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

Spatial spillover effect of environmental factors on the tuberculosis occurrence among the elderly: a surveillance analysis for nearly a dozen years in eastern China

BACKGROUND

In many areas of China, over 30% of tuberculosis cases occur among the elderly. We aimed to investigate the spatial distribution and environmental factors that predicted the occurence of tuberculosis in this group.

METHODS

Data were collected on notified pulmonary tuberculosis (PTB) cases aged ≥ 65 years in Zhejiang Province from 2010 to 2021. We performed spatial autocorrelation and spatial-temporal scan statistics to determine the clusters of epidemics. Spatial Durbin Model (SDM) analysis was used to identify significant environmental factors and their spatial spillover effects.

RESULTS

77,405 cases of PTB among the elderly were notified, showing a decreasing trend in the notification rate. Spatial-temporal analysis showed clustering of epidemics in the western area of Zhejiang Province. The results of the SDM indicated that a one-unit increase in PM2.5 led to a 0.396% increase in the local notification rate. The annual mean temperature and precipitation had direct effects and spatial spillover effects on the rate, while complexity of the shape of the greenspace (SHAPE_AM) and SO2 had negative spatial spillover effects.

CONCLUSION

Targeted interventions among the elderly in Western Zhejiang may be more efficient than broad, province-wide interventions. Low annual mean temperature and high annual mean precipitation in local and neighboring areas tend to have higher PTB onset among the elderly.

Scaling law characteristics and spatiotemporal multicomponent analysis of syphilis from 2016 to 2022 in Zhejiang Province, China

Background

Syphilis has caused epidemics for hundreds of years, and the global syphilis situation remains serious. The reported incidence rate of syphilis in Zhejiang Province has ranked first in the province in terms of notifiable infectious diseases for many years and is the highest in China. This study attempts to use the scaling law theory to study the relationship between population size and different types of syphilis epidemics, while also exploring the main driving factors affecting the incidence of syphilis in different regions.

Methods

Data on syphilis cases and affected populations at the county level were obtained from the China Disease Control and Prevention Information System. The scaling relationship between different stages of syphilis and population size was explained by scaling law. The trend of the incidence from 2016 to 2022 was tested by the joinpoint regression. The index of distance between indices of simulation and observation (DISO) was applied to evaluate the overall performance of joinpoint regression model. Furthermore, a multivariate time series model was employed to identify the main driving components that affected the occurrence of syphilis at the county level. The p value less than 0.05 or confidence interval (CI) does not include 0 represented statistical significance for all the tests.

Results

From 2016 to 2022, a total of 204,719 cases of syphilis were reported in Zhejiang Province, including 2 deaths, all of which were congenital syphilis. Latent syphilis accounted for 79.47% of total syphilis cases. The annual percent change (APCs) of all types of syphilis, including primary syphilis, secondary syphilis, tertiary syphilis, congenital syphilis and latent syphilis, were - 21.70% (p < 0.001, 95% CI: -26.70 to -16.30), -16.80% (p < 0.001, 95% CI: -20.30 to -13.30), -8.70% (p < 0.001, 95% CI: -11.30 to -6.00), -39.00% (p = 0.001, 95% CI: -49.30 to -26.60) and - 7.10% (p = 0.008, 95% CI: -11.20 to -2.80), respectively. The combined scaling exponents of primary syphilis, secondary syphilis, tertiary syphilis, congenital syphilis and latent syphilis based on the random effects model were 0.95 (95% CI: 0.88 to 1.01), 1.14 (95% CI: 1.12 to 1.16), 0.43 (95% CI: 0.37 to 0.49), 0.0264 (95% CI: -0.0047 to 0.0575) and 0.88 (95% CI: 0.82 to 0.93), respectively. The overall average effect values of the endemic component, spatiotemporal component and autoregressive component for all counties were 0.24, 0.035 and 0.72, respectively. The values of the autoregressive component for most counties were greater than 0.7. The endemic component of the top 10 counties with the highest values was greater than 0.34. Two counties with value of the spatiotemporal component higher than 0.1 were Xihu landscape county and Shengsi county. From 2016 to 2022, the endemic and autoregressive components of each county showed obvious seasonal changes.

Conclusion

The scaling exponent had both temporal trend characteristics and significant heterogeneity in the association between each type of syphilis and population size. Primary syphilis and latent syphilis exhibited a linear pattern, secondary syphilis presented a superlinear pattern, and tertiary syphilis exhibited a sublinear pattern. This suggested that further prevention of infection and transmission among high-risk populations and improvement of diagnostic accuracy in underdeveloped areas is needed. The autoregressive components and the endemic components were the main driving factors that affected the occurrence of syphilis. Targeted prevention and control strategies must be developed based on the main driving modes of the epidemic in each county.

Spatiotemporal cluster of mpox in men who have sex with men: A modeling study in 83 countries

Mpox outbroke globally during 2022-2023, with more than 90% of cases occurring in men who have sex with men (MSM). However, the spatiotemporal distribution of mpox is not well established yet. This study aimed to explore the spatiotemporal clustering of mpox cases in MSM worldwide. We obtained the numbers of mpox cases from Our World in Data, the number of MSM from the Joint United Nations Programme on HIV/AIDS (UNAIDS), UNAIDS DATA 2021 and UNAIDS Global AIDS Update 2022 and literature. We evaluated the spatiotemporal cluster of mpox in MSM using retrospective space-time analyses method. The total number of mpox cases was 85 795 during May 1, 2022 to March 31, 2023. The most likely cluster was Spain (likelihood ratio = 4764.97; p < 0.001), with a cluster period from July 26 to August 14, 2022. There were 11 secondary clusters, which included 46 countries located in western Europe, eastern and northern South America, northern Europe, Canada, Central Africa, southern and central Europe, Latin America, Turkey, Dominican Republic, New Zealand, and Australia. The findings may inform current and future control strategies of mpox and might provide references for the identification of the spatiotemporal distribution of new and emerging infectious diseases in specific populations.

Epidemiological analysis of syphilis surveillance among entry-exit population at Shanghai Port, China from 2014 to 2022

OBJECTIVE

To investigate the epidemiological characteristics of syphilis cases detected among entry-exit personnel at Shanghai ports from 2014 to 2022 and the changing trend of the syphilis epidemic in the region so as to provide data support for the scientific and effective prevention and control of syphilis at ports.

METHODS

From January 2014 to December 2022, the subjects of syphilis screening at Shanghai port were selected. Physical examination and serological testing were used to confirm syphilis. All the data used were downloaded from the HIS system of Shanghai International Travel Healthcare Center. Descriptive epidemiology was used to analyze the characteristics of the detected cases, and the linear trend Chi-square test was used to analyze the trend between groups.

RESULTS

From 2014 to 2022, a total of 918 cases of syphilis were detected among entry-exit personnel at Shanghai port, with a total detection rate of 154.68/100 000. The detection rate was the highest in 2015 and the lowest in 2022, showing a downward trend year by year since 2015. 54.36% of syphilis patients from East Asia were detected. Syphilis cases were reported in all age groups; most cases were under 39 years old, accounting for 36.06%. The syphilis detection rate in males was significantly higher than in females (79.63% vs. 20.4%). The main way of transmission was sexual transmission, accounting for 60.89%, among which male-to-male transmission was the primary way (22.36%).

CONCLUSION

The detection rate of syphilis among entry-exit personnel at Shanghai port has been decreasing continuously in recent years. Targeted health intervention should be carried out according to the monitoring results.