2015 European guideline on the management of Chlamydia trachomatis infections

Surveying genetic markers of antibiotic resistance and genomic background in Chlamydia trachomatis: insights from a multiplex NGS-based approach in clinical strains from Portugal

OBJECTIVES

To survey genetic markers of potential antimicrobial resistance (AMR) to macrolides and fluoroquinolones among Chlamydia trachomatis-positive samples from the collection of the Portuguese National Reference Laboratory for Sexually Transmitted Infections (STIs), and explore a multiplex PCR approach coupled with NGS to provide complementary information regarding a strain's genomic backbone.

METHODS

A total of 502 C. trachomatis-positive samples, mostly anorectal exudates, were subjected to PCR and sequencing of five targets, including loci potentially driving AMR (23S rRNA, gyrA and parC) and loci potentially informative about a strain's genomic backbone with emphasis on differentiation of lymphogranuloma venereum (LGV)/non-LGV and L2/L2b (a 9 bp insertion in pmpH, a 74 bp insertion upstream from CT105 and the polymorphic CT442).

RESULTS

No samples evidenced 23S rRNA mutations recognizably linked to macrolide resistance. Three samples harboured the Ser83Ile mutation in GyrA putatively driving fluoroquinolone resistance: two recombinant L2-L2b/D-Da (0.4%) and one L2 (0.2%). The screened regions in pmpH, upstream CT105 and CT442 were fully concordant with LGV/non-LGV differentiation. As expected, the pmpH L2b-specific genetic trait locus was detected in all L2b and recombinant L2-L2b/D-Da ompA genotypes, but also in 96.0% of L2 specimens, which also likely possess an L2b genomic backbone. The insertion upstream from CT105 exhibited full LGV specificity, constituting a promising target for the development of rapid LGV diagnostic assays.

CONCLUSIONS

This study contributes to enhancing the knowledge of C. trachomatis molecular epidemiology, suggesting that the known genetic determinants of AMR are not disseminated in clinical C. trachomatis strains, and presents an exploratory approach that can be suitable for LGV/non-LGV and L2/L2b genomic background differentiation.

Doctors' preferences in the choice of antibacterial drugs in pregnant women (PIKAP study)

BackgroundThe use of rational and safe antibiotic therapies for pregnant women remains an important issue within the medical community.ObjectiveTo analyze the preferences in the choice of antimicrobial drugs (AMD) among obstetricians-gynecologists of Central Russia in treatment of infectious diseases in pregnancy.MethodsThis is anonymous survey of obstetrician and gynecology specialists conducted in Central Russia between September 1st, and November 30th, 2017. Study included five healthcare facilities (ambulatory and in-patient), located in regional center, city Belgorod. Questionnaire contained six open-ended questions to evaluate AMD preferences in treatment of Chlamydia trachomatis, Mycoplasma hominis or genitalium, Ureaplasma species, acute cystitis, pyelonephritis, and other conditions, such as placental insufficiency, fetal growth restriction. Descriptive statistics was used including absolute and relative frequencies, minimum and maximum values, mean, frequency of prescribing AMD, and their proportion in the total number prescribed.ResultsA total of 52 responses were included in final analysis. There was significant rate of 15.4% of prescribing pregnancy unsafe (fluoroquinolones, tetracyclines) or non-rational AMD or deviation from existing clinical protocols and guidelines.ConclusionsThere were large variations in provider's AMD preference between healthcare facilities.

2025 European guideline on the management of Chlamydia trachomatis infections

Sexually transmitted Chlamydia trachomatis infections remain common globally and most frequently are asymptomatic. The 2025 European C. trachomatis guideline provides up-to-date guidance regarding indications for testing and treatment of C. trachomatis infections. It includes advice on urogenital and extragenital C. trachomatis testing including the use of self-collected specimens; recommendation to use only validated NAATs for diagnosis; and recommendation to treat all C. trachomatis infections with doxycycline as first line in preference to single-dose azithromycin regimens. The absence of evidence and limited value of broad screening in asymptomatic populations for C. trachomatis infections is also discussed.

Improving effective antimicrobial resistance (AMR) prevention in ambulatory care: lessons from secondary appraisal of Belgian anti-infectious treatment care guidelines

The emergence of antimicrobial resistance (AMR) has been designated as a global threat by the World Health Organization. To combat AMR in Belgium, the Belgian Antibiotic Policy Coordination Committee (BAPCOC) has, among others, developed guidelines for the appropriate use of antimicrobials in the ambulatory practice. We aim to assess the current guidelines from an antimicrobial stewardship perspective and procide suggestions for improving the ambulatory antibiotic guidelines for first-line healthcare providers. The 2022 BAPCOC guidelines were independently evaluated by 7 antimicrobial stewardship experts based on the five "Ds" of antimicrobial stewardship. The results were aggregated, summarized, and consensus was sought. Recommendations improving the guidelines were formulated. A total of 52 recommendations were made, covering 16 different (sub)chapters. The most frequently covered topics were urinary tract infections, followed by skin and soft tissue infections. Among the top five recommendations deemed to have the greatest impact on antimicrobial stewardship outcomes, three were related to the diagnosis or treatment duration of urinary tract infections. Tailoring infectious disease and antibiotic treatment guidelines to antimicrobial stewardship principles and the latest literature is essential in combating antimicrobial resistance. Implementing our proposed recommendations in the Belgian ambulatory treatment guidelines could significantly enhance rational and judicious antibiotic use while minimizing the risk of 'antibiotic undertreatment. The proposed 'Choosing Wisely' recommendations have the potential to be applied to a broader (European) context.

Chlamydia trachomatis: From Urogenital Infections to the Pathway of Infertility

Chlamydia trachomatis (CT) is a major cause of sexually transmitted infections (STIs) worldwide, with significant implications for reproductive health. The bacterium's genome contains highly polymorphic regions, influencing both the type and severity of infections. These genetic variations, particularly those occurring in the major outer membrane protein (MOMP) gene, are critical for classifying the bacterium into distinct serovars and enable CT to adapt to diverse host environments, contributing to its immune evasion, persistence, and pathogenicity. Persistent or untreated urogenital infections can lead to chronic inflammation, tissue damage, and pelvic inflammatory disease, ultimately increasing the risk of ectopic pregnancy, spontaneous abortion, and infertility. This review consolidates current knowledge on the genetic diversity of CT, its potential role in modulating infection outcomes, and its immune evasion mechanisms. By integrating scientific evidence linking chlamydial infections to infertility, we underscore the urgent need for targeted research to address this critical public health challenge.

The global prevalence of Chlamydia trachomatis genital infection in pregnant women: a meta-analysis

BACKGROUND

Chlamydia trachomatis genital infection is one of the most common sexually transmitted bacterial infections with severe detrimental effects on pregnant women and fetuses. CTGI increases the risk of ectopic pregnancy, exogenous fetal infection, and respiratory complications such as bronchitis and pneumonia. According to the different published reports, this systematic review and meta-analysis study aimed to evaluate the global prevalence of CTGI in pregnant women.

METHODS

Initial searching was applied using valid databases of PubMed, ScienceDirect, Embase, WoS, Scopus, and Google Scholar using MeSH keywords (by October 2023). Following duplicate detection and data exclusion, the Title and Abstract of other remaining papers were evaluated (primary screening). Full-texts of selected papers were assessed (secondary screening) and eligible studies were included for data extraction (total No of investigated pregnant women and the number of positive cases). The PRISMA approach was used for paper selection, and the quality assessment was determined according to the STROBE checklist. Data meta-analysis, heterogeneity, publication bias, and the factors affecting heterogeneity index were analyzed using CMA software. The findings were presented in the Forest Plot diagram and Static tables. Besides, heterogeneity was analyzed using I2 test and diffusion bias was demonstrated in Funnel Plot.

RESULTS

Among 1061 selected articles, 44 eligible investigations were enrolled for meta-analysis. The global prevalence of chlamydia trachomatis genital infection (CTGI) was found 8.4% (95% CI 5.8 - 12.1). Meta-regression analysis showed that following the increase in sample size and year of paper publication, the prevalence of Chlamydia trachomatis genital infection in pregnant women decreased significantly (p < 0.05).

CONCLUSION

The global prevalence of Chlamydia trachomatis genital infection in pregnant women is considerably influenced by some interfering factors including Age, Socioeconomic status, Geographic region, and Individual behaviors. Thus, the implementation of more comprehensive health programs for prevention, screening, and treatment seems necessary, especially for high-risk pregnant cases.

Antimicrobial Resistance in Curable Sexually Transmitted Infections

PURPOSE OF REVIEW

Antimicrobial resistance in sexually transmitted infections (STIs) has become an urgent global public health threat, raising the specter of untreatable infections. This review summarizes the determinants of resistance among the five most common curable STIs Neisseria gonorrhoeae, Chlamydia trachomatis, Mycoplasma genitalium, Treponema pallidum, and Trichomonas vaginalis, as well as strategies to mitigate the spread of resistance.

RECENT FINDINGS

Genetic mutations are key drivers of resistance for N. gonorrhoeae and M. genitalium. Resistance in T. vaginalis can also occur because of genetic mutations, yet differential regulation of genes critical in antibiotic metabolism as well as co-infection with organisms that inactivate therapy play important roles. While resistance in C. trachomatis and T. pallidum has not been a substantial clinical concern, resistance selection via the continued widespread use of antimicrobials remains possible. While resistance determinants are diverse and differ by pathogen, the strategies required to mitigate the continued emergence of resistance are similar: prevention of infection and treatment diversification. Underpinning those strategies, surveillance remains essential for monitoring and responding to the threat of drug-resistant infections.

No impact of a positive Chlamydia trachomatis serology on live-birth rate after intra-uterine insemination

OBJECTIVE

To study the impact of a CT serology on intrauterine insemination (IUI) cumulative live-birth rate (cLBR) in women with documented bilateral tubal patency.

DESIGN

Cohort study SUBJECTS: Infertile women with documented bilateral tubal patency and medical indication of IUI matched on the following criteria: woman's age, number of cycles completed and number of motile sperm inseminated (NMSI).

EXPOSURE

This retrospective, observational and monocentric cohort study compared women with positive CT serology matched 1:1 to control women with negative CT serology.

MAIN OUTCOME MEASURES

Cumulative LBR, rates of clinical pregnancy, spontaneous abortion, biochemical pregnancy.

RESULTS

A total of 71 women in the CT positive group were matched to 71 women in the negative CT group, leading to compare 136 cycles per group. No statistically significant difference was observed between groups regarding the demographic and medical characteristics of couples. Cumulative LBR per woman was similar in both groups with 32.4% (n = 23) in the negative serology group Vs 25.4% (n = 18) in the positive CT group (NS). The rates of clinical pregnancy, spontaneous abortion, biochemical pregnancy were comparable between the two groups.

CONCLUSION

In a population of infertile women with patent tubes, our study suggests that the serological status for CT has no impact on the IIU cLBR.

[Translated article] AEDVAEDV Expert Recommendations on the Management of Suppurative Sexually Transmitted Infections

The incidence of sexually transmitted infections (STIs) is increasing in Spain. Suppurative STIs are one of the most frequent reasons for consultation in specialized centers. The reason for suppurative STIs is multiple and their empirical treatment varies with the currently growing problem of antimicrobial resistance. Dermatologists are trained and prepared to treat these diseases, but their correct management requires active knowledge of national and international guidelines. The present document updates, reviews and summarizes the main expert recommendations on the management and treatment of these STIs.

AEDV Expert Recommendations on the Management of Suppurative Sexually Transmitted Infections

The incidence of sexually transmitted infections (STIs) is increasing in Spain. Suppurative STIs are one of the most frequent reasons for consultation in specialized centers. The reason for suppurative STIs is multiple and their empirical treatment varies with the currently growing problem of antimicrobial resistance. Dermatologists are trained and prepared to treat these diseases, but their correct management requires active knowledge of national and international guidelines. The present document updates, reviews and summarizes the main expert recommendations on the management and treatment of these STIs.

Evaluating the home-based intervention strategy (HIS-UK) to reduce new chlamydia infection among young men aged 16-25 years by promoting correct and consistent condom use: findings from a randomised controlled trial

BACKGROUND

Correct and consistent condom use is the most effective method to reduce transmission of sexually transmitted infections (STIs).

OBJECTIVE

To compare the HIS-UK intervention to usual condom information and distribution care for effect on chlamydia test positivity.

METHODS

Trial design A 3-parallel arm randomised controlled trial (1:1:1 allocation, two intervention arms vs. control). Randomisation using permuted blocks of varying lengths, with stratification by site, ethnicity and sexual-partnering risk. Repeated measures design with monthly follow-up to six months post-randomisation. Setting Sexual health services in seven NHS Trusts and one university medical centre. Telephone and video consultations, online and in participants' homes in England, UK. Participants Target sample of 2231 men and people with penises, aged 16-25, at risk of STIs. Intervention HIS-UK delivered (1) face-to-face by health professionals (proHIS) or (2) digitally (eHIS). Two-weeks self-practice and experimentation using the HIS-UK condom kit. Primary health outcome Chlamydia test positivity by six-months. Secondary outcomes Frequency of unprotected sexual intercourse, reported condom use errors and problems, attitudes and use experience. Analyses Chlamydia test positivity by six months analysed by logistic regression. Secondary outcomes analysed using linear mixed effects models with fixed effects and a random effect for the repeated measures, and generalised estimating equations with a logit link, adjusting for fixed effects and specifying an autoregressive-1 correlation structure.

RESULTS

Seven hundred twenty-five participants (proHIS:241, eHIS:243, control:241) randomised. 575 participants completed all baseline activities, 189 (32.9%) reached six-months post-randomisation. The absolute difference in chlamydia test positivity between arms was -4.9 percentage points at six months (7.9% HIS-UK, 12.8% control). The odds of chlamydia test positivity during follow-up were 55% lower for HIS-UK participants (p=.261). HIS-UK showed a positive impact on recent condom use over time (p<.001). Significant reductions in condom errors and problems among HIS-UK participants were observed (p=.035). Lubricant use increased among HIS-UK participants, with evidence of an intervention-by-time interaction (p=.051), and a decline in poor condom fit and feel reports, but without intervention effect.

CONCLUSIONS

This study provides valuable insights into the potential of HIS-UK to enhance sexual health practices among at-risk populations at-risk of STI transmission.

TRIAL REGISTRATION

ISRCTN registration: 11400820 (23/10/2019).

Performance and acceptability of self-collected specimens for diagnosis of rectal and pharyngeal Chlamydia trachomatis and Neisseria gonorrhoeae infections among men who have sex with men in China: a randomized controlled trial

BACKGROUND

Extragenital Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) infections are prevalent among men who have sex with men (MSM). Self-sampling could potentially eliminate barriers to extragenital CT/NG testing for MSM that are hard to reach, who refuse to go for clinician-based testing, or who decline an examination. However, the required evidence to determine whether self-collected specimens are as accurate as clinician-taken specimens in terms of CT/NG diagnostic accuracy was limited in low and middle income countries. We therefore compared self-collected rectal and pharyngeal specimens with clinician-taken specimens for diagnostic accuracy among MSM in China.

METHODS

This was a prospective convenience sample from 6 sexually transmitted infection (STI) clinics in China. We randomized the order of self-collected and clinician-taken specimens from the pharynx and rectum, plus first-void urine, for CT/NG detection. Self-sampling performance was compared with clinician-sampling as to agreement, sensitivity, and specificity. The acceptability of self-sampling was evaluated by questionnaire.

RESULTS

Among the 325 participants, prevalences of rectal CT and NG infections were 13.6% and 5.2% and pharyngeal CT and NG prevalences were 1.5% and 2.8%, respectively. The agreements between the CT tests with the self-collected and clinician-taken specimens were 98.8% (κ = 0.95, 95% CI 0.89-1.00) for rectal site and 99.4% (κ = 0.83, 95% CI 0.60-1.00) for pharyngeal site; and the agreements between NG tests were 99.4% (κ = 0.94, 95% CI 0.86-1.00) for rectal site and 98.2% (κ = 0.72, 95% CI 0.50-0.93) for pharyngeal site. The sensitivity and specificity of self-collected swabs was as follows: rectal CT: 93.0% and 99.6%; pharyngeal CT: 100.0% and 99.4%; rectal NG: 100.0% and 99.4%; pharyngeal NG: 88.9% and 98.4%. Self-collection was highly acceptable, showing that 62.0% MSM preferred self-sampling over clinician-sampling; 90.2% would use self-sampling for detection of CT and NG again.

CONCLUSIONS

Extragenital screening for CT and NG should be recommended as part of STI services to MSM population. Self-collection of rectal and pharyngeal specimens had good performance for CT and NG tests and acceptability to the target population.

TRIAL REGISTRATION

This trial was registered with the Chinese Clinical Trial Registry, ChiCTR2300073473. Registered 12/07/2023.

A novel method for the preparation of reproducible, stable, and non-infectious quality control materials for Chlamydia trachomatis nucleic acid detection

Chlamydia trachomatis (CT) is a significant sexually transmitted pathogen known to evoke severe complications, including infertility. Nucleic acid amplification tests (NAATs) are recommended by the World Health Organization to detect CT infection. Furthermore, the establishment of methods, performance validation, internal quality control, and external quality assessment for CT NAATs necessitate the utilization of quality control materials (QCs). QCs are specimens or solutions that are analyzed for quality control purposes in a test system. In this study, we established a novel cell line that stably integrates CT amplification target sequences for producing QCs for CT NAATs. Utilizing clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 technology, we integrated the CT plasmid-mediated sequence (comprising the full length of the cryptic plasmid and the major outer membrane protein gene, 9,136 bp) into the MUC4 gene of HEK293T cells. Positive clones were screened through flow cytometric sorting, single-cell culture, and PCR-based identification, followed by the establishment of stable cell lines. These cells were then processed using optimized cell preservation procedures to prepare QCs. The sequence insertion copy number was confirmed by real-time quantitative PCR. This novel CT QCs demonstrate excellent clinical applicability, non-infectiousness, quantifiability, and stability. With an integrated sequence exceeding 9 kb in length, it offers exceptional flexibility for adapting to new kit developments. Furthermore, maintaining a well-defined copy number and stable shelf life, the QCs closely aligns with the quality control requirements of CT NAATs. This study presents an innovative method for preparing QCs for CT nucleic acid detection, making a valuable contribution to improving the performance of CT NAATs.IMPORTANCEUntreated CT infections impose significant burdens on individuals and communities, underscoring the importance of early and accurate testing via CT NAATs for disease control. QCs are instrumental in identifying testing process issues. Hence, we developed a cell line integrating CT-amplified target sequences as readily accessible non-infectious QCs. These QCs boast several advantages: the integration of over 9 kb of CT sequence allows for broad applicability, allowing flexible adaptation to the development of new kits. Confirming the CT sequence copy number provides a reliable basis for QC concentration preparation and kit detection limit evaluation. Optimized preservation protocol enhances QC stability during storage, facilitating convenient shipment to clinical laboratories at ambient temperatures. In summary, our novel CT QCs offer a powerful tool for improving CT NAAT performance and present a fresh perspective on QC preparation for detecting nucleic acids from intracellular parasitic pathogens.

Epidemiological impact of Neisseria gonorrhoeae and Chlamydia trachomatis screening in men having sex with men: a modelling study

OBJECTIVES

The impact of the systematic screening of Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) in men having sex with men (MSM) on these pathogens' epidemiology remains unclear. We conducted a modelling study to analyse this impact in French MSM.

METHODS

We modelled NG and CT transmission using a site-specific deterministic compartmental model. We calibrated NG and CT prevalence at baseline using results from MSM enrolled in the Dat'AIDS cohort. The baseline scenario was based on 1 million MSM, 40 000 of whom were tested every 90 days and 960 000 every 200 days. Incidence rate ratios (IRRs) at steady state were simulated for NG, CT, NG and/or CT infections, for different combinations of tested sites, testing frequency and numbers of frequently tested patients.

RESULTS

The observed prevalence rate was 11.0%, 10.5% and 19.1% for NG, CT and NG and/or CT infections. The baseline incidence rate was estimated at 138.2 per year per 100 individuals (/100PY), 86.8/100PY and 225.0/100PY for NG, CT and NG and/or CT infections. Systematically testing anal, pharyngeal and urethral sites at the same time reduced incidence by 14%, 23% and 18% (IRR: 0.86, 0.77 and 0.82) for NG, CT and NG and/or CT infections. Reducing the screening interval to 60 days in frequently tested patients reduced incidence by 20%, 29% and 24% (IRR: 0.80, 0.71 and 0.76) for NG, CT and NG and/or CT infections. Increasing the number of frequently tested patients to 200 000 reduced incidence by 29%, 40% and 33% (IRR: 0.71, 0.60 and 0.67) for NG, CT and NG and/or CT infections. No realistic scenario could decrease pathogens' incidence by more than 50%.

CONCLUSIONS

To curb the epidemic of NG and CT in MSM, it would not only be necessary to drastically increase screening, but also to add other combined interventions.

Tracking Chlamydia - Host interactions and antichlamydial activity in Caenorhabditis elegans

The fading efficacy of antibiotics is a growing global health concern due to its life-threatening consequences and increased healthcare costs. Non-genetic mechanisms of antimicrobial resistance, such as those employed by Chlamydia pneumoniae and Chlamydia trachomatis, complicate treatment as these bacteria can enter a non-replicative, persistent state under stress, evading antibiotics and linking to inflammatory conditions. Understanding chlamydial persistence at the molecular level is challenging, and new models for studying Chlamydia-host interactions in vivo are urgently needed. Caenorhabditis elegans offers an alternative given its immune system and numerous orthologues of human genes. This study established C. elegans as an in vivo model for chlamydial infection. Both Chlamydia species reduced the worm's lifespan, their DNA being detectable at three- and six-days post-infection. Azithromycin at its MIC (25 nM) failed to prevent the infection-induced lifespan reduction, indicating a persister phenotype. In contrast, the methanolic extract of Schisandra chinensis berries showed anti-chlamydial activity both in vitro (in THP-1 macrophages) and in vivo, significantly extending the lifespan of infected C. elegans and reducing the bacterial load. Moreover, S. chinensis increased the transcriptional activity of SKN-1 in the worms, but was unable to impact the bacterial load or lifespan in a sek-1 defective C. elegans strain. In summary, this study validated C. elegans as a chlamydial infection model and showcased S. chinensis berries' in vivo anti-chlamydial potential, possibly through SEK/SKN-1 signaling modulation.

Antimicrobial treatment and resistance in sexually transmitted bacterial infections

Sexually transmitted infections (STIs) have been part of human life since ancient times, and their symptoms affect quality of life, and sequelae are common. Socioeconomic and behavioural trends affect the prevalence of STIs, but the discovery of antimicrobials gave hope for treatment, control of the spread of infection and lower rates of sequelae. This has to some extent been achieved, but increasing antimicrobial resistance and increasing transmission in high-risk sexual networks threaten this progress. For Neisseria gonorrhoeae, the only remaining first-line treatment (with ceftriaxone) is at risk of becoming ineffective, and for Mycoplasma genitalium, for which fewer alternative antimicrobial classes are available, incurable infections have already been reported. For Chlamydia trachomatis, in vitro resistance to first-line tetracyclines and macrolides has never been confirmed despite decades of treatment of this highly prevalent STI. Similarly, Treponema pallidum, the cause of syphilis, has remained susceptible to first-line penicillin.

Kanoi B, Kimani R, Maina M, Waweru H, Kamita M, Ndirangu I, M. Abkallo H, Oduor B, Pamme N, Dupaty J, M. Klapperich C, Raju Lolabattu S, Gitaka J. Multi-repeat sequences identification using genome mining techniques for developing highly sensitive molecular diagnostic assay for the detection of Chlamydia trachomatis

Chlamydia trachomatis ( C. trachomatis) is a common sexually transmitted infection (STI). In 2019, the World Health Organization reported about 131 million infections. The majority of infected patients are asymptomatic with cases remaining undetected. It is likely that missed C. trachomatis infections contribute to preventable adverse health outcomes in women and children. Consequently, there is an urgent need of developing efficient diagnostic methods. In this study, genome-mining approaches to identify identical multi-repeat sequences (IMRS) distributed throughout the C. trachomatis genome were used to design a primer pair that would target regions in the genome. Genomic DNA was 10-fold serially diluted (100pg/μL to 1×10 -3pg/μL) and used as DNA template for PCR reactions. The gold standard PCR using 16S rRNA primers was also run as a comparative test, and products were resolved on agarose gel. The novel assay, C. trachomatis IMRS-PCR, had an analytical sensitivity of 4.31 pg/µL, representing better sensitivity compared with 16S rRNA PCR (9.5 fg/µL). Our experimental data demonstrate the successful development of lateral flow and isothermal assays for detecting C. trachomatis DNA with potential use in field settings. There is a potential to implement this concept in miniaturized, isothermal, microfluidic platforms, and laboratory-on-a-chip diagnostic devices for reliable point-of-care testing.

Orogenital and anal infection by Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium, and other sexually transmitted infections in men who have sex with men in Lisbon

BACKGROUND

Men who have sex with men (MSM) are at risk for sexually transmitted infections (STIs), but more data on extragenital carriage are needed.

AIM

We assessed the genital and extragenital prevalence of bacterial and other STIs in MSM in a Lisbon sexual health clinic.

METHODS

We screened oral, anal, and urine samples of MSM visiting the GAT-CheckpointLX clinic June 2017-December 2021 for Chlamydia trachomatis (including lymphogranuloma venereum, LGV), Neisseria gonorrhoeae, Mycoplasma genitalium, Trichomonas vaginalis, Mycoplasma hominis, Ureaplasma urealyticum, and U. parvum. Ano-oro-genital lesions were tested for LGV, Treponema pallidum, and Herpes Simplex Virus. Blood was tested for HIV and T. pallidum antibodies.

RESULTS

N. gonorrhoeae was found in 16.6% of the MSM followed by C. trachomatis (13.2%), M. genitalium (10.3%) and T. vaginalis (0.2%). The most frequent occurrence was anorectal (C. trachomatis, M. genitalium) and oral (N. gonorrhoeae). We found high carriage of U. urealyticum (36.1%) and M. hominis (22.1%). LGV was detected in 21.8% of chlamydia-positive anorectal swabs. Syphilis was detected in 22.6% of tested MSM, while 13.8% had HIV. Gonorrhoea and chlamydia were significantly more prevalent in MSM with concomitant HIV or syphilis.

CONCLUSION

The substantial extragenital prevalence of bacterial STIs in MSM, and HIV and syphilis coinfections, suggest screening has value in identifying hidden carriage and in contributing for providing better care.

STI pathogens in the oropharynx: update on screening and treatment

PURPOSE OF REVIEW

The rise in antimicrobial resistance in several STI pathogens such as Neisseria gonorrhoeae has become a public health threat as only one first-line treatment remains. Reducing screening interval for gonorrhoea and chlamydia in high-prevalence populations has been proposed to address antimicrobial stewardship, but this remains controversial. This review aimed to revisit the epidemiology of infections at the oropharynx and review the current screening recommendations and treatment guidelines in different populations.

RECENT FINDINGS

Emerging evidence suggests that the oropharynx is the primary anatomical site for gonorrhoea transmission but maybe not for chlamydia transmission. Most international guidelines recommend 3-monthly oropharyngeal gonorrhoea and chlamydia screening for high-prevalence populations (e.g. men who have sex with men) but not low-prevalence populations (e.g. heterosexuals) given the clinical and public health benefits of screening in low-prevalence populations are still unclear. Doxycycline remains the first-line treatment for oropharyngeal chlamydia in most guidelines. However, some countries have moved from dual therapy (ceftriaxone and azithromycin) to monotherapy (ceftriaxone) for oropharyngeal gonorrhoea treatment to address antimicrobial stewardship.

SUMMARY

The transmission of gonorrhoea and chlamydia is still not fully understood. Further work will be required to evaluate the benefits and harms of reducing screening in high-prevalence populations.

Chlamydia trachomatis infections in Kenya - sexually transmitted and ocular infections: a scoping review

Background

Chlamydia trachomatis (CT), a Gram-negative intracellular bacterium, is differentiated into three biovars associated with distinct clinical syndromes, ranging from trachoma, the world's cause of preventable blindness, to the most common sexually transmitted infection. This variability underscores CT's significant impact on public health, particularly in low-resource settings. In Kenya, where the demographic is predominantly younger, the burden of CT remains poorly understood and potentially underestimated.

Objectives

This study aimed to assess the prevalence of both sexually transmitted and ocular CT across various regions and populations within Kenya.

Eligibility criteria

Articles on CT population testing and laboratory detection, from 2014 to date, in English or Swahili only.

Sources of evidence

Electronic databases of PubMed and Google Scholar were used.

Design

A scoping review.

Charting methods

This study conducted a systematic scoping review, following Arksey and O'Malley's framework and adhering to PRISMA guidelines for scoping reviews (PRISMA-ScR).

Results

This study incorporates findings from 19 original studies on sexually transmitted CT and seven on ocular CT. CT prevalence for four identified populations: sexually active females 2%-13%, men who have sex with men 1.3%-51%, pregnant women 2.5%-14.9% and other population groups 2.8%-16.4%. By contrast, studies on ocular CT, all performed in rural settings, found prevalence surpassing the WHO's 10% threshold primarily amongst children and mothers.

Conclusion

The variability in CT prevalence across different demographics and geographical regions emphasizes the impact of socio-economic, environmental and diagnostic factors on disease transmission and detection. The insights gained here can serve as a foundation for evidence-based health policies and interventions aimed at mitigating the burden of CT in Kenya.

Sexually transmitted infections and HIV in ophthalmology

The ocular and periocular manifestations of sexually transmitted infections are heterogeneous in etiology, manifestations, and complications. Etiologic agents include bacteria, viruses, parasites, and protozoa, which are most frequently transmitted via direct ocular contact with an active lesion or infected bodily fluid, autoinoculation, or dissemination from a distant site. Vertical transmission most commonly occurs perinatally during vaginal delivery. The complications of ophthalmia neonatorum can be severe, with the potential for permanent blindness or life-threatening systemic involvement if untreated. Clinical features, diagnostic modalities, and therapeutic regimens vary based on etiology and are summarized in this review. Prompt diagnosis is imperative, given the severe sequelae that may result from ocular involvement in these infections, including permanent vision loss. A multidisciplinary approach, involving both ophthalmology and dermatology, to diagnosis and management is essential to mitigate the risk of morbidity associated with sexually transmitted infections resulting in eye disease.

An isothermal CRISPR-based diagnostic assay for Neisseria gonorrhoeae and Chlamydia trachomatis detection

IMPORTANCE

A method for Neisseria gonorrhoeae (NG)/Chlamydia trachomatis (CT) detection is developed using multiplex-recombinase polymerase amplification and Cas12a/Cas13a. This method can detect NG and CT simultaneously with high sensitivity and specificity. This method has great potential to be further developed into larger-scale screening and point-of-care testing (POCT).

Pharmacodynamics of zoliflodacin plus doxycycline combination therapy against Neisseria gonorrhoeae in a gonococcal hollow-fiber infection model

Antimicrobial resistance in the sexually transmitted bacterium Neisseria gonorrhoeae is compromising the management and control of gonorrhea globally. Optimized use and enhanced stewardship of current antimicrobials and development of novel antimicrobials are imperative. The first in class zoliflodacin (spiropyrimidinetrione, DNA Gyrase B inhibitor) is a promising novel antimicrobial in late-stage clinical development for gonorrhea treatment, i.e., the phase III randomized controlled clinical trial (ClinicalTrials.gov Identifier: NCT03959527) was recently finalized, and zoliflodacin showed non-inferiority compared to the recommended ceftriaxone plus azithromycin dual therapy. Doxycycline, the first-line treatment for chlamydia and empiric treatment for non-gonococcal urethritis, will be frequently given together with zoliflodacin because gonorrhea and chlamydia coinfections are common. In a previous static in vitro study, it was indicated that doxycycline/tetracycline inhibited the gonococcal killing of zoliflodacin in 6-h time-kill curve analysis. In this study, our dynamic in vitro hollow-fiber infection model (HFIM) was used to investigate combination therapies with zoliflodacin and doxycycline. Dose-range experiments using the three gonococcal strains WHO F (susceptible to relevant therapeutic antimicrobials), WHO X (extensively drug-resistant, including ceftriaxone-resistant; zoliflodacin-susceptible), and SE600/18 (zoliflodacin-susceptible strain with GyrB S467N substitution) were conducted simulating combination therapy with a single oral dose of zoliflodacin 0.5-4 g combined with a doxycycline daily oral dose of 200 mg administered as 100 mg twice a day, for 7 days (standard dose for chlamydia treatment). Comparing combination therapy of zoliflodacin (0.5-4 g single dose) plus doxycycline (200 mg divided into 100 mg twice a day orally, for 7 days) to zoliflodacin monotherapy (0.5-4 g single dose) showed that combination therapy was slightly more effective than monotherapy in the killing of N. gonorrhoeae and suppressing emergence of zoliflodacin resistance. Accordingly, WHO F was eradicated by only 0.5 g single dose of zoliflodacin in combination with doxycycline, and WHO X and SE600/18 were both eradicated by a 2 g single dose of zoliflodacin in combination with doxycycline; no zoliflodacin-resistant populations occurred during the 7-day experiment when using this zoliflodacin dose. When using suboptimal (0.5-1 g) zoliflodacin doses together with doxycycline, gonococcal mutants with increased zoliflodacin MICs, due to GyrB D429N and the novel GyrB T472P, emerged, but both the mutants had an impaired biofitness. The present study shows the high efficacy of zoliflodacin plus doxycycline combination therapy using a dynamic HFIM that more accurately and comprehensively simulate gonococcal infection and their treatment, i.e., compared to static in vitro models, such as short-time checkerboard experiments or time-kill curve analysis. Based on our dynamic in vitro HFIM work, zoliflodacin plus doxycycline for the treatment of both gonorrhea and chlamydia can be an effective combination.

Knowledge about and prevalence of Chlamydia trachomatis in a population-based sample of emerging Croatian adults

To determine the prevalence of genital Chlamydia trachomatis (chlamydia) infection, knowledge about chlamydia and experience of previous testing for chlamydia, we carried out a national probability-based survey in emerging adults aged 18-25 years in Croatia in 2021-2022. Participants (n = 1197), members of a national online panel, completed a web-based questionnaire that collected information on socio-demographics, sexual behaviours and knowledge about sexually transmitted infections (STIs). Urine specimens from a sample of sexually experienced participants were self-collected and tested for chlamydia using Cobas 4800 CT/NG test. To achieve broad representativeness of the emerging adult population in the country, we applied post-hoc weighting for gender and age. Multivariable ordinary least squares linear regression was used to determine correlates of knowledge about chlamydia infection and binomial logistic regression to assess correlates of the willingness to test for chlamydia. Among 448 participants who sent in their urine specimens chlamydia prevalence was 2.5% (95% CI 1.2-5.1) in women and 1.0% (0.3-3.2%) in men. A total of 8.0% of women and 4.7% men reported testing for chlamydia prior to the survey. About a quarter of the sample was characterized by not answering correctly any of the six questions related to knowledge about chlamydia, while only 9.6% had five or six correct answers. In the multivariable analysis, significantly higher odds of willingness to test for chlamydia were found in females compared to males (OR = 1.34, p = 0.024), those with better knowledge about the infection (OR = 1.11, p = 0.005), and those with lower religiosity (OR = 0.91, p = 0.017). In conclusion, prevalence of chlamydia in emerging adults in Croatia is considerable. Efforts to control this infection should focus on primary prevention and targeted testing combined with effective case management strategies.

Results of a Community-Based Screening Program for Chlamydia trachomatis Genital Infection in Young People Aged 18-25 Years

Introduction and aim Chlamydia trachomatis (CT) cases have increased in the last decade. The aim of the study was to assess the prevalence of CT genital infection in asymptomatic, sexually active young people and determine whether a community screening program would be effective in reducing the number of cases. Methods A descriptive cross-sectional studyof consecutive inclusion of asymptomatic people aged 18-25 years between September 2021 and May 2022. Community interventions in high schools, universities, and cultural events were planned to realize the screening. Sociodemographic variables of gender, age, country of origin, and educational level, as well as sexual habits, were recorded for each patient. CT was detected via urine samples. An estimate of the prevalence of CT genital infection and its 95% confidence interval (CI) was made based on the exact binomial distribution, assuming that the sample is representative of the study population. Results A total of 628 subjects participated in the study, of whom 33 had a CT infection, giving a prevalence of 5.2% (95% CI: 3.6%, 7.3%). 93.9% of subjects with CT infection were female (p≤0.019) and 85% of the participants were Spanish nationals. Among vocational training students, the prevalence was 8.1%. Having had four or more sexual partners in the last month and in the previous year was significantly associated with CT infection (p<0.001). Conclusion Screening for CT genital infection in young sexually active women should be implemented in our country, as recommended by the various guidelines.

Chlamydial and Gonococcal Genital Infections: A Narrative Review

Sexually transmitted infections (STIs) constitute one of the leading causes of disease burden worldwide, leading to considerable morbidity, mortality, health expenditures, and stigma. Of note are the most common bacterial STIs, chlamydial and gonococcal infections, whose etiological agents are Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG), respectively. Despite being usually asymptomatic, in some cases these infections can be associated with long-term severe complications, such as pelvic inflammatory disease, chronic pelvic pain, infertility, ectopic pregnancy, and increased risk of other STIs acquisition. As the symptoms, when present, are usually similar in both infections, and in most of the cases these infections co-occur, the dual-test strategy, searching for both pathogens, should be preferred. In line with this, herein we focus on the main aspects of CT and NG infections, the clinical symptoms as well as the appropriate state-of-the-art diagnostic tests and treatment. Cost-effective strategies for controlling CT and NG infections worldwide are addressed. The treatment for both infections is based on antibiotics. However, the continuing global rise in the incidence of these infections, concomitantly with the increased risk of antibiotics resistance, leads to difficulties in their control, particularly in the case of NG infections. We also discuss the potential mechanism of tumorigenesis related to CT infections. The molecular bases of CT and NG infections are addressed, as they should provide clues for control or eradication, through the development of new drugs and/or effective vaccines against these pathogens.

A Nationwide Survey on Detection of Chlamydia trachomatis in Health Facilities in China

BACKGROUND

This study evaluated the clinical laboratory capacity for the diagnosis of Chlamydia trachomatis (CT) in China to provide recommendations to improve the diagnostic capacity and quality of this clinically important sexually transmitted disease.

METHODS

An electronic questionnaire-based cross-sectional, survey study was conducted by the National Center for STD Control among different types of healthcare facilities in China from July to December 2021.

RESULTS

The surveyed laboratory facilities were located in 332 cities in 31 provinces in China. A total of 4640 records from clinical laboratories were included in the data set for the final analysis. Less than half of the laboratories (41.6% [1931 of 4640]) performed the CT diagnostic test; of these, 721 laboratories (15.5% [721 of 4640]) carried out nucleic acid amplification test (NAAT) methods, and 1318 laboratories (28.4% [1318 of 4640]) performed antigen-based immunochromatographic assays. Most laboratories were equipped with biological safety cabinets (93.7% [4348 of 4640]), 49.2% (2283 of 4640) were equipped with fully automated nucleic acid extractors, and 55.2% (2560 of 4640) were equipped with polymerase chain reaction amplification instruments. The laboratories from Southern China or third-class hospitals (i.e., the highest rated hospitals) had the highest proportion using NAATs to diagnose CT among the surveyed health facilities.

CONCLUSIONS

Advancing laboratories to use NAAT to detect CT should be phased step-by-step by different areas and levels of hospitals according to the current situation.

The Relationship Between Directly Observed Therapy for Chlamydia Infections and Retesting Rates in an Adolescent Population

BACKGROUND

Chlamydia trachomatis is the most common reportable sexually transmitted infection in the United States, with >60% of reported cases occurring in individuals aged 15 to 24 years. US practice guidelines recommend directly observed therapy (DOT) for the treatment of chlamydia in adolescents, but almost no research has been done to evaluate whether DOT results in improved outcomes.

METHODS

We conducted a retrospective cohort study of adolescents who sought care at 1 of 3 clinics within a large academic pediatric health system for a chlamydia infection. The study outcome was return for retesting within 6 months. Unadjusted analyses were performed using χ2 , Mann-Whitney U , and t tests, and adjusted analyses were performed using multivariable logistic regression.

RESULTS

Of the 1970 individuals included in the analysis, 1660 (84.3%) received DOT and 310 (15.7%) had a prescription sent to a pharmacy. The population was primarily Black/African American (95.7%) and female (78.2%). After controlling for confounders, individuals who had a prescription sent to a pharmacy were 49% (95% confidence interval, 31%-62%) less likely than individuals who received DOT to return for retesting within 6 months.

CONCLUSIONS

Despite clinical guidelines recommending the use of DOT for chlamydia treatment in adolescents, this is the first study to describe the association between DOT and an increase in the number of adolescents and young adults who return for sexually transmitted infection retesting within 6 months. Further research is needed to confirm this finding in diverse populations and explore nontraditional settings for the provision of DOT.

Phenotypic and Genotypic Antimicrobial Susceptibility Testing of Chlamydia trachomatis Isolates from Patients with Persistent or Clinical Treatment Failure in Spain

The aim of this multicentre project (seven hospitals across the Spanish National Health Service) was to study the phenotypic and genotypic susceptibility of C. trachomatis to the main antimicrobials used (macrolides, doxycycline, and quinolones) in isolates from patients with clinical treatment failure in whom reinfection had been ruled out. During 2018-2019, 73 clinical isolates were selected. Sixty-nine clinical specimens were inoculated onto confluent McCoy cell monolayers for phenotypic susceptibility testing. The minimum inhibitory concentration for azithromycin and doxycycline was defined as the lowest concentration associated with an at least 95% reduction in inclusion-forming units after one passage in the presence of the antibiotic compared to the initial inoculum for each strain (control). Sequencing analysis was performed for the genotypic detection of resistance to macrolides, analysing mutations in the 23S rRNA gene (at positions 2057, 2058, 2059, and 2611), and quinolones, analysing a fragment of the gyrA gene, and searching for the G248T mutation (Ser83->Ile). For tetracyclines, in-house RT-PCR was used to test for the tet(C) gene. The phenotypic susceptibility testing was successful for 10 isolates. All the isolates had minimum inhibitory concentrations for azithromycin ≤ 0.125 mg/L and for doxycycline ≤ 0.064 mg/L and were considered sensitive. Of the 73 strains studied, no mutations were found at positions T2611C or G248T of the gyrA gene. We successfully sequenced 66 isolates. No macrolide resistance-associated mutations were found at positions 2057, 2058, 2059, or T2611C. None of the isolates carried the tet(C) gene. We found no evidence for genomic resistance in this large, clinically relevant dataset.

Alarming incidence of reinfections after treatment for Chlamydia trachomatis and gonorrhoea: Can we predict and prevent them?

BACKGROUND

Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) infections are a public health problem, worsened by frequent reinfections, whose incidence rate is not known in Spain. The objective of this study is to estimate in patients diagnosed with NG, CT or mixed infection (NG and CT): (1) the incidence of reinfections by the same microorganism, (2) the total incidence of Sexually Transmitted Infections (STI), both by the same microorganism and by infections other than the initial one, and (3) to identify predictors of reinfection.

METHODS

Observational prospective case series involving 986 patients with CT and/or NG at specialized STI clinics in Biscay (Spain) between 2016 and 2019.

RESULTS

The six month cumulative incidence of reinfection by the same microorganism was 17.24% (CI95%: 14.9-19.7) and 24.65% (CI95%: 21.9-27.4) for any STI (reinfection or other). Being an immigrant (OR=1.8; CI95%: 1.3-2.6), men who have sex with men (OR=1.8; CI95%: 1.3-2.6), number of sexual partners (OR=4.3; CI95%: 2.7-6.8 for more than 5 partners), having a new partner (OR=1.7; CI95%: 1.08-2.6), not always using a condom (OR=1.4; CI95%: 1.02-1.9) and consumption of alcohol prior to sex (OR=3.8; CI95%: 1.5-9.5) were associated with reinfection by any STI.

CONCLUSION

These characteristics allow doctors to identify patients in whom to prioritize short-term rescreening for repeated infections with any STIs after initial treatment for NG or CT.

Patterns of within-host spread of Chlamydia trachomatis between vagina, endocervix and rectum revealed by comparative genomic analysis

Introduction

Chlamydia trachomatis, a gram-negative obligate intracellular bacterium, commonly causes sexually transmitted infections (STIs). Little is known about C. trachomatis transmission within the host, which is important for understanding disease epidemiology and progression.

Methods

We used RNA-bait enrichment and whole-genome sequencing to compare rectal, vaginal and endocervical samples collected at the same time from 26 study participants who attended Fijian Ministry of Health and Medical Services clinics and tested positive for C. trachomatis at each anatomic site.

Results

The 78 C. trachomatis genomes from participants resolved into two major clades of the C. trachomatis phylogeny (the "prevalent urogenital and anorectal" clade and "non-prevalent urogenital and anorectal" clade). For 21 participants, genome sequences were almost identical in each anatomic site. For the other five participants, two distinct C. trachomatis strains were present in different sites; in two cases, the vaginal sample was a mixture of strains.

Discussion

The absence of large numbers of fixed SNPs between C. trachomatis genomes within many of the participants could indicate recent acquisition of infection prior to the clinic visit without sufficient time to accumulate significant genetic variation in different body sites. This model suggests that many C. trachomatis infections may be resolved relatively quickly in the Fijian population, possibly reflecting common prescription or over-the-counter antibiotics usage.

Andueza Lillo J, Sanjurjo-Sáez M. Appropriateness of Empirical Antibiotic Therapy for Cervicitis and Urethritis Prescribed in the Emergency Department

Objectives

Sexually transmitted infections are a prevalent global health care problem. Treatment guidelines have recently been updated as a result of antimicrobial resistance and public health trends. The aim of the study was to assess the appropriateness of empirical antibiotic therapy prescribed for cervicitis and urethritis in the emergency department.

Methods

We designed a retrospective observational cohort study. We included adult patients with suspected cervicitis or urethritis who attended the emergency department of a tertiary hospital in 2020. We excluded patients with suspected pelvic inflammatory disease, pregnancy or prostatitis and those requiring admission to hospital. Appropriateness of empirical antibiotic therapy was evaluated taking into account 4 aspects: indication, dosing, duration of therapy, and route of administration. Data were obtained from the electronic medical record, the electronic prescription program, and the discharge summary.

Results

The study population comprised 176 patients; mean age was 28.9 years (SD = 7.7), and 90.9% were men. The most prescribed treatment was the combination of ceftriaxone and azithromycin (83.0%). Treatment was inappropriate in 71.6% of patients. A total of 159 drug errors were recorded. The most frequent cause was undertreatment (36.4%) related to underdosing (46.5%), particularly with regard to ceftriaxone. The percentage of errors was 11.9% for indication, 84.9% for dosing, 3.1% for duration, and 0% for route of administration.

Conclusions

A high percentage of patients who attended the emergency department for suspected cervicitis or urethritis received an inappropriate empirical antibiotic regimen. The main reason was undertreatment due to underdosing.

Patterns of within-host spread of Chlamydia trachomatis between vagina, endocervix and rectum revealed by comparative genomic analysis

Chlamydia trachomatis , a gram-negative obligate intracellular bacterium, commonly causes sexually transmitted infections (STIs). Little is known about C. trachomatis transmission within the host, which is important for understanding disease epidemiology and progression. We used RNA-bait enrichment and whole-genome sequencing to compare rectal, vaginal and endocervical samples collected at the same time from 26 study participants who attended Fijian Ministry of Health and Medical Services clinics and tested positive for C. trachomatis at each anatomic site. The 78 C. trachomatis genomes from participants were from two major clades of the C. trachomatis phylogeny (the "prevalent urogenital and anorecta"l clade and "non-prevalent urogenital and anorectal" clade). For 21 participants, genome sequences were almost identical in each anatomic site. For the other five participants, two distinct C. trachomatis strains were present in different sites; in two cases, the vaginal sample was a mixture of strains. The absence of large numbers of fixed SNPs between C. trachomatis strains within many of the participants could indicate recent acquisition of infection prior to the clinic visit without sufficient time to accumulate significant variation in the different body sites. This model suggests that many C. trachomatis infections may be resolved relatively quickly in the Fijian population, possibly reflecting common prescription or over-the-counter antibiotics usage.

Importance

Chlamydia trachomatis is a bacterial pathogen that causes millions of sexually transmitted infections (STIs) annually across the globe. Because C. trachomatis lives inside human cells, it has historically been hard to study. We know little about how the bacterium spreads between body sites. Here, samples from 26 study participants who had simultaneous infections in their vagina, rectum and endocervix were genetically analyzed using an improved method to extract C. trachomatis DNA directly from clinical samples for genome sequencing. By analyzing patterns of mutations in the genomes, we found that 21 participants shared very similar C. trachomatis strains in all three anatomic sites, suggesting recent infection and spread. For five participants two C. trachomatis strains were evident, indicating multiple infections. This study is significant in that improved enrichment methods for genome sequencing provides robust data to genetically trace patterns of C. trachomatis infection and transmission within an individual for epidemiologic and pathogenesis interrogations.

Prospective screening for sexually transmitted infections among US service members with Chlamydia trachomatis or Neisseria gonorrhoeae infection

BACKGROUND

Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) are the most common bacterial causes of sexually transmitted infection (STI) in the United States (US). The purpose of this study was to determine the frequency of reinfection during a six-month study period and to evaluate the retesting interval for those infected with CT or NG.

METHODS

We conducted a prospective, six-month follow-up study among US military personnel with new onset, laboratory-confirmed CT or NG, recruited from an STI clinic at a large military base from January 2018 to January 2020. Each participant was randomly assigned to one of four groups, which differed only by the timing of the first study-associated follow-up visit after CT or NG diagnosis.

RESULTS

Of the 347 initially recruited into the study, 267 participants completed a follow-up visit prior to their scheduled, final visit 6 months after initial infection. The median age at enrollment was 22 years and 41.0% were female. There were 32 (12.0%) reinfections (30 CT and 2 NG) after treatment of an index diagnosis of CT or NG within the six-month study period. Six of the CT reinfections were only detected at the final visit. A review of medical records revealed additional CT and NG reinfections. The probability of detecting a reinfection did not vary significantly by timing of follow-up.

CONCLUSIONS

The likelihood of detecting CT or NG reinfection did not differ according to time of follow up visit among study participants, thus supporting CDC guidance to retest three months post treatment. Efforts should continue to focus on STI prevention and risk reduction.

Therapeutic Options for Chlamydia trachomatis Infection: Present and Future

Sexually transmitted infections (STIs), such as Chlamydia trachomatis (Ct) infection, have serious consequences for sexual and reproductive health worldwide. Ct is one of the most common sexually transmitted bacterial infections in the world, with approximately 129 million new cases per year. C. trachomatis is an obligate intracellular Gram-negative bacterium. The infection is usually asymptomatic, notwithstanding, it could also be associated with severe sequels and complications, such as chronic pain, infertility, and gynecologic cancers, and thus there is an urgent need to adequately treat these cases in a timely manner. Consequently, beyond its individual effects, the infection also impacts the economy of the countries where it is prevalent, generating a need to consider the hypothesis of implementing Chlamydia Screening Programs, a decision that, although it is expensive to execute, is a necessary investment that unequivocally will bring financial and social long-term advantages worldwide. To detect Ct infection, there are different methodologies available. Nucleic acid amplification tests, with their high sensitivity and specificity, are currently the first-line tests for the detection of Ct. When replaced by other detection methods, there are more false negative tests, leading to underreported cases and a subsequent underestimation of Ct infection's prevalence. Ct treatment is based on antibiotic prescription, which is highly associated with drug resistance. Therefore, currently, there have been efforts in line with the development of alternative strategies to effectively treat this infection, using a drug repurposing method, as well as a natural treatment approach. In addition, researchers have also made some progress in the Ct vaccine development over the years, despite the fact that it also necessitates more studies in order to finally establish a vaccination plan. In this review, we have focused on the therapeutic options for treating Ct infection, expert recommendations, and major difficulties, while also exploring the possible avenues through which to face this issue, with novel approaches beyond those proposed by the guidelines of Health Organizations.

Chlamydia Trachomatis/Neisseria Gonorrhea Retesting Among Adolescents and Young Adults in a Primary Care Network

PURPOSE

Chlamydia trachomatis/Neisseria gonorrhea (CT/NG) retesting three months after diagnosis is a guideline-recommended strategy to detect re-infections. Adolescents and young adults are priority populations in the U.S. Sexually Transmitted Infections National Strategic Plan, but there is a lack of research examining CT/NG retesting among these populations. This study describes retesting following CT/NG diagnosis among adolescent and young adult patients at Title X and non-Title X clinics and measures the association of patient-level factors with CT/NG retesting.

METHODS

We evaluated electronic medical records from 2014 to 2020 from an academic urban-suburban primary care network. The primary outcome was retesting, defined as a diagnostic test for CT or NG ordered 8-16 weeks after index diagnosis. Mixed effects logistic regression modeling stratified by Title X funding was conducted to evaluate the association of patient-level factors with CT/NT retesting.

RESULTS

Overall, 23.5% (n = 731) of patients were retested within 8-16 weeks following index CT/NG diagnosis. A significantly greater proportion of Title X patients were retested compared to non-Title X patients. Males were significantly less likely to be retested compared to females, and the proportion of patients retested decreased significantly over the study period.

DISCUSSION

Guideline-recommended retesting following CT/NG diagnosis was low in this young primary care cohort, especially among male and non-Title X clinic patients. Decreases in CT/NG retesting over the study period may be contributing to worsening of the STI epidemic. Our results provide insights into CT/NG retesting that can inform efforts to end the STI epidemic.

Sexually transmitted pathogens causing urethritis: A mini-review and proposal of a clinically based diagnostic and therapeutic algorithm

The purpose of this mini-review was to provide the latest information and concepts on diagnosis and treatment of the most common sexually transmitted pathogens causing urethritis. The incidence of several sexually transmitted infections that cause urethritis is increasing, and this genitourinary syndrome is among the most common reason young men see clinical care. The authors performed a literature search including the currently valid guidelines, and an overview of the most relevant pathogens is given. Moreover, the authors developed a clinically applicable diagnostic and therapeutic algorithm, because early diagnosis and correct treatment can sometimes prevent infected individuals from significant morbidity. Future research will focus on new methods to combat pathogens that cause urethritis, including vaccination.

Clinical and epidemiological characteristics of Chlamydia trachomatis infection among sexually transmitted infection clinics patients

BACKGROUND

Chlamydia trachomatis (CT) infections are a public health problem because of its high incidence and consequences on reproductive health. Our aim is to describe the socio-demographic, behavioral and clinical characteristics of patients with CT infection in order to adapt preventive interventions for the highest risk groups.

METHODS

Prospective case series of all patients diagnosed with CT between September 2016 and January 2019 in the reference STI clinics of Osakidetza (Basque Health Service) in Bizkaia (Spain).

RESULTS

847 patients (88.2%) agreed to participate: 41% women, 33.8% heterosexual men and 25% men who has sex with men (MSM); 33% were immigrants and 26% were under the age of 25 (33% of the women). Only 20% systematically used condoms. 36% had previously had STI and 28% had simultaneously another STI. 55% of the infections were asymptomatic (70% among women). In MSM, the rectum was affected in 69.5% of cases, the urethra in 31.4%, and the pharynx in 14.5%. The cervix was affected in 86.5% of the women, the rectum in 17.6%, and the pharynx in 13.8%. A contact study was only carried out in 58% of cases. The reinfection rate at 4 weeks was 17% among those with criteria to perform a test of cure.

CONCLUSION

Our results justify implement opportunistic screening in women under the age of 25 and young immigrants of both sexes, by taking genital and extragenital samples, as well as developing appropriate guidelines for the notification and follow-up of contacts.

Doxycycline versus azithromycin for the treatment of anorectal Chlamydia trachomatis infection in women concurrent with vaginal infection (CHLAZIDOXY study): a multicentre, open-label, randomised, controlled, superiority trial

BACKGROUND

Anorectal infections with Chlamydia trachomatis are commonly found in women. Although the efficacy of doxycycline and azithromycin is comparable in the treatment of urogenital infection, their efficacies toward anorectal infection remain unclear. We therefore aimed to compare a single dose of azithromycin with a 7-day course of doxycycline for the treatment of anorectal C trachomatis infection in women with concurrent vaginal infection.

METHODS

We did a multicentre, open-label, randomised, controlled, superiority trial involving four sexually transmitted infection screening centres and three pregnancy termination centres in France. We included sexually active adult women (≥18 years) with a positive C trachomatis vaginal swab who agreed to provide self-collected anorectal swabs for C trachomatis detection. Participants were randomly assigned (1:1), using block sizes of six and eight and stratification by each investigating centre, to orally receive either azithromycin (a single 1-g dose, with or without food) or doxycycline (100 mg in the morning and evening at mealtimes for 7 days [ie, 100 mg of doxycycline twice per day for 7 days]). All laboratory staff who did the bacteriological analyses, but not the participants and the investigators, were masked to the treatment groups. The primary outcome was the microbiological anorectal cure rate defined as a C trachomatis-negative nucleic acid amplification test (NAAT) result in anorectal specimens 6 weeks after treatment initiation among women who had a baseline C trachomatis-positive anorectal NAAT result. The primary analysis was done in the modified intention-to-treat population, with multiple imputation, which included all women who underwent randomisation and had a C trachomatis-positive vaginal and anorectal NAAT result at baseline. Adverse events were reported in all women who underwent randomisation. This study is registered with ClinicalTrials.gov, number NCT03532464.

FINDINGS

Between Oct 19, 2018, and April 17, 2020, we randomly assigned a total of 460 participants to either the doxycycline group (n=230) or the azithromycin group (n=230). Four (1%) of 460 participants were excluded because they refused to take doxycycline or were found to be ineligible after randomisation. Among the 456 participants, 357 (78%) had a concurrent C trachomatis-positive anorectal NAAT result at baseline; 184 (52%) of 357 were in the doxycycline group and 173 (48%) were in the azithromycin group (ie, the modified intention-to-treat population). Microbiological anorectal cure occurred in 147 (94%) of 156 participants in the doxycycline group (28 missing values) versus 120 (85%) of 142 in the azithromycin group (31 missing values; adjusted odds ratio with imputation of missing values 0·43 [95% CI 0·21-0·91]; p=0·0274). Reported adverse events possibly related to treatment were notified in 53 (12%) of 456 women: 24 (11%) of 228 in the doxycycline group and 29 (13%) of 228 in the azithromycin group. Gastrointestinal disorders were the most frequently occurring, in 43 (9%) of 456 women: 17 (8%) of 228 in the doxycycline group and 26 (11%) of 228 in the azithromycin group.

INTERPRETATION

The microbiological anorectal cure rate was significantly lower among women who received a single dose of azithromycin than among those who received a 1-week course of doxycycline. This finding suggests that doxycycline should be the first-line therapy for C trachomatis infection in women.

FUNDING

French Ministry of Health.

TRANSLATION

For the French translation of the abstract see Supplementary Materials section.

Better In Vitro Tools for Exploring Chlamydia trachomatis Pathogenesis

Currently, Chlamydia trachomatis still possesses a significant impact on public health, with more than 130 million new cases each year, alongside a high prevalence of asymptomatic infections (approximately 80% in women and 50% in men). C. trachomatis infection involves a wide range of different cell types, from cervical epithelial cells, testicular Sertoli cells to Synovial cells, leading to a broad spectrum of pathologies of varying severity both in women and in men. Several two-dimensional in vitro cellular models have been employed for investigating C. trachomatis host–cell interaction, although they present several limitations, such as the inability to mimic the complex and dynamically changing structure of in vivo human host-tissues. Here, we present a brief overview of the most cutting-edge three-dimensional cell-culture models that mimic the pathophysiology of in vivo human tissues and organs for better translating experimental findings into a clinical setting. Future perspectives in the field of C. trachomatis research are also provided.

Tetracyclines-An Important Therapeutic Tool for Dermatologists

Tetracyclines are a group of antibiotics whose first representative was discovered over 70 years ago. Since then, they have been of great interest in dermatology. In addition to their antibacterial activity, they are able to inhibit metalloproteinases and exhibit anti-inflammatory, anti-apoptotic and antioxidant effects. The side effects have been thoroughly studied over the years, the most characteristic and important ones in daily dermatological practice being: phototoxicity, hyperpigmentation, onycholysis, photoonycholysis, induced lupus erythematosus, and idiopathic intracranial hypertension. In this article, we summarize the use of tetracyclines in infectious diseases and inflammatory dermatoses, and further discuss the instances where the efficacy and safety of tetracyclines have been highlighted over the past few years.

Prevalence of Chlamydia trachomatis in the general population in Germany – a triangulation of data from two population-based health surveys and a laboratory sentinel system

Background

Chlamydia trachomatis (chlamydia) is a common, frequently asymptomatic, sexually transmitted infection. It can result in severe sequelae, such as ectopic pregnancy and infertility. In Germany, chlamydia is not notifiable. An opportunistic screening program for women < 25 years was introduced in 2008. The aim of this research was to triangulate different data sources to describe the epidemiological situation of chlamydia in Germany and to investigate whether the current target group of the chlamydia screening program aligns with these findings.

Methods

Urine specimens from participants from population-based health examination surveys of children (2014–17) and adults (2008–11) were tested for chlamydia, using nucleic acid amplification testing. These data were used to generate weighted chlamydia prevalence estimates by age group and sex. Data from a nationwide chlamydia laboratory sentinel system (2014–16) were used to calculate the positive proportion among individuals tested for chlamydia by age, sex and test reason.

Results

Using data from the population-based surveys, we found a chlamydia prevalence estimate of 2.8% (95% confidence interval (CI) 1.0–7.5%) among all 15- to 17-year-old girls and of 9.6% (95% CI 0.0–23) among those reporting to be sexually active. In adult women, we found the highest prevalence among 18- to 24-year-olds (all: 2.3%; 95% CI 1.0–5.3%; sexually active: 3.1%; 95% CI 1.3–7.0%). In adult men, we found the highest prevalence among 25- to 29-year-olds (all: 3.5%; 95% CI 1.6–7.7%; sexually active: 3.3%; 95% CI 1.3–7.8%). Data from the chlamydia laboratory sentinel showed the highest positive proportion among those opportunistically screened in 19-year-old women (6.1%; 95%- CI 5.9–6.4%), among those screened due to pregnancy in 15-year-old girls (10%; 95% CI 8.5–12%), and among those tested due to symptoms or a positive partner in 19-year-old women (10%; 95% CI 9.8–11%) and 19-year-old men (24%; 95% CI 22–26%).

Conclusions

Chlamydia seems to mainly affect adolescents and young adults in Germany, with similar overall prevalence in men and women, but with slightly different age distributions. Women at highest risk of chlamydia are covered by the current screening program but given the on-going discussions in high-income countries on cost-effectiveness and benefit-to-harm ratio of these programs, the program-aim needs reconsideration.

Sexual transmission of infections across Europe: appraising the present, scoping the future

Objectives: Our journal partnered with the Europe section of the International Union against STI (IUSTI) at a workshop held at the 18th European AIDS Conference in London on 30 October 2021. The workshop reviewed epidemiological trends and discussed STI care provision within HIV services across Europe. Methods and Results: We started by highlighting trends in bacterial STIs reported to the European Centre for Disease Prevention and Control from countries in the European Union/European Economic Area. This showed that notifications of bacterial STIs reached an all-time high in 2019, but are expected to be impacted by the COVID-19 pandemic in 2020-2021. We then reviewed the evolving relationship between STIs and HIV and pointed out how antiretroviral treatment and pre-exposure prophylaxis remain highly effective against HIV transmission despite the rising incidence of STIs. Within emerging concepts in STIs, we appraised the benefits and risks of asymptomatic screening for chlamydia, and also considered the potential perils of routinely testing for agents that lack a defined role in disease. Finally, we discussed standards of STI care for people living with HIV, informed by a brief survey of IUSTI Europe country representatives and members of the Euroguidelines in Central and Eastern Europe network. Conclusions: The survey indicated substantial variability and identified key improvement targets: fighting barriers to effective service provision and access, increasing diagnostic capability and taking leadership in driving up the quality of care. We must not forget the STI-related needs of the many people who will be living with HIV for decades into the future.

Direct assessment of possible mutations in the 23S rRNA gene encoding macrolide resistance in Chlamydia trachomatis

Reports of potential treatment failure have raised particular concerns regarding the efficacy of the single dose azithromycin regimen in the treatment of urogenital and anorectal Chlamydia trachomatis (CT) infections. Several factors have been suggested, including heterotypic resistance. Antimicrobial susceptibility testing in CT requires cell culture with serial dilutions of antibiotics, which is laborious and for which there is no standardized testing methodology. One method to partly overcome these difficulties would be to use a genotypic resistance assay, however most current available assays do still require prior CT culture. In order to facilitate the assessment of genotypic resistance directly from clinical samples, without the need for prior culture, the aim of this study was to develop a CT specific PCR assay for the assessment of resistance associated mutations (RAMs) in the 23S rRNA gene, and to evaluate a sample of clinical cases in which CT PCR’s remained positive during follow-up despite azithromycin treatment. Neither the in silico analysis nor the analytical specificity testing demonstrated clinically relevant cross-reactivity with other bacterial species. These results in conjunction with the analytical sensitivity demonstrating consistent CT 23S rRNA gene detection in the range of 10e3 IFU/mL, exemplify the assay’s apt performance. Although no known macrolide RAMs were detected in the clinical cases, the described assay allows future culture independent macrolide RAM surveillance in CT, and increases accessibility for other laboratories to engage in screening.

Evaluation of a Multiplex Real-Time PCR Assay for Detecting Chlamydia trachomatis in Vaginal Samples

Chlamydia trachomatis is an important cause of sexually transmitted infections (STI) in Western countries. It is often asymptomatic, and thus, left untreated, and can have severe negative consequences, such as tubal infertility or adverse pregnancy outcomes. Other sexually transmitted microorganisms, such as Neisseria gonorrhoeae and Trichomonas vaginalis, as well as normal residents of the vaginal flora, such as genital mycoplasmas, also negatively impact human sexual and reproductive health. We evaluated the reliability of the Seegene Allplex STI Essential Assay for C. trachomatis detection using the real-time qPCR routinely used in our diagnostic laboratories as the gold standard. The Seegene assay displayed a sensitivity of 97.8% and a specificity of 98.9%. As this assay can also detect six other urogenital pathogens, we applied it to 404 samples from women who attended Lausanne University Maternity Hospital and obtained the following prevalence rates: 2.5% for C. trachomatis, 3.5% for Mycoplasma hominis, 6.3% for Ureaplasma urealyticum, and 27.7% for Ureaplasma parvum. Two samples were positive for Trichomonas vaginalis, and one sample was positive for Mycoplasma genitalium. Bacterial vaginosis was present in 4.5% of the cases and was strongly associated with M. hominis. Finally, we confirmed the association between C. trachomatis infection and pre-term birth (p = 0.03) but could not detect any association of this condition with other urogenital pathogens (Mycoplasma/Ureaplasma). In conclusion, given its high sensitivity and specificity for C. trachomatis DNA detection as well as its multiplex format, which simultaneously provides results for six other urogenital pathogens, the Seegene Allplex™ STI Essential Assay represents an appealing diagnostic tool in modern microbiology laboratories.