Outbreaks of syphilis among men who have sex with men attending STI clinics between 2007 and 2015 in the Netherlands: a space-time clustering study

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

Background

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

Methods

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

Results

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

Conclusions

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

Simple-to-use nomogram for predicting the risk of syphilis among MSM in Guangdong Province: results from a serial cross-sectional study

Background

The purpose of this study was to develop and validate a simple-to-use nomogram for the prediction of syphilis infection among men who have sex with men (MSM) in Guangdong Province.

Methods

A serial cross-sectional data of 2184 MSM from 2017 to 2019 was used to develop and validate the nomogram risk assessment model. The eligible MSM were randomly assigned to the training and validation dataset. Factors included in the nomogram were determined by multivariate logistic regression analysis based on the training dataset. The receiver operating characteristic (ROC) curves was used to assess its predictive accuracy and discriminative ability.

Results

A total of 2184 MSM were recruited in this study. The prevalence of syphilis was 18.1% (396/2184). Multivariate logistic analysis found that age, the main venue used to find sexual partners, condom use in the past 6 months, commercial sex in the past 6 months, infection with sexually transmitted diseases (STD) in the past year were associated with syphilis infection using the training dataset. All these factors were included in the nomogram model that was well calibrated. The C-index was 0.80 (95% CI 0.76–0.84) in the training dataset, and 0.79 (95% CI 0.75–0.84) in the validation dataset.

Conclusions

A simple-to-use nomogram for predicting the risk of syphilis has been developed and validated among MSM in Guangdong Province. The proposed nomogram shows good assessment performance.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06912-z.

Syphilis in pregnant women and congenital syphilis: spatial pattern and relationship with social determinants of health in Mato Grosso

INTRODUCTION

The increasing incidence of syphilis among pregnant women (PS) and congenital syphilis (CS) has negatively affected maternal-child health in Brazil. The spatial approach to diseases with social indicators improves knowledge of health situations. Herein, we aimed to evaluate the spatiotemporal distribution of incidences, identify the priority areas for infection control actions, and analyze the relationship of PS and CS clusters with social determinants of health in Mato Grosso.

METHODS

This is an ecological study with data from different health information systems. After data procedure linkage, we analyzed the Bayesian incidences of triennial infections during specific periods. We performed SATSCAN screenings to identify spatiotemporal clusters. Further, we verified the differences between the clusters and indicators using Pearson's chi-square test.

RESULTS

The variations in PS incidence were 0.9-20.5/1,000 live births (LB), 0.6-46.3/1,000 LB, and 2.1-23.2/1,000 LB in the first, second, and last triennium, respectively; for CS, the variations were 0-7.1/1,000 LB, 0-7.5/1,000 LB, and 0.3-10.8/1,000 LB in the first, second, and last triennium, respectively. Three clusters each were identified for PS (RR=2.02; RR=0.30; RR=21.45, p<0.0001) and CS (RR=3.55; RR=0.10; RR=0.26, p<0.0001). The high-risk clusters overlapped in time-space; CS incidence was associated with municipalities with a higher proportion of LB mothers of race/non-white color and with poor sanitary conditions, lower proportion of pregnant teenagers, and under 8 years of schooling.

CONCLUSIONS

The increase in the spatiotemporal evolution of PS and CS incidences and the extension of areas with persistent infections indicate the need for monitoring, especially of priority areas in the state.

The resurgence of syphilis in high-income countries in the 2000s: a focus on Europe

Syphilis can cause severe complications and sequelae. Following a decrease in reported cases in European Union/European Economic Area (EU/EEA) and other high-income countries in the 1980s and 1990s as a result of the HIV epidemic and ensuing changes in sexual behaviour, trends started to increase in the 2000s in a number of EU/EEA Member States with higher rates among men and a large proportion of cases reported among men who have sex with men (MSM), particularly HIV-positive MSM. Trends in EU/EEA Member States vary however with some countries continuing to report decreases in the number of reported cases (mostly in the Eastern part of EU/EEA) whereas many Western European countries report increasing numbers of cases. Increasing rates among women, although still relatively low, have been observed in a number of countries leading to concerns around mother-to-child transmission of syphilis and congenital syphilis. Similar overall trends are observed in other high-income countries with the exception of Japan where rates among heterosexual men and women have been rising at alarming levels. Control of syphilis requires use of comprehensive, evidence-based strategies which take into account lessons learned from previous control efforts as well as consideration of biomedical interventions.

Distribution of reported syphilis cases in South China: spatiotemporal analysis

There was a varied spatial distribution of reported syphilis cases across cities in South China. This study aims to identify and describe spatiotemporal clusters of primary and secondary syphilis (P/S) cases in this region. Reported syphilis cases in Guangdong Province, China, from January 2014 to June 2015 were collected from the national centralized reporting system. Spatiotemporal clusters of P/S were identified and cross-validated by calculating local Moran's I, performing hotspot analysis (Getis-Ord Gi*), and constructing a discrete Poisson model in SaTScan. Reported cases within and outside the clusters were compared by bivariable and multivariable logistic regression. Out of 17,691 reported P/S cases, 11% were in the identified spatiotemporal clusters. The monthly P/S notification rate (per 100,000 persons) ranged between 0.6 and 1. The identified clusters were located in 14, out of 126, counties in eight, out of 21, cities. Cases of older age, living in rural area and taking self-initiated syphilis test were more likely to be in the clusters. Some areas bore a greater burden of P/S in Guangdong Province. Routine spatiotemporal analysis of P/S cases may be useful for enhancing syphilis control programs by strategic location-based service planning.

An Update on the Global Epidemiology of Syphilis

PURPOSE OF REVIEW

Syphilis continues to cause morbidity and mortality worldwide. While syphilis infection is easily identifiable and treatable, rates of syphilis infection continue to increase among select populations in high-income countries and remain at endemic levels in low- and middle-income counties.

RECENT FINDINGS

World Health Organization recommended strategies have led to the dual elimination of mother-to-child transmission of syphilis and HIV in several countries, however outbreaks among select populations need to be adequately addressed.

SUMMARY

Continued vigilance and investment is needed to address syphilis worldwide. The epidemiology of syphilis differs in high-income and low- and middle-income counties.