed to synthesize the economic evidence on the cost-effectiveness of syphilis screening in pregnant women that might contribute to making recommendations on the future direction of syphilis screening approaches.

Methods

We systematically searched MEDLINE, PubMed, and Web of Science databases for relevant studies published before 19 January 2023 and identified the cost-effectiveness analyses for syphilis screening in pregnant women. The methodological design quality was appraised by the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) 2022 checklist.

Results

In total, 17 literature met the eligibility criteria for a full review. Of the 17 studies, four evaluated interventions using different screening methods, seven assessed a combination of syphilis testing and treatment interventions, three focused on repeat screening intervention, and four evaluated the interventions that integrated syphilis and HIV testing. The most cost-effective strategy appeared to be rapid syphilis testing with high treatment rates in pregnant women who were positive.

Discussion

The cost-effectiveness of syphilis screening for pregnancy has been widely demonstrated. It is very essential to improve the compliance with maternal screening and the treatment rates for positive pregnant women while implementing screening.

Syphilis Prevalence Among People Living With and Without HIV in Sub-Saharan Africa: A Systematic Review and Meta-Analysis

BACKGROUND

Syphilis is a curable sexually transmitted infection that, untreated, is associated with significant morbidity and mortality. In people living with HIV (PLWH), syphilis carries greater risks of disease progression. We estimated syphilis prevalence among PLWH in the general population in sub-Saharan Africa and compared the prevalence among PLWH and without HIV.

METHODS

We searched for studies published January 1, 2011, to March 28, 2022, reporting syphilis prevalence among PLWH in sub-Saharan Africa (PROSPERO No. CRD42020167328). We excluded studies in high-risk subpopulations. We estimated pooled syphilis prevalence among PLWH using random-effects modeling and compared the prevalence with people without HIV when included in the same study. We examined influences of region, study setting, and test type in subgroup analyses.

RESULTS

We identified 926 studies; 53 were included in the meta-analysis. Pooled syphilis prevalence among PLWH was 7.3% (95% confidence interval [CI], 6.3%-8.5%). Prevalence differed by region: 3.1% (95% CI, 2.2%-4.0%) in Southern, 5.5% (95% CI, 2.3%-9.3%) in West/Central, and 10.5% (95% CI, 8.0%-13.1%) in Eastern Africa. Prevalence also differed by study setting: 13.8% (95% CI, 5.7%-23.0%) in sexual and reproductive health/sexually transmitted infection care, 8.7% (95% CI, 5.0%-12.8%) in HIV care, 7.1% (95% CI, 5.8%-8.5%) in antenatal care, and 3.8% (95% CI, 2.0%-5.8%) in household/community-based settings. Syphilis prevalence was higher among PLWH than without HIV (relative risk, 3.5; 95% CI, 2.8-4.5).

CONCLUSIONS

Syphilis is highly prevalent among PLWH in sub-Saharan Africa and is more common among PLWH than without HIV. Integration of syphilis screening and management into HIV care may reduce complications of HIV-syphilis coinfection among PLWH in sub-Saharan Africa.

Seroconversion and seroprevalence of TORCH infections in a pregnant women cohort study, Mombasa, Kenya, 2017-2019

Women infected during pregnancy with TORCH (Toxoplasmosis, Other, Rubella, Cytomegalovirus, and Herpes simplex viruses) pathogens have a higher risk of adverse birth outcomes including stillbirth / miscarriage because of mother-to-child transmission. To investigate these risks in pregnant women in Kenya, we analyzed serum specimens from a pregnancy cohort study at three healthcare facilities. A sample of 481 participants was selected for TORCH pathogen antibody testing to determine seroprevalence. A random selection of 285 from the 481 participants was selected to measure seroconversion. These sera were tested using an IgG enzyme-linked immunosorbent assay against 10 TORCH pathogens. We found that the seroprevalence of all but three of the 10 TORCH pathogens at enrollment was >30%, except for Bordetella pertussis (3.8%), Treponema pallidum (11.4%), and varicella zoster virus (0.5%). Conversely, very few participants seroconverted during their pregnancy and were herpes simplex virus type 2 (n = 24, 11.2%), parvovirus B19 (n = 14, 6.2%), and rubella (n = 12, 5.1%). For birth outcomes, 88% of the participant had live births and 12% had stillbirths or miscarriage. Cytomegalovirus positivity at enrolment had a statistically significant positive association with a live birth outcome (p = 0.0394). Of the 10 TORCH pathogens tested, none had an association with adverse pregnancy outcome.

Syphilis epidemic among men who have sex with men: A global systematic review and meta-analysis of prevalence, incidence, and associated factors

Background

We aimed to estimate the prevalence and incidence of syphilis at global, regional and national levels for human immunodeficiency virus (HIV)-positive and HIV-negative men who have sex with men (MSM) and explore the association between demographic and social behavioural factors and syphilis infection.

Methods

We searched PubMed, Embase, and the Cochrane Library from 1 January 2012 to 31 December 2022 for studies of reported crude syphilis prevalence or incidence in MSM or with sufficient data to calculate prevalence or incidence rate in MSM.

Results

We included 376 articles reporting on 409 records from 62 countries to calculate syphilis prevalence and incidence in MSM. The pooled prevalence of syphilis in MSM was 10.4%, with substantial differences between countries and regions. Syphilis prevalence was substantially higher in HIV-positive than in HIV-negative MSM. The pooled incidence of syphilis in MSM was 76.4 per 1000 person-years. Older age, lower education, nitrite or recreational drug use, group sex, and multiple sexual partners were identified as risk factors for syphilis infection.

Conclusions

A disproportionate geographic pattern of syphilis infection in MSM and significant threats of syphilis infection were revealed. The 'hidden risk' in specific regions and the inadequately elucidated drivers of high-risk behaviours, need to be fully acknowledged and addressed.

Registration

PROSPERO: CRD42023422218.

The prevalence of gestational syphilis in Malawi between 2014 and 2022: spatiotemporal modeling of population-level factors

Background

Mother-to-child transmission of syphilis remains high especially in the WHO AFRO region with a prevalence of 1.62%, resulting in a congenital syphilis rate of 1,119 per 100,000 live births. Elimination efforts can be supported by an understanding of the spatial and temporal changes in disease over time, which can identify priority areas for targeted interventions aimed at reducing transmission.

Methods

We collated routine surveillance data from health facilities and covariate data from demographic and health surveys conducted in Malawi between 2014 and 2022. We fitted a Bayesian hierarchical mixed model with spatial and temporally structured random effects to model the district-level monthly counts of maternal syphilis notifications as a function of individual- and district-level predictors. We then generated district-level spatiotemporally explicit risk profiles to estimate the effect of individual- and district-level covariates on maternal syphilis notifications and to identify hotspot areas.

Results

Overall, the national prevalence of maternal syphilis increased from 0.28% (95% CI: 0.27-0.29%) in 2014 to peaking in 2021 at 1.92% (95% CI: 1.89-1.96%). Between 2020 and 2022, there was a decline in prevalence, with the most significant decline seen in Zomba District (1.40, 95% CI: 1.12-1.66%). In regression models, a one percentage point increase in district-level antenatal HIV prevalence was associated with increased maternal syphilis (prevalence ratio [PR]: 1.15, 95% credible interval [CrI]: 1.10-1.21). There was also an increased prevalence of maternal syphilis associated with an increased district-level mean number of sex partners (PR: 1.05, 95% CrI: 0.80-1.37). The number of districts with a high prevalence of maternal syphilis also increased between 2014 and 2022, especially in the southern region, where most had a high probability (approaching 100%) of having high maternal syphilis (defined as relative risk >1 compared to the standard population of women aged 15-49 years) in 2022.

Conclusion

Maternal syphilis prevalence in Malawi shows an increasing upward trend, with an estimated six times relative increase between 2014 and 2022 (0.28% to 1.73%) and strong associations with higher district-level HIV prevalence. Controlling syphilis depends on reaching vulnerable populations at the sub-national level, which may be disproportionately affected. Our findings support the move to integrate the elimination of mother-to-child transmission (EMTCT) of syphilis programs with existing prevention of mother-to-child transmission (PMTCT) of HIV programs.

Interventions in maternal syphilis care globally: A scoping review

Infectious and Congenital Syphilis rates continue to rise globally. Current recommendations for syphilis screening and treatment may be insufficient, and there is a pressing need for improved programs and services to address the increase in cases. A scoping review was conducted to examine approaches to maternal syphilis screening and treatment. Theoretical underpinnings and the key characteristics of these interventions were studied to identify gaps in the existing literature to guide future research. Developing a modified version of the socio-ecological model to guide data analysis, we included 33 academic studies spanning 31 years, covering a range of interventions, programs, and policies globally. We highlight key facets of interventions aligning with the five levels of the modified model that include: individual, interpersonal, institutional, community and policy. In this review, we provide valuable insights into the characteristics and principles of maternal syphilis screening and treatment interventions.

Determinants of stillbirths in sub-Saharan Africa: A systematic review

BACKGROUND

Sub-Saharan African (SSA) countries have high stillbirth rates compared with high-income countries, yet research on risk factors for stillbirth in SSA remain scant.

OBJECTIVES

To identify the modifiable risk factors of stillbirths in SSA and investigate their strength of association using a systematic review.

SEARCH STRATEGY

CINAHL Plus, EMBASE, Global Health and MEDLINE databases were searched for literature.

SELECTION CRITERIA

Observational population- and facility-level studies exploring stillbirth risk factors, published in 2013-2019 were included.

DATA COLLECTION AND ANALYSIS

A narrative synthesis of data was undertaken and the potential risk factors were classified into subgroups.

MAIN RESULTS

Thirty-seven studies were included, encompassing 20 264 stillbirths. The risk factors were categorised as: maternal antepartum factors (0-4 antenatal care visits, multiple gestations, hypertension, birth interval of >3 years, history of perinatal death); socio-economic factors (maternal lower wealth index and basic education, advanced maternal age, grand multiparity of ≥5); intrapartum factors (direct obstetric complication); fetal factors (low birthweight and gestational age of <37 weeks) and health systems factors (poor quality of antenatal care, emergency referrals, ill-equipped facility). The proportion of unexplained stillbirths remained very high. No association was found between stillbirths and body mass index, diabetes, distance from the facility or HIV.

CONCLUSIONS

The overall quality of evidence was low, as many studies were facility based and did not adjust for confounding factors. This review identified preventable risk factors for stillbirth. Focused programmatic strategies to improve antenatal care, emergency obstetric care, maternal perinatal education, referral and outreach systems, and birth attendant training should be developed. More population-based, high-quality research is needed.

A Rare Case of Neurosyphilis with Calvaria Osteitis Presenting in Pregnancy

Background

The incidence of syphilis throughout the world is increasing. Rates in pregnancy are similarly rising, presenting risks of an untreated syphilis infection that can be detrimental to the mother and fetus. Although routine screening for syphilis infections is recommended at the initial prenatal visit, there is a lack of universal agreement on rescreening pregnant people and approximately 50% of syphilis cases are asymptomatic in the general population. Furthermore, some symptoms of syphilis can overlap with nonspecific pregnancy-related symptoms. Meanwhile, Treponema pallidum can spread to various maternal and fetoplacental tissues quickly after infection and occur at any stage of syphilis.

Case

A 26-year-old gravida 5 para 2 presented with a new onset headache and visual and auditory changes at 23 weeks of gestation. A computerized tomography scan revealed numerous ill-defined lytic lesions throughout the calvarium, suspicious for syphilitic osteitis. She tested positive for syphilis antibodies with a rapid plasma reagin (RPR) titer of 1 : 32. Cerebrospinal fluid evaluation from a lumbar puncture resulted in reactive fluorescent treponemal antibody (FTA) testing. She was diagnosed with secondary syphilis with osteitis and neuro and otic components. She completed 14 days of intravenous aqueous crystalline penicillin G with additional benzathine penicillin G 2.4 million units intramuscular weekly for two weeks. There was no evidence of congenital syphilis on neonatal examination.

Conclusion

Syphilitic osteitis and neuro, otic, or ocular syphilis infections occur rarely in the nonpregnant population, and therefore, little data in pregnancy is available to inform outcomes in these specific disease states. It is of paramount importance to complete appropriate syphilis screening, recognize symptoms, and consider utilizing rescreen protocols to ensure prompt infection identification and treatment. For neuro, otic, and ocular syphilis, aqueous crystalline penicillin G (as opposed to benzathine penicillin G) is required to achieve treponemicidal concentrations in those physiologic compartments. There is no agreement as to the appropriate treatment regimen for the rare finding of syphilitic osteitis.

Treponema pallidum Promotes the Polarization of M2 Subtype Macrophages to M1 Subtype Mediating the Apoptosis and Inhibiting the Angiogenesis of Human Umbilical Vein Endothelial Cells

M2 macrophages were related to local immune homeostasis and maternal-fetal tolerance in normal pregnancy; whether M2 macrophages can respond to the stimulation of Treponema pallidum to mediate placental vascular inflammation injury is unclear. In this study, M2 macrophages were constructed to investigate the impact of T. pallidum on macrophage polarization and the underlying signaling pathway involved in this process, and the influence of macrophage polarization triggered by T. pallidum on the apoptosis and angiogenesis of human umbilical vein endothelial cells (HUVEC) was also explored. The results showed that M2 macrophage markers (CD206 and PPARγ) and anti-inflammatory factors (TGFβ and CCL18) were decreased, while M1 macrophage marker CD80 and inflammatory cytokines (IL1β and TNFα) were increased when M2 macrophages were treated with T. pallidum, indicating that T. pallidum promoted the polarization of M2 subtype macrophages to the M1 subtype. Moreover, T. pallidum-induced M1 macrophage polarization was found to be significantly correlated with the activation of Janus kinase 1 (JAK1) and signal transducer and activator of transcription 1 (STAT1). In addition, T. pallidum-induced M1 macrophages were found to promote apoptosis and inhibit the angiogenesis of HUVECs, and JAK1 or STAT1 inhibitors could weaken the apoptosis rate and promote the angiogenesis of HUVECs. These findings revealed that T. pallidum promoted the polarization of M2 macrophages to the M1 subtype through the JAK1-STAT1 signal pathway mediating the apoptosis and inhibiting angiogenesis of HUVECs, which may provide a possible mechanism for T. pallidum-induced adverse pregnancy outcomes.

Growth and development of syphilis-exposed and -unexposed uninfected children during their first 18 months of life in Suzhou, China: a nested case-control study with propensity score matching

Background

With the successful implementation of Prevention of Mother-to-Child Transmission (PMTCT) policies, the proportion of infants with exposure to both syphilis and antibiotic medication in utero has increased in China, but there is limited evidence about the early growth and development of such infants.

Methods

We conducted a retrospective nested case-control study based on data from the China PMTCT program conducted in Suzhou from 2016 to 2021. Propensity score matching (PSM) was employed to extract 826 syphilis-exposed but uninfected (SEU) infants and 1,652 syphilis-unexposed uninfected (SUU) infants from a total of 712,653 infants. Maternal characteristics were collected through questionnaires, such as parity, age, education level, smoking and drinking habits during pregnancy. Infantile characteristics were retrieved from medical records or via questionnaires, such as gestational age, gender, mode of delivery, Apgar scores, birth weight and length, outdoor time, vitamin D intake, and feed pattern. Mixed effects models, adjusting for potential influencing factors, were used to investigate the early infantile growth pattern of SEU and SUU infants. All statistical analysis were conducted using R (version 4.2.0).

Results

Length and weight were slightly higher in SEU infants than in the SUU infants at some time points (months 0 and 18 for length, p-values <0.05; months 0, 6, and 18 for weight, p < 0.05). In the mixed effects model, SEU group was found to be associated with higher weight [exponentiated beta exp.(β) = 1.15, 95% Confidence Interval (CI) = 1.06, 1.25], length [exp(β) = 1.42, 95% CI = 1.14, 1.77], and BMI z-score [exp(β) = 1.09, 95% CI = 1.00, 1.19].

Conclusion

With the effective prevention of congenital syphilis under the PMTCT program, SEU infants have non-inferior growth patterns during their first 18 months of life compared with SUU controls in Suzhou, China.

Determinants of congenital syphilis in Fortaleza, Brazil: A retrospective case-control study

Congenital syphilis (CS) is a significant public health problem in Brazil. Despite efforts to increase syphilis testing and treatment among pregnant women, rates of CS in the country remain high. We conducted a retrospective case-control study to identify potential associations between the mothers' sociodemographic characteristics, clinical factors related to the current and previous pregnancies, and the occurrence of CS among newborns in Fortaleza, a populous city with one of the highest incidences of CS in Brazil. Data from newborns diagnosed with CS between 2017 and 2020 were extracted from SINAN, the national database for notifiable diseases. Data from women who had delivered an infant with CS were extracted from SINASC, the national database for registration of live births, and linked with their infant's data. CS cases and non-CS controls were matched by year of birth at a ratio of 1:3 respectively. Potential associations were estimated using a multivariate regression model accounting for sociodemographic, obstetric, and antenatal care-related factors. Epidemiological data from 8,744 live births were included in the analysis, including 2,186 cases and 6,588 controls. The final multivariate regression model identified increased odds of delivering an infant with CS among pregnant women and girls aged below 20 years (OR 1.29), single women (OR 1.48), women who had less than 8 years of formal education (OR 2.42), women who delivered in a public hospital (OR 6.92), women who had more than 4 previous pregnancies (OR 1.60), and women who had one or more prior fetal loss (OR 1.19). The odds of delivering an infant with CS also increased as the number of antenatal visits decreased. Women who did not attend any antenatal visits had 3.94 times the odds of delivering an infant with CS compared to women who attended 7 or more visits. Our study found that increased odds of delivering an infant with CS were highly associated with factors related to socioeconomic vulnerability. These determinants not only affect the access to essential antenatal care services, but also the continuity and quality of such preventive measures. Future policies aimed at reducing the incidence of CS should not only target those pregnant women and adolescents with identifiable risk factors for testing, but also assure high quality care, treatment and follow-up for this group.

Barriers to optimal management of syphilis in pregnancy and congenital syphilis in south-east Queensland: a qualitative investigation

BACKGROUND

Australia, like many high-income countries, is experiencing a resurgence of infectious syphilis in pregnancy and congenital syphilis. Evaluations of public health notifications and clinical records suggest that healthcare systems may not be providing optimal care to women and their neonates. This study aims to explore the barriers to optimal management of syphilis in pregnancy and congenital syphilis to identify key areas for improvement.

METHODS

Between 2021 and 2022, 34 healthcare workers (HCW) practicing in south-east Queensland (SEQ) Australia were recruited to complete semi-structured interviews regarding their perceptions towards management of syphilis in pregnancy and congenital syphilis. Interviews were analysed thematically.

RESULTS

Thematic analysis identified four themes related to the management of syphilis in pregnancy. These included poor communication between disciplines, services, and teams from delivery through to management and post-delivery, lack of formal internal and external referral pathways, unclear and often complex maternal and congenital syphilis management procedures, and limited HCW knowledge of infectious syphilis in pregnancy and congenital syphilis.

CONCLUSION

As congenital syphilis numbers continue to rise in SEQ, it is imperative that healthcare systems and HCWs identify and address gaps in the provision of health care.

Congenital syphilis: performance of primary care services in São Paulo, 2017

OBJECTIVE

To evaluate congenital syphilis prevention actions in primary health care services in the state of São Paulo.

METHODS

Cross-sectional evaluative research that used indicators extracted from the Survey of Evaluation and Monitoring of Primary Care Services ( Avaliação e Monitoramento de Serviços da Atenção Básica - QualiAB) in the state of São Paulo in 2017. An evaluative matrix composed of 31 indicators of prevention of congenital syphilis, categorized into four domains of analysis: diagnosis and treatment of acquired syphilis (10); basic infrastructure and resources (7); prevention of congenital syphilis during prenatal care (7); and educational actions and prevention of sexually transmitted infections (7). The frequency of services with positive responses for each indicator and the percentage of service performance were calculated based on the proportion of indicators reported per service and the overall average observed. Subsequently, services were classified into four quality groups, and associations between groups and each indicator, type of organizational arrangement and location were estimated.

RESULTS

2,565 services participated, located in 503 municipalities, with an overall average performance of 74.9%. The domain "diagnosis and treatment of acquired syphilis" had the highest performance (89.8%), followed by "infrastructure and basic resources" (79.5%), "prevention of congenital syphilis in prenatal care" (73.3%) and "educational actions and prevention of sexually transmitted infections" (56.8%). There was a significant difference between quality groups and all indicators and types of organizational arrangements.

CONCLUSIONS

The evaluated services have limitations in the development of actions to prevent congenital syphilis, mainly related to health education and actions included in prenatal care, such as screening and adequate treatment of pregnant women and their partners. Changes are needed in the work process, with the expansion of educational and surveillance actions, as well as the qualification of the teams to effectively comply with the protocols.

Subnational certification of elimination of mother-to-child transmission of HIV and/or syphilis: a Brazilian experience report

OBJECTIVE

to describe the subnational implementation process of the certification for elimination of mother-to-child transmission of HIV and/or syphilis, its main barriers, challenges and opportunities.

METHODS

in 2022, indicators from the last full year for impact targets and the last two full years for process targets, available in national information systems, were evaluated; descriptive reports were analyzed and actions were acknowledged within four thematic axes, according to PAHO/WHO recommendations.

RESULTS

43 municipalities ≥ 100,000 inhabitants were certified, covering 24.6 million inhabitants; one municipality achieved dual elimination (HIV-syphilis), 28 municipalities achieved elimination of HIV and 10 received silver tiers; regarding syphilis, one elimination was observed, along with 4 gold tiers, 13 silver tiers and 4 bronze tiers; a higher number of certifications was identified in the Southeast and South regions.

CONCLUSION

barriers and challenges of the process were overcome through tripartite collaboration; the experience provided better integration of surveillance with care and improved actions aimed at preventing mother-to-child transmission.

MAIN RESULTS

First experience of the sub-national process of certification of elimination of mother-to-child transmission (MTCT) of HIV and/or syphilis at a global level. In 2022, 43 municipalities ≥ 100,000 inhabitants were certified, covering 24.6 million inhabitants.

IMPLICATIONS FOR SERVICES

The experience of sub-national certification of the EMTCT was important in mobilizing the municipalities that engaged in its initiatives, worked to improve the quality of care and surveillance and emerging as the main proponents in the process.

PERSPECTIVES

Through this ongoing and dynamic initiative, there is an anticipation of over 100 municipalities and states joining in 2023. Sub-national certification aims to enhance comprehensive care for pregnant women, in order to achieve national certification of EMTCT.

Deep proteome coverage advances knowledge of Treponema pallidum protein expression profiles during infection

Comprehensive proteome-wide analysis of the syphilis spirochete, Treponema pallidum ssp. pallidum, is technically challenging due to high sample complexity, difficulties with obtaining sufficient quantities of bacteria for analysis, and the inherent fragility of the T. pallidum cell envelope which further complicates proteomic identification of rare T. pallidum outer membrane proteins (OMPs). The main aim of the present study was to gain a deeper understanding of the T. pallidum global proteome expression profile under infection conditions. This will corroborate and extend genome annotations, identify protein modifications that are unable to be predicted at the genomic or transcriptomic levels, and provide a foundational knowledge of the T. pallidum protein expression repertoire. Here we describe the optimization of a T. pallidum-specific sample preparation workflow and mass spectrometry-based proteomics pipeline which allowed for the detection of 77% of the T. pallidum protein repertoire under infection conditions. When combined with prior studies, this brings the overall coverage of the T. pallidum proteome to almost 90%. These investigations identified 27 known/predicted OMPs, including potential vaccine candidates, and detected expression of 11 potential OMPs under infection conditions for the first time. The optimized pipeline provides a robust and reproducible workflow for investigating T. pallidum protein expression during infection. Importantly, the combined results provide the deepest coverage of the T. pallidum proteome to date.

Placental weights of neonates born with symptomatic congenital syphilis

Background

Syphilis during pregnancy remains an important global health concern causing miscarriage, stillbirth, preterm birth and neonatal death. As part of the fetal infection, placental changes occur which may include a heavier placenta than expected.

Methods

A cohort of 50 neonates with symptomatic congenital syphilis has previously been described. This cohort was admitted to Groote Schuur neonatal unit in Cape Town South Africa from 2011 to 2013. For this study, the placental weights of the neonates were analyzed and compared to population based placental centiles.

Results

There was data for 37 placentae. Heavy placentae (>90th centile) occurred in 76% of placentae in the study. All 6 infants with birth weights ≥2,500 g had heavy placentae. There was no correlation between placental centile and death.

Conclusion

Heavy placenta are an important and frequent finding with symptomatic congenital syphilis, especially in the larger neonates.

Factors associated with adverse pregnancy outcomes of maternal syphilis in Henan, China, 2016-2022

Maternal syphilis not only seriously affects the quality of life of pregnant women themselves but also may cause various adverse pregnancy outcomes (APOs). This study aimed to analyse the association between the related factors and APOs in maternal syphilis. 7,030 pregnant women infected with syphilis in Henan Province between January 2016 and December 2022 were selected as participants. Information on their demographic and clinical characteristics, treatment status, and pregnancy outcomes was collected. Multivariate logistic regression models and chi-squared automatic interaction detector (CHAID) decision tree models were used to analyse the factors associated with APOs. The multivariate logistic regression results showed that the syphilis infection history (OR = 1.207, 95% CI, 1.035-1.409), the occurrence of abnormality during pregnancy (OR = 5.001, 95% CI, 4.203-5.951), not receiving standard treatment (OR = 1.370, 95% CI, 1.095-1.716), not receiving any treatment (OR = 1.313, 95% CI, 1.105-1.559), and a titre ≥1:8 at diagnosis (OR = 1.350, 95%CI, 1.079-1.690) and before delivery (OR = 1.985, 95%CI, 1.463-2.694) were risk factors. A total of six influencing factors of APOs in syphilis-infected women were screened using the CHAID decision tree model. Integrated prevention measures such as early screening, scientific eugenics assessment, and standard syphilis treatment are of great significance in reducing the incidence of APOs for pregnant women infected with syphilis.

Predicting adverse pregnancy outcomes of pregnant mothers with syphilis based on a logistic regression model: a retrospective study

Objective

Maternal syphilis could cause serious consequences. The aim of this study was to identify risk factors for maternal syphilis in order to predict an individual's risk of developing adverse pregnancy outcomes (APOs).

Methods

A retrospective study was conducted on 768 pregnant women with syphilis. A questionnaire was completed and data analyzed. The data was divided into a training set and a testing set. Using logistic regression to establish predictive models in the training set, and its predictive performance was evaluated in the testing set. The probability of APOs occurrence is presented through a nomogram.

Results

Compared with the APOs group, pregnant women in the non-APOs group participated in a longer treatment course. Course, time of the first antenatal care, gestation week at syphilis diagnosis, and gestation age at delivery in weeks were independent predictors of APOs, and they were used to establish the nomogram.

Conclusions

Our study investigated the impact of various characteristics of syphilis pregnant women on pregnancy outcomes and established a prediction model of APOs in Suzhou. The incidence of APOs can be reduced by controlling for these risk factors.

Congenital syphilis in Switzerland: a marker of inequality? A mini-review

Syphilis remains a global public health problem, with growing incidence in most regions of the world, particularly among women of childbearing age. This alarming trend has led to an increase in cases of congenital syphilis, resulting in devastating consequences. While the implementation of measures by the World Health Organization (WHO) and various governments has contributed to a decline in the global incidence of congenital syphilis, many countries are facing an escalating crisis, as incidence continues to rise. This mini-review aims to provide an overview of the current state of this disease in different parts of the world, focusing on the most affected populations and highlighting congenital syphilis as a marker of vulnerability. It also focuses on Switzerland, a country with a robust economy, to identify shortcomings in the healthcare system that contribute to the persistence of congenital syphilis, even though the infection is easily detectable and treatable. In conclusion, this mini-review highlights the persistent risk of congenital syphilis worldwide, regardless of country prevalence or economic status, and underscores the need for sustained efforts to reach underserved women, emphasizing the vital role of comprehensive training for healthcare professionals.

Spatial distribution of congenital syphilis in the state of Bahia, Brazil from 2009 to 2018

Objective

To describe the temporal trend and spatial distribution of congenital syphilis (CS) cases in the state of Bahia, Brazil between 2009 and 2018.

Method

Mixed ecological study conducted through the analysis of data obtained from the Notifiable Diseases Information System and the Live Birth Information System. Global Moran Index I was performed in order to analyze spatial autocorrelation of CS cases in the municipalities of Bahia and the Local Spatial Association Indicator (LISA) was used to identify the formation of spatial regimes in the GeoDA software.

Results

8,786 cases of CS were registered in the period. An increasing growth in CS incidence, with a 511% increase between 2009 and 2018. Spatial autocorrelation was observed between the municipalities (I Moran = 0.452; p < 0.001) and four clusters were identified. More frequently, mothers were aged 20-29 years (50.7%); had incomplete primary education (54.9%); were Black and multiracial (93.2%); received prenatal care (82.2%); 49.0% were diagnosed with syphilis during prenatal care; 68.8% were not adequately treated, and 81.1% of their partners were not treated.

Conclusion

The results showed that CS consolidates as a serious public health problem in Bahia, with an incidence 8.4 times higher in the period than the WHO target of 0.5/1,000 live births, predominantly related to inadequate prenatal care and social vulnerability indicators: young mothers with low education levels, as well as individuals identified as Black and multiracial. Thus, programs aimed at women of childbearing age and pregnant women need to be intensified.

Demystifying Ocular Syphilis - A Major Review

Syphilis, caused by the spirochaete, Treponema pallidum, continues to be a public health challenge globally with its rates steadily increasing in the past few years. The disease is transmitted through small breaks in the skin during sexual contact, or via congenital transmission in utero, either across the placenta or by contact with an active genital lesion during delivery. Estimated 5.7-6 million new cases are detected every year worldwide in the 15-49 years age group. An increased incidence has been reported in most populations with particular clusters in special groups like men who have sex with men, female sex workers, and their male clients. Ocular syphilis has a varied presentation and is considered a great mimicker in all cases of uveitis. The laboratory diagnosis of syphilis is predominantly based on serological tests including TPHA and VDRL. Parenteral penicillin is the cornerstone of treatment for all stages of ocular syphilis.

Estimating the real burden of gestational syphilis in Brazil, 2007-2018: a Bayesian modeling study

Background

Although several studies have estimated gestational syphilis (GS) incidence in several countries, underreporting correction is rarely considered. This study aimed to estimate the level of under-registration and correct the GS incidence rates in the 557 Brazilian microregions.

Methods

Brazilian GS notifications between 2007 and 2018 were obtained from the SINAN-Syphilis system. A cluster analysis was performed to group microregions according to the quality of GS notification. A Bayesian hierarchical Poisson regression model was applied to estimate the reporting probabilities among the clusters and to correct the associated incidence rates.

Findings

We estimate that 45,196 (90%-HPD: 13,299; 79,310) GS cases were underreported in Brazil from 2007 to 2018, representing a coverage of 87.12% (90%-HPD: 79.40%; 95.83%) of registered cases, where HPD stands for the Bayesian highest posterior density credible interval. Underreporting levels differ across the country, with microregions in North and Northeast regions presenting the highest percentage of missed cases. After underreporting correction, Brazil's estimated GS incidence rate increased from 8.74 to 10.02 per 1000 live births in the same period.

Interpretation

Our findings highlight disparities in the registration level and incidence rate of GS in Brazil, reflecting regional heterogeneity in the quality of syphilis surveillance, access to prenatal care, and childbirth assistance services. This study provides robust evidence to enhance national surveillance systems, guide specific policies for GS detection disease control, and potentially mitigate the harmful consequences of mother-to-child transmission. The methodology might be applied in other regions to correct disease underreporting.

Funding

National Council for Scientific and Technological Development; The Bill Melinda Gates Foundation and Wellcome Trust.

Adverse pregnancy outcomes and associated risk factors among pregnant women with syphilis during 2013-2018 in Hunan, China

Objective

To investigate the adverse pregnancy outcomes and associated risk factors among pregnant women with syphilis.

Design

Pregnant women with syphilis in the registry for the prevention of mother-to-child transmission of AIDS, syphilis and hepatitis B in Hunan Province, China, from January 1, 2013 to December 31, 2018 were included in the study.

Results

Among the 14,219 pregnant women with syphilis, 11,346 had definite pregnancy outcomes and were in singleton pregnancy. The risk factors related to adverse pregnancy outcomes include the age of pregnant women with syphilis <20 years old (aOR = 1.274, 95% CI: 1.088-1.493) or ≥ 35 years old (aOR = 1.402, 95% CI: 1.167-1.686), not married (aOR = 1.855, 95% CI: 1.453-2.367), initial syphilis detection in the late pregnancy (aOR = 1.266, 95% CI: 1.032-1.555), diagnosis of syphilis in the late pregnancy (aOR = 5.806, 95% CI: 1.796-18.770), diagnosis of syphilis during labor (aOR = 4.102, 95% CI: 1.263-13.330), husband/sexual partner infected with syphilis (aOR = 1.222, 95% CI: 1.068-1.398), untreated (aOR = 6.756, 95% CI: 5.586-8.197), and nonstandard medication (aOR = 3.300, 95% CI: 2.841-3.846).

Conclusion

The prevalence of adverse pregnancy outcomes among pregnant women with syphilis in Hunan Province, China from 2013 to 2018 was relatively high. The adverse pregnancy outcomes associated with syphilis could be reduced by early detection and standard treatment of syphilis for pregnant women and their husbands/sexual partners.

Congenital Syphilis: a Review of Global Epidemiology

In 2007, the World Health Organization (WHO) launched a global health initiative for the elimination of mother-to-child transmission (MTCT) of syphilis. This condition is highly preventable through antenatal identification of syphilis infection and treatment with penicillin during pregnancy. This review summarizes the global status of MTCT of syphilis and concludes that this condition remains a significant issue worldwide. There are large variations in case rates by region, with the highest numbers of cases in the African and Eastern Mediterranean regions, where there are also the least data available. There are also pockets of high-incidence areas within the other regions. Although the general trend is of decreasing rates over time, there are concerning indications of consistently increasing congenital syphilis cases in some areas, particularly in areas which have previously had very low case numbers. A concerted effort will be required to achieve the 2007 WHO goal of worldwide elimination of MTCT of syphilis in the near future.

Characteristics of Kenyan women using HIV PrEP enrolled in a randomized trial on doxycycline postexposure prophylaxis for sexually transmitted infection prevention

INTRODUCTION

The global incidence of sexually transmitted infections (STIs) has been rapidly increasing over the past decade, with more than one million curable STIs being acquired daily. Young women in sub-Saharan Africa have a high prevalence and incidence of both curable STIs and HIV. The use of doxycycline as a prophylaxis to prevent STIs is promising; however, clinical trials, to date, have only been conducted among men who have sex with men (MSM) in high-income settings. We describe the characteristics of participants enrolled in the first trial to determine the efficacy of doxycycline post-exposure prophylaxis (PEP) to reduce STI incidence among women taking daily, oral HIV pre-exposure prophylaxis (PrEP).

METHODS

This is an open-label 1:1 randomized clinical trial on the efficacy of doxycycline PEP compared with standard of care (e.g., quarterly STI screening and treatment) to reduce incident bacterial STIs - Neisseria gonorrhoeae, Chlamydia trachomatis, and Treponema pallidum - among Kenyan women aged ≥18 and ≤30 years. All were also taking HIV pre-exposure prophylaxis (PrEP). We describe the baseline characteristics, STI prevalence, and STI risk perception of participants.

RESULTS

Between February 2020 and November 2021, 449 women were enrolled. The median age was 24 years (IQR 21-27), the majority were never married (66.1%), 370 women (82.4%) reported having a primary sex partner, and 33% had sex with new partners in the three months prior to enrolment. Two-thirds (67.5%, 268 women) did not use condoms, 36.7% reported transactional sex, and 43.2% suspected their male partners of having sex with other women. Slightly less than half (45.9%, 206 women) were recently concerned about being exposed to an STI. The prevalence of STIs was 17.9%, with C. trachomatis accounting for the majority of infections. Perceived risk of STIs was not associated with the detection of an STI.

CONCLUSION

Young cisgender women using HIV PrEP in Kenya and enrolled in a trial of doxycycline postexposure prophylaxis had a high prevalence of curable STIs and represent a target population for an STI prevention intervention.

A large screen identifies beta-lactam antibiotics which can be repurposed to target the syphilis agent

Syphilis, caused by the spirochete Treponema pallidum subsp. pallidum (hereafter called T. pallidum), is re-emerging as a worldwide sexually transmitted infection. A single intramuscular dose of benzathine penicillin G is the preferred syphilis treatment option. Both supply shortage concerns and the potential for acquired antibiotic resistance further the need to broaden the repertoire of syphilis therapeutics. We reasoned that other β-lactams may be equally or more effective at targeting the disease-causing agent, Treponema pallidum, but have yet to be discovered due to a previous lack of a continuous in vitro culture system. Recent technical advances with respect to in vitro T. pallidum propagation allowed us to conduct a high-throughput screen of almost 100 β-lactams. Using several molecular and cellular approaches that we developed or adapted, we identified and confirmed the efficacy of several β-lactams that were similar to or outperformed the current standard, benzathine penicillin G. These options are either currently used to treat bacterial infections or are synthetic derivatives of naturally occurring compounds. Our studies not only identified additional potential therapeutics in the resolution of syphilis, but provide techniques to study the complex biology of T. pallidum-a spirochete that has plagued human health for centuries.

Maternal and congenital syphilis in Indigenous Peoples: a scoping review of the worldwide literature

BACKGROUND

Syphilis is among the most common sexually transmitted infections worldwide. When it occurs during pregnancy, it can seriously affect the fetus and newborn`s health. The scarcity of studies on maternal and congenital syphilis in Indigenous Peoples remains an obstacle to its control in these populations. This study aimed to explore the breadth of the literature, map updated evidence, and identify knowledge gaps on maternal and congenital syphilis in Indigenous Peoples worldwide.

METHODS

We conducted a Scoping review following Preferred Reporting Items for Systematic Reviews and Meta-Analyses - Extension for Scoping Reviews. In March 2021, we collected data through a priority search on PubMed, Web of Science, Embase, and SciELO.

RESULTS

The strategy yielded 24 studies for analysis. Data in the articles were collected from 1989 to 2020, half from 2015 onwards. Studies were in Oceania and the Americas, mainly in South America (66.7%), particularly in Brazil (50.0%). The topics assessed were Data quality related to maternal and congenital syphilis (20.8%); Diagnosis, provision, access, and use of health services (62.5%); Disease frequency and health inequities (54.2%); Determinants of maternal syphilis and congenital syphilis (20.8%); and Outcomes of maternal and congenital syphilis in the fetus (20.8%). The results show that the available literature on maternal and congenital syphilis is sparse and concentrated in some geographic areas; the frequency of these diseases in Indigenous Peoples varies but is generally higher than in the non-indigenous counterparts; the quality of surveillance data and health information systems is poor; multiple healthcare barriers exist; and the diversity of terms to identify Indigenous Peoples is a challenge to mapping scientific outputs on Indigenous Peoples' health.

CONCLUSIONS

Maternal and congenital syphilis in Indigenous Peoples is a double-neglected condition and research in this area should be given the priority and encouragement it deserves globally. Reliable data and improving access to health care are needed to reduce the burden of syphilis and correctly inform policies and health services response to mitigate ethnic-racial inequalities in maternal and congenital syphilis.

Optimal vaccine allocation for the control of sexually transmitted infections

The burden of sexually transmitted infections (STIs) poses a challenge due to its large negative impact on sexual and reproductive health worldwide. Besides simple prevention measures and available treatment efforts, prophylactic vaccination is a powerful tool for controlling some viral STIs and their associated diseases. Here, we investigate how prophylactic vaccines are best distributed to prevent and control STIs. We consider sex-specific differences in susceptibility to infection, as well as disease severity outcomes. Different vaccination strategies are compared assuming distinct budget constraints that mimic a scarce vaccine stockpile. Vaccination strategies are obtained as solutions to an optimal control problem subject to a two-sex Kermack-McKendrick-type model, where the control variables are the daily vaccination rates for females and males. One important aspect of our approach relies on conceptualizing a limited but specific vaccine stockpile via an isoperimetric constraint. We solve the optimal control problem via Pontryagin's Maximum Principle and obtain a numerical approximation for the solution using a modified version of the forward-backward sweep method that handles the isoperimetric budget constraint in our formulation. The results suggest that for a limited vaccine supply ([Formula: see text]-[Formula: see text] vaccination coverage), one-sex vaccination, prioritizing females, appears to be more beneficial than the inclusion of both sexes into the vaccination program. Whereas, if the vaccine supply is relatively large (enough to reach at least [Formula: see text] coverage), vaccinating both sexes, with a slightly higher rate for females, is optimal and provides an effective and faster approach to reducing the prevalence of the infection.

Factors influencing treatment status of syphilis among pregnant women: a retrospective cohort study in Guangzhou, China

BACKGROUND

Many syphilis infected pregnant women do not receive treatment, representing a major missed opportunity to reduce the risk of syphilis-related adverse pregnancy outcomes. This study explored correlates of treatment among pregnant women with syphilis in Guangzhou, China.

METHODS

Pregnant women with a diagnosis of syphilis in Guangzhou between January 2014 and December 2016 were included. Information of syphilis treatment and correlates were extracted from a comprehensive national case-reporting system. Multivariate logistic regression was used to identify the correlations between information on the demographic characteristics, previous history, clinical characteristics about current syphilis, information of diagnosing hospital, and receiving no treatment or inadequate treatment among syphilis-seropositive pregnant women. A causal mediation analysis was used to explore the potential mediating role of the timing of syphilis diagnosis in the correlates.

RESULTS

Among 1248 syphilis-seropositive pregnant women, 379 (30.4%) women received no treatment or inadequate treatment. Migrant pregnant women (adjusted OR = 1.83, 95% CI: 1.25-2.73), multiparous participants (adjusted OR = 3.68, 95% CI: 2.51-5.50), unmarried participants (adjusted OR = 3.21, 95% CI: 1.97-5.28) and unemployed participants (adjusted OR = 2.43, 95% CI: 1.41-4.39) were more likely to receive no treatment or inadequate treatment. Participants who with history of syphilis infection (adjusted OR = 0.59, 95% CI: 0.42-0.82) and with high school and higher education participants (adjusted OR = 0.69, 95% CI: 0.49-0.97) were less likely to receive untreated or inadequately treatment. And that the impact of all these factors (except for the migrants) on treatment status are fully mediated through the syphilis diagnosis time, with the direct effect of migrants that would have resulted in a higher rate of no or inadequate treatment (OR = 2.34, 95% CI: 1.08-5.32) was partially cancelled out by the syphilis diagnosis time.

CONCLUSIONS

Pregnant women who were migrant without local residence and women with syphilis diagnosed at a later gestational age were more likely to slip through the cracks of the existing antenatal care system. More programs should focus on eliminating these gaps of residence-related health inequalities. This research highlights actionable elements for health services interventions that could increase syphilis treatment rates among pregnant women.

Syphilis vaccine: challenges, controversies and opportunities

Syphilis is a sexually or vertically (mother to fetus) transmitted disease caused by the infection of Treponema pallidum subspecie pallidum (TPA). The incidence of syphilis has increased over the past years despite the fact that this bacterium is an obligate human pathogen, the infection route is well known, and the disease can be successfully treated with penicillin. As complementary measures to preventive campaigns and early treatment of infected individuals, development of a syphilis vaccine may be crucial for controlling disease spread and/or severity, particularly in countries where the effectiveness of the aforementioned measures is limited. In the last century, several vaccine prototypes have been tested in preclinical studies, mainly in rabbits. While none of them provided protection against infection, some prototypes prevented bacteria from disseminating to distal organs, attenuated lesion development, and accelerated their healing. In spite of these promising results, there is still some controversy regarding the identification of vaccine candidates and the characteristics of a syphilis-protective immune response. In this review, we describe what is known about TPA immune response, and the main mechanisms used by this pathogen to evade it. Moreover, we emphasize the importance of integrating this knowledge, in conjunction with the characterization of outer membrane proteins (OMPs), to expedite the development of a syphilis vaccine that can protect against TPA infection.

Syphilis screening coverage and positivity by HIV treatment status among South African pregnant women enrolled in the 2019 antenatal HIV sentinel survey

We describe coverage of maternal syphilis screening, syphilis positivity, coverage of treatment and their association with maternal HIV infection and antiretroviral treatment (ART) status among pregnant women attending South African antenatal clinics. The 2019 antenatal care sentinel survey was a cross-sectional survey conducted from 1 October to 15 November 2019 at 1589 sentinel sites in all nine provinces of the country and aimed to enrol 36,000 pregnant women ages 15-49 years regardless of HIV, ART or syphilis status. Data collection procedures included obtaining written informed consent, a brief interview, medical record review and blood specimen collection. Completed data collection forms and specimens were sent to designated regional laboratories for data capture and HIV serology testing. Data analysis determined four outcomes i) syphilis screening coverage ii) syphilis positivity iii) coverage of any treatment and iv) with Benzathine penicillin G (BPG). Multivariable logistic regression models with or without interaction between HIV infection and ART status with province were used to determine factors associated with syphilis positivity. Of the 41 598 women enrolled, 35 900 were included in the analysis for syphilis screening coverage. The weighted syphilis screening coverage was 96.4% [95% Confidence Interval (CI) 95.9-96.7%] nationally and was lowest among HIV positive women not on ART at 93.5% (95% CI 92.2-94.5%). Syphilis positivity was 2.6% (95% CI 2.4-2.9%) nationally. Among those who were syphilis positive, 91.9% (95% CI 89.8-93.7%) had documentation of syphilis treatment status, of whom 92.0% (95% CI 89.8-93.9%) were treated, with the majority treated with one or more doses of BPG [92.2% (95% CI 89.8-94.3%)]. HIV-positive women, not on ART [adjusted odd ratio (aOR) 2.24 (95% 1.71-2.93)] and those on ART [aOR 2.25 (95% CI 1.91-2.64)] were more likely to be syphilis positive compared to those who were HIV negative. The national syphilis screening coverage met the global screening target of 95%. Syphilis positivity was higher among HIV positive women compared to negative women. Introduction of rapid syphilis testing and ensuring a universal supply of appropriate treatment for syphilis will reduce the likelihood of mother-to-child transmission of syphilis.