Sexually transmitted infections: challenges ahead

TtrAgo-mediated nucleic acid detection system and portable device for rapid detection of sexually transmitted diseases

The development of rapid and multiplexed point-of-care (POC) diagnostic tools is vital for the prevention and control of sexually transmitted diseases (STIs). Here, we developed a POC-comprehensive Thermococcus thioreducensArgonaute (TtrAgo)-mediated nucleic acid detection system (POC-CANDY) and palm-sized portable detection device "Owl-1" for the simultaneous detection of Ureaplasma urealyticum, Chlamydia trachomatis, Neisseria gonorrhoeae, human papillomavirus types 16/18 and antibiotic resistance molecular markers [tetM, and gyrA mutation (S91F)]. Using recombinase polymerase amplification (RPA), the optimized POC-CANDY could finish the whole detection procedure within 55 min and achieve a limit of detection of 10 copies/μL. When validated by clinical STI samples, POC-CANDY showed 100% consistency with quantitative PCR. Additionally, compared with the PfAgo-based system, POC-CANDY significantly improved the sensitivity of distinguishing single nucleotide variations. The results demonstrated that POC-CANDY can be easily applied locally or on site. This study also promotes the utility of the TtrAgo-mediated technique in clinical diagnosis.

Prevalence, trends, and correlates of HIV, syphilis, and HCV infections among male attendees at STD clinics in Southwest China: a 13-year cross-sectional study (2010-2022)

BACKGROUND

Sexually transmitted infections (STIs) impose a substantial health burden and pose a significant threat to human health. However, data regarding long-term epidemiology patterns of STIs among high-risk groups are scarce. This study aimed to evaluate the prevalence, trends, and correlates of HIV, syphilis, and HCV among male attendees at sexually transmitted disease (STD) clinics in Southwest China.

METHODS

Serial cross-sectional surveys were performed annually among male STD clinic attendees in Southwest China from 2010 to 2022. Blood specimens were collected to test HIV, syphilis, and HCV infections. Mann-Kendall trend test was used to assess the trends of HIV, syphilis, and HCV prevalence. Rare even logistic regression model (relogit) was used to identify correlates of HIV, syphilis, and HCV infections.

RESULTS

This study included a total of 23,964 male attendees at STD clinics. The prevalence of HIV, syphilis, and HCV among participants was 0.98%, 2.16%, and 0.61%, respectively. While the prevalence of syphilis and HCV decreased from 3.64% to 1.81% in 2010 to 1.05% and 0.38% in 2022, the HIV prevalence did not show a downward trend. Relogit analysis revealed that participants with a history of STD had significantly increased risks of HIV (aOR = 1.90, 95%CI: 1.14-3.15) and HCV (aOR = 4.91, 95%CI: 3.22-7.49) infections. Participants who had ever engaged in homosexual behavior had significantly increased risks of HIV (aOR = 14.66, 95%CI: 5.49-39.14) and syphilis (aOR = 3.95, 95%CI:1.41-13.71) infections. Age also played a role, with those aged 50 years and above having a higher likelihood of HIV infection (aOR = 2.55, 95%CI: 1.91-3.39), while those under 50 years were more likely to be infected with HCV (aOR = 1.94, 95%CI: 1.19-3.16). Moreover, individuals of Han ethnicity were more likely to be infected with syphilis (aOR = 2.12, 95%CI: 1.75-2.57) and HCV (aOR = 1.65, 95%CI: 1.16-2.33). Being married or cohabiting increased the likelihood of syphilis infection (aOR = 1.40, 95%CI: 1.09-1.80), and a history of intravenous drug use (IDU) significantly increased the risk of HCV infection (aOR = 10.97, 95%CI: 5.21-23.12).

CONCLUSIONS

This study found a low prevalence of HIV, syphilis, and HCV among male attendees at STD clinics. Despite the declining prevalence of syphilis and HCV, HIV prevalence did not show a downward trend. This underscores the crucial need for continued and targeted prevention efforts, especially promoting STIs testing for men who have sex with men (MSM) and individuals with a history of intravenous drug use (IDU).

Abkallo H, Maina M, Waweru H, Kamita M, Pamme N, Dupaty J, Klapperich CM, Lolabattu SR, Gitaka J. Highly sensitive molecular assay based on Identical Multi-Repeat Sequence (IMRS) algorithm for the detection of Trichomonas vaginalis infection

INTRODUCTION

Annually, approximately 174 million people globally are affected by Trichomonas vaginalis (T. vaginalis) infection. Half of these infections occur in resource-limited regions. Untreated T. vaginalis infections are associated with complications such as pelvic inflammatory disease and adverse pregnancy outcomes mostly seen in women. In resource-limited regions, the World Health Organization (WHO) advocates for syndromic case management. However, this can lead to unnecessary treatment. Accurate diagnosis of T. vaginalis is required for effective and prompt treatment. Molecular tests such as Polymerase Chain Reaction (PCR) have the advantage of having a short turn-around time and allow the use of non-invasive specimens such as urine and vaginal swabs. However, these diagnostic techniques have numerous disadvantages such as high infrastructure costs, false negative and positive results, and interstrain variation among others. This study aimed to evaluate the use of identical multi-repeat sequences (IMRS) as amplification primers for developing ultrasensitive diagnostic for T. vaginalis.

METHODS

We used genome-mining approaches based on identical multi-repeat sequences (IMRS) algorithm to identify sequences distributed on the T. vaginalis genome to design a primer pair that targets a total of 69 repeat sequences. Genomic T. vaginalis DNA was diluted from 5.8×102 to 5.8×10-4 genome copies/μl and used as a template in the IMRS-based amplification assay. For performance comparison, 18S rRNA PCR assay was employed.

RESULTS

The T. vaginalis -IMRS primers offered a higher test sensitivity of 0.03 fg/μL compared to the 18S rRNA PCR (0.714 pg/μL). The limit of detection for the Isothermal assay was 0.58 genome copies/mL. Using real-time PCR, the analytical sensitivity of the T. vaginalis -IMRS primers was <0.01 pg/μL, equivalent to less than one genome copy/μL.

CONCLUSION

De novo genome mining of T. vaginalis IMRS as amplification primers serves as a platform for developing ultrasensitive diagnostics for Trichomoniasis and a wide range of infectious pathogens.

Cost-effectiveness of 4CMenB Vaccination Against Gonorrhea: Importance of Dosing Schedule, Vaccine Sentiment, Targeting Strategy, and Duration of Protection

BACKGROUND

Observational evidence suggests the 4CMenB meningococcal vaccine may partially protect against gonorrhea, with 1 dose being two-thirds as protective as 2 doses. We examined the cost-effectiveness of vaccinating men who have sex with men (MSM) in England, with 1- or 2-dose primary vaccination.

METHODS

Integrated transmission-dynamic health-economic modeling explored the effects of targeting strategy, first- and second-dose uptake levels, and duration of vaccine protection, using observational estimates of vaccine protection.

RESULTS

Vaccination with 1 or 2 primary doses is always cost-saving, irrespective of uptake, although vaccine sentiment is an important determinant of impact and cost-effectiveness. The most impactful and cost-effective targeting is offering "vaccination according to risk" (VaR), to all patients with gonorrhea plus those reporting high numbers of sexual partners. If VaR is not feasible to implement then the more restrictive strategy of "vaccination on diagnosis" (VoD) with gonorrhea is cost-effective, but much less impactful. Under conservative assumptions, VaR (2-dose) saves £7.62M (95% credible interval [CrI], 1.15-17.52) and gains 81.41 (95% CrI, 28.67-164.23) quality-adjusted life-years (QALYs) over 10 years; VoD (2-dose) saves £3.40M (95% CrI, .48-7.71) and gains 41.26 (95% CrI, 17.52-78.25) QALYs versus no vaccination. Optimistic versus pessimistic vaccine-sentiment assumptions increase net benefits by approximately 30% (VoD) or approximately 60% (VaR).

CONCLUSIONS

At UK costs, targeted 4CMenB vaccination of MSM gains QALYs and is cost-saving at any uptake level. Promoting uptake maximizes benefits and is an important role for behavioral science.

Prevalence of Chlamydia trachomatis, Neisseria gonorrhoeae and Mycoplasma genitalium at pharyngeal and anorectal sites in patients presenting to an STI outpatient ward

BACKGROUND

The incidence of sexually transmitted infections (STIs) is unbridled and on the rise. Extragenital STIs (anal and pharyngeal infections) are commonly asymptomatic, resulting in delayed diagnosis and treatment and consequently higher chances of onward transmission.

OBJECTIVE

The aim of this observational single-centre study was to determine the prevalence of STIs at extragenital sites in symptomatic and asymptomatic patients presenting at an STI outpatient clinic.

METHODS

We conducted a retrospective analysis of patients who presented between October 2019 and February 2021 at the STI outpatient clinic of a tertiary centre in Central Europe. Patients were included in the study if they received at least one pharyngeal and/or anorectal swab in addition to a genital swab for multiplex-PCR STI diagnostics. Demographic data, symptoms and serological results were collected and analysed.

RESULTS

Data collected from 440 patients were analysed (mean age: 33.9 years, male: n = 345, 78.4%, female: n = 95, 21.6%). Ninety-seven males reported having sex with men (MSM); 174 patients identified as heterosexual (132 males, 42 females), and 10 females as bisexual. The sexual orientation was not reported in 159 cases. An STI was confirmed in 195 patients (44.3%) and, among those, 109 patients (55.9%) tested positive for an STI at extragenital sites. Seventy-one patients had a pharyngeal STI whereas 61 were infected in the anorectal region. Of those suffering from an extragenital STI, 64.2% (70 out of 109) tested negative for relevant pathogens at genital sites. The most frequently detected extragenital pathogen was Neisseria gonorrhoeae (71.8% of all pharyngeal STIs [51 out of 71], 55.7% of anorectal STIs [34 out of 61]), followed by Chlamydia trachomatis (41.0% of all anal infections [25 out of 61], 5.6% of pharyngeal infections [4 out of 71]). Pharyngeal and anorectal infections were asymptomatic in 88.7% [63 out of 71] and 65.6% [40 out of 61] of the cases, respectively.

CONCLUSIONS

These results underline the need to perform multisite testing, regardless of the presence of symptoms.

Challenges and considerations in liposomal hydrogels for the treatment of infection

INTRODUCTION

Liposomal hydrogels are novel drug delivery systems that comprise preformed liposomes incorporated in hydrogels destined for mostly localized drug therapy, herewith antimicrobial therapy. The formulation benefits from versatility of liposomes as lipid-based nanocarriers that enable delivery of various antimicrobials of different lipophilicities, and secondary vehicle, hydrogel, that assures better retention time of formulation at the infection site. Especially in an era of alarming antimicrobial resistance, efficient localized antimicrobial therapy that avoids systemic exposure of antimicrobial and related side effects is crucial.

AREAS COVERED

We provide an overview of liposomal hydrogels that were developed for superior delivery of antimicrobials at different infections sites, with focus on skin and vaginal infections. The review summarizes the challenges of infection site and most common infection-causing pathogens and offers commentary on most relevant features the formulation needs to optimize to increase the therapy outcome. We discuss the impact of liposomal composition, size, and choice of polymer-forming hydrogel on antimicrobial outcome based on the literature overview and own experience in the field.

EXPERT OPINION

Liposomal hydrogels offer improved therapy outcome in localized antimicrobial therapy. By fine-tuning of liposomal as well as hydrogel properties, formulations with superior performance can be optimized targeting specific infection site.

A new epidemic model of sexually transmittable diseases: a fractional numerical approach

This study aims at investigating the dynamics of sexually transmitted infectious disease (STID), which is serious health concern. In so doing, the integer order STID model is progressed in to the time-delayed non-integer order STID model by introducing the Caputo fractional derivatives in place of integer order derivatives and including the delay factors in the susceptible and infectious compartments. Moreover, unique existence of the solution for the underlying model is ensured by establishing some benchmark results. Likewise, the positivity and boundedness of the solutions for the projected model is explored. The basic reproduction number is [Formula: see text] is found out for the model. The time-delayed non-integer order STID model holds two steady states, namely, the STID free and endemic steady state. The model stability is carried out at the steady states. The non-standard finite difference (NSFD) technique is hybridized with the Grunwald Letnikov (GL) approximation for finding the numerical solutions of the time-delayed non-integer order STID model. The boundedness and non-negativity of the numerical scheme is confirmed. The simulated graphs are presented with the help of an appropriate test example. These graphs show that the proposed numerical algorithm provides the positive bounded solutions. The article is ended with productive outcomes of the study.

Self-reported sexually transmitted infections and associated factors among sexually active men in East Africa: a multilevel analysis of recent demographic and health surveys

BACKGROUND

Sexually transmitted infections (STIs) are a significant global health challenge, demanding attention and intervention. Despite many STIs being manageable, their asymptomatic nature poses a formidable threat to both mental and physical well-being. This silent impact can lead to substantial morbidity and mortality, which is particularly pronounced in East Africa.

OBJECTIVE

To investigate the prevalence and factors associated with self-reported STIs among sexually active men in East Africa.

DESIGN

Cross-sectional study design.

SETTING

10 East African countries.

PARTICIPANTS

66 833 sexually active men.

PRIMARY OUTCOME MEASURE

Self-reported STI in the 12 months preceding the survey. A multilevel mixed-effects logistic regression model was fitted to identify factors associated with self-reported STIs. An adjusted OR with the corresponding 95% CI was used to estimate the strength of the association, and statistical significance was set at a p value <0.05.

RESULTS

The pooled prevalence of self-reported STIs among sexually active men in East Africa was 5.22% (95% CI: 5.34, 5.69). Being married, having multiple sexual partners excluding a spouse and being informed about STIs were significantly associated with higher odds of self-reported STIs. However, being aged 44 years and above, having a higher education level, starting sex after the age of 20, being circumcised and being a rural resident were associated with lower odds of self-reported STIs.

CONCLUSION

The prevalence of self-reported STIs was higher than the findings from most previous studies. It is essential to educate men about STIs and increase awareness of the risks associated with having multiple sexual partners. Implementing targeted public health initiatives for men with lower education levels, as well as devising strategies to address factors that elevate the risk of STI contraction, is also crucial.

Phase Transition of Wax Enabling CRISPR Diagnostics for Automatic At-Home Testing of Multiple Sexually Transmitted Infection Pathogens

Sexually transmitted infections (STIs) significantly impact women's reproductive health. Rapid, sensitive, and affordable detection of these pathogens is essential, especially for home-based self-testing, which is crucial for individuals who prioritize privacy or live in areas with limited access to healthcare services. Herein, an automated diagnostic system called Wax-CRISPR has been designed specifically for at-home testing of multiple STIs. This system employs a unique strategy by using the solid-to-liquid phase transition of wax to sequentially isolate and mix recombinase polymerase amplification (RPA) and CRISPR assays in a microfluidic chip. By incorporating a home-built controlling system, Wax-CRISPR achieves true one-pot multiplexed detection. The system can simultaneously detect six common critical gynecological pathogens (CT, MG, UU, NG, HPV 16, and HPV 18) within 30 min, with a detection limit reaching 10-18 M. Clinical evaluation demonstrates that the system achieves a sensitivity of 96.8% and a specificity of 97.3% across 100 clinical samples. Importantly, eight randomly recruited untrained operators performe a double-blinded test and successfully identified the STI targets in 33 clinical samples. This wax-transition-based one-pot CRISPR assay offers advantages such as low-cost, high-stability, and user-friendliness, making it a useful platform for at-home or field-based testing of multiple pathogen infections.

Identifying High-Risk Populations for Sexually Transmitted Infections in Chinese Men Who Have Sex With Men: A Cluster Analysis

Background

This study aimed to identify subpopulations of Chinese men who have sex with men (MSM) with distinct sexual behavioral patterns and explore their correlations with sexually transmitted infections (STIs).

Methods

We recruited 892 eligible MSM in Xi'an, China, collecting sociodemographic, sexual behavior, and STI data. Cluster analysis identified distinct sexual behavioral patterns, allowing us to examine STI differences across clusters.

Results

Among the 892 MSM analyzed, 3 clusters were identified. Cluster 1 (n = 157) exhibited high-risk sexual behavioral patterns, including the highest median number of sexual partners (5 vs 1 in cluster 2 vs 3 in cluster 3, P < .001), lowest consistent condom use for insertive anal sex (0% vs 64.12% vs 99.76%, P = .004) and receptive anal sex (9.22% vs 67.71% vs 98.91%, P = .006), highest uncertainty of partners' STIs (77.07% vs 57.89% vs 64.5%, P < .001), all recent partners being casual, longest length of sequential sexual acts (6 vs 5 vs 5, P = .045), and highest rates of gonorrhea (20.38% vs 10.09% vs 14.99%, P = .019) and chlamydia (16.56% vs 8.33% vs 13.21%, P = .045). Cluster 2 (n = 228) showed the lowest engagement in high-risk behaviors and STIs, characterized by the fewest sexual partners, highest certainty of partner's STIs, and all recent partners being regular. Cluster 3 (n = 507) showed moderate levels of high-risk behaviors and STIs, with the highest consistent condom use during anal sex.

Conclusions

This study identified 3 subpopulations of Chinese MSM with distinct sexual behavioral patterns. Targeted public health interventions to the most at-risk subpopulations of MSM are essential for STI prevention.

Cannabinoids as cytotoxic agents and potential modulators of the human parasite Trichomonas vaginalis

Trichomoniasis, a globally prevalent sexually transmitted infection caused by Trichomonas vaginalis, affects approximately 278 million people each year. It presents a challenge due to resistance to the current treatment, Metronidazole (MTZ), which is also associated with side effects. Cannabis sativa, with more than 100 phytocannabinoids and numerous studies for therapeutic applications, including parasitic infections, has undergone a significant shift in acceptance worldwide, highlighted by legalizations and substantial revenue projections. In this context, the present study delves into the effects of cannabinoids, specifically WIN 55,212-2 (WIN), Cannabivarin (CBV) showcasing their anti-parasitic actions that influence the growth and morphology of T. vaginalis. The analysis extends to encompass the pharmacokinetic properties of these cannabinoids. Among the analyzed cannabinoids, CBV stands out for adhering to Lipinski's rules, indicating its potential suitability for oral drug delivery. They also demonstrated inhibitory effects on the growth of T. vaginalis trophozoites and a reduction in the parasite's adhesion to host cells. Several morphological alterations were observed, such as membrane projections, blebbing, autophagosomes and damaged hydrogenosomes. These results highlight the need for further research to explore the therapeutic potential of cannabinoids and understand their mechanisms of action in T. vaginalis.

Chlamydia and gonorrhoea testing and positivity within an urban Aboriginal and Torres Strait Islander Community Controlled Health Service 2016-2021

Background This study describes chlamydia and gonorrhoea testing, positivity, treatment, and retesting among individuals aged ≥15years attending an urban Aboriginal Community Controlled Health Service during the period 2016-2021. Method Utilising routinely collected clinical data from the ATLAS program (a national sentinel surveillance network), a retrospective time series analysis was performed. The study assessed testing rates, positivity, treatment efficacy, retesting and trends over time within an urban Aboriginal Community Controlled Health Service. Results Testing rates for chlamydia and gonorrhoea varied between 10 and 30% over the study period, and were higher among clients aged 15-29years and among females. Positivity rates for both infections varied by age, with clients aged 15-24years having higher positivity than older clients. Gonorrhoea positivity rates decreased after 2016. Treatment and retesting practices also showed sex disparities, with men having a slightly higher treatment rate within 7days, whereas females had significantly higher retesting rates within 2-4months, indicating differences in follow-up care between sexes. Conclusion The study emphasises the need for clinical and public health interventions within urban Aboriginal and Torres Strait Islander populations to further reduce chlamydia and gonorrhoea. Prioritising improved access to testing, timely treatment and consistent retesting can significantly contribute to lowering STI prevalence and enhancing sexual health outcomes in these communities.

Using an extended information-motivation-behavioral skills model to explain HPV vaccination intention among men who have sex with men only and men who have sex with men and women

Men who have sex with men and women (MSMW) have been reported to differ in psychosocial and sexual behavior patterns from men who have sex with men only (MSMO). However, results regarding the differences in HPV vaccination intention/behavior were inconclusive. We compared HPV vaccination intention between MSMO and MSMW and analyzed the differences in potentially associated factors in China. MSM participants were recruited online using a snowball sampling method. Cross-sectional data were collected via a questionnaire based on the extended information-motivation-behavioral skills model. Structural equation modeling was conducted to examine the relationship between the variables, followed by multi-group analysis to test differences between groups. Of 914 MSM, 77.68% were MSMO and 22.32% were MSMW. MSMW had a higher rate of reluctance to vaccinate than MSMO (23.53% vs. 16.20%, p = .016). Differences between the two groups were statistically significant in risky sexual behavior, behavioral skills, and promotional attitude. In both groups, promotional attitude was the most significant predictor of vaccination intention. Vaccination intention was directly influenced by motivation and indirectly by risky sexual behavior in MSMO, but not significantly in MSMW. Additionally, the direct effect of information on behavioral skills in MSMW was significantly greater than that in MSMO, but we did not find any effect of behavioral skills on vaccination intention. MSMW had lower vaccination intention than MSMO. MSMO may be influenced by risky sexual behavior and motivation, positively impacting their vaccination intention, unlike MSMW. Targeted strategies could help promote HPV vaccination, especially in MSMW.

Evaluation of Metronidazole Resistance of Vaginal Swab Isolates from South African Women Treated for Bacterial Vaginosis

Background/Objectives: The high recurrence rate of bacterial vaginosis (BV) after antibiotic treatment is at least partially attributed to resistant bacteria. The CAPRISA 083 (CAP083) study investigated the influence of metronidazole (MTZ) treatment on the vaginal microbiome in 56 South African women diagnosed with BV. To explore the etiology of recurrent BV in this cohort, we retrospectively analyzed vaginal swabs collected in CAP083 before and after MTZ treatment. Methods: We isolated over 1200 bacterial strains, including Gardnerella, Lactobacillus, Prevotella, and Fannyhessa, and determined the minimum inhibitory concentration (MIC) of MTZ and the resistance status according to CLSI and EUCAST guidelines. Results: At baseline, 64% (CLSI) of Gardnerella isolates were resistant to MTZ, rising to 80% after MTZ treatment by the 12-week visit. Lactobacillus species consistently exhibited resistance of 100%, while Fannyhessea vaginae maintained resistance rates of 78-91% across visits. Prevotella strains varied, showing two susceptible isolates at baseline and one resistant isolate at the 6-week visit. Susceptible and resistant Gardnerella isolates were often isolated from the same swab, and 70% (CLSI) of participants had at least one resistant Gardnerella strain already at baseline. Sensitive Gardnerella isolates were not a predictor of an MTZ-mediated reduction in Gardnerella abundance. Conclusions: Our data indicate that the 23% cure rate in CAP083 was associated with a combination of a high share of MTZ-resistant bacteria at baseline, a potentially insufficient MTZ dose regimen, and a constantly high average abundance of Gardnerella. Future research should explore novel therapeutic strategies to enhance treatment efficacy and combat antibiotic resistance.

Young, deprived women are more at risk of testing positive for Chlamydia trachomatis: Results from a cross-sectional multicentre study in French health examination centres

Objectives

Chlamydia Trachomatis (CT) is the most sexually transmitted infection in France. This study aimed to assess the feasibility of systematic screening for CT among people attending a preventive health examination in Health Examination Centres (HECs) and to compare positive CT cases according to deprivation.

Design

A cross-sectional multicentre study in thirteen HECs in France in January 2018.

Methods

Self-sampling CT screening was proposed among 18-25 years women and 18-30 years men, who were sexually active and without recent CT treatment. Related data and referred specimens were collected among attendees for the study, including deprivation and health status. CT positivity was estimated by genders. We explored association between CT infection and deprivation by univariate and multivariate modelling.

Results

The CT screening was proposed to 1701 eligible young people. 90.1 % [88.6-91.5] accepted and participated with 43.6 % being women, 54.3 % being deprived people. 75.4 % [72.1-78.6] screened women performed self-taken vaginal swabs and others took urinary tests. Screening was conducted in 1486 people. Overall prevalence of CT infection was 4.7 % [3.7%-5.9 %], significantly higher for women than men (6.4 % vs 3.4 %, p=0.009). Among women, being deprived increased the likelihood of CT positivity (aOR 4.95; 95 % CI 2.02 to 12.00) more than it did for men.

Conclusions

Individual deprivation was significantly associated with having a CT infection among women. The feasibility of CT screening in HECs was demonstrated, with a high acceptance, and led to the implementation of CT screening in all HECs. Promoting access to CT screening to deprived population might contribute to reduce social inequalities in health.

Advantages of Syndromic Diagnostics: Detection of the Pathogens Causing Urethritis/Cervicitis with the STI CNM Real-Time PCR Kit from Vitro S.A

The STI CNM Real-Time PCR Kit from Vitro S.A. (Spain) demonstrates high sensitivity and specificity, is cost-effective, and can detect the three main etiological agents of urethritis/cervicitis in a single multiplex PCR. Sexually transmitted infections (STIs) are a significant public health problem and a significant burden of morbidity and mortality in hospitals. The World Health Organization (WHO) estimates the number of daily infections to be 1 million. Currently, the number of infections and antimicrobial-resistant strains is rising. A rapid and accurate etiologic diagnosis is critical to solving this problem. In this study, we compared the STI CNM Real-Time PCR Kit using the Xpert® CT/NG technique (Cepheid®, USA) as Gold Standard for the diagnosis of Chlamydia trachomatis and Neisseria gonorrhoeae and EasyNAT® MG (Ustar Biotechnologies (Hangzhou) Ltd., China) as Gold Standard for the diagnosis of Mycoplasma genitalium infection. Regarding C. trachomatis and N. gonorrhoeae, out of 200 samples, there was a match in 199 cases, with only one positive sample not being detected by the STI CNM Real-Time PCR Kit. This results in a sensitivity of 96% and a specificity of 100% for this kit. Diagnosing M. genitalium infection, out of 200 samples, the STI CNM Real-Time PCR Kit correctly detected all negative and positive samples, with 100% agreement compared to the reference technique. In summary, the STI assay has a very high sensitivity and specificity, comparable to other commercial diagnostic kits. Furthermore, it has the advantage of bundling the detection of the three main bacterial agents of urethritis/cervicitis, resulting in better cost efficiency.

Mechanisms of S. agalactiae promoting G. vaginalis biofilm formation leading to recurrence of BV

Previous research has established that the formation of Gardnerella vaginalis (GV) biofilm is one of the primary reasons for bacterial vaginosis (BV) recurrence. This study was the first to explore the impact of Streptococcus agalactiae (group B Streptococcus, GBS) on GV biofilm in a co-culture scenario. The results revealed that GBS could significantly increased the GV biomass in 48-hours dual-species biofilms. The luxS gene of GBS was significantly higher in dual-species biofilm, while knockdown of the luxS gene resulted in a significant decrease in mono- and dual-species biofilms. Meanwhile, in vitro addition of AI-2 (product of luxS gene) substantially increased biofilm biomass. Furthermore, we found that the expression of two genes related to biofilm formation was notably elevated in GV after receiving AI-2 signals. Collectively, these findings suggest that GBS enhances GV biofilm formation via luxS/AI-2 in an in vitro co-culture model, which in turn may promotes recurrence of BV.

Prevalence of gonococcal and chlamydial infections among men who have sex with men in sub-Saharan Africa: a systematic review and meta-analysis

BACKGROUND

Men who have sex with men (MSM) are disproportionately affected by sexually transmitted infections (STI) including Neisseria gonorrhoeae (Ng) and Chlamydia trachomatis (Ct). The lack of robust data on STIs among African MSM has limited the development of evidence-based screening strategies. This study aimed at documenting the pooled prevalence of Ng/Ct among MSM in sub-Saharan Africa (SSA).

METHODS

This systematic review was performed according to the Preferred Reporting Items for Systematic Review and Meta-analyses (PRISMA) 2020 guidelines. Relevant articles from the following databases were searched: PubMed, Scopus, ISI Web of Science, and the Directory of Open Access Journals (DOAJ). Eligible studies reported on the prevalence of Ng/Ct among the MSM population in SSA. Publication bias was assessed using the Hoy tool, Doi plot, and LFK ratio. Due to heterogeneity among studies, subgroup analyses were performed using the MetaXL add-on tool for Microsoft Excel.

RESULTS

Of 525 articles screened, 20 were selected for inclusion. Six were cross-sectional, four had a prospective cohort study design, and one was an epidemiological study. The pooled prevalence of Ng/Ct in MSM was 27% (95% CI, 19-39%), with an I2 of 98% signifying heterogeneity among the studies. Subgroup analysis by country revealed South Africa had the highest prevalence (38%).

DISCUSSION

Interpretation The high prevalence of Ng/Ct infection among MSM in SSA is of concern. Limitations Due to limited data available on Ng/Ct prevalence, the true prevalence of SSA and its associated risk factors is uncertain.

CONCLUSION

As the first study to systematically review the available literature on STI prevalence among the MSM population in SSA, it showed the burden of Ng/Ct is higher than in other regions, warranting the strengthening of health systems to improve education, testing, and treatment in MSM population.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42022327095.

Polymicrobial consortia in the pathogenesis of biofilm vaginosis visualized by FISH. Historic review outlining the basic principles of the polymicrobial infection theory

The manuscript disputes the exclusive mono-infectious way of thinking, which presumes that for every infection only one pathogen is responsible and sufficient, when infectious vectors, close contact and reduced immunity meet. In situations involving heavily colonized anatomical sites such an approach often ends in insoluble contradictions. Upon critical reflection and evaluation of 20 years research on spatial organization of vaginal microbiota it is apparent, that in some situations, pathogens may act and operate in permanent, structurally organized consortia, whereas its individual components may be innocuous and innocent, failing to express any pathogenic effect. In these cases, consortia are the true pathogens responsible for many infectious conditions, which usually remain unrecognized as long as improperly diagnosed. The structure of such consortia can be unraveled using ribosomal fluorescence in situ hybridization (FISH). FISH methodology, that not only offers an ex vivo opportunity to recognize bacterial species, but provides unique physical insight into their specific role in the pathogenesis of polymicrobial infections. Ribosomal FISH technique applied to both, women with bacterial vaginosis (BV) and their male partners, has added significantly to our understanding of the pathogenesis of this condition and contributed to appreciating the mechanisms of polymicrobial, community-based infection, potentially leading to therapeutic advances.

Analysis of risk factors associated with cervical HPV infection and their effects on female sexual function and anxiety: a multicenter cross-sectional study based on Chinese women

Introduction

This research aimed to explore the determinants of cervical HPV infection and evaluate how cervical cancer screening outcomes influence sexual functioning and anxiety among women across three provinces in China.

Methods

Study participants were categorized into HPV-positive or HPV-negative groups, after which they completed the General Characteristics Questionnaire and the SAS Anxiety Scale. The HPV-positive cohort was further divided into four subgroups: Subgroup 1 consisted of individuals with HPV types 16 or 18 but no cytological abnormalities. Subgroup 2 included those with cytological abnormalities and infections with HPV types 16 or 18. Subgroup 3 included participants infected with high-risk HPV types other than 16 and 18, who did not show cytological abnormalities, while Subgroup 4 encompassed individuals with both cytological abnormalities and infections with high-risk HPV types other than 16 and 18. All participants were assessed using the Female Sexual Function Index Scale (FSFI), which measures sexual function across these subgroups.

Results

A total of 531 questionnaires were analyzed. Logistic regression identified several risk factors for HPV infection, including manual labor, service occupations, other occupations, low- and middle-income groups, and cervical columnar epithelial ectasia, as well as an increase in the number of previous sexual partners. Conversely, protective factors included condom use during sexual activity and mutual genital hygiene prior to intercourse. The incidence of lower genital tract infections was significantly higher in the HPV-positive group compared to the HPV-negative group, with rates of chlamydia (13.3% versus 4.6%, P<0.001), gonococcal infections (5.2% versus 0.4%, P<0.001), and mycobacterial diseases (38.9% versus 23.4%, P<0.001). Additionally, anxiety levels were significantly higher in the HPVpositive group compared to the HPV-negative group (p<0.005). Anxiety levels and cytological outcomes were significantly correlated across the four HPV-positive subgroups (p<0.05), with type 16/18 infections being associated with notably lower FSFI scores compared to other high-risk HPV types (p<0.05).

Conclusions

The findings suggest that infections with HPV type 16/18, especially when accompanied by abnormal cytological findings,significantly elevate anxiety and distress in women and are associated with reduced FSFI scores. These results highlight the complex impact of HPV infection on women's sexual health and psychological well-being with HPV type 16/.

CT584 Is Not a Protective Vaccine Antigen against Respiratory Chlamydial Challenge in Mice

Background:Chlamydia trachomatis is the most prevalent bacterial sexually transmitted pathogen in humans worldwide. Since chlamydial infection is largely asymptomatic with the potential for serious complications, a preventative vaccine is likely the most viable long-term answer to this public health threat. Cell-free protein synthesis (CFPS) utilizes the cellular protein manufacturing machinery decoupled from the requirement for maintaining cellular viability, offering the potential for flexible, rapid, and decentralized production of recombinant protein vaccine antigens. Methods: Here, we use CFPS to produce the full-length putative chlamydial type three secretion system (T3SS) needle-tip protein, CT584, for evaluation as a vaccine antigen in mouse models. High-speed atomic force microscopy (HS-AFM) (RIBM, Tsukuba, Japan) imaging and computer simulations confirm that CFPS-produced CT584 retains a native-like structure prior to immunization. Female mice were primed with CT584 adjuvanted with CpG-1826 intranasally (i.n.) or CpG-1826 + Montanide ISA 720 intramuscularly (i.m.), followed four weeks later by an i.m. boost before respiratory challenge with 104 inclusion forming units (IFU) of Chlamydia muridarum. Results: Immunization with CT584 generated robust antibody responses but weak cell-mediated immunity and failed to protect against i.n. challenge as demonstrated by body weight loss, increased lung weights, and the presence of high numbers of IFUs in the lungs. Conclusion: While CT584 was not a protective vaccine candidate, the speed and flexibility with which CFPS can be used to produce other potential chlamydial antigens make it an attractive technique for antigen production.

Sexual Victimization and Sexually Transmitted Infections Among a Nationally Representative Sample of Adolescents and Young Adults in Haiti

Sexual assault victims are at major risk of being infected by sexually transmitted infections (STI). This article aims to examine and compare the prevalence of eight STIs (e.g., chlamydia, gonorrhea, hepatitis B, HIV/AIDS, human papillomavirus) among victims and non-victims of sexual abuse. A national cross-sectional study was conducted in Haiti, using a multistage sampling frame, stratified by geographical department, urban or rural setting, gender, and age groups (15-19 and 20-24 years). The final sample included 3586 household participants (47.6% female). A weighted sample of 3945 individuals was obtained and used in the following analyses. Overall, 21.75% (95% CI 19.91-23.59) of participants reported having been diagnosed with at least one STI in their lifetime, with a higher prevalence among men (25.70%; 95% CI 22.89-28.52), compared to women (18.11%; 95% CI 15.73-20.49), χ2 = 16.43; p < 0.001). Sexual abuse victims were more likely to report STIs (31.27%; 95% CI 29.21-33.34), compared to non-victims (18.40%; 95% CI 16.68-20.13), χ2 = 27.89; p < .001. Sexual abuse was associated to an increased risk of contracting at least one STI (OR = 1.74; 95% CI 1.35, 2.24). The results demonstrate that sexual abuse is associated with a general increase of reporting STIs. They indicate the need for national sexual abuse prevention programs at early ages. These programs should be implemented in schools and churches, focusing on the role of families in sexuality education. Finally, programs must be developed to eradicate community violence-especially in the cities-as increased political and social violence has always been associated with increased sexual abuse in Haiti.

Mobility and sexually transmitted infections: Exploring intersectional axes of alcohol consumption and risky sexual behavior among Indian men

OBJECTIVE

Studies in India and other low-income countries find an inconsistent association between mobility/migration and sexually transmitted infections (STIs) among men. This study comprehensively examined the association between mobility and STIs among men in India. It also assessed heterogeneous associations of mobility, alcohol consumption, and risky sexual behavior with STIs using interaction analysis.

METHODS

We utilized a sample of 71,128 sexually active men aged 15-54 years from the 2019-21 National Family Health Survey-5. Binary logistic regression models were employed to study the associations.

RESULTS

Among the study participants, 16% were mobile and away from home for a month or more in the last 12 months. Around 29% of men reported alcohol consumption and 6% had risky sexual behavior (sexual intercourse with a non-marital/non-cohabitating partner). Regression results suggest that mobility (AOR: 1.41, 95% CI: 1.29-1.55 [short-duration]; AOR: 1.95, 95% CI: 1.77-2.13 [long-duration]) and alcohol consumption (AOR: 1.32, 95% CI: 1.24-1.40) were significantly associated with an increased risk of STIs, even after controlling for socio-demographic covariates. Interaction analysis further reveals that mobile men who consumed alcohol and engaged in risky sexual behavior had a significantly higher likelihood of contracting an STI-twice as high in cases of short-duration mobility and three times higher in cases of long-duration mobility.

CONCLUSION

Our study indicates that both short and long-duration mobility are significantly associated with an increased risk of STIs among men. Alcohol consumption and risky sexual behavior further exacerbate the risk of STIs in mobile men. Initiatives for STI/HIV prevention among men must pay particular attention to temporary mobile men for both short and long durations.

Generation and capture of naphthoquinonynes: a new frontier in the development of trypanocidal quinones via aryne chemistry

The regioselective synthesis of functionalized naphthoquinones via the formation and capture of naphthoquinonynes has been used to prepare trypanocidal compounds. The target compounds are functionalized on the aromatic ring, leaving the quinoidal ring intact. Using this technique, eighteen functionalized naphthoquinones were succesfull obtained, divided in two main groups: the first scope using N-nucleophiles, and the second scope using pyridine N-oxides, with yields up to 74%. Evaluation against bloodstream trypomastigotes of T. cruzi has identified fourteen compounds that are more potent than benznidazole (Bz); for instance, compounds 29b-I and 30b, with IC50/24 h values of 10.5 and 10.1 μM, respectively, are approximately 10-fold more active than Bz. This study provides the first examples of the application of naphthoquinonyne chemistry for the synthesis of new compounds with potent trypanocidal activities.

Longitudinal genomic analysis of Neisseria gonorrhoeae transmission dynamics in Australia

N. gonorrhoeae, which causes the sexually transmissible infection gonorrhoea, remains a significant public health threat globally, with challenges posed by increasing transmission and antimicrobial resistance (AMR). The COVID-19 pandemic introduced exceptional circumstances into communicable disease control, impacting the transmission of gonorrhoea and other infectious diseases. Through phylogenomic and phylodynamic analysis of 5881 N. gonorrhoeae genomes from Australia, we investigated N. gonorrhoeae transmission over five years, including a time period during the COVID-19 pandemic. Using a novel cgMLST-based genetic threshold, we demonstrate persistence of large N. gonorrhoeae genomic clusters over several years, with some persistent clusters associated with heterosexual transmission. We observed a decline in both N. gonorrhoeae transmission and genomic diversity during the COVID-19 pandemic, suggestive of an evolutionary bottleneck. The longitudinal, occult transmission of N. gonorrhoeae over many years further highlights the urgent need for improved diagnostic, treatment, and prevention strategies for gonorrhoea.

Determinants of care-seeking behavior for sexually transmitted infections among sexually active men in East Africa: A multilevel mixed effect analysis

BACKGROUND

Addressing the global challenge of sexually transmitted infections (STIs) is crucial and demands immediate attention. Raising awareness, improving healthcare facilities, and implementing preventive measures are necessary to reduce the spread and mitigate their adverse effects. The treatment seeking behavior of individuals in relation to STIs is an important factor in STI prevention and control. Thus, this study aimed to identify factors associated with STI-related care-seeking behavior among sexually active men in East Africa.

METHODS

A weighted sample of 3,302 sexually active men from recent Demographic and Health Surveys (DHSs) in East African countries were included for analysis. To accommodate the inherent clustering in DHS data and the binary nature of the dependent variable, we applied a multi-level mixed-effect logistic regression model. The deviance value was used to select the best-fitted model. The strength of the association was estimated using an adjusted odds ratio, along with a 95% confidence interval, and statistical significance was determined at a p-value < 0.05.

RESULT

The pooled prevalence of STI-related care-seeking behavior among sexually active men in East Africa was 71% (95%CI: 69.76, 72.75). In the multivariable multilevel model, individuals in the age groups of 25-34 (AOR = 1.58, 95%CI: 1.22, 2.04) and 44 years and above (AOR = 1.44, 95%CI: 1.01, 2.02), those who were married (AOR = 1.62, 95%CI: 1.25, 2.11), had 1 (AOR = 1.88, 95%CI: 1.50, 2.35) and ≥2 (AOR = 2.53, 95%CI: 1.89, 3.39) sexual partners excluding their spouse, had ever been tested for HIV (AOR = 1.86, 95%CI: 1.52, 2.28), and had media exposure (AOR = 1.30, 95%CI: 1.04, 1.62) had a positive association with care-seeking behavior for STIs.

CONCLUSION

Based on our findings, seven out of ten sexually active men in East Africa exhibit care-seeking behavior for STIs. It is crucial to implement policies and strategies aimed at improving the health-seeking habits of young, unmarried men. Utilizing diverse media platforms to disseminate accurate information and success stories about STI symptoms is pivotal in achieving this goal.

Protective Mechanisms of Vaginal Lactobacilli against Sexually Transmitted Viral Infections

The healthy cervicovaginal microbiota is dominated by various Lactobacillus species, which support a condition of eubiosis. Among their many functions, vaginal lactobacilli contribute to the maintenance of an acidic pH, produce antimicrobial compounds, and modulate the host immune response to protect against vaginal bacterial and fungal infections. Increasing evidence suggests that these beneficial bacteria may also confer protection against sexually transmitted infections (STIs) caused by viruses such as human papillomavirus (HPV), human immunodeficiency virus (HIV) and herpes simplex virus (HSV). Viral STIs pose a substantial public health burden globally, causing a range of infectious diseases with potentially severe consequences. Understanding the molecular mechanisms by which lactobacilli exert their protective effects against viral STIs is paramount for the development of novel preventive and therapeutic strategies. This review aims to provide more recent insights into the intricate interactions between lactobacilli and viral STIs, exploring their impact on the vaginal microenvironment, host immune response, viral infectivity and pathogenesis, and highlighting their potential implications for public health interventions and clinical management strategies.

[Increase In Sexually Transmitted Infections: A New Undeniable Reality in Portugal]

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Epidemiology of Trichomonas vaginalis infection in the Middle East and North Africa: systematic review, meta-analyses, and meta-regressions

BACKGROUND

Trichomoniasis, caused by the parasite Trichomonas vaginalis (TV), remains an underappreciated sexually transmitted infection (STI), primarily due to inadequate understanding of its epidemiology and public health implications. This study aimed to characterize TV epidemiology in the Middle East and North Africa (MENA).

METHODS

Systematic review and analysis of evidence sourced from international, regional, and national databases were conducted. Findings were reported following PRISMA guidelines. Random-effects meta-analyses and meta-regressions were performed to determine pooled mean prevalence, investigate associations with prevalence, and identify sources of between-study heterogeneity.

FINDINGS

The review identified 263 relevant publications, encompassing 462 TV prevalence measures. The pooled mean TV prevalence was estimated as follows: 4.7% (95% CI: 3.9-5.6%) in the general population of women, 17.2% (95% CI: 5.4-33.6%) among intermediate-risk populations, 10.3% (95% CI: 6.2-15.3%) among female sex workers, 13.9% (95% CI: 12.3-15.6%) among symptomatic women, 7.4% (95% CI: 1.9-15.5%) among infertility clinic attendees, 2.3% (95% CI: 0.1-6.3%) among women with miscarriages or ectopic pregnancies, and 1.6% (95% CI: 0.8-2.7%) among STI clinic attendees. Limited data were found for men. Multivariable meta-regressions explained >40% of the prevalence variation, unveiling a hierarchical prevalence pattern by population type, an inverse correlation with national income, and a prevalence decline at a rate of 1% per calendar year.

INTERPRETATION

Despite conservative sexual norms, MENA has a substantial TV prevalence, comparable to the global TV prevalence. The unexpectedly high prevalence of this curable infection may, in part, be attributed to limited access to and underutilization of STI screening and treatment services.

FUNDING

This work was supported by the Qatar Research, Development, and Innovation Council [ARG01-0522-230273] and by the Biomedical Research Program at Weill Cornell Medicine-Qatar.

Surge in Ceftriaxone-Resistant Neisseria gonorrhoeae FC428-Like Strains, Asia-Pacific Region, 2015-2022

Ceftriaxone-resistant Neisseria gonorrhoeae FC428-like strains have disseminated across the Asia-Pacific region, with a continuous rise in prevalence during 2015-2022. To mitigate the effect of these strains, we advocate for enhanced molecular diagnostics, expanded surveillance networks, and a regionally coordinated effort to combat the global spread of FC428-like strains.

Vaccine value profile for Neisseria gonorrhoeae

Neisseria gonorrhoeae infection (gonorrhoea) is a global public health challenge, causing substantial sexual and reproductive health consequences, such as infertility, pregnancy complications and increased acquisition or transmission of HIV. There is an urgency to controlling gonorrhoea because of increasing antimicrobial resistance to ceftriaxone, the last remaining treatment option, and the potential for gonorrhoea to become untreatable. No licensed gonococcal vaccine is available. Mounting observational evidence suggests that N. meningitidis serogroup B outer membrane vesicle-based vaccines may induce cross-protection against N. gonorrhoeae (estimated 30%-40% effectiveness using the 4CMenB vaccine). Clinical trials to determine the efficacy of the 4CMenB vaccine against N. gonorrhoeae are underway, as are Phase 1/2 studies of a new gonococcal-specific vaccine candidate. Ultimately, a gonococcal vaccine must be accessible, affordable and equitably dispensed, given that those most affected by gonorrhoea are also those who may be most disadvantaged in our societies, and most cases are in less-resourced settings. This vaccine value profile (VVP) provides a high level, holistic assessment of the current data to inform the potential public health, economic and societal value of pipeline vaccines. This was developed by a working group of subject matter experts from academia, non-profit organizations, public private partnerships and multi-lateral organizations. All contributors have extensive expertise on various elements of the N. gonorrhoeae VVP and collectively aimed to identify current research and knowledge gaps. The VVP was developed using published data obtained from peer-reviewed journals or reports.

Condom use across casual and committed relationships: The role of relationship characteristics

BACKGROUND

While the existence of a complex variety of casual sexual relationships (CSRs) has been acknowledged, studies rarely describe the prevalence of condom use across these relationships or how their hybrid nature, specifically relationship characteristics, affect condom use. This study aims to describe condom use within committed relationships and various types of casual sexual relationships (CSRs), examining the influence of relationship characteristics on condom use among culturally validated relationship types (committed, friends with benefits, hookups, booty call).

METHODS

Emerging adults (N = 728, 18-29 years, M = 22.56; SD = 3.01) completed a survey with four blocks: sociodemographics; brief sexual history; relationships over the previous year; and current relationship, assessing relationship type, ten relationship characteristics (e.g., commitment, emotional and sexual exclusivity, partner acquaintance, sexual involvement) and condom use (vaginal, oral, and anal), operationalized by three measures (use at last encounter, likert-type scale and percentage of use).

RESULTS

The results showed patterns in condom use by relationship type and illuminated how relationship characteristics-grouped into three factors: commitment, intimacy, and sexuality-mediate condom use. Condom use was more frequent in vaginal than anal and oral sex, and less frequent in committed relationships. No significant differences were found in condom use in vaginal sex between committed relationships and hookups, with condom in these relationships being significantly lower than in booty call. Intimacy mediated between all contrasts tested and condom use in vaginal sex, while sexuality mediated between committed vs. CSRs and condom use in anal and oral sex.

CONCLUSIONS

Findings point to the need of considering the diversity of CSRs for understanding condom use and highlight the role of intimacy as a relevant mechanism associated with condom use in vaginal sex and of sexuality in oral and anal sex, which should be taken into consideration in the tailoring of health promoting efforts.

Improvement and exacerbation of multiple disparities in sexually transmitted infections among children and adolescents aged 6-22 years: An analysis of national surveillance data from 2013 to 2021

To investigate the progress of disparities in human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS), gonorrhea, and syphilis among children and adolescents aged 6-22 years in China during 2013-2021. A total of 614 325 cases data were extracted from the Chinese Information System for Infectious Diseases Control and Prevention during 2013-2021. Puberty health education data were drew from the Student Health Surveillance in 2021. Disparity patterns and average annual percentage changes (AAPCs) in sexually transmitted infections (STIs) incidence or new cases in China were examined using descriptive statistics and joinpoint regression. The incidence across 345 cities was stratified by gross domestic product (GDP). Between 2013 and 2021, there were 614 325 reported cases of HIV/AIDS, gonorrhea, and syphilis among children and adolescents aged 6-22, with an annual average incidence of 24.0967 per 100 000. The expansion of HIV/AIDS has halted, yet the surge in gonorrhea and syphilis remains notably pronounced. The ratio of male to female AIDS incidence increased from 2.75 (2.60, 2.90) to 7.13 (6.68, 7.62), but that of syphilis changed from 0.33 (0.32, 0.34) to 0.56 (0.55, 0.57). Students and out-of-school individuals aged 13-15 experienced a notably high increase in STI cases, surpassing other age groups, with an average annual percentage increase of 29.2% and 26.3%, respectively. Nonstudents consistently had a higher incidence rate than students, with an IRR reaching 31.80 (31.24, 32.37) in 2021. A noticeable clustering pattern of new cases emerged in the southeastern region of the Heihe-Tengchong line, extending inland from the coastal areas. Districts and counties with lower rates of puberty sexual health education tended to have higher average STI incidence rates. At the prefecture and city levels, there was a noticeable upward trend on average STI incidence rates in cities with per capita GDPs. Strategies to address those disparities include promoting equitable health education, and widespread sexual health education, particularly in areas with limited access to education and experiencing rapid economic development. The effectiveness of sexual health education intervention needs to be further evaluated in well-designed studies.

Prevalence of Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, and Mycoplasma genitalium and risk factors among pregnant women in Brazil: Results from the national molecular diagnosis implementation project

BACKGROUND

Sexually transmitted infections (STIs) are a public health problem. The aim of the present study was to assess the prevalence and risk factors associated with at least one STI (Chlamydia trachomatis [CT], Neisseria gonorrhoeae [NG], Trichomonas vaginalis [TV], and Mycoplasma genitalium [MG]) in Brazil.

METHODS

A cross-sectional study was conducted using secondary data from the pilot implementation of the National Service for molecular diagnosis of CT, NG, TV, and MG in pregnancy. We obtained Ministry of Health surveillance data from the implementation project. Data encompassing pregnant women aged 15-49 years from public antenatal clinics in Brazil in 2022 were included.

RESULTS

A total of 2728 data of pregnant women were analyzed. The prevalence of at least one infection was 21.0% (573), with the highest prevalence in the Southeast region (23.3%) and the lowest in the Center-West region (15.4%). The prevalence of CT was 9.9% (270), NG 0.6% (16), TV 6.7% (184), and MG 7.8% (212). Factors associated with any infection were from 15 to 24 years (AOR = 1.93; 95% CI: 1.58-2.35); reported family income up to US$400 (AOR = 1.79; 95% CI: 1.03-3.34); declared not living maritally with their partners (AOR = 1.90, 95% CI: 1.52-2.37) and had more than one sexual partner in their lifetime (AOR = 2.09, 95% CI: 1.55-2.86).

CONCLUSION

This study showed a high prevalence of at least one STI among pregnant women in Brazil, particularly among younger women. It also provides up-to-date national data on CT, NG, TV, and MG infections in this population. These findings underscore the importance of enhancing access to STI screening for young pregnant women within the Brazilian public health system.

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.

Molecular characterization of vaginal microbiota using a new 22-species qRT-PCR test to achieve a relative-abundance and species-based diagnosis of bacterial vaginosis

Background

Numerous bacteria are involved in the etiology of bacterial vaginosis (BV). Yet, current tests only focus on a select few. We therefore designed a new test targeting 22 BV-relevant species.

Methods

Using 946 stored vaginal samples, a new qPCR test that quantitatively identifies 22 bacterial species was designed. The distribution and relative abundance of each species, α- and β-diversities, correlation, and species co-existence were determined per sample. A diagnostic index was modeled from the data, trained, and tested to classify samples into BV-positive, BV-negative, or transitional BV.

Results

The qPCR test identified all 22 targeted species with 95 - 100% sensitivity and specificity within 8 hours (from sample reception). Across most samples, Lactobacillus iners, Lactobacillus crispatus, Lactobacillus jensenii, Gardnerella vaginalis, Fannyhessea (Atopobium) vaginae, Prevotella bivia, and Megasphaera sp. type 1 were relatively abundant. BVAB-1 was more abundant and distributed than BVAB-2 and BVAB-3. No Mycoplasma genitalium was found. The inter-sample similarity was very low, and correlations existed between key species, which were used to model, train, and test a diagnostic index: MDL-BV index. The MDL-BV index, using both species and relative abundance markers, classified samples into three vaginal microbiome states. Testing this index on our samples, 491 were BV-positive, 318 were BV-negative, and 137 were transitional BV. Although important differences in BV status were observed between different age groups, races, and pregnancy status, they were statistically insignificant.

Conclusion

Using a diverse and large number of vaginal samples from different races and age groups, including pregnant women, the new qRT-PCR test and MDL-BV index efficiently diagnosed BV within 8 hours (from sample reception), using 22 BV-associated species.

The Prevalence of Sexually Transmitted Infections among Male Patients at a Dermato-Venereology Outpatient Clinic in Gdańsk, Poland: Findings from a Single-Center Study

Background: Sexually transmitted infections (STIs) are a significant public health concern worldwide, yet data on their prevalence and epidemiology, particularly in Central and Eastern Europe, remain scarce. This study aimed to assess the prevalence, anatomical localization, symptomatic/asymptomatic course, and co-infection patterns of STIs among men. Methods: This retrospective study analyzed data collected between May 2021 and July 2023, including sociodemographic, sexual behavior, and clinical data from 139 male participants. Molecular polymerase chain reaction (PCR) tests were conducted for Neisseria gonorrhoeae (NG), Chlamydia trachomatis (CT), Mycoplasma genitalium, and Trichomonas vaginalis. Results: Of the participants, 36% tested positive for at least one STI, with the urethra being the most common site of infection. NG and CT were the most prevalent infections. The majority of infections were asymptomatic, highlighting the importance of comprehensive screening, especially in high-risk populations like men who have sex with men (MSM). Conclusions: This study emphasizes the need for targeted screening strategies, particularly for extragenital STIs, and underscores the role of MSM in STI epidemiology. The findings highlight the importance of routine screening, even for asymptomatic individuals, to effectively control STI spread. Future research should validate and expand upon these findings to enhance STI prevention and management efforts.

Validity of dried blood spot testing for sexually transmitted and blood-borne infections: A narrative systematic review

Testing for human immunodeficiency virus (HIV) and hepatitis C virus (HCV) using dried blood spot (DBS) specimens has been an integral part of bio-behavioural surveillance in Canada for almost two decades, though less is known regarding the use of DBS in surveillance of other sexually transmitted and blood-borne infections (STBBI). A systematic review was conducted using a peer-reviewed search strategy to assess the current evidence regarding the validity of STBBI testing using DBS specimens. Eligibility criteria included studies reporting use of DBS specimens for STBBI testing with either commercially available or "in-house" tests in populations 15 years of age or older. Studies reporting a measure of validity such as sensitivity, specificity, positive and negative predictive values were eligible for inclusion. Quality of studies and risk of bias were assessed using the QUADAS-2 tool. A total of 7,132 records were identified. Of these, 174 met the criteria for inclusion. Among the studies that reported validity measures, a substantial proportion demonstrated high sensitivity (≥90%) in 62.5% of cases (N = 334/534 sensitivity measurements), and high specificity (≥90%) was observed in 84.9% of instances (N = 383/451 specificity measurements). However, the quality of the studies varied greatly. Our findings support the validity of the use of DBS specimens in STBBI testing where sufficient evidence was available, but validity is highly dependent on thorough method development and validation.

Investigating possibilities for surveillance of long term chlamydia complications in the Netherlands: A qualitative study

OBJECTIVES

Chlamydia trachomatis (chlamydia) is one of the most reported bacterial sexually transmitted infections (STI) worldwide. Chlamydia can cause long term complications such as pelvic inflammatory disease (PID), ectopic pregnancy (EP) and tubal factor infertility (TFI). Changing testing strategies, for example reduced asymptomatic testing, influence chlamydia surveillance, highlighting the need for exploring alternative ways of monitoring chlamydia. We investigated the possibility of introducing routine surveillance of chlamydia related long term complications.

METHODS

A qualitative study including 15 in-depth interviews with a purposive sample of gynaecologists, general practitioners (GP), sexual health and emergency doctors was conducted in the Netherlands in 2021-2022. A semi-structured interview guide focused on experiences with diagnosis and registration of PID, EP and TFI and how a change in asymptomatic chlamydia testing strategy might influence this. Interviews were transcribed and analysed using a thematic approach.

RESULTS

Analysis showed that gynaecologists most frequently reported diagnosing PID, EP and TFI. Other professions rarely diagnose these complications, with emergency doctors only diagnosing EP. Most respondents reported unique registration codes for PID and EP, but the coding for TFI is more ambiguous. They reflected that diagnosis and registration of PID, EP and TFI are handled differently within their professions. Most respondents acknowledged registration in diagnostic codes as a useful surveillance tool. They expressed concerns in representativeness (e.g. differences in interpretation of diagnosis criteria) and data quality for surveillance.

CONCLUSIONS

Patient files of gynaecologists are likely to be most complete for monitoring trends of diagnosed chlamydia related long term complications in the Netherlands. However, when establishing a chlamydia complication surveillance system, professionals should be engaged in further standardizing diagnosis and registration practices. This will improve the quality and interpretability of complication surveillance and facilitate comparison between countries.

Clinical diagnosis and treatment of seven patients diagnosed pneumonia caused by Chlamydia abortus: a case series report

Background

Chlamydia abortus pneumonia is very rare in normal people. At present, there is a lack of clinical data on the clinical characteristics and diagnosis and treatment experience of patients with this type of infection. Our team had recently treated 7 cases of these patients. This study aims to comprehensively summarize and analyze the clinical characteristics and treatment methods of Chlamydia abortus pneumonia, and to provide clinical evidence for the diagnosis and treatment of Chlamydia abortus pneumonia.

Methods

Clinical data were retrospectively collected from patients diagnosed with Chlamydia abortus pneumonia through metagenomic next-generation sequencing (mNGS) at the Department of Pulmonary and Critical Care Medicine, Meizhou People's Hospital.

Results

Seven patients with Chlamydia abortus pneumonia reported a history of poultry exposure, experiencing fever alongside respiratory or digestive symptoms. Marked elevation of blood inflammation markers, accompanied by hypoproteinemia and liver damage, was observed. Chest CT scans revealed pneumonia and pleural effusion. Chlamydia abortus was detected in blood or bronchoalveolar lavage fluid (BALF) through mNGS, often co-occurring with Chlamydia psittaci or other bacteria infections. Notably, Doxycycline demonstrated efficacy in treating Chlamydia abortus.

Conclusion

Chlamydia abortus infection is a zoonotic disease, particularly among individuals with a history of poultry exposure, and mNGS emerges as a reliable diagnostic tool for its detection. Chlamydia abortus infection manifests with systemic and lung inflammation, effectively addressed through Doxycycline therapy.

Evaluation in mice of cell-free produced CT584 as a Chlamydia vaccine antigen

Chlamydia trachomatis is the most prevalent bacterial sexually transmitted pathogen worldwide. Since chlamydial infection is largely asymptomatic with the potential for serious complications, a preventative vaccine is likely the most viable long-term answer to this public health threat. Cell-free protein synthesis (CFPS) utilizes the cellular protein manufacturing machinery decoupled from the requirement for maintaining cellular viability, offering the potential for flexible, rapid, and de-centralized production of recombinant protein vaccine antigens. Here, we use CFPS to produce the putative chlamydial type three secretion system (T3SS) needle-tip protein, CT584, for use as a vaccine antigen in mouse models. High-speed atomic force microscopy (HS-AFM) imaging and computer simulations confirm that CFPS-produced CT584 retains a native-like structure prior to immunization. Female mice were primed with CT584 adjuvanted with CpG-1826 intranasally (i.n.) or CpG-1826 + Montanide ISA 720 intramuscularly (i.m.), followed four-weeks later by an i.m. boost before respiratory challenge with 104 inclusion forming units (IFU) of Chlamydia muridarum. Immunization with CT584 generated robust antibody responses but weak cell mediated immunity and failed to protect against i.n. challenge as demonstrated by body weight loss, increased lungs' weights and the presence of high numbers of IFUs in the lungs. While CT584 alone may not be the ideal vaccine candidate, the speed and flexibility with which CFPS can be used to produce other potential chlamydial antigens makes it an attractive technique for antigen production.

Relative Cost and Infectious Days Averted Associated With Rapid Gonorrhea and Chlamydia Testing Among Men Who Have Sex With Men

BACKGROUND

Standard-of-care nucleic acid amplification tests (routine NAATs) for Neisseria gonorrhoeae (GC) and Chlamydia trachomatis (CT) can take several days to result and therefore delay treatment. Rapid point-of-care GC/CT NAAT (rapid NAAT) could reduce the time to treatment and therefore onward transmission. This study evaluated the incremental cost per infectious day averted and overall cost of implementation associated with rapid compared with routine NAAT.

METHODS

Prospective sexually transmitted infection (STI) treatment data from men who have sex with men and transgender women in San Diego who received rapid NAAT between November 2018 and February 2021 were evaluated. Historical time from testing to treatment for routine NAAT was abstracted from the literature. Costs per test for rapid and routine NAAT were calculated using a micro-costing approach. The incremental cost per infectious day averted comparing rapid to routine NAAT and the costs of rapid GC/CT NAAT implementation in San Diego Public Health STI clinics were calculated.

RESULTS

Overall, 2333 individuals underwent rapid NAAT with a median time from sample collection to treatment of 2 days compared with 7 to 14 days for routine NAAT equating to a reduction of 5 to 12 days. The cost of rapid and routine GC/CT NAAT was $57.86 and $18.38 per test, respectively, with a cost-effectiveness of between $2.43 and $5.82 per infectious day averted. The incremental cost of rapid NAAT improved when at least 2000 tests were performed annually.

CONCLUSIONS

Although rapid GC/CT NAAT is more expensive than routine testing, the reduction of infectious days between testing and treatment may reduce transmission and provide improved STI treatment services to patients.

[Translated article] AEDV Expert Consensus Document on the Organization of a Multidisciplinary Unit for Patients With or at Risk of Venereal Infections

Over the past few years, venereal or sexually transmitted infections (STIs) have been on the rise worldwide requiring additional specialized monographic consultations to specifically treat STIs. Therefore, the Spanish Academy of Dermatology and Venereology (AEDV) Research Working Group on STIs and HIV has drafted this document with the necessary requirements in terms of infrastructure, personnel, technology, specific materials for sample collection, and needs for current therapeutic options. Strict emphasis is placed on the protection of patient privacy. A health care circuit model is outlined too. Additionally, a section has been included on contact tracking and reporting, key elements for the effective prevention and control of STIs. These clinical practice guidelines seek to establish a clinical action framework adapted to the current challenges posed by STIs and HIV in the dermatology, venereology, and multidisciplinary settings.

AEDV Expert Consensus Document on the Organization of a Multidisciplinary Unit for Patients With or at Risk of Venereal Infections

Over the past few years, venereal or sexually transmitted infections (STIs) have been on the rise worldwide requiring additional specialized monographic consultations to specifically treat STIs. Therefore, the Spanish Academy of Dermatology and Venereology (AEDV) Research Working Group on STIs and HIV has drafted this document with the necessary requirements in terms of infrastructure, personnel, technology, specific materials for sample collection, and needs for current therapeutic options. Strict emphasis is placed on the protection of patient privacy. A health care circuit model is outlined too. Additionally, a section has been included on contact tracking and reporting, key elements for the effective prevention and control of STIs. These clinical practice guidelines seek to establish a clinical action framework adapted to the current challenges posed by STIs and HIV in the dermatology, venereology, and multidisciplinary settings.

Development of a DNA-Based Lateral Flow Strip Membrane Assay for Rapid Screening and Genotyping of Six High-Incidence STD Pathogens

Sexually transmitted diseases (STDs) are a global concern because approximately 1 million new cases emerge daily. Most STDs are curable, but if left untreated, they can cause severe long-term health implications, including infertility and even death. Therefore, a test enabling rapid and accurate screening and genotyping of STD pathogens is highly awaited. Herein, we present the development of the DNA-based 6STD Genotyping 9G Membrane test, a lateral flow strip membrane assay, for the detection and genotyping of six STD pathogens, including Trichomonas vaginalis, Ureaplasma urealyticum, Neisseria gonorrhoeae, Chlamydia trachomatis, Mycoplasma hominis, and Mycoplasma genitalium. Here, we developed a multiplex PCR primer set that allows PCR amplification of genomic materials for these six STD pathogens. We also developed the six ssDNA probes that allow highly efficient detection of the six STD pathogens. The 6STD Genotyping 9G Membrane test lets us obtain the final detection and genotyping results in less than 30 m after PCR at 25 °C. The accuracy of the 6STD Genotyping 9G membrane test in STD genotyping was confirmed by its 100% concordance with the sequencing results of 120 clinical samples. Therefore, the 6STD Genotyping 9G Membrane test emerges as a promising diagnostic tool for precise STD genotyping, facilitating informed decision-making in clinical practice.

Aetiological molecular identification of sexually transmitted infections that cause urethral discharge syndrome and genital ulcer disease in Brazilian men: a nationwide study

BACKGROUND

Little is known about the aetiology of urethral discharge syndrome (UDS) and genital ulcer disease (GUD) in Brazil due to limited access to laboratory tests and treatment based mainly on the syndromic approach.

OBJECTIVES

To update Brazilian treatment guidelines according to the current scenario, the first nationwide aetiological study for UDS and GUD was performed.

METHODS

Male participants with urethral discharge (UD) and/or genital ulcer (GU) reports were enrolled. Sample collection was performed by 12 sentinel sites located in the five Brazilian regions. Between 2018 and 2020, 1141 UD and 208 GU samples were collected in a Universal Transport Medium-RT (Copan). A multiplex quantitative PCR kit (Seegene) was used to detect UD: Chlamydia trachomatis (CT), Mycoplasma genitalium (MG), M. hominis (MH), Neisseria gonorrhoeae (NG), Trichomonas vaginalis (TV), Ureaplasma parvum (UP), U. urealyticum (UU) and another kit to detect GU: cytomegalovirus (CMV), Haemophilus ducreyi (HD), herpes simplex virus type 1 (HSV1), herpes simplex virus type 2 (HSV2), lymphogranuloma venereum (LGV), Treponema pallidum (TP) and varicella-zoster virus (VZV).

RESULTS

In UD samples, the frequency of pathogen detection was NG: 78.38%, CT: 25.6%, MG: 8.3%, UU: 10.4%, UP: 3.5%, MH: 3.5% and TV: 0.9%. Coinfection was assessed in 30.9% of samples, with 14.3% of NG/CT coinfection. The most frequent pathogen identified in GU was HSV2, present in 40.8% of the samples, followed by TP at 24.8%, LGV and CMV at 1%, and HSV1 at 0.4%. Coinfection of TP/HSV2 was detected in 4.4% of samples. VZV and HD were not detected. In 27.7% of the GU samples, no pathogen was detected.

CONCLUSION

This study provided the acquisition of unprecedented data on the aetiology of UDS and GUD in Brazil, demonstrated the presence of a variety of pathogens in both sample types and reaffirmed the aetiologies known to be most prevalent globally.

Estimates of the incidence, prevalence, and factors associated with common sexually transmitted infections among Lebanese women

BACKGROUND

We analyzed the prevalence of active infection with common curable sexually transmitted infections (STIs) including N. gonorrhea, C. trachomatis, T. vaginalis, and T. pallidum, as well as active infection with HPV, herpes simplex virus types I (HSV-1) and II (HSV-2), M. hominis, M. genitalium, C. albicans, and Ureaplasma in 351 Lebanese women.

METHODS

A cross-sectional study, involving 351 sexually active women, 40 years or younger, who were recruited from outpatient Obstetrics and Gynecology clinic attendees between September 2016 and November 2017.

RESULTS

The prevalence of active infection was low at 0.3% for N. gonorrhea, 0.6% for HSV-2, 2.8% for C. trachomatis, and 2.9% for any curable STIs. Prevalence of active HPV infection was high assessed at 15.7% for high-risk and 12.2% for low-risk genotypes. Furthermore, the prevalence was 2.0% for M. genitalium, 6.8% for ureaplasma, 13.7% for Candida albicans, and 20.5% for M. hominis. No active infections with T. vaginalis, T. pallidum, or HSV-1 were observed. Significant age differences were noted in the prevalence of high-risk and low-risk HPV genotypes, but no such differences were noted in the prevalence of other infections. No appreciable variations were identified in the prevalence of key STIs based on smoking, marital status, or the number of sexual partners.

CONCLUSIONS

The study documented active infection with substantial prevalence for multiple STIs among women attending outpatient gynecology and obstetrics clinics in Lebanon. These findings underscore the importance of strengthening STI surveillance, linkage to care, and prevention interventions in reducing STI incidence among women.

Prevalence of sexually transmitted infections (STIs), associations with sociodemographic and behavioural factors, and assessment of the syndromic management of vaginal discharge in women with urogenital complaints in Mozambique

In Mozambique, sexually transmitted infections (STIs) are estimated to be prevalent, but diagnosis and treatment of curable STIs rely only on syndromic management. We examined the prevalence of four non-viral STIs and HIV-1/2, based on etiological diagnosis, associations with sociodemographic and behavioural factors, and the STI diagnostic accuracy of the vaginal discharge syndromic management in women with urogenital complaints in Maputo, Mozambique. A cross-sectional study was performed in Maputo, Mozambique, February 2018-January 2019, enrolling 924 women of reproductive age with urogenital complaints. Endocervical/vaginal swabs were sampled and chlamydia, gonorrhoea, trichomoniasis and Mycoplasma genitalium infections were diagnosed using a multiplex real-time PCR (AmpliSens; InterLabServices). Serological testing was performed for HIV-1/2. A structured questionnaire collected metadata. All data were analyzed in STATA/IC 12.1 using descriptive statistics, chi-square tests and logistic regression model. About 40% of the women were less than 24 years old, 50.8% were single, 62.1% had their sexual debut between 12 and 17 years of age, and the main complaint was vaginal discharge syndrome (85%). The prevalence of chlamydia was 15.5%, trichomoniasis 12.1%, gonorrhoea 4.0%, M. genitalium 2.1%, and HIV-1/2 22.3%. The vaginal discharge syndrome flowchart had a sensitivity of 73.0%-82.5% and a specificity of 14%-15% for the detection of any individual non-viral STI in women with urogenital complaints. In total, 19.2% of the symptomatic women with chlamydia, trichomoniasis or gonorrhoea would not be detected and accordingly treated using the vaginal discharge syndromic management (missed treatment) and 70.0% of the women would be treated despite not being infected with any of these three STIs (overtreatment). In conclusion, a high prevalence of especially chlamydia, trichomoniasis, and HIV-1/2 was found in women of childbearing age with urogenital complaints in Maputo, Mozambique. Syndromic management of vaginal discharge revealed low accuracy in the detection of STIs in symptomatic women, especially low specificity, which resulted in under-treatment of STI-positive cases and incorrect or over-treatment of women with urogenital complaints, many of whom were negative for all the non-viral STIs. Etiological diagnosis is imperative for effective management of STIs in symptomatic and asymptomatic women.

Multicentre double-blind randomised placebo-controlled trial evaluating the efficacy of the meningococcal B vaccine, 4CMenB (Bexsero), against Neisseria gonorrhoeae infection in men who have sex with men: the GoGoVax study protocol

INTRODUCTION

Gonorrhoea, the sexually transmissible infection caused by Neisseria gonorrhoeae, has a substantial impact on sexual and reproductive health globally with an estimated 82 million new infections each year worldwide. N. gonorrhoeae antimicrobial resistance continues to escalate, and disease control is largely reliant on effective therapy as there is no proven effective gonococcal vaccine available. However, there is increasing evidence from observational cohort studies that the serogroup B meningococcal vaccine four-component meningitis B vaccine (4CMenB) (Bexsero), licensed to prevent invasive disease caused by Neisseria meningitidis, may provide cross-protection against the closely related bacterium N. gonorrhoeae. This study will evaluate the efficacy of 4CMenB against N. gonorrhoeae infection in men (cis and trans), transwomen and non-binary people who have sex with men (hereafter referred to as GBM+).

METHODS AND ANALYSIS

This is a double-blind, randomised placebo-controlled trial in GBM+, either HIV-negative on pre-exposure prophylaxis against HIV or living with HIV (CD4 count >350 cells/mm3), who have had a diagnosis of gonorrhoea or infectious syphilis in the last 18 months (a key characteristic associated with a high risk of N. gonorrhoeae infection). Participants are randomised 1:1 to receive two doses of 4CMenB or placebo 3 months apart. Participants have 3-monthly visits over 24 months, which include testing for N. gonorrhoeae and other sexually transmissible infections, collection of demographics, sexual behaviour risks and antibiotic use, and collection of research samples for analysis of N. gonorrhoeae-specific systemic and mucosal immune responses. The primary outcome is the incidence of the first episode of N. gonorrhoeae infection, as determined by nucleic acid amplification tests, post month 4. Additional outcomes consider the incidence of symptomatic or asymptomatic N. gonorrhoeae infection at different anatomical sites (ie, urogenital, anorectum or oropharynx), incidence by N. gonorrhoeae genotype and antimicrobial resistance phenotype, and level and functional activity of N. gonorrhoeae-specific antibodies.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the St Vincent's Hospital Human Research Ethics Committee, St Vincent's Hospital Sydney, NSW, Australia (ref: 2020/ETH01084). Results will be disseminated in peer-reviewed journals and via presentation at national and international conferences.

TRIAL REGISTRATION NUMBER

NCT04415424.

Understanding dynamics and overlapping epidemiologies of HIV, HSV-2, chlamydia, gonorrhea, and syphilis in sexual networks of men who have sex with men

Introduction

We aimed to investigate the overlapping epidemiologies of human immunodeficiency virus (HIV), herpes simplex virus type 2 (HSV-2), chlamydia, gonorrhea, and syphilis in sexual networks of men who have sex with men (MSM), and to explore to what extent the epidemiology of one sexually transmitted infection (STI) relates to or differs from that of another STI.

Methods

An individual-based Monte Carlo simulation model was employed to simulate the concurrent transmission of STIs within diverse sexual networks of MSM. The model simulated sexual partnering, birth, death, and STI transmission within each specific sexual network. The model parameters were chosen based on the current knowledge and understanding of the natural history, transmission, and epidemiology of each considered STI. Associations were measured using the Spearman's rank correlation coefficient (SRCC) and maximal information coefficient (MIC).

Results

A total of 500 sexual networks were simulated by varying the mean and variance of the number of partners for both short-term and all partnerships, degree correlation, and clustering coefficient. HSV-2 had the highest current infection prevalence across the simulations, followed by HIV, chlamydia, syphilis, and gonorrhea. Threshold and saturation effects emerged in the relationship between STIs across the simulated networks, and all STIs demonstrated moderate to strong associations. The strongest current infection prevalence association was between HIV and gonorrhea, with an SRCC of 0.84 (95% CI: 0.80-0.87) and an MIC of 0.81 (95% CI: 0.74-0.88). The weakest association was between HSV-2 and syphilis, with an SRCC of 0.54 (95% CI: 0.48-0.59) and an MIC of 0.57 (95% CI, 0.49-0.65). Gonorrhea exhibited the strongest associations with the other STIs while syphilis had the weakest associations. Across the simulated networks, proportions of the population with zero, one, two, three, four, and five concurrent STI infections were 48.6, 37.7, 11.1, 2.4, 0.3, and < 0.1%, respectively. For lifetime exposure to these infections, these proportions were 13.6, 21.0, 22.9, 24.3, 13.4, and 4.8%, respectively.

Conclusion

STI epidemiologies demonstrate substantial overlap and associations, alongside nuanced differences that shape a unique pattern for each STI. Gonorrhea exhibits an "intermediate STI epidemiology," reflected by the highest average correlation coefficient with other STIs.