Trend in prevalence of syphilis among voluntary blood donors in Xi'an, China from 2006 to 2010

Epidemiological characteristics and risk factors of syphilis among blood donors in Huzhou

OBJECTIVE

To investigate the epidemiological characteristics and risk factors for syphilis in Huzhou City, and to provide data to support the design of more effective health counselling and screening measures for blood donors.

METHODS

A retrospective study was conducted to analyse the demographic characteristics and seropositivity of syphilis among blood donors from 2019 to 2021. The differences in the serological status of syphilis among different populations under different demographic factors were compared, and conditional logistic regression analysis was used to identify the risk factors for syphilis.

RESULTS

The seropositivity rate of syphilis among blood donors in Huzhou City was 133/100,000, which decreased year by year. There were significant differences in the syphilis seropositivity rate among different groups in terms of age, education level, occupation, household registration, marital status and blood donation history (P < 0.05). The multivariate logistic regression model showed that all six factors, including age, education level, occupation, household registration, marital status and blood donation history, had significant effects on syphilis infection (P < 0.01), with OR values and 95% CIs of 2. 387 (1.381-4.127), 3.607 (1.609-8.086), 2.784 (1.657-4.679), 5.074 (1.865-13.804), 11.177 (3.481-35.888), and 11.244 (3.940-32.091), respectively.

CONCLUSION

There is room for improvement in pre-donation health counselling and screening of high-risk populations. Timely monitoring and updating of demographic data for specific high-risk populations is essential.

Association between syphilis seroprevalence and age among blood donors in Southern China: an observational study from 2014 to 2017

OBJECTIVE

This study investigated the association between syphilis seroprevalence and age among blood donors, and described the distribution of serological titres among syphilis-infected donors, aiming to confirm the syphilis epidemic characteristics and to promote effective interventions for older adults.

METHODS

Data were obtained from the Shenzhen Programme for Syphilis Prevention and Control in 2014-2017. Blood samples were screened using the ELISAs, and confirmed using the Treponema pallidum particle agglutination assay (TPPA) and toluidine red unheated serum test (TRUST).

RESULTS

Among 394 792 blood donors, 733 tested TPPA and TRUST positive (active infection), and 728 tested only TPPA positive (historical infection). The overall prevalence of syphilis seropositivity was 370.1 per 100 000 (95% CI 351.1 to 389.0 per 100 000); the prevalence of active infection was 185.7 per 100 000 (95% CI 172.2 to 199.1 per 100 000). People aged ≥45 years displayed a prevalence of 621.8 per 100 000 in syphilis seropositivity and 280.5 per 100 000 in active infection, which were 3.8 times and 2.4 times higher than that for people aged <25 years, respectively. The prevalence of syphilis seropositivity (χ²_trend=311.9, p _trend<0.001) and active infection (χ²_trend=72.1, p _trend<0.001) increased significantly with age. After stratification by gender and year of donation, the increasing trend of prevalence with age remained (p _trend<0.05), except for the prevalence of active infection in males and females in 2014. About 16.3% of donors with active infection and aged ≥45 years had a TRUST titre of ≥1∶8, lower than that of patients aged <25 years (51.3%) and 25-34 years (34.1%).

CONCLUSIONS

The findings confirm the high prevalence of syphilis among older adults, and suggest the need to increase awareness among healthcare providers and deliver more targeted prevention interventions for older adults to promote early testing.

Seroepidemiology of Syphilis Infection among 2 Million Reproductive-age Women in Rural China: A Population-based, Cross-sectional Study

BACKGROUND:

Quantifying syphilis prevalence is important for planning interventions and advocating for resources on syphilis. However, data on large sample studies regarding the prevalence of syphilis among reproductive-age women in rural China were not available for analysis. The aim of the study was to determine the prevalence, epidemiological characteristics, and related factors of syphilis infection among reproductive-age women in rural China.

METHODS:

Data were obtained from a nationwide, population-based, cross-sectional study under the National Free Preconception Health Examination Project which covered all the 31 provinces in Mainland China. Women intending to get pregnant within the next 6 months were enrolled between January 1, 2010, and December 31, 2012. Sociodemographic, gynecological and obstetric characteristics, and other relevant information were obtained through face-to-face interviews. Treponema pallidum particle agglutination assay test was used to detect positive samples of syphilis. Univariate and multivariate logistic regressions were performed to assess the associations between syphilis seropositivity and related factors.

RESULTS:

The overall seroprevalence of syphilis (SPS) among the 2,044,126 women who received syphilis screening test during 2010-2012 was 0.37% (95% confidence interval [CI]: 0.36-0.37%). The SPS appeared 0.24% (95% CI: 0.23-0.26%) and 0.66% (95% CI: 0.59-0.72%) in women at 21-24 and 40-44 years of age, respectively, showing an increase of SPS, parallel with age, and the difference was significant. SPS was significantly higher in ethnic minorities than that in Han nationality (0.58% vs. 0.35%, respectively, odds ratio [OR] = 1.41, 95% CI: 1.30-1.53) and higher in workers than that in farmers (0.45% vs. 0.36%, respectively, OR = 1.27, 95% CI: 1.14-1.41). Women with primary school or below level had a higher SPS as compared to those with college or above educational level (0.61% vs. 0.32%, respectively, OR = 2.49, 95% CI: 2.14-2.89), and the increase reversely correlated with the levels of education. Women whose spouses were syphilis seropositive had significant greater risk (OR = 48.26, 95% CI: 44.38-52.48) as compared those whose spouses were seronegative. Women who reported having had a history of sexually transmitted infections were more likely to be tested positive for serological syphilis (OR = 27.17, 95% CI: 20.44-36.11) as compared to those without.

CONCLUSIONS:

High SPS is seen among reproductive-age women in rural China that calls for targeted interventions on syphilis prevention and control in this target population, with emphasis on those who are 35 years of age and above, less educated, being minor ethnicity, workers, and living in the western regions of China.

Preventing of transfusion syphilis

Goal of the study. To study the prevalence of syphilis markers in donors in the Russian Federation, and to evaluate the effectiveness of measures to prevent blood transfusion syphilis and other bloodborne infections in the Blood Service in Russia. Materials and methods. Performance analysis of sectoral statistical surveys Russian Ministry of Health in the form number 39, «Report of the station, department of blood transfusion, hospital blood leading procurement» and the explanatory notes to them for the period from 2009 to 2013. Analysis of the results of screening donated blood for markers of syphilis. Results. It was found that the incidence of syphilis markers in donors in the whole of Russia was significantly (p < 0,05) decreased (from 0.79% in 2009 to 0.49% in 2013). However, there was heterogeneity in the proportion of donors with markers of syphilis in different regions of the Russian Federation. (From 0.68 to 0.35%). In 2013, the causative agent of syphilis markers are more often detected in donors of the North Caucasus and Siberian Federal Districts, seldom in donors in the North-Western and Urals Federal District. Hence, there remains a certain risk of transfusion transmission of syphilis. In recent years, widely implemented method viral inactivation of plasma and platelet concentrate. In 2013, the procedure viral inactivation subjected to 8% of the total issued for transfusion platelet concentrate. Conclusion. There remains a certain risk of transfusion transmission of syphilis. Further implementation of the methods of inactivation of pathogens in Blood Service of Russia will also contribute to reducing the risk of blood-borne transmission of Treponema pallidum.

A novel ELISA using a recombinant outer membrane protein, rTp0663, as the antigen for serological diagnosis of syphilis

BACKGROUND

The lack of Treponema pallidum-specific antigens with highly accurate diagnosis makes the diagnosis of syphilis challenging.

METHODS

A soluble recombinant version of a new diagnostic protein Tp0663 has been produced. The serodiagnostic potential of this protein was assessed by screening 3326 serum samples simultaneously evaluated by rapid plasma reagin and T. pallidum particle agglutination tests. Kappa (κ) coefficients were used to compare the concordance between clinical diagnosis and the Tp0663-based ELISA or the ARCHITECT Syphilis TP chemiluminescent immunoassay (Abbott GmbH and Co. KG).

RESULTS

Using the results of clinical diagnosis as the gold standard, the sensitivity and specificity of Tp0663 were found to be 98.83% (95% confidence interval (CI) 96.61-99.60%) and 100% (95% CI 99.88-100%), respectively. In comparison, the ARCHITECT Syphilis TP assay was found to have a lower sensitivity (97.27%, 95% CI 94.46-98.67%) and specificity (99.61%, 95% CI 99.32-99.78%). In particular, the ARCHITECT Syphilis TP exhibited a false-positive rate of 0.39%. Moreover, the ELISA was in perfect agreement with the gold standard, with a κ value of 0.99, comparable to that of ARCHITECT Syphilis TP (0.96).

CONCLUSION

These results identified Tp0663 as a novel serodiagnostic candidate with great potential for developing novel tests for the diagnosis of syphilis.

Syphilis seroprevalence estimates of Santa Catarina blood donors in 2010

INTRODUCTION

Knowledge of blood donor characteristics is essential to better guide clinical and serological screening for hemotherapy. The objective of this study was to determine the syphilis seroprevalence and the associated factors of blood donors in the State of Santa Catarina, Brazil.

METHODS

This population-based study from the State of Santa Catarina used information obtained from blood donation records. We analyzed 83,396 blood donor records generated from donors who were considered eligible to donate between January and August 2010. The aim of the study was to estimate the syphilis seroprevalence and its relationship with educational level, age, gender, geographical region and having donated blood in the past 12 months. We used descriptive analyses and a Poisson regression to calculate the prevalence ratios for the variables of interest.

RESULTS

We found a 0.14% overall seroprevalence and significant differences among the following: first-time blood donors (0.19%) versus repeat donors (0.03% to 0.08%); low educational levels (0.30%) versus medium and high educational levels (0.08% to 0.19%); and donors who did not report their residence (0.88%) or age (6.94%) versus those who did. Increased syphilis seroprevalence was also significantly associated with increased age.

CONCLUSION

High syphilis seroprevalence was associated with lower educational level, age, first-time donation and the failure to provide age or residence information.