The Netherlands Chlamydia cohort study (NECCST) protocol to assess the risk of late complications following Chlamydia trachomatis infection in women

Therapeutic potential of botanical drugs and their metabolites in the treatment of pelvic inflammatory disease

The application of botanical drugs and their metabolites in the treatment of pelvic inflammatory disease (PID) has garnered significant attention. Owing to their broad-spectrum activity, global accessibility, and structural diversity, botanical drugs have emerged as promising candidates for adjunctive or alternative therapies. This review systematically summarizes botanical drugs and their metabolites, focusing on their antimicrobial potential against endogenous and exogenous pathogens associated with PID. Specifically, it addresses various underlying antibacterial mechanisms, including interference with bacterial cell membranes and cell walls, inhibition of pathogen-specific efflux pumps, modulation of pathogen-related gene expression, and synergistic effects when combined with conventional antibiotics. This review highlights the therapeutic promise of botanical drugs and their metabolites, emphasizing critical findings regarding their inhibitory effects on PID-associated pathogens. Such insights provide valuable guidance for future therapeutic strategies and may support ongoing antibiotic discovery and development.

A male patient with Chlamydia peritonitis: Case report

Pelvic inflammatory disease (PID) is a well-known entity in women. However, on rare occasions, men can present with peritonitis caused by Chlamydia trachomatis as well. It is important to know and recognise this entity in order to avoid unnecessary investigations and commence prompt treatment.

Causal relationship between genetically predicted antibody-Mediated Immune Responses and female infertility

OBJECTIVE

This study aims to explore the causal relationship between Antibody-Mediated Immune Response (AIR) and female infertility using Mendelian randomization analysis, providing new targets and insights for treating female infertility.

METHODS

Exposure data from a genome-wide association study (GWAS) involving 9724 participants provided information on 46 types of AIR. Outcome data were sourced from a large-scale meta-analysis of female infertility, which included 899 cases and 246,641 controls. Five different Mendelian randomization analysis methods were used to assess the genetic causal relationship between AIR and female infertility, with the inverse variance-weighted method as the primary approach. The robustness of the study results was evaluated through heterogeneity analysis, pleiotropy tests, and leave-one-out validation. Replication and meta-analysis were conducted using FinnGen data to further identify AIR.

RESULTS

Through rigorous genetic variant screening, IVW, sensitivity analysis, replication, and meta-analysis, the results indicate that only seropositivity of anti-polyomavirus 2 IgG shows significant evidence of association with female infertility. The reverse MR analysis did not reveal a genetic causal association between female infertility and this antibody-influencing relationship. Sensitivity analysis showed no evidence of pleiotropy or heterogeneity. Replication and meta-analysis using FinnGen data further supported that only anti-polyomavirus 2 IgG seropositivity has a significant association with female infertility.

CONCLUSION

Using Mendelian randomization analysis in two independent samples, this study presents evidence of a genetic association between anti-polyomavirus 2 IgG seropositivity and female infertility. These findings carry significant implications for the prevention and treatment of female infertility in clinical practice.

Reproductive tract complication risks following Chlamydia trachomatis infections: a long-term prospective cohort study from 2008 to 2022

Background

The clinical and public health relevance of widespread testing for asymptomatic Chlamydia trachomatis (chlamydia) infections is under debate. To address uncertainties in screening programs, we estimate reproductive tract complication risks following asymptomatic and symptomatic chlamydia infections in a long-term prospective cohort.

Methods

A cohort of 5704 reproductive-age women recruited from a chlamydia screening study was followed for up to 14 years. Chlamydia positivity was determined using screening polymerase chain reaction test results, self-reported diagnoses (with/without symptoms), and chlamydia Immunoglobulin G antibodies. Outcome data (pregnancies, pelvic inflammatory disease (PID), ectopic pregnancy, and tubal factor infertility) were collected through self-completed questionnaires. Cox regression calculated adjusted hazard ratios (aHR) with confidence intervals (CI) to compare outcomes between time-updated chlamydia groups since sexual debut.

Findings

During 104,612 person-years, 2103 (36.9%) women were chlamydia-positive and 3692 women (64.7%) had been pregnant at least once. Risks for PID, ectopic pregnancy and tubal factor infertility were 1.62 (95% CI 1.20-2.17), 1.84 (95% CI 1.14-2.95) and 2.75 (95% CI 1.53-4.94), compared to chlamydia-negatives. aHRs for PID after symptomatic and asymptomatic infections were 2.29 (95% CI 1.62-3.25) and 1.06 (95% CI 0.66-1.69), respectively. Incidence of PID, ectopic pregnancy and tubal factor infertility after symptomatic chlamydia infection remained low with rates per 1000 person-years of 5.8, 1.9, and 1.8, respectively.

Interpretation

We found a significantly higher risk of PID, ectopic pregnancy and tubal factor infertility in chlamydia-positive women compared to chlamydia-negative women, although the overall incidence rates of complications remained low. Symptomatic, but not asymptomatic, chlamydia infections were associated with PID risk, suggesting the largest disease burden of complications is in this group.

Funding

The Netherlands Organisation for Health Research and Development (ZonMW Netherlands) and Research Funding from the Ministry of Health, Welfare and Sports.

Shifting Grounds-Facilitating Self-Care in Testing for Sexually Transmitted Infections Through the Use of Self-Test Technology: Qualitative Study

BACKGROUND

Chlamydia remains prevalent worldwide and is considered a global public health problem. However, testing rates among young sexually active people remain low. Effective clinical management relies on screening asymptomatic patients. However, attending face-to-face consultations of testing for sexually transmitted infections is associated with stigmatization and anxiety. Self-testing technology (STT) allows patients to test themselves for chlamydia and gonorrhea without the presence of health care professionals. This may result in wider access to testing and increase testing uptake. Therefore, the sexual health clinic at Odense University Hospital has designed and developed a technology that allows patients to get tested at the clinic through self-collected sampling without a face-to-face consultation.

OBJECTIVE

This study aimed to (1) pilot-test STT used in clinical practice and (2) investigate the experiences of patients who have completed a self-test for chlamydia and gonorrhea.

METHODS

The study was conducted as a qualitative study inspired by the methodology of participatory design. Ethnographic methods were applied in the feasibility study and the data analyzed were inspired by the action research spiral in iterative processes using steps, such as plan, act, observe, and reflect. The qualitative evaluation study used semistructured interviews and data were analyzed using a qualitative 3-level analytical model.

RESULTS

The findings from the feasibility study, such as lack of signposting and adequate information, led to the final modifications of the self-test technology and made it possible to implement it in clinical practice. The qualitative evaluation study found that self-testing was seen as more appealing than testing at a face-to-face consultation because it was an easy solution that both saved time and allowed for the freedom to plan the visit independently. Security was experienced when the instructions balanced between being detail-oriented while also being simple and illustrative. The anonymity and discretion contributed to preserving privacy and removed the fear of an awkward conversation or being judged by health care professionals thus leading to the reduction of intrusive feelings.

CONCLUSIONS

Accessible health care services are crucial in preventing and reducing the impact of sexually transmitted infections and STT may have the potential to increase testing uptake as it takes into account some of the barriers that exist. The pilot test and evaluation have resulted in a fully functioning implementation of STT in clinical practice.

The Risk of Pelvic Inflammatory Disease in Women Infected With Chlamydia (Chlamydia trachomatis): A Literature Review

A literature review was undertaken to examine the risk of developing pelvic inflammatory disease (PID) in women infected with Chlamydia trachomatis. A search of OVID Medline and Embase databases was conducted for studies published between 1946 and 26 June 2023. This review looked solely at prospective cohort study designs and searched reference lists of studies selected for inclusion. This literature review confirmed that C. trachomatisis a key factor in the development of PID in women through different pathogenic mechanisms. However, to reach more firm conclusions on the subject, further prospective cohort studies with a larger cohort size and a longer follow-up time are needed.

Challenges in Chlamydial Serology: Insights from a Belgian and a Dutch Population Cohort

Serology routinely serves as a diagnostic tool to confirm Chlamydia infections in humans. Particularly in delayed settings, such as post-outbreak scenarios where the acute phase of infection has subsided, serology is invaluable. Multiple studies, nonetheless, indicate deficiencies in specificity and sensitivity of current chlamydial antibody detection assays. Incorporation of multiple antigens per target is known to improve the accuracy of chlamydial serological assays. We, therefore, used the recomLine test (Mikrogen diagnostics) on serological samples of two cohorts, as it is the only commercially available test allowing detection of antibodies against three human pathogenic Chlamydia species (C. trachomatis, C. pneumoniae and C. psittaci) using multiple antigens per target. The first cohort (n = 156; samples collected between 2008 and 2022 during a C. trachomatis screening initiative) comprised women from the Netherlands (NL) with past exposure to C. trachomatis, while the second cohort (n = 44; samples collected in 2018 in a health examination survey) consisted of Belgian citizens (BE) with occupational or recreational exposure to chickens, representing a risk population for C. psittaci. The test indicated a statistically equivalent C. pneumoniae seroprevalence in both cohorts (39.10% in NL and 34.09% in BE; p = 0.337). As expected C. trachomatis seroprevalence was significantly higher (p < 0.001) in the Dutch cohort (48.72%), as compared to the Belgian cohort (4.55%). Lastly, C. psittaci seroprevalence did not significantly differ between the two groups (2.27% in BE and 1.92% in NL; p = 0.633), even though a higher prevalence was expected for the Belgian cohort. This prompts us to question whether the Belgian cohort truly constituted a C. psittaci risk population or whether the recomLine test is susceptible to cross-reaction of species-specific antibodies, thereby increasing C. psittaci prevalence in the Dutch cohort. We advocate for the development of affordable, highly sensitive antibody detection assays that can effectively distinguish between chlamydial species, addressing the increasing demand for enhanced serological testing methodologies.

Prevalence of Chlamydia trachomatis in Women Who Are Candidates for In Vitro Fertilization in a Private Reference Service in Southern Brazil: A Cross-Sectional Study

Introduction Chlamydia trachomatis (CT) has been related to fallopian tube damage and infertility. Its prevalence in the population that attend public services is known; however, there is scant data on this factor in private infertility clinics. The objective of this study is to verify the prevalence of CT among women attending a private in vitro fertilization (IVF) reference clinic in southern Brazil. Methods This is a cross-sectional study carried out between January 1, 2019, and August 30, 2021, at an IVF private clinic in southern Brazil. Infertile women between 18 and 50 years old, who provided a morning urinary sample for reverse transcription-polymerase chain reaction (RT-PCR) test for CT analysis, were included in the study. The variables studied included the patient's age, body mass index (BMI), duration of infertility, type of infertility, indication for IVF, and detection or not of CT in the urine. Results The prevalence of CT was 10.84% (22 out of 203; 95% CI: 7.27-15.87). Patients with secondary infertility were older and had more ovarian and tubal factors compared to cases of primary infertility. The tubal factor was the most prevalent (27.3% in women with primary infertility and 35.8% in those with secondary). Time of infertility and BMI were similar between groups. Our results are derived from a single private IVF clinic which reduces the external validity. Conclusion The prevalence of 10.84% of CT in this population raises the importance of screening for sexually transmitted infections for proper treatment and to achieve better IVF outcomes.

Tubal factor infertility and its impact on reproductive freedom of African American women

In the past, the reproductive freedom of African American women was hindered by forced reproduction and sterilization campaigns. Unfortunately, these involuntary practices have now mostly been replaced by inequality because of disproportionate tubal factor infertility rates within African American communities. Our work aimed to describe the inequities in increased rates of pelvic inflammatory disease and tubal factor infertility as it relates to African American women. In addition, we highlighted the need for improved access to screening and treatment of sexually transmitted infections, access to barrier contraception, and health literacy related to the understanding and prevention of tubal factor infertility in African American women.

Chlamydia trachomatis and Neisseria gonorrhoeae PCR detection in women treated for ectopic pregnancy

The aim of this study was to determine the presence of Chlamydia trachomatis (ChT) and Neisseria gonorrhoae (NG) in the genital tract of women with ectopic pregnancy and to compare the positive results with patients' self-reported history of PID. Overall 40 women were eligible for the study. The samples for the ChT and NG Polymerase Chain-reaction (PCR) detection were obtained from the cervix, endometrium and fallopian tube. The results of testing for NG at all sites were negative as were the results from cervical testing for ChT. The prevalence of ChT in the upper genital tract was 12.5%. No statistically significant correlation was found between the positive cases and the previous signs of PID and laparoscopic findings. We found statistically significant relationship between signs of pelvic inflammation in a pacients' history and histopathological findings of tubal inflammation. 12.5% prevalence of ChT confirms the ascending genital infection. There was no association between the positive PCR result and clinical history of pelvic inflammation.IMPACT STATEMENTWhat is already known on this subject? Pelvic inflammatory disease, Chlamydia trachomatis and Neisseria gonorrhoae infections are the main risks for ectopic pregnancy. Clinical history of PID and perioperative adhesions may suggest prior upper genital infection.What do the results of this study add? Chlamydia trachomatis positive PCR result can be found in the upper genital tract without the positivity of cervical smear in women with ectopic pregnancy. Our study is unique in assessing the endometrial biopsy for the presence of Chlamydia trachomatis and Neisseria gonorrhoae.What are the implications of these findings for future clinical practice and/or future clinical research? There is no statistically significant association between positive PCR result and clinical history of PID or pelvic adhesions found during laparoscopy for tubal pregnancy. Therefore there is no need for the preventive antibiotic treatment in patients with these findings.

Pregnancies and Time to Pregnancy in Women With and Without a Previous Chlamydia trachomatis Infection

BACKGROUND

A Chlamydia trachomatis infection (chlamydia) can result in tubal factor infertility in women. To assess if this association results in fewer pregnant women, we aimed to assess pregnancy incidences and time to pregnancy among women with a previous chlamydia infection compared with women without one and who were participating in the Netherlands Chlamydia Cohort Study (NECCST).

METHODS

The NECCST is a cohort of women of reproductive age tested for chlamydia in a chlamydia screening trial between 2008 and 2011 and reinvited for NECCST in 2015 to 2016. Chlamydia status (positive/negative) was defined using chlamydia screening trial-nucleic acid amplification test results, chlamydia immunoglobulin G presence in serum, or self-reported chlamydia infections. Data on pregnancies were collected via questionnaires in 2015-2016 and 2017-2018. Overall pregnancies (i.e., planned and unplanned) and time to pregnancy (among women with a pregnancy intention) were compared between chlamydia-positive and chlamydia-negative women using Cox regressions.

RESULTS

Of 5704 women enrolled, 1717 (30.1%; 95% confidence interval [CI], 28.9-31.3) women was chlamydia positive. Overall pregnancy proportions were similar in chlamydia-positive and chlamydia-negative women (49.0% [95% CI, 46.5-51.4] versus 50.5% [95% CI, 48.9-52.0]). Pregnancies per 1000 person-years were 53.2 (95% CI, 51.5-55.0) for chlamydia negatives and 83.0 (95% CI, 78.5-87.9) for chlamydia positives. Among women with a pregnancy intention, 12% of chlamydia-positive women had a time to pregnancy of >12 months compared with 8% of chlamydia negatives (P < 0.01).

CONCLUSIONS

Overall pregnancy rates were not lower in chlamydia-positive women compared with chlamydia-negative women, but among women with a pregnancy intention, time to pregnancy was longer and pregnancy rates were lower in chlamydia-positive women.

TRIAL REGISTRATION NUMBER

Dutch Trial Register NTR-5597.

Can Previous Associations of Single Nucleotide Polymorphisms in the TLR2, NOD1, CXCR5, and IL10 Genes in the Susceptibility to and Severity of Chlamydia trachomatis Infections Be Confirmed?

Clear inter-individual differences exist in the response to C. trachomatis (CT) infections and reproductive tract complications in women. Host genetic variation like single nucleotide polymorphisms (SNPs) have been associated with differences in response to CT infection, and SNPs might be used as a genetic component in a tubal-pathology predicting algorithm. Our aim was to confirm the role of four genes by investigating proven associated SNPs in the susceptibility and severity of a CT infection. A total of 1201 women from five cohorts were genotyped and analyzed for TLR2 + 2477 G > A, NOD1 + 32656 T −> GG, CXCR5 + 10950 T > C, and IL10 − 1082 A > G. Results confirmed that NOD1 + 32656 T −>GG was associated with an increased risk of a symptomatic CT infection (OR: 1.9, 95%CI: 1.1–3.4, p = 0.02), but we did not observe an association with late complications. IL10 − 1082 A > G appeared to increase the risk of late complications (i.e., ectopic pregnancy/tubal factor infertility) following a CT infection (OR = 2.8, 95%CI: 1.1–7.1, p = 0.02). Other associations were not found. Confirmatory studies are important, and large cohorts are warranted to further investigate SNPs’ role in the susceptibility and severity of a CT infection.

Chlamydia trachomatis Whole-Proteome Microarray Analysis of The Netherlands Chlamydia Cohort Study

Chlamydia trachomatis (Ct) whole-proteome microarrays were utilized to identify antibody patterns associated with infection; pelvic inflammatory disease (PID), tubal factor infertility, chronic pelvic pain (CPP) and ectopic pregnancy in a subsample of the Netherlands Chlamydia cohort study. Serum pools were analyzed on whole-proteome arrays. The 121 most reactive antigens identified during whole-proteome arrays were selected for further analysis with minimized microarrays that allowed for single sera analysis. From the 232 single sera; 145 (62.5%) serum samples were reactive for at least one antigen. To discriminate between positive and negative serum samples; we created a panel of in total 18 antigens which identified 96% of all microarray positive samples. Antigens CT_858; CT_813 and CT_142 were most reactive. Comparison of antibody reactivity's among women with and without Ct related sequelae revealed that the reactivity of CT_813 and CT_142 was less common among women with PID compared to women without (29.0% versus 58.6%, p = 0.005 and 25.8% versus 50.6%, p = 0.017 respectively). CT_858 was less common among CPP cases compared to controls (33.3% versus 58.6; p = 0.028). Using a whole-proteome array to select antigens for minimized arrays allows for the identification of novel informative antigens as general infection markers or disease associated antigens.

Chlamydia trachomatis and the Risk of Pelvic Inflammatory Disease, Ectopic Pregnancy, and Female Infertility: A Retrospective Cohort Study Among Primary Care Patients

BACKGROUND

We evaluated the risk of pelvic inflammatory disease (PID), ectopic pregnancy, and infertility in women with a previous Chlamydia trachomatis (CT) diagnosis compared with women who tested negative for CT and CT untested women, considering both targeted and incidental (ie, prescribed for another indication) use of CT-effective antibiotics.

METHODS

This was a retrospective study of women aged 12-25 years at start of follow-up within the Clinical Practice Research Datalink GOLD database linked to index of multiple deprivation quintiles, 2000-2013. CT test status and antibiotic use were determined in a time-dependent manner. Risk of PID, ectopic pregnancy, or female infertility were evaluated using of Cox proportional hazard models.

RESULTS

We studied 857 324 women, contributing 6 457 060 person-years. Compared with women who tested CT-negative, women who tested CT-positive had an increased risk of PID (adjusted hazard ratio [aHR], 2.36; 95% confidence interval [CI], 2.01-2.79), ectopic pregnancy (aHR, 1.87; 95% CI, 1.38-2.54), and infertility (aHR, 1.85; 95% CI, 1.27-2.68). The PID risk was higher for women with 2 or more positive CT tests than those with 1 positive test. PID risk increased with the number of previous antibiotic prescriptions, regardless of CT test status.

CONCLUSIONS

We showed an association between CT-positive tests and 3 adverse reproductive health outcomes. Moreover, this risk increased with repeat CT infections. CT-effective antibiotic use showed no decreased risks of subsequent PID regardless of CT history. Our results confirm the reproductive health burden of CT, which requires adequate public health interventions.

Antibody Testing in Estimating Past Exposure to Chlamydia trachomatis in the Netherlands Chlamydia Cohort Study

The asymptomatic course of Chlamydia trachomatis (CT) infections can result in underestimated CT lifetime prevalence. Antibody testing might improve this estimate. We assessed CT antibody positivity and predictive factors thereof in the Netherlands Chlamydia Cohort Study. Women who had ≥1 CT Nucleic Acid Amplification Test (NAAT) in the study (2008–2011) and who provided self-reported information on NAATs were tested for CT major outer membrane protein specific IgG in serum (2016). CT antibody positivity was assessed and predictive factors were identified using multivariable logistic regressions, separately for CT-positive women (≥1 positive NAAT or ≥1 self-reported positive CT test) and CT-negative women (negative by study NAAT and self-report). Of the 3,613 women studied, 833 (23.1%) were CT -positive. Among the CT-negative women, 208 (7.5%, 95% CI 6.5–8.5) tested positive for CT antibodies. This increased CT lifetime prevalence with 5.8% (95% CI 5.0–6.5). Among women with a CT-positive history, 338 (40.6%, 95% CI 38.5–44.1) tested positive. Predictive factors for antibody positivity related to lower social economic status, sexual risk behavior, multiple infections, higher body mass index, and non-smoking. CT antibody testing significantly increased the lifetime prevalence. Combining NAAT outcomes, self-reported positive tests, and antibody testing reduced misclassification in CT prevalence estimates.

The Potential Role for Host Genetic Profiling in Screening for Chlamydia-Associated Tubal Factor Infertility (TFI)-New Perspectives

Host immunogenetic factors can affect late complications of urogenital infections with Chlamydia trachomatis. These findings are creating new avenues for updating existing risk prediction models for C. trachomatis-associated tubal factor infertility (TFI). Research into host factors and its utilization may therefore have future implications for diagnosing C. trachomatis-induced infertility. We outline the epidemiological situation regarding C. trachomatis and TFI in high-income countries. Thereupon, we review the main characteristics of the population undergoing fertility work-up and identify screening and diagnostic strategies for TFI currently in place. The Netherlands is an exemplary model for the state of the art in high-income countries. Within the framework of existing clinical approaches, we propose a scenario for the translation of relevant genome-based information into triage of infertile women, with the objective of implementing genetic profiling in the routine investigation of TFI. Furthermore, we describe the state of the art in relevant gene- and single nucleotide polymorphism (SNP) based clinical prediction models and place our perspectives in the context of these applications. We conclude that the introduction of a genetic test of proven validity into the assessment of TFI should help reduce patient burden from invasive and costly examinations by achieving a more precise risk stratification.

Relation between Chlamydia trachomatis infection and pelvic inflammatory disease, ectopic pregnancy and tubal factor infertility in a Dutch cohort of women previously tested for chlamydia in a chlamydia screening trial

OBJECTIVES

A better understanding of Chlamydia trachomatis infection (chlamydia)-related sequelae can provide a framework for effective chlamydia control strategies. The objective of this study was to estimate risks and risk factors of pelvic inflammatory disease (PID), ectopic pregnancy and tubal factor infertility (TFI) with a follow-up time of up until 8 years in women previously tested for chlamydia in the Chlamydia Screening Implementation study (CSI) and participating in the Netherlands Chlamydia Cohort Study (NECCST).

METHODS

Women who participated in the CSI 2008-2011 (n=13 498) were invited in 2015-2016 for NECCST. Chlamydia positive was defined as a positive CSI-PCR test, positive chlamydia serology and/or self-reported infection (time dependent). Data on PID, ectopic pregnancy and TFI were collected by self-completed questionnaires. Incidence rates and HRs were compared between chlamydia-positive and chlamydia-negative women corrected for confounders.

RESULTS

Of 5704 women included, 29.5% (95% CI 28.3 to 30.7) were chlamydia positive. The incidence rate of PID was 1.8 per 1000 person-years (py) (1.6 to 2.2) overall, 4.4 per 1000 py (3.3 to 5.7) among chlamydia positives compared with 1.4 per 1000 py (1.1 to 1.7) for chlamydia negatives. For TFI, this was 0.4 per 1000 py (0.3 to 0.5) overall, 1.3 per 1000 py (0.8 to 2.1) and 0.2 per 1000 py (0.1 to 0.4) among chlamydia positives and negatives, respectively. And for ectopic pregnancy, this was 0.6 per 1000 py (0.5 to 0.8) overall, 0.8 per 1000 py (0.4 to 1.5) and 0.6 per 1000 py (0.4 to 0.8) for chlamydia negatives. Among chlamydia-positive women, the strongest risk factor for PID was symptomatic versus asymptomatic infection (adjusted HR 2.88, 1.4 to 4.5) and for TFI age <20 versus >24 years at first infection (HR 4.35, 1.1 to 16.8).

CONCLUSION

We found a considerably higher risk for PID and TFI in chlamydia-positive women, but the incidence for ectopic pregnancy was comparable between chlamydia-positive and chlamydia-negative women. Overall, the incidence rates of sequelae remained low.

TRIAL REGISTRATION

NTR-5597.

Advancing the public health applications of Chlamydia trachomatis serology

Genital Chlamydia trachomatis infection is the most commonly diagnosed sexually transmitted infection. Trachoma is caused by ocular infection with C trachomatis and is the leading infectious cause of blindness worldwide. New serological assays for C trachomatis could facilitate improved understanding of C trachomatis epidemiology and prevention. C trachomatis serology offers a means of investigating the incidence of chlamydia infection and might be developed as a biomarker of scarring sequelae, such as pelvic inflammatory disease. Therefore, serological assays have potential as epidemiological tools to quantify unmet need, inform service planning, evaluate interventions including screening and treatment, and to assess new vaccine candidates. However, questions about the performance characteristics and interpretation of C trachomatis serological assays remain, which must be addressed to advance development within this field. In this Personal View, we explore the available information about C trachomatis serology and propose several priority actions. These actions involve development of target product profiles to guide assay selection and assessment across multiple applications and populations, establishment of a serum bank to facilitate assay development and evaluation, and development of technical and statistical methods for assay evaluation and analysis of serological findings. The field of C trachomatis serology will benefit from collaboration across the public health community to align technological developments with their potential applications.

Diagnostic value of detection of serum β-HCG and CT-IgG combined with transvaginal ultrasonography in early tubal pregnancy

The diagnostic value of detection of serum β-human chorionic gonadotropin (β-HCG) and Chlamydia trachomatis immunoglobulin G (CT-IgG) combined with transvaginal ultrasonography in early tubal pregnancy was investigated. A total of 55 patients with early tubal pregnancy were selected as the tubal pregnancy group, while 55 subjects of normal intrauterine pregnancy were enrolled as the intrauterine pregnancy group. Transvaginal ultrasonography and quantitative detection of serum β-HCG and CT-IgG were performed for all patients, and the clinical examination results were analyzed and compared. The endometrial thickness and serum β-HCG level of patients with early tubal pregnancy were significantly lower than those of women with intrauterine pregnancy (6.7±1.5 vs. 11.6±1.2 mm; 776±109 vs. 5,598±187 U/l), and the differences were statistically significant (p<0.01); the serum CT-IgG antibody positive rate of patients in tubal pregnancy group (49.1%) was significantly higher than that in intrauterine pregnancy group (12.7%) (p<0.01); the serum CT-IgG antibody positive rates of patients with degree I, II and III of pelvic adhesion intubal pregnancy group were 28.6, 75.0 and 81.8%, respectively; the more severe the pelvic adhesion was, the higher the CT-IgG positive rate would be. The diagnostic coincidence rate of combined detection was significantly higher than that of single detection of serum β-HCG, progesterone and endometrial thickness. The detection of serum β-HCG and CT-IgG combined with transvaginal ultrasonography can diagnose the early tubal pregnancy soonest possible, and help choose the appropriate therapeutic methods depending on the situation to reduce the tubal damage of patients, so as to provide a reliable basis for the diagnosis, treatment and prognosis, and it has important clinical application value.

Chlamydia trachomatis antibody detection in home-collected blood samples for use in epidemiological studies

Capillary blood collected in serum tubes was subjected to centrifugation delay while stored at room temperature. Chlamydia trachomatis (CT) IgG concentrations in aliquoted serum of these blood samples remained stable for seven days after collection. CT IgG concentrations can reliably be measured in mailed blood samples in epidemiological studies.