Globally, Sexually Transmitted Infections (STIs) are a serious public health concern. The most common bacterial STI pathogen is Chlamydia trachomatis (C. trachomatis). Over 80% of individuals with this infection remain asymptomatic, which may lead to undiagnosed cases. A persistent infection with C. trachomatis can spread to the upper genital tract, resulting in Pelvic Inflammatory Disease (PID). If left untreated, this may lead to long-term sequelae, such as infertility. Early diagnosis and treatment of infected individuals are required to prevent the spread of the disease and its severe consequences. Tissue culture was once thought to be the most reliable method of diagnosis. However, diagnosis has become quick and simple with the development of improved diagnostic tools, especially molecular techniques, which are not only very sensitive and specific but also cost-effective. This review elucidates the effects of genital infections caused by Chlamydia on human health and recommends further research on the frequency, prevalence, and pathogenic mechanisms of C. trachomatis Infection (CTI) to gain a better understanding of the long-term consequences caused by this illness. Lastly present review confirms that the evidence presented can encourage changes in the country’s healthcare system in the future. For instance, future infection control measures could be planned, prevention campaigns could be created to increase public awareness of the risk factors for this infection, and screening techniques for Chlamydia could be updated.

Sexually transmitted infections (STIs) caused by Chlamydia trachomatis (CT), Mycoplasma genitalium (MG), and Neisseria gonorrhoeae (NG) are major public health concerns. While nucleic acid amplification tests (NAATs) are the primary diagnostic tool for these pathogens, research on pathogen-specific characteristics and risk factors for NAAT clearance failure remain limited in Korea. This study analyzed clinical features of STIs and post-treatment NAAT changes. This retrospective cohort study included adult, non-pregnant patients diagnosed with CT, MG, or NG via NAAT at a secondary care hospital between 2012 and 2024. Clinical characteristics were compared using the Kruskal-Wallis test, and multivariate logistic regression identified risk factors for NAAT clearance failure in patients with follow-up NAAT within three months. Among 500 STI cases, 80.8% were female, with a median age of 27.0 years. CT was the most common pathogen (53.8%), followed by MG (37.2%) and NG (9.0%). CT infections had the highest complication rate (28.6%), while NG infections were more frequently symptomatic (77.8%) and associated with pyuria (46.4%). Of 221 patients with follow-up NAAT, 14.9% failed clearance. MG infection (adjusted odds ratio [aOR], 6.100; 95% confidence interval [CI], 2.711-13.725; P < 0.001) and symptomatic presentation (aOR, 2.542; 95% CI, 1.103-5.861; P = 0.029) were independent risk factors for clearance failure. CT showed the highest complication rate and NG was the most symptomatic. MG was a key predictor of NAAT clearance failure, underscoring the need for antimicrobial resistance monitoring and optimized retreatment strategies.

Introduction. Cervical squamous intraepithelial lesions associated with high-risk human papillomavirus represent a significant concern in gynecological practice. Investigating the risk factors for this pathology is essential for improving methods of prevention and early diagnosis. Objective: to assess the clinical and anamnestic characteristics of patients with cervical squamous intraepithelial lesions and to identify the risk factors for this pathology in women of early reproductive age. Materials and Methods. A prospective cohort study was conducted from 2020 to 2025 at the clinical base of the Department of Obstetrics and Gynecology with Advanced Training and Retraining at the Belarusian State Medical University, in cooperation with the 1st City Clinical Hospital in Minsk. The study included 186 women aged 18–35 years with histologically confirmed cervical intraepithelial lesions. The participants were divided into two groups: group 1 – 102 women with low-grade squamous intraepithelial lesions (LSIL), group 2 – 84 women with high-grade squamous intraepithelial lesions (HSIL). A comprehensive analysis of anamnestic, clinical, and laboratory data was carried out. Results. It was established that early onset of sexual activity, smoking, frequent change of sexual partners, a history of induced abortions, and the use of coitus interruptus as a contraceptive method are significant risk factors (p &lt; 0,001) for the development of highgrade cervical intraepithelial lesions. Statistically significant associations were also found with a family history of cervical cancer (p = 0,015), as well as comorbidities of the digestive and respiratory systems (p &lt; 0,001). Particular attention is warranted by the identified association of HSIL with HPV type 16 (p &lt; 0,001), chlamydial infection (p = 0,042), and recurrent vaginitis (p &lt; 0,001).

Purpose: To emphasize the diagnostic role of magnetic resonance imaging (MRI) in identifying Fitz-Hugh–Curtis syndrome (FHCS) in an adolescent patient with a subtleclinical presentation. Methods: A 17-year-old female presented with acute onset right upper quadrant and right shoulder pain. The initial diagnostic workup, including ultrasound (US), computedtomography (CT), and laboratory testing was inconclusive. Due to persistent symptoms and elevated inflammatory markers, MRI of the abdomen and pelvis was subsequentlyperformed. Results: MRI demonstrated a bilateral pyosalpinx with restricted diffusion, free fluid in the pelvis and subhepatic region, and linear adhesions between the hepatic capsule and peritoneum, which was consistentwith pelvic inflammatory disease (PID) complicated by FHCS. Microbiologic analysis confirmed a Chlamydia trachomatis infection. The patient received targeted antibiotic therapy with clinical improvement. Conclusion: FHCS represents a rare but importantcomplication of PID that may present with non-specificor extra-pelvic symptoms. MRI is the modality of choicefor confirming PID-related complications and perihepatic inflammation, offering high sensitivity and the advantage of radiation-free imaging, which is especially relevant in the adolescent population.

Background: Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) accounts for 25% urology clinic visits. Due to significant overlap with other conditions, CP/CPPS is frequently misdiagnosed and inadequately managed. Therefore, we provided a simplified diagnostic and treatment approach to CP/CPPS by subdividing it into distinct subcategories. Materials and methods: We systematically reviewed the published literature about CP/CPPS and its “associated entities”, including interstitial cystitis/bladder pain syndrome, chronic bacterial vesiculitis, symptomatic prostate calcification, pudendal neuropathy, male accessory gland Inflammation, and Chlamydia trachomatis infection. We applied the UPOINTS system to differentiate CP/CPPS phenotypes, using male accessory gland inflammation solely to flag potential inflammatory–pelvic pain overlap. Results: The review yielded an evidence base of 140 articles pertaining to CP/CPPS treatment antibiotics, α-blockers, anti-inflammatory drugs, phytotherapeutics, neuromodulators, physical therapy, local blocks, injections, and minimal invasive treatments. CP/CPPS, interstitial cystitis/bladder pain syndrome, chronic bacterial vesiculitis, symptomatic prostate calcification, pudendal neuropathy, and C trachomatis infection, and developed type-specific, step-by-step diagnostic and therapeutic algorithms. The proposed treatment model includes physiotherapy, minimally invasive options, and innovative interventions. Conclusions: Dividing CP/CPPS into 6 distinct subtypes offers clinicians more targeted guidance when selecting appropriate diagnostic tools and therapeutic interventions. Sperm analysis is recommended for patients with a history of infertility, painful ejaculation, or hematospermia, whereas pyospermia warrants investigation using semen cultures, polymerase chain reaction testing, and transrectal ultrasound. Ct-infection should be ruled out in young patients with prostatitis-like symptoms, burning micturition, “penile tip irritation,” and a thick urethral discharge. Patients over 50 years of age who have failed conventional therapy may require cystoscopy. Transrectal ultrasound can help rule out clustered prostatic calcifications, especially in older, overweight patients with a persistently elevated International Prostate Symptom Score and an increased white blood cell count in postprostatic massage urine. This approach is recommended for guiding CP/CPPS treatment.

Chlamydia trachomatis, an intracellular pathogen, is recognized as the most common sexually transmitted bacterial infection among women worldwide. Chlamydia infections can lead to undesirable clinical outcomes, including pelvic inflammatory disease and infertility. Recently, the gut has been identified as a niche for Chlamydia colonization in human gut-derived organoids. However, despite the biological impact on the host remaining under investigation, oral inoculation of Chlamydia as a whole-organism vaccine has been reported as a promising strategy for preventing genital Chlamydia infections in mice. Few studies have evaluated the impact of oral Chlamydia vaccination on the gut microbiome and metabolite changes. In this study, we assessed time-series alterations in the gut microbiome and metabolites following oral Chlamydia muridarum inoculation in a mice model, and we analyzed the composition and correlation between serum immune parameters and the sequencing profiles in the host. We identified 129 microbial changes and 186 differentially abundant metabolites in the gut across various vaccination approaches during the 30-day immunization process. Additionally, we discussed the potential influence of live Chlamydia on gut epithelium and the biomarkers of effective immunization based on correlation analysis.IMPORTANCEChlamydia infections primarily lead to morbidity rather than mortality. Consequently, in developing and implementing a Chlamydia vaccine, the utmost priority is evaluation of safety. As a promising yet controversial approach, live oral vaccination for Chlamydia raises concerns regarding its impact on the host's gut environment. Our study not only investigates changes in the gut microbiome and metabolites during vaccination but also identifies changes in gut epithelium during vaccination and potential biomarkers during immunization. These findings are crucial for the development of whole-organism oral Chlamydia vaccines and provide valuable insights into the long-term colonization of Chlamydia in the gut.

Aim: The present study determines the patterns of sexually transmitted infections in Federal Medical Center Asaba in the past five years, with relation to their socio-demographic characteristics. Study Design: A five-year retrospective study. Place and Duration of Study: Federal Medical Centre, Asaba, Delta State, Nigeria between 1st of January 2019 to 31st of December 2023. Methodology: A retrospective study on sexually transmitted infections (syphilis, gonorrhea, and chlamydia) in the hospital, from 2019 – 2023, a review of the medical records from FMC Asaba to collect data on the socio-demographics of patients, prevalence of the infections reported over the past five years. Results: In a comprehensive analysis of 89 subjects, it was found that a substantial majority, specifically 62 individuals (69.7%), were identified as male, while the remaining 27 subjects (30.3%) were female. This demographic distribution indicated a significant male predominance, with a calculated male-to-female ratio of 2.8:1 throughout the examined period. Notably, this ratio was not static; rather, it exhibited fluctuations that varied from year to year, emphasizing the dynamic nature of the population under study. Delving deeper into the patient demographics, the mean age of male patients during the five-year assessment period was recorded at 32.3 years. In contrast, female patients presented with a slightly older average age of 38 years, suggesting potential differences in risk factors and health seeking behaviors between the genders. When examining the types of sexually transmitted infections (STIs) present in this study, Syphilis clearly emerged as the predominant infection, accounting for a striking 71 cases, which constituted 79.8% of the total infections documented, this was followed by Gonorrhea, with a total of 12 cases representing 13.5% of the population. Additionally, there was one case each (1.1%) of genital warts and mixed infections that involved both Syphilis and Chlamydia. Moreover, it is significant to note that four cases (4.5%) were identified as HIV positive individuals who also had concurrent Syphilis infections. Conclusion: The findings of our study indicate a discernible reduction in the number of patients diagnosed with STIs attending the healthcare facility in comparison to trends observed in preceding years. The reasons underlying this decline remain speculative; it may either reflect a genuine decrease in the prevalence of STIs within the community or lack of resources to carry out these tests. Enhanced access to diagnostic laboratories and treatment centers for STIs may have contributed to this observed decrease in patient visits, as individuals may now feel more empowered to seek care in alternative settings.

Antibiotics disrupt mucosal microbial communities, yet the effects on microbiomes infected with Chlamydia trachomatis (Ct) remain poorly understood. Some data exist on vaginal microbiomes, but none exist for the endocervix or rectum that are primary sites of infection. We applied metagenomic shotgun sequencing to vaginal, endocervical and rectal samples collected longitudinally from women who cleared their infection post-treatment (n = 10), had persistent infection (n = 11), or remained uninfected (n = 18) to evaluate azithromycin-induced changes in microbial composition, function, and the resistome over time. Our results show shifts in composition and function post-treatment that support persistent Ct, nonsynonymous Ct L22 amino acid substitutions that may be linked to azithromycin resistance, and significant endocervical increases in azithromycin resistance genes in Lactobacillus iners and Gardnerella vaginalis strains with moderate/high biofilm formation potential. These findings highlight the unintended ecological consequences of azithromycin treatment, including likely resistance gene propagation, emphasizing the need for novel treatment and microbiome-preserving strategies.

Global incidence of chlamydia infection and HIV pre-exposure prophylaxis.

Asymptomatic transmission, inequitable access to diagnostics, and rising antimicrobial resistance are major barriers to controlling the bacterial sexually transmitted infections (STIs) gonorrhea, chlamydia, and syphilis. Developing vaccines against these infections has therefore become a key STI research priority, requiring innovative research, expedited clinical development, and increased investment.

Cisgender women are underserved by current HIV prevention efforts, and substantial gender disparities persist in pre-exposure prophylaxis (PrEP) use. Recent diagnoses with a bacterial sexually transmitted infection (STI) are objective, readily available indicators of PrEP-eligibility that could be used to improve PrEP prescribing for cisgender women. To better understand missed opportunities for prescribing, we examined the prevalence and correlates of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) diagnoses among cisgender women seeking care at a New York City obstetrics and gynecology (Ob/Gyn) clinic, along with the number of PrEP prescriptions provided post-STI diagnosis. A cross-sectional, retrospective review of electronic health record data was conducted for all HIV-negative cisgender women tested for CT and/or NG at the clinic between September 1, 2021 and September 19, 2022. Counts and prevalence for CT and NG infection were calculated, and multivariable log-binomial regression was used to examine associated factors. Among 7593 cisgender women receiving CT/NG testing during the study period, 186 had ≥ 1 CT infection (prevalence: 2.45%) and 18 had ≥ 1 NG infection (prevalence: 0.24%). In a multivariable model, CT/NG infection was significantly associated with age, having Spanish as a primary language, and a marital status of divorced, widowed, or separated. No cisgender women who received CT or NG diagnoses were prescribed PrEP during the study period. These findings highlight how opportunities to prescribe PrEP to cisgender women continue to be missed, even with readily available indicators for PrEP eligibility. More effective strategies are needed to promote PrEP prescribing among diverse populations of cisgender women, particularly in Ob/Gyn settings.

Surfactant-enriched liposomes to enhance azithromycin efficacy in Chlamydia trachomatis infections.

Abstract OP 34: Diseases and Interventions 2, B304 (FCSH), September 5, 2025, 10:15 - 11:15 International migrants are often disproportionately affected by HIV and other blood-borne viruses, particularly in high-income countries. However, evidence regarding the prevalence of sexually transmitted infections (STIs) more broadly among migrants is scattered. This study aimed to synthesise the global evidence on the prevalence of STIs among migrants and specific subgroups and summarise the risk of migrants having STIs compared to non-migrants. We conducted a systematic review and meta-analysis of peer-reviewed literature published since 2014. We searched MEDLINE, Embase, and Ovid Global Health without language limitations. The primary outcome was the prevalence of STIs namely chlamydia, gonorrhoea, syphilis, genital warts, genital herpes, trichomoniasis, mpox, lymphogranuloma venereum, chancroid and donovanosis, and associated clinical syndromes. We conducted a narrative synthesis of populations studied, study setting, and barriers and facilitators of migrants’ access to sexual health services; and used meta-analysis to calculate the pooled prevalence by infection and relative risk among migrants compared to non-migrant populations. We identified 2,529 records and included 79 studies from 30 countries covering ten infections/conditions. 74 studies were included in the pooled measures of prevalence and 27 in the pooled risk ratio. Of the 27 studies with a comparison group, two thirds reported a higher prevalence of the studied infection in migrants compared to non-migrants. Compared to non-migrants, migrants were twice as likely to have a current syphilis (4 studies, pooled RR = 2.39, 95% CI = 0.13-4.65) or chlamydia infection (8 studies, pooled RR = 2.02, 95% CI = 1.09-2.96) while the risk for gonorrhoea and HSV-2 was similar between groups. While STI prevalence and relative risk among migrants varies by setting, population, study type and infection, there is a clear need to address migrants’ unmet needs for sexual health information and services. This will not only improve health equity but is crucial to addressing the multiple epidemics of STIs.

Association of chemsex and risk of chlamydia, gonorrhoea, and syphilis infections: a systematic review and meta-analysis.

Analysis of main indicators of dermatovenereology service of the Russian Federation in 2022-2024 is presented in the paper, including the following: the number of specialized medical organizations and departments, provision of the population of the Russian Federation with dermatovenereologists, dermatovenereologic beds, performance bed rates of dermatovenereologic 24-hour and day hospitals. The incidence of sexually transmitted infections in the entire population of the Russian Federation is presented: the incidence of various forms of syphilis, gonococcal infection, trichomoniasis, chlamydial infection, anogenital herpes viral infection and anogenital venereal warts; the contribution of foreign citizens to syphilis incidence is estimated. The prevalence and incidence rates of skin and subcutaneous tissue diseases by class, atopic dermatitis, psoriasis, contact dermatitis, other dermatitis (eczema), localized scleroderma, discoid lupus erythematosus. for the entire population of the Russian Federation are described.

We retrospectively analyzed the epidemiological characteristics, mixed infections, and complications of chlamydial infection in pediatric inpatients based on a national database. The discharge data of pediatric inpatients with chlamydial infection was obtained from the Futang Research Center of Pediatric Development database from January 2016 to December 2022. A total of 10,211 patients with chlamydial infection were obtained, with patients < 1year old predominantly (44.17%, 4510/10211). Bronchopneumonia was the most prevalent (42.67%, 4355/10207) complication, followed by bronchitis (11.11%, 1134/10207) and chlamydial pneumonia (10.15%, 1036/10207). Mixed infections were identified in 60.40% of cases, with Mycoplasma pneumoniae being the predominant co-pathogen (47.69%, 2941/6167). Among viral and bacterial co-infections, respiratory syncytial virus (21.91%, 632/2885) and Streptococcus pneumoniae (26.67%, 268/1005) were most frequently detected, respectively. From 2016 to 2018, the rate of hospitalized patients with chlamydial infection exhibited an almost constant level (16.95%-18.27%), peaked to 21.75% in 2019, then declined to 6.75% in 2022. The epidemics of chlamydial infection were mainly in winter (33.29%), with the highest proportion in January (12.11%, 1237/10211). The highest median hospitalization expense was incurred by patients aged < 1year and co-infected fungi infection. Four patients died, all with respiratory failure, co-infected with multiple pathogenic infections, and other associated complications. Hospitalized pediatric chlamydial infection primarily occurred in patients under four years old. Bronchopneumonia was the most prevalent complications in pediatric chlamydial infection. Over half chlamydial infection cases were identified with mixed infections with Mycoplasma pneumonia predominantly.

The koala (Phascolarctos cinereus) is an endangered species in parts of Australia, in part due to chlamydial infections. Treatment is difficult due to the hepatic metabolism of the koala, and the critical reliance on a gut microbiota for survival. This study aimed to identify new compounds for treatment of Chlamydia infections by screening a drug re-purposing library. Screening was conducted using an in vitro cell culture model prior to in vivo mouse infection model testing of two candidates identified from the in vitro screen. One lead, bisoprolol fumarate, showed an impact on chlamydial infection and burden in vitro and in vivo. Whilst the mechanism of action may not support progressing this lead further, the approach to screening the library and list of candidates may enable identification of other new koala treatments. This study demonstrates the potential to apply drug re-purposing to koala treatment and presents a list of candidates that could be explored further.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-29789-3.

Chlamydia trachomatis (C.t.), the leading bacterial cause of sexually transmitted infections, replicates within a unique intracellular compartment called the inclusion, which is modified by secreted proteins known as inclusion membrane (Inc) proteins. Here, we further characterize CpoS, an Inc protein previously shown to be critical for bacterial replication and inclusion development. We demonstrate that CpoS directly binds multiple coiled-coil region-containing Incs and engages Rab GTPases at a separate site. Notably, CpoS-InaC interactions facilitate the recruitment of select Arf GTPases to the inclusion membrane, while Rab recruitment occurs independently of these interactions. Biochemical and biophysical analyses revealed that Incs self-oligomerize to form higher-ordered structures, with CpoS adopting a tetrameric conformation resembling that of eukaryotic SNARE proteins. We propose that these assemblies serve as scaffolds to orchestrate vesicle docking, tethering, and fusion. Our findings highlight the intricate interplay between bacterial and host factors, revealing how C.t. leverages both Inc-Inc interactions and host protein engagement to manipulate vesicular trafficking and sustain infection.

The primary objective was to measure the impact of passive exposure to an educational video aboutChlamydia trachomatisinfection shown in a gynaecology department waiting room on young women's knowledge on the subject. The secondary objective was to explore the participants' interest in improving their knowledge ofChlamydia trachomatisand their opinions on receiving this information during a consultation in the emergency room. A prospective, interventional, controlled, non-randomised study. Participants were recruited between January and June 2022. 120 women aged 15-35 years were included. The intervention consisted of passive exposure to a 2-minute cartoon presenting basic foundational points ofChlamydia trachomatisdisplayed in the waiting room. The control group was not exposed to the video. After the intervention, an in-person knowledge interview was performed with each participant. The main outcome measures were the knowledge scores obtained in the interviews with the exposed and control groups. Both groups were similar regarding sociodemographic variables. The average knowledge scores from the interview were similar in the two groups. Video exposure was not associated with diminution of lower scores. Participants' baseline knowledge was higher than expected on the basis of a literature review. The passive learning intervention described in this study did not improve the participants' knowledge aboutChlamydia trachomatis. During the one-to-one interview, participants were keen to receive information aboutChlamydia trachomatisbut the quantitative results show that the short video in the waiting room had no impact on their knowledge. Future studies should focus on pre-assessed, randomised, one-to-one or small-group active interventions.

Chlamydia trachomatis infection causes pelvic inflammatory disease and infertility, but how host immune factors control pathogen clearance or pathology is not fully understood. Using a mouse model of genital tract infection with Chlamydia muridarum, we examined the role of CD1d-restricted Natural killer T (NKT) cells. Invariant NKT cell-deficient mice (Jα18−/−) showed prolonged vaginal shedding of infectious elementary bodies (EBs), delayed clearance, and decreased early cytokine production compared to wild-type (WT) controls. Conversely, CD1d−/− mice, which lack both invariant and diverse NKT cells, did not show significant differences in vaginal shedding compared to WT mice. Surprisingly, both NKT-deficient mice (Jα18−/− and CD1d−/−) produced higher levels of inflammatory cytokines in the oviduct at day 35 post-infection (p.i.) and experienced more frequent upper genital tract pathology (hydrosalpinx) at day 80 p.i. However, no infectious EBs were recovered from the oviducts or uterine horns of NKT-deficient mice after day 35 p.i. Cortisone acetate reactivated infectious shedding in chronically infected NKT-deficient mice at day 100 p.i. These findings highlight distinct roles for NKT cell subsets: invariant NKT cells promote early clearance via rapid cytokine production, while the broader NKT population helps limit tissue damage. Targeting NKT pathways could help prevent chronic infection and infertility.