Global Estimates of the Prevalence and Incidence of Four Curable Sexually Transmitted Infections in 2012 Based on Systematic Review and Global Reporting

Intranasal delivery of Salmonella OMVs decorated with Chlamydia trachomatis antigens induces specific local and systemic immune responses

Chlamydia trachomatis is an obligate intracellular pathogen responsible for the most prevalent bacterial sexually transmitted disease globally. The high prevalence of chlamydial infections underscores the urgent need for licensed and effective vaccines to prevent transmission in populations. Bacterial outer membrane vesicles (OMVs) have emerged as promising mucosal vaccine carriers due to their inherent adjuvant properties and the ability to display heterologous antigens. In this proof-of-concept study, we evaluated the immunogenicity of Salmonella OMVs decorated with C. trachomatis MOMP-derived CTH522 or HtrA antigens in mice. Following a prime-boost intranasal vaccination approach, two OMV-based C. trachomatis vaccines elicited significant humoral responses specific to the antigens in both systemic and vaginal compartments. Furthermore, we demonstrated strong antigen-specific IFN-γ and IL17a responses in splenocytes and cervical lymph node cells of vaccinated mice, indicating CD4+ Th1 and Th17 biased immune responses. Notably, the OMV-CTH522 vaccine also induced the production of spleen-derived CD8+ T cells expressing IFN-γ. In conclusion, these results highlight the potential of OMV-based C. trachomatis vaccines for successful use in future challenge studies and demonstrate the suitability of our modular OMV platform for intranasal vaccine applications.

Novelty in the gut: a review of the gastrointestinal manifestations of syphilis

Syphilis is a systemic infection caused by the spirochete Treponema pallidum. It is transmitted during pregnancy or through sexual contact. Signs and symptoms vary depending on the clinical stage of the disease. Syphilis has been well-studied, and the introduction of penicillin has resulted in a decline in the number of new cases and deaths. Recently, however, there has been a surge in new cases in young people, especially those with human immunodeficiency virus (HIV). This epidemiological shift has been attributed to increased sexual activity, risky sexual behaviors, and immunodeficiency. There is a paucity of data on gastrointestinal (GI) manifestations of syphilis owing to its rarity and lack of physician awareness. T. pallidum can seed to any part of the GI tract, resulting in esophagitis, gastritis, hepatitis, pancreatitis, or proctocolitis. Depending on the affected part of the GI tract, syphilis can present with nausea, vomiting, painless esophageal ulcers, dysphagia, abdominal pain, weight loss due to early satiety, diarrhea, melena, hematochezia, dyschezia, or anorectal ulcers. Given its indolent clinical course and vague presentation, GI syphilis can mimic other GI disorders, which can delay diagnosis and treatment. A detailed medical history, physical examination, serological tests, and endoscopy can provide a definitive diagnosis. Syphilis and its GI complications are usually treated with long-acting intramuscular penicillin benzathine, and rarely with a 14-day course of intravenous penicillin. Herein, we describe the clinical features, etiopathogenesis, diagnosis, and treatment of GI syphilis. This primer should aid clinicians in timely diagnosis and treatment of various presentations of GI syphilis.

Unique T cell signatures associated with reduced Chlamydia trachomatis reinfection in a highly exposed cohort

Chlamydia trachomatis (CT) is the most common bacterial sexually transmitted infection globally. Understanding natural immunity to CT will inform vaccine design. This study aimed to profile immune cells and associated functional features in CT-infected women, and determine immune profiles associated with reduced risk of ascended endometrial CT infection and CT reinfection. PBMCs from CT-exposed women were profiled by mass cytometry and random forest models identified key features that distinguish outcomes. CT+ participants exhibited higher frequencies of CD4+ Th2, Th17, and Th17 DN CD4 T effector memory (TEM) cells than uninfected participants with decreased expression of T cell activation and differentiation markers. No significant differences were detected between women with or without endometrial CT infection. Participants who remained follow-up negative (FU-) showed higher frequencies of CD4 T central memory (TCM) Th1, Th17, Th1/17, and Th17 DN but reduced CD4 TEM Th2 cells than FU+ participants. Expression of markers associated with central memory and Th17 lineage were increased on T cell subsets among FU- participants. These data indicate that peripheral T cells exhibit distinct features associated with resistance to CT reinfection. The highly plastic Th17 lineage appears to contribute to protection. Addressing these immune nuances could promote efficacy of CT vaccines.

GRAPHICAL ABSTRACT

A review of the application of in-vivo confocal microscopy on conjunctival diseases

Over the past few decades, the expanded applications of in-vivo confocal microscopy (IVCM) have greatly enhanced the knowledge of a variety of conjunctival diseases. IVCM allows non-invasively detailed observation of tarsal, palpebral and bulbar conjunctiva, from the superficial to the substantia propria at the cellular level. IVCM has been shown as a powerful tool for the assessment of morphological changes in both physiological and pathological conditions. High-resolution images of different cellular phenotypes, together with quantifiable results, open new insights into understanding the mechanisms of conjunctival diseases, as well as provide valuable and longitudinal information for the diagnosis and therapeutic evaluation. This review aims to provide an overview of the current knowledge on the applications of IVCM on conjunctival disorders, including aging changes, dry eye-related morphological changes, glaucoma and glaucoma surgery-related morphological changes, conjunctival neoplasm, pterygium, allergic conjunctivitis, trachomatous scarring, and the conjunctiva-associated lymphoid tissue (CALT) changes. In this review, we highlight the key findings of previous studies and discusses the current limitations and challenges of IVCM in assessing the structural characteristics of the conjunctiva. Furthermore, we consider possible future directions for unlocking the full potential of IVCM applications. The insights presented here will contribute to a more comprehensive understanding of the applications of IVCM in conjunctival diseases.

Comparison of the urinary microbiome in men who have sex with men with and without Chlamydia trachomatis infection

PURPOSE

The urinary tract is colonized by microbial communities that impact urinary health. Previous studies have suggested that the bacterial composition of the male urinary microbiota is related to STIs. This study assessed the bacterial composition of the urinary microbiome in South African MSM with and without C. trachomatis.

METHODS

This study used urine samples from MSM attending care at the King Edward VIII hospital and the Aurum Institute in Durban, South Africa. A total of 200 samples were tested for C. trachomatis infection using the Applied Biosystems™ TaqMan® Assays. Urinary microbiomes of 23 samples were characterized using 16 S rRNA (V3 and V4) gene sequencing on the Illumina MiSeq platform.

RESULTS

Bacterial taxonomic analysis showed a high abundance of Streptococcus, Corynebacterium, and Staphylococcus in all the sequenced samples. Moreover, Prevotella and Lactobacillus were detected in urine samples of MSM. Alpha diversity metrics showed a slight increase in microbial diversity in C. trachomatis positive samples; however, this was not significant (ANOVA, P > 0.05). Principal coordinates analysis (PCoA) showed that the microbiome of C. trachomatis infected MSM was not clearly different from those uninfected. Distinct bacterial communities were not detected between positive and negative samples (PERMANOVA F1,22= 1.0284, R2 = 0.047%, P = 0.385).

CONCLUSION

Most microbiome studies on MSM to date have focused on the gut microenvironment. Few studies, however, have provided data regarding the normal composition of the male urethral microbiomes or if these microbiomes are associated with male STIs. This study adds to the growing body of knowledge highlighting the urinary microbiome in MSM.

Feasibility and Acceptability of Point-of-Care Testing for Sexually Transmitted Infections in Outpatient Clinics Offering Integrated Services in Eswatini

BACKGROUND

Lack of point-of-care testing (POCT) for sexually transmitted infections (STIs) is a continuing missed opportunity in Sub-Saharan Africa. We assessed feasibility and acceptability of STI POCT in Eswatini.

METHODS

Sexually transmitted infection POCT for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) was piloted among sexually active adults 18 to 45 years old attending 2 urban outpatient clinics offering integrated services. Women were randomized 1:1 to provide urine or vaginal swab, and all men provided urine samples for CT/NG testing using Cepheid CT/NG cartridges on existing GeneXpert platforms. Results were returned in-person or by telephone call. We assessed duration of procedures, participant and health care worker acceptability of services (5-point Likert scale), time spent on STI POCT services, and correlates of CT/NG infection.

RESULTS

Of 250 adults triaged, 99% (248 of 250) accepted STI POCT, including 44% (109 of 248) people living with HIV. Sexually transmitted infection POCT procedures took a median of 3:22 hours. Most adults (90% [224 of 248]) received results within a day (61% same day, 29% next day). CT/NG was detected among 22% (55 of 248): 31 of 55 CT, 21 of 55 NG, and 3 of 55 coinfections. Youth 18 to 25 years old, history of any sexual intercourse, and condomless sex within the previous 7 days were significantly associated with CT/NG detected ( P < 0.05). Most adults with CT/NG were treated (51 of 55 [93%]). Most participants were satisfied with STI POCT (217 of 241 [90%]) and would accept again/recommend it. All 32 health care workers who participated were satisfied with STI POCT.

CONCLUSIONS

Sexually transmitted infection POCT was feasible, acceptable, and identified a high prevalence of STIs, highlighting the urgent need for this testing.

Intradermal administration of novel particulate Chlamydia trachomatis vaccine candidates drives protective immune responses

Chlamydia trachomatis causes the most prevalent bacterial sexually transmitted infection worldwide. Its complex lifecycle and the lack of appropriate antigen delivery vehicles make it difficult to develop an effective C. trachomatis vaccine. Recently, bacterial protein bodies (PBs) have emerged as promising bioparticles for vaccine antigen delivery. By developing a PB-tag for translational fusion, we were able to induce the aggregation of recombinant antigens expressed in Escherichia coli into PBs. Here, we investigated the immunogenicity and efficacy of PBs containing either the C. trachomatis MOMP-derived CTH522-SP or HtrA antigen in mice. Intradermal administration of c-di-AMP-adjuvanted PB-CTH522-SP and PB-HtrA vaccines, produced in an LPS-detoxified E. coli strain, induced antigen-specific cellular immunity, as measured by significant release of IFN-γ and IL17a in draining cervical lymph node and splenic cell cultures. Moreover, significant induction of HtrA-specific IFN-γ expressing CD4+ and CD8+ T cells was detected in the spleens. While immunization with the two PB vaccines led to prominent levels of specific antibodies in both serum and vaginal compartments, only antiserum against PB-CTH522-SP exhibited C. trachomatis-specific neutralization activity. Importantly, intradermal immunization with PB-CTH522-SP significantly reduced bacterial counts following C. trachomatis genital challenge. These data highlight the potential of the PB-based platform for the development of C. trachomatis vaccines.

High rates of Treponema pallidum, Neisseria gonorrhoeae, Chlamydia trachomatis, or Trichomonas vaginalis co-infection in people with HIV: a systematic review and meta-analysis

PURPOSE

People living with HIV (PWH) experience a disproportionate burden of sexually transmitted infections (STIs), leading to more severe health outcomes and increasing the risk of HIV transmission. The presence of untreated STIs can accelerate HIV disease progression, while HIV infection can complicate STI diagnosis and treatment. Despite this interconnectedness, comprehensive data on the global prevalence of specific STIs among PWH remain limited. This systematic review aims to synthesize existing data to provide a more accurate picture of the prevalence of co-infection with Treponema pallidum, Neisseria gonorrhoeae, Chlamydia trachomatis or Trichomonas vaginalis in PWH, while also identifying critical knowledge gaps and informing future research priorities.

METHODS

We searched databases for eligible studies reporting the prevalence of Treponema pallidum, Neisseria gonorrhoeae, Chlamydia trachomatis, or Trichomonas vaginalis among PWH, published from January 1, 2000, to February 1, 2023. From 22,290 identified articles, 127 independent studies meeting the inclusion criteria were included in this meta-analysis.

RESULTS

The overall global co-infection prevalence of Treponema pallidum, Neisseria gonorrhoeae, Chlamydia trachomatis, and Trichomonas vaginalis in PWH, was 4.8% (95%CI: 4.7-5.0%), 0.8% (95%CI: 0.6-0.9%), 2.5% (95%CI: 2.2-2.7%), and 3.0% (95%CI: 2.7-3.3%), respectively. The global prevalence of these four STIs in PWH is high, especially in Africa and Southeast Asia and in MSM and TGW populations. Based on the subgroup analyses, we further found that there was a high prevalence of Treponema pallidum and Chlamydia trachomatis in Southeast Asia and a high infection of Trichomonas vaginalis in the whole of Africa. Treponema pallidum infection was more common in males than females, and Chlamydia trachomatis and Trichomonas vaginalis infections were more common in females than males. Besides, high infection rates of Treponema pallidum, Neisseria gonorrhoeae, and Chlamydia trachomatis were detected in men who have sex with men (MSM) + transgender women (TGW), while high infection rates of Trichomonas vaginalis were found in sex workers and pregnant women.

CONCLUSION

The study confirmed high prevalence of four sexually transmitted pathogens in PWH, noting regional, gender, and subpopulation-specific differences. It offered insights for targeted interventions and healthcare strategies. The research underscored the necessity for enhanced data collection and expanded screening/treatment for vulnerable populations and regions.

Chlamydia trachomatis modulates the expression of JAK-STAT signaling components to attenuate the type II interferon response of epithelial cells

Chlamydia trachomatis has adapted to subvert signaling in epithelial cells to ensure successful intracellular development. Interferon-γ (IFNγ) produced by recruited lymphocytes signals through the JAK/STAT pathway to restrict chlamydial growth in the genital tract. However, during Chlamydia infection in vitro, addition of IFNγ does not fully induce nuclear localization of its transcription factor STAT1 and expression of its target gene, IDO1. We hypothesize that this altered interferon response is a result of Chlamydia targeting components of the IFNγ-JAK/STAT pathway. To assess the ability of replicating Chlamydia to dampen interferon signaling, HEp2 human epithelial cells were infected with C. trachomatis serovar L2 for 24 hours prior to exposure to physiologically relevant levels of IFNγ (500 pg/mL). This novel approach enabled us to observe reduced phospho-activation of both STAT1 and its kinase Janus Kinase 2 (JAK2) in infected cells compared with mock-infected cells. Importantly, basal JAK2 and STAT1 transcript and protein levels were dampened by infection even in the absence of interferon, which could have implications for cytokine signaling beyond IFNγ. Additionally, target genes IRF1, GBP1, APOL3, IDO1, and SOCS1 were not fully induced in response to IFNγ exposure. Infection-dependent decreases in transcript, protein, and phosphoprotein were rescued when de novo bacterial protein synthesis was inhibited with chloramphenicol, restoring expression of IFNγ-target genes. Similar Chlamydia-dependent dampening of STAT1 and JAK2 transcript levels was observed in infected HeLa and END1 endocervical cells and in HEp2s infected with C. trachomatis serovar D, suggesting a conserved mechanism of dampening the interferon response by reducing the availability of key signaling components.

IMPORTANCE

As an obligate intracellular pathogen that has evolved to infect the genital epithelium, Chlamydia has developed strategies to prevent detection and antimicrobial signaling in its host to ensure its survival and spread. A major player in clearing Chlamydia infections is the inflammatory cytokine interferon-γ (IFNγ), which is produced by immune cells that are recruited to the site of infection. Reports of IFNγ levels in endocervical specimens from Chlamydia-infected patients range from 1 to 350 pg/mL, while most in vitro studies of the effects of IFNγ on chlamydial growth have used 15-85-fold higher concentrations. By using physiologically relevant concentrations of IFNγ, we were able to assess Chlamydia's ability to modulate its signaling. We found that Chlamydia decreases the expression of multiple components that are required for inducing gene expression by IFNγ, providing a possible mechanism by which Chlamydia trachomatis can attenuate the immune response in the female genital tract to cause long-term infections.

Epidemic of multiple Treponema pallidum strains in men who have sex with men in Japan: efficient multi-locus sequence typing scheme and indicator biomarkers

BACKGROUND

The challenges in culturing Treponema pallidum have hindered molecular-biological analysis. This study aims to establish a molecular epidemiological analysis of syphilis among Japanese men who have sex with men (MSM) and to investigate the relationship between bacteremia and associated pathophysiology.

METHODS

We used whole blood specimens from syphilis-diagnosed individuals in Tokyo, collected between February 2019 and June 2022. All individuals were MSM, and most were people with HIV (97.2%). We used a multi-locus sequence typing (MLST) scheme for epidemiological analysis. Sequences for MLST (TP0136, TP0548, and TP0705) were obtained.

RESULTS

Out of 71 whole blood samples, 26 samples (36.6%) were positive for TP0136, and we sequenced three loci for MLST in 22 samples (31.0%). The most frequently detected sequence type (ST) was ST3 (n = 9), followed by ST6 (n = 6). Phylogenetic analysis revealed that 12 samples belonged to the SS14-like group (60%), and 8 samples belonged to the Nichols-like group (40%). Treponema pallidum subsp. endemicum (TEN), the cause of bejel was detected in three samples (12%). There was a significant association between TP0136 detection rate and C- reactive protein (CRP) (77.0% at a cut-off:0.5 mg/dL).

CONCLUSION

Both SS14-like and Nichols-like strains were circulating concurrently, and TEN could have been sexually transmitted among MSM with HIV. Elevated CRP may indicate the presence of the pathogen in the blood.

Risk factors of severe Chlamydia trachomatis pneumonia in children: a retrospective case-control study

This study explored the clinical characteristics of Chlamydia trachomatis (C. trachomatis) pneumonia in children and the risk factors for severe C. trachomatis pneumonia. This retrospective case-control study included children with C. trachomatis pneumonia who were admitted to the Department of Pediatrics, Women and Children's Hospital, School of Medicine, Xiamen University (Xiamen, China) between January 2018 and December 2021. Among 117 children, 33 (28.2%) had severe C. trachomatis pneumonia and 84 children had mild-to-moderate C. trachomatis pneumonia. According to the results of the binary logistic regression analysis, congenital heart disease [odds ratio (OR) = 0.09, 95% confidence interval (CI): 0.01-0.74, P-value = .024], mixed infection (OR = 0.17, 95%CI: 0.05-0.51, P-value = .002), white blood cell count greater than 15 000 cells/dl (OR = 1.20, 95%CI: 1.03-1.40, P-value = .022), and partial pressure of carbon dioxide (PaCO2) (OR = 1.14, 95%CI: 1.02-1.26, P-value = .016) were found as independent predictive factors for severe C. trachomatis pneumonia in children. This study explored key risk factors for severe C. trachomatis pneumonia, a condition underreported in tropical regions where pediatric respiratory infections are a leading cause of morbidity and mortality. By identifying risk factors, such as congenital heart disease, mixed infections, and elevated PaCO2, this research may guide early intervention strategies in resource-limited settings, potentially reducing pediatric pneumonia deaths.

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.

Viral-vectored boosting of OmcB- or CPAF-specific T-cell responses fail to enhance protection from Chlamydia muridarum in infection-immune mice and elicits a non-protective CD8-dominant response in naïve mice

A vaccine is needed to combat the Chlamydia epidemic. Replication-deficient viral vectors are safe and induce antigen-specific T-cell memory. We tested the ability of intramuscular immunization with modified vaccinia Ankara (MVA) virus or chimpanzee adenovirus (ChAd) expressing chlamydial outer membrane protein (OmcB) or the secreted protein, chlamydial protease-like activating factor (CPAF), to enhance T-cell immunity and protection in mice previously infected with plasmid-deficient Chlamydia muridarum CM972 and elicit protection in naïve mice. MVA.OmcB or MVA.CPAF increased antigen-specific T cells in CM972-immune mice ∼150 and 50-fold, respectively, but failed to improve bacterial clearance. ChAd.OmcB/MVA.OmcB prime-boost immunization of naïve mice elicited a cluster of differentiation (CD) 8-dominant T-cell response dominated by cluster of differentiation (CD)8 T cells that failed to protect. ChAd.CPAF/ChAd.CPAF prime-boost also induced a CD8-dominant response with a marginal reduction in burden. Challenge of ChAd.CPAF-immunized mice genetically deficient in CD4 or CD8 T cells showed that protection was entirely CD4-dependent. CD4-deficient mice had prolonged infection, whereas CD8-deficient mice had higher frequencies of CPAF-specific CD4 T cells, earlier clearance, and reduced burden than wild-type controls. These data reinforce the essential nature of the CD4 T-cell response in protection from chlamydial genital infection in mice and the need for vaccine platforms that drive CD4-dominant responses.

Identifying the Impact of Chlamydia trachomatis Screening and Treatment on Mother-to-Child Transmission, and Respiratory Neonatal Outcomes in Mexico

Chlamydia trachomatis (C. trachomatis) screening and treatment in pregnancy allows the opportunity to reduce adverse pregnancy and neonatal outcomes worldwide. Although C. trachomatis infection is easily treated and cured with antibiotics, only some countries have routine pregnancy screening and treatment programs. We therefore evaluated whether just one maternal screening for C. trachomatis is enough to prevent adverse pregnancy and negative neonatal outcomes. Among the 4087 first-time gynecological-obstetric consultations granted at the National Institute of Perinatology in 2018, we selected the study population according to a case-cohort design. Antenatal C. trachomatis screening and treatment interventions were performed on 628 pregnant women using COBAS® TaqMan CT. C. trachomatis DNA was also detected in samples from 157 infants of these mothers. In the maternal cohort, incidence of C. trachomatis infection was 10.5%. The vertical transmission rate was 1.5% for the cohort of mothers who tested positive for C. trachomatis and received treatment, and 29.7% for those with a negative test. By evaluating symptomatic neonatal infection, the hazard rate of perinatal pneumonia was 3.6 times higher in C. trachomatis-positive babies than in C. trachomatis-negative babies. Despite the low rate of mother-to-child transmission in women positive for C. trachomatis, possible maternal infection that is not detected in pregnancy significantly increases the risk of neonatal infection with consequent perinatal pneumonia.

Intranasal immunization with CPAF combined with cyclic-di-AMP induces a memory CD4 T cell response and reduces bacterial burden following intravaginal infection with Chlamydia muridarum

Chlamydia trachomatis (Ct) is the most common bacterial sexually transmitted infection globally, and a vaccine is urgently needed to stop transmission and disease. Chlamydial Protease Activity Factor (CPAF) is an immunoprevalent and immunodominant antigen for CD4 T cells and B cells, which makes it a strong vaccine candidate. Due to the tolerogenic nature of the female genital tract (FGT) and its lack of secondary lymphoid tissue, effective induction of protective cell-mediated immunity will likely require potent and safe mucosal adjuvants. To address this need, we produced CPAF in a cell-free protein synthesis platform and adjuvanted it with the TLR9-agonist CpG1826, STING (stimulator of interferon genes) agonist cyclic-di-AMP (CDA), and/or the squalene oil-in-water nanoemulsion, AddaS03. We determined that intranasal immunization with CPAF plus CDA was well tolerated in female mice, induced CD4 T cells that produced IL-17A or IFNγ, significantly reduced bacterial shedding, and shortened the duration of infection in mice intravaginally challenged with Chlamydia muridarum . These data demonstrate the potential for CDA as a mucosal adjuvant for vaccines against Chlamydia genital tract infection.

Interferon-γ Responses to Chlamydia trachomatis Vaccine Candidate Proteins in Women With Different Chlamydia Outcomes

BACKGROUND

Chlamydia trachomatis testing and treatment strategies have not decreased infection rates, justifying need for a chlamydia vaccine. A murine study showed that a vaccine consisting of major outer membrane protein (MOMP) and polymorphic membrane proteins (Pmps) E, F, G, and H elicited protective immunity; studies on human cellular immune responses to Pmps are sparse.

METHODS

Interferon gamma (IFN-γ) responses to these 5 proteins were measured by ELISPOT in peripheral blood mononuclear cells from women returning for treatment of a positive chlamydia test. Responses were compared in those with spontaneous chlamydia clearance versus persisting infection at baseline and no reinfection versus reinfection at a 3-month follow-up visit.

RESULTS

IFN-γ response to 1 or more proteins was detected in 39% at baseline and 51.5% at follow-up, most often to PmpE and MOMP. IFN-γ responses to MOMP were detected less often at follow-up versus baseline in women with reinfection, but were maintained in those without reinfection. Women with spontaneous clearance had a higher magnitude of IFN-γ response to PmpE and MOMP.

CONCLUSIONS

IFN-γ responses to these 5 C. trachomatis vaccine candidate proteins were heterogenous and primarily directed against MOMP and PmpE. Spontaneous chlamydia clearance and absence of reinfection may be clinical correlates of protection.

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.

Serological Responses to Trachoma Antigens prior to the Start of Mass Drug Administration: Results from Population-Based Baseline Surveys, North Darfur, Sudan

After years of programmatic inaccessibility, in 2019-2020 the Sudan Federal Ministry of Health Trachoma Control Program conducted population-based trachoma surveys in three localities (districts) in North Darfur state, Sudan. These baseline surveys were to determine the prevalence of trachomatous inflammation-follicular (TF) among children aged 1-9 years and to further use serological markers to understand the historical trachoma burden within this mass drug administration (MDA)-naive area. Trained and certified graders collected trachoma clinical data, and trained nurses collected dried blood spot (DBS) samples. The DBSs were assayed on a multiplex bead array for antibody responses to the Chlamydia trachomatis antigens Pgp3 and CT694. Across the three localities, 3,613 individuals aged 1-9 years and 3,542 individuals aged ≥15 years were examined for clinical signs, and 8,322 DBSs were collected. The prevalence of TF among children aged 1-9 years was endemic (≥5%) in two localities (El Seraif, 15.6%, and Saraf Omrah, 11.0%) and below the TF elimination threshold (<5%) in the third (Kotom, 1.4%). The Pgp3 seroprevalence among children aged 1-9 years was 34.1% in El Seraif, 35.0% in Saraf Omrah, and 11.0% in Kotom. Locality prevalence results were similar for Pgp3 and CT694. Seroprevalence increased with age in all three localities. Serological data collected within these surveys demonstrate that all three localities have had a long history of exposure to Chlamydia trachomatis and that two of the three localities require MDA to reach elimination as a public health problem threshold.

Detection of Trichomonas vaginalis by microscopy and molecular methods in women referred to health centers in Tabriz, Northwest Iran

Trichomoniasis is a parasitic disease that affects the human reproductive and urinary systems, representing a substantial non-viral sexually transmitted infection worldwide. Given its impact on reproductive health, and the limited available information on the prevalence of Trichomonas vaginalis, this study aimed to evaluate the prevalence of T. vaginalis among women referred to health centers in Tabriz, Northwest Iran. Study was conducted on 448 suspicious women who attended to 29Bahman hospital in Tabriz, Northwest Iran, during September 2020 to September 2021. Demographic data were collected according to the study protocol. Vaginal discharges were obtained using sterile swabs, and the prevalence of T. vaginalis was determined using Papanicolauo staining and PCR method. Among the 448 cases studied, 48 (10.7%) samples were suspected as a T. vaginalis infection, while 4 (0.89%) confirmed using the PCR method. The mean age of infected individuals was 41.7 ± 9.4 years. No statistical correlation was observed between inflammation, method of contraception and infection (p = 0.8). The present study revealed a relatively low prevalence of T. vaginalis infection within the study population. Additionally, the utilization of the PCR method can be beneficial in confirming suspected samples.

Dynamics of Neisseria gonorrhoeae transmission among female sex workers and clients: A mathematical modeling study

BACKGROUND

This study aimed to examine the transmission dynamics of Neisseria gonorrhoeae (NG) in heterosexual sex work networks (HSWNs) and the impact of variation in sexual behavior and interventions on NG epidemiology.

METHODS

The study employed an individual-based mathematical model to simulate NG transmission dynamics in sexual networks involving female sex workers (FSWs) and their clients, primarily focusing on the Middle East and North Africa region. A deterministic model was also used to describe NG transmission from clients to their spouses.

RESULTS

NG epidemiology in HSWNs displays two distinct patterns. In the common low-partner-number HSWNs, a significant proportion of NG incidence occurs among FSWs, with NG prevalence 13 times higher among FSWs than clients, and three times higher among clients than their spouses. Interventions substantially reduce incidence. Increasing condom use from 10 % to 50 % lowers NG prevalence among FSWs, clients, and their spouses from 12.2 % to 6.4 %, 1.2 % to 0.5 %, and 0.4 % to 0.2 %, respectively. Increasing symptomatic treatment coverage among FSWs from 0 % to 100 % decreases prevalence from 10.6 % to 4.5 %, 0.8 % to 0.4 %, and 0.3 % to 0.1 %, respectively. Increasing asymptomatic treatment coverage among FSWs from 0 % to 50 % decreases prevalence from 8.2 % to 0.4 %, 0.6 % to 0.1 %, and 0.2 % to 0.0 %, respectively, with very low prevalence when coverage exceeds 50 %. In high-partner-number HSWNs, prevalence among FSWs saturates at a high level, and the vast majority of incidence occurs among clients and their spouses, with a limited impact of incremental increases in interventions.

CONCLUSION

NG epidemiology in HSWNs is typically a "fragile epidemiology" that is responsive to a range of interventions even if the interventions are incremental, partially efficacious, and only applied to FSWs.

Immunohistochemistry and RT-PCR as ancillary tools in the diagnosis of acquired oral syphilis

OBJECTIVE

To investigate Treponema pallidum detection using immunohistochemistry (IHC) and reverse transcription-polymerase chain reaction (RT-PCR) assays in acquired oral syphilis (AOS).

MATERIALS AND METHODS

Thirty-seven paraffin-embedded tissue specimens of AOS (32 secondary and five primary) were analyzed, integrating double-positive serological results with clinicodemographic and histopathological data. T. pallidum presence was semiquantitatively assessed by IHC, while RT-PCR targeted T. pallidum DNA. Sensitivity, specificity, and the area under the curve (AUC) were calculated with 95% confidence intervals (CI).

RESULTS

The study included mostly females (62.2%) with a mean age of 27.1 years. T. pallidum was detected in all samples by IHC, predominantly in the epithelium across all layers (43.2%). RT-PCR identified T. pallidum DNA in 32 cases, with negative results observed in cases of secondary AOS. The AUC for IHC versus disease stage was 62.5% (95% CI: 45.1-77.8), and for RT-PCR, it was 57.8% (95% CI: 40.5-73.8). The AUC comparing IHC to RT-PCR was 83.8% (95% CI: 67.9-93.8).

CONCLUSION

This study represents the first attempt to evaluate the proposed direct detection algorithm for AOS. IHC and RT-PCR serve as ancillary tools for detecting T. pallidum in both primary and secondary stages of AOS.

Evaluation of artificial intelligence-powered screening for sexually transmitted infections-related skin lesions using clinical images and metadata

BACKGROUND

Sexually transmitted infections (STIs) pose a significant global public health challenge. Early diagnosis and treatment reduce STI transmission, but rely on recognising symptoms and care-seeking behaviour of the individual. Digital health software that distinguishes STI skin conditions could improve health-seeking behaviour. We developed and evaluated a deep learning model to differentiate STIs from non-STIs based on clinical images and symptoms.

METHODS

We used 4913 clinical images of genital lesions and metadata from the Melbourne Sexual Health Centre collected during 2010-2023. We developed two binary classification models to distinguish STIs from non-STIs: (1) a convolutional neural network (CNN) using images only and (2) an integrated model combining both CNN and fully connected neural network (FCN) using images and metadata. We evaluated the model performance by the area under the ROC curve (AUC) and assessed metadata contributions to the Image-only model.

RESULTS

Our study included 1583 STI and 3330 non-STI images. Common STI diagnoses were syphilis (34.6%), genital warts (24.5%) and herpes (19.4%), while most non-STIs (80.3%) were conditions such as dermatitis, lichen sclerosis and balanitis. In both STI and non-STI groups, the most frequently observed groups were 25-34 years (48.6% and 38.2%, respectively) and heterosexual males (60.3% and 45.9%, respectively). The Image-only model showed a reasonable performance with an AUC of 0.859 (SD 0.013). The Image + Metadata model achieved a significantly higher AUC of 0.893 (SD 0.018) compared to the Image-only model (p < 0.01). Out of 21 metadata, the integration of demographic and dermatological metadata led to the most significant improvement in model performance, increasing AUC by 6.7% compared to the baseline Image-only model.

CONCLUSIONS

The Image + Metadata model outperformed the Image-only model in distinguishing STIs from other skin conditions. Using it as a screening tool in a clinical setting may require further development and evaluation with larger datasets.

Structural Assessment of Chlamydia trachomatis Major Outer Membrane Protein (MOMP)-Derived Vaccine Antigens and Immunological Profiling in Mice with Different Genetic Backgrounds

Chlamydia trachomatis (Ct) is the most common cause of bacterial sexually transmitted infections (STIs) worldwide. Ct infections are often asymptomatic in women, leading to severe reproductive tract sequelae. Development of a vaccine against Chlamydia is crucial. The Chlamydia major outer membrane protein (MOMP) is a prime vaccine antigen candidate, and it can elicit both neutralizing antibodies and protective CD4+ T cell responses. We have previously designed chimeric antigens composed of immunogenic variable regions (VDs) and conserved regions (CDs) of MOMP from Chlamydia muridarum (Cm) expressed into a carrier protein (PorB), and we have shown that these were protective in a mouse model of Cm respiratory infection. Here, we generated corresponding constructs based on MOMP from Ct serovar F. Preliminary structure analysis of the three antigens, PorB/VD1-3, PorB/VD1-4 and PorB/VD1-2-4, showed that they retained structure features consistent with those of PorB. The antigens induced robust humoral and cellular responses in mice with different genetic backgrounds. The antibodies were cross-reactive against Ct, but only anti-PorB/VD1-4 and anti-PorB/VD1-2-4 IgG antibodies were neutralizing, likely due to the antigen specificity. The cellular responses included proliferation in vitro and production of IFN-γ by splenocytes following Ct re-stimulation. Our results support further investigation of the PorB/VD antigens as potential protective candidates for a Chlamydia subunit vaccine.

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.

Combination of compound screening with an animal model identifies pentamidine to prevent Chlamydia trachomatis infection

Chlamydia trachomatis (Ct) is the most common cause for bacterial sexually transmitted infections (STIs) worldwide with a tremendous impact on public health. With the aim to unravel novel targets of the chlamydia life cycle, we screen a compound library and identify 28 agents to significantly reduce Ct growth. The known anti-infective agent pentamidine-one of the top candidates of the screen-shows anti-chlamydia activity in low concentrations by changing the metabolism of host cells impairing chlamydia growth. Furthermore, it effectively decreases the Ct burden upon local or systemic application in mice. Pentamidine also inhibits the growth of Neisseria gonorrhea (Ng), which is a common co-infection of Ct. The conducted compound screen is powerful in exploring antimicrobial compounds against Ct in a medium-throughput format. Following thorough in vitro and in vivo assessments, pentamidine emerges as a promising agent for topical prophylaxis or treatment against Ct and possibly other bacterial STIs.

Structure-Based Design and Synthesis of Covalent Inhibitors for Deubiquitinase and Acetyltransferase ChlaDUB1 of Chlamydia trachomatis

Upon infection by an intracellular pathogen, host cells activate apoptotic pathways to limit pathogen replication. Consequently, efficient proliferation of the obligate intracellular pathogen Chlamydia trachomatis, a major cause of trachoma and sexually transmitted diseases, depends on the suppression of host cell apoptosis. C. trachomatis secretes deubiquitinase ChlaDUB1 into the host cell, leading among other interactions to the stabilization of antiapoptotic proteins and, thus, suppression of host cell apoptosis. Targeting the bacterial effector protein may, therefore, lead to new therapeutic possibilities. To explore the active site of ChlaDUB1, an iterative cycle of computational docking, synthesis, and enzymatic screening was applied with the aim of lead structure development. Hereby, covalent inhibitors were developed, which show enhanced inhibition with a 22-fold increase in IC50 values compared to previous work. Comprehensive insights into the binding prerequisites to ChlaDUB1 are provided, establishing the foundation for an additional specific antichlamydial therapy by small molecules.

Structural analysis of resistance-nodulation cell division transporters

SUMMARYInfectious bacteria have both intrinsic and acquired mechanisms to combat harmful biocides that enter the cell. Through adaptive pressures, many of these pathogens have become resistant to many, if not all, of the current antibiotics used today to treat these often deadly infections. One prominent mechanism is the upregulation of efflux systems, especially the resistance-nodulation-cell division class of exporters. These tripartite systems consist of an inner membrane transporter coupled with a periplasmic adaptor protein and an outer membrane channel to efficiently transport a diverse array of substrates from inside the cell to the extracellular space. Detailed mechanistic insight into how these inner membrane transporters recognize and shuttle their substrates can ultimately inform both new antibiotic and efflux pump inhibitor design. This review examines the structural basis of substrate recognition of these pumps and the molecular mechanisms underlying multidrug extrusion, which in turn mediate antimicrobial resistance in bacterial pathogens.

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.

Chlamydia trachomatis induces disassembly of the primary cilium to promote the intracellular infection

Chlamydia trachomatis is a clinically important bacterium that infects epithelial cells of the genitourinary and respiratory tracts and the eye. These differentiated cells are in a quiescent growth state and have a surface organelle called a primary cilium, but the standard Chlamydia cell culture infection model uses cycling cells that lack primary cilia. To investigate if these differences are relevant, we performed infections with host cells that have a primary cilium. We found that C. trachomatis caused progressive loss of the primary cilium that was prevented by disrupting Aurora A (AurA), HDAC6 or calmodulin, which are components of the cellular cilia disassembly pathway. Stabilization of the primary cilium by targeting this pathway caused a large reduction in infectious progeny although there were no changes in chlamydial inclusion growth, chlamydial replication or the ultrastructural appearance of dividing and infectious forms (RBs and EBs, respectively). Thus, the presence of a primary cilium interfered with the production of infectious EBs at a late step in the developmental cycle. C. trachomatis infection also induced quiescent cells to re-enter the cell cycle, as detected by EdU incorporation in S-phase, and Chlamydia-induced cilia disassembly was necessary for cell cycle re-entry. This study therefore describes a novel host-pathogen interaction in which the primary cilium limits a productive Chlamydia infection, and the bacterium counteracts this host cell defense by activating the cellular cilia disassembly pathway.

Time trends in positive gonorrhoea diagnoses at the Christchurch Sexual Health Service (2012-2022): a data audit study

Background Gonorrhoea infections and antimicrobial resistance are rising in many countries, particularly among men who have sex with men, and an increasing proportion of infection is detected at extragenital sites. This study assessed trends in gonorrhoea diagnoses and antibiotic resistance at a sexual health service in New Zealand that followed national guidelines for specimen collection. Methods Routinely-collected data from Canterbury Health Laboratories of specimens taken at the Christchurch Sexual Health Service 2012-2022 were audited. Descriptive results included the number of patient testing events positive for gonorrhoea per year and site of infection (extragenital/urogenital). Annual test-positivity was calculated (number of positive patient testing events divided by total number of testing events) and the Cochran-Armitage Test for Trend was used to assess whether there was an association between test-positivity and year. Results Of 52,789 patient testing events, 1467 (2.8%) were positive for gonorrhoea (81% male). Half (49.3%) of people (57.9% of males, 12.2% of females) with a gonorrhoea infection had an extragenital infection in the absence of a urogenital infection. The number of extragenital infections increased at a faster rate than urogenital among males. Test-positivity increased from 1.3% in 2012 to 5.8% in 2022 (P Conclusions This study highlights the importance of extragenital sampling and maintaining bacterial culture methods for accurate diagnosis and treatment. The observation that gonorrhoea positivity rate and antimicrobial resistance rates are rising in New Zealand calls for urgent action.

A systematic review of barriers and facilitators to antenatal screening for HIV, syphilis or hepatitis B in Asia: Perspectives of pregnant women, their relatives and health care providers

BACKGROUND

Despite improvements, the prevalence of HIV, syphilis, and hepatitis B remains high in Asia. These sexually transmitted infections (STIs) can be transmitted from infected mothers to their children. Antenatal screening and treatment are effective interventions to prevent mother-to-child transmission (MTCT), but coverage of antenatal screening remains low. Understanding factors influencing antenatal screening is essential to increase its uptake and design effective interventions. This systematic literature review aims to investigate barriers and facilitators to antenatal screening for HIV, syphilis, and hepatitis B in Asia.

METHODS

We conducted a systematic review by searching Ovid (MEDLINE, Embase, PsycINFO), Scopus, Global Index Medicus and Web of Science for published articles between January 2000 and June 2023, and screening abstracts and full articles. Eligible studies include peer-reviewed journal articles of quantitative, qualitative and mixed-method studies that explored factors influencing the use of antenatal screening for HIV, syphilis or hepatitis B in Asia. We extracted key information including study characteristics, sample, aim, identified barriers and facilitators to screening. We conducted a narrative synthesis to summarise the findings and presented barriers and facilitators following Andersen's conceptual model.

RESULTS

The literature search revealed 23 articles suitable for inclusion, 19 used quantitative methods, 3 qualitative and one mixed method. We found only three studies on syphilis screening and one on hepatitis B. The analysis demonstrates that antenatal screening for HIV in Asia is influenced by many barriers and facilitators including (1) predisposing characteristics of pregnant women (age, education level, knowledge) (2) enabling factors (wealth, place of residence, husband support, health facilities characteristics, health workers support and training) (3) need factors of pregnant women (risk perception, perceived benefits of screening).

CONCLUSION

Knowledge of identified barriers to antenatal screening may support implementation of appropriate interventions to prevent MTCT and help countries achieve Sustainable Development Goals' targets for HIV and STIs.

Asymptomatic infections with Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis among women in low- and middle-income countries: A systematic review and meta-analysis

Syndromic management of sexually transmitted infections (STIs) is common in settings with limited access to diagnostic testing. However, this approach does not capture asymptomatic STIs. Untreated asymptomatic infections may result in serious complications and sequelae in women. We aimed to estimate the proportion and the prevalence of asymptomatic Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), and Trichomonas vaginalis (TV) infections among women in low- and middle-income countries. We searched Medline, Scopus, and Web of Science for articles published between 2000 and 2022. We used random effect models to compute the proportion and prevalence estimates and performed sub-group analysis. We evaluated the quality of each article using the Appraisal tool for Cross-Sectional Studies and performed sensitivity analyses. This study was registered with PROSPERO, CRD42022286673. Forty-eight eligible studies were included. The proportion of asymptomatic CT, NG, and TV infections were: 60.7% [95% Confidence Interval (CI): 50.4; 70.5], 53.3% [37.1; 69.1], and 56.9% [44.6; 68.9], respectively. The proportion of women with asymptomatic infections was the highest in Africa for the three pathogens. The pooled prevalence of asymptomatic CT, NG, and TV infection was 4.70 per 100 women [95%CI: 3.39; 6.20], 3.11 [1.34; 5.54], and 5.98 [3.46; 9.12], respectively. More than half of the women infected by CT, NG, or TV were asymptomatic. To avoid undiagnosed and untreated asymptomatic infections leading to complications, alternative approaches to syndromic management urgently need to be considered.

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.

Accuracy of self-collected versus healthcare worker collected specimens for diagnosing sexually transmitted infections in females: an updated systematic review and meta-analysis

The use of self-collected specimens as an alternative to healthcare worker-collected specimens for diagnostic testing has gained increasing attention in recent years. This systematic review aimed to assess the diagnostic accuracy of self-collected specimens compared to healthcare worker-collected specimens across different sexually transmitted infections (STIs) including Chlamydia trachomatis (CT), human papillomavirus (HPV), Mycoplasma genitalium (MG), Neisseria gonorrhoea (NG), Treponema pallidum and Trichomonas vaginalis (TV) in females. A rigorous process was followed to screen for studies in various electronic databases. The quality of included studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 tool. There were no studies on syphilis that met the criteria for inclusion in the review. A total of six studies for chlamydia, five studies for HPV, four studies for MG, and seven studies for gonorrhoea and trichomoniasis were included in the review. However, not all studies were included in the sub-group meta-analysis. The analysis revealed that self-collected specimens demonstrated comparable diagnostic accuracy to healthcare worker-collected specimens across most STIs. This indicates that the diagnostic accuracy of self-collected specimens can provide accurate results and enhance access to diagnostic testing, potentially improving healthcare service delivery. Future research should further explore the diagnostic accuracy of self-collected specimens in larger and more diverse populations.

Retrospective Cohort Study of Syphilis-Related Stillbirths in Winnipeg, Manitoba From 2017-2020

OBJECTIVE

Syphilis-related stillbirths (SRSBs) disproportionately affect marginalized women with 11% of all local stillbirths having maternal syphilis as a contributory factor in 2020. This study describes the incidence and perinatal factors associated with SRSB.

METHODS

This was a retrospective cohort study of all stillbirths occurring from 1 January 2017 to 31 December 2020, at a single tertiary-level referral hospital in Winnipeg, Manitoba. Cases that met criteria for SRSB were identified from hospital records and included in the final analysis. Maternal demographics, comorbidities, prenatal care attendance, sexually transmitted infection testing, treatment, and diagnostic investigations at time of stillbirth were collected from hospital charts using a standardized data collection form. Descriptive statistics were performed to present the results.

RESULTS

The proportion of SRSB increased over the period of study from 0%-11%. Eleven cases were identified as SRSB, with diagnosis occurring intrapartum in 7 cases and antenatally in 4 cases. Of the 4 antenatal cases, only 2 had identifiable treatment responses indicated by microbiological and pathology workup. Commonly identified risk factors for SRSB were homelessness, mental illness, substance use, sexually transmitted co-infections, and lack of prenatal care.

CONCLUSIONS

Cases of SRSB are rising in Winnipeg with 11% of all stillbirths having maternal syphilis as a contributory factor by 2020. SRSBs disproportionately affect marginalized women. The dramatic and rapid changes in the epidemiology of syphilis in Winnipeg are likely shared by other Canadian regions and warrant increased prevention strategies to improve outcomes.

Addressing Sexually Transmitted Infections Due to Neisseria gonorrhoeae in the Present and Future

It was in the 1800s when the first public publications about the infection and treatment of gonorrhoea were released. However, the first prevention programmes were only published a hundred years later. In the 1940s, the concept of vaccination was introduced into clinical prevention programmes to address early sulphonamide resistance. Since then, tons of publications on Neisseria gonorrhoeae are undisputed, around 30,000 publications today. Currently, the situation seems to be just as it was in the last century, nothing has changed or improved. So, what are we doing wrong? And more importantly, what might we do? The review presented here aims to review the current situation regarding the resistance mechanisms, prevention programmes, treatments, and vaccines, with the challenge of better understanding this special pathogen. The authors have reviewed the last five years of advancements, knowledge, and perspectives for addressing the Neisseria gonorrhoeae issue, focusing on new therapeutic alternatives.

Sexually Transmitted Infections in Adolescents and Young Adults: A Cross Section of Public Health

INTRODUCTION

Sexually transmitted infections (STIs) can be caused by a number of microorganisms that vary greatly in size, life cycle, clinical manifestations, and sensitivity to available treatments. Transmission of STIs can occur during unprotected (or condomless) sexual contact and through the exchange of body fluids during any type of activity. The prevalence of sexually transmitted diseases remains high in the world, despite diagnostic and therapeutic improvements for these infectious diseases that rapidly eliminate the contagiousness of patients. Our study determines the prevalence of STI pathogens in adolescents and young adults in the population of the Province of Macerata (Italy). We will analyze data in correspondence to age and gender, and we will compare our results to international studies.

MATERIALS AND METHOD

We analyzed STI test results from the entire database of a Provincial Health Authority for the period 2021-2022. The samples came from the following age groups: 0-12, 13-18, 19-25, and 26-35 from 2021 to 2022. The results came from vaginal and cervical swabs (for females); urethral, rectal, and pharyngeal swabs (for males and females); and seminal fluid (for males) for the following infections: HPV, Chlamydia trachomatis, Mycoplasma genitalium, Ureaplasmas, Gardnerella, Trichomonas vaginalis, Neisseria gonorrhoeae, and Treponema pallidum. The results also came from blood tests for HIV, hepatitis C, hepatitis B, and Treponema pallidum (TPHA, VDRL). In addition, we examined results from urine tests for chlamydia, Neisseria gonorrhoeae, trichomonas, and Treponema pallidum.

CONCLUSIONS

The literature for other countries reports the need for comprehensive, culturally and developmentally sensitive care to address sexuality-related issues in adolescents and young adults, a need that also applies to Italy. These data will be of great importance in adopting evidence-based STI control programs in Marche Region. This study could, indeed, represent a landmark for public health officials and professionals, with the aim of promoting adolescents' access to sexual health services to receive useful information, strengthening preventive measures in younger age groups, and designing sexual education programs.

Vitamin D effects on Chlamydia trachomatis infection: a case-control and experimental study

Introduction

Vitamin D deficiency is the most common nutritional deficiency worldwide. Chronic vitamin D deficiency causes immune system dysfunction, which increases susceptibility to pathogens such as bacteria, especially intracellular parasites, and viruses. Chlamydia trachomatis (C. t) is an obligate intracellular parasitic bacterium that causes a variety of sequelae. We speculated that vitamin D might be associated with C. t infection. This study aimed to address this gap in knowledge by investigating the relationship between vitamin D and C. t infection using both in vitro and in vivo models.

Methods and results

The addition of calcitriol to McCoy cell culture in vitro delayed and reduced the quantity and volume of inclusions compared to the control group. Macrophages of peritoneally lavaged mice co-cultured with McCoy decreased the infection rate and delayed the appearance of inclusions. In mice models of vitamin D deficiency, mice in the VD-group exhibited more severe genital tract inflammation and a longer duration of infection after inoculation with C. t in the genital tract. Supplementing these mice with vitamin D3 during treatment enhanced the therapeutic effect of antibiotics. We also conducted a case-control study involving 174 C. t-positive patients (95 males and 79 females) and 380 healthy volunteers (211 males and 169 females) aged 20-49 from January 2016 to March 15, 2017. Serum 25-(OH)D concentration was measured by assessing morning fasting blood samples of healthy volunteers and C. t-positive patients 1 day before antibiotic treatment and the next day after one course of treatment. The patients were followed up for 1 month and evaluated for recovery. The results showed that vitamin D deficiency was a risk factor for C. t infection and treatment failure.

Conclusion

In summary, findings from experimental and clinical studies indicate a close association between vitamin D levels and C. t infection and treatment outcomes. Given the affordability and safety of vitamin D, both healthy individuals and patients should focus on vitamin D intake. Vitamin D supplementation could enhance treatment success and should be used as an adjunctive therapy alongside antibiotic therapy for C. t infections, pending confirmation in larger, prospective, randomized controlled trials.

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.

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.

A TriAdj-Adjuvanted Chlamydia trachomatis CPAF Protein Vaccine Is Highly Immunogenic in Pigs

Chlamydia trachomatis (Ct) infections are the most common sexually transmitted infection (STI). Despite effective antibiotics for Ct, undetected infections or delayed treatment can lead to infertility, ectopic pregnancies, and chronic pelvic pain. Besides humans, chlamydia poses similar health challenges in animals such as C. suis (Cs) in pigs. Based on the similarities between humans and pigs, as well as their chlamydia species, we use pigs as a large biomedical animal model for chlamydia research. In this study, we used the pig model to develop a vaccine candidate against Ct. The vaccine candidate consists of TriAdj-adjuvanted chlamydial-protease-like activity factor (CPAF) protein. We tested two weekly administration options-twice intranasal (IN) followed by twice intramuscular (IM) and twice IM followed by twice IN. We assessed the humoral immune response in both serum using CPAF-specific IgG (including antibody avidity determination) and also in cervical and rectal swabs using CPAF-specific IgG and IgA ELISAs. The systemic T-cell response was analyzed following in vitro CPAF restimulation via IFN-γ and IL-17 ELISpots, as well as intracellular cytokine staining flow cytometry. Our data demonstrate that while the IN/IM vaccination mainly led to non-significant systemic immune responses, the vaccine candidate is highly immunogenic if administered IM/IN. This vaccination strategy induced high serum anti-CPAF IgG levels with strong avidity, as well as high IgA and IgG levels in vaginal and rectal swabs and in uterine horn flushes. In addition, this vaccination strategy prompted a pronounced cellular immune response. Besides inducing IL-17 production, the vaccine candidate induced a strong IFN-γ response with CD4 T cells. In IM/IN-vaccinated pigs, these cells also significantly downregulated their CCR7 expression, a sign of differentiation into peripheral-tissue-homing effector/memory cells. Conclusively, this study demonstrates the strong immunogenicity of the IM/IN-administered TriAdj-adjuvanted Ct CPAF vaccine candidate. Future studies will test the vaccine efficacy of this promising Ct vaccine candidate. In addition, this project demonstrates the suitability of the Cs pre-exposed outbred pig model for Ct vaccine development. Thereby, we aim to open the bottleneck of large animal models to facilitate the progression of Ct vaccine candidates into clinical trials.

Neurosyphilis is characterized by a compartmentalized and robust neuroimmune response but not by neuronal injury

BACKGROUND

Neurosyphilis is increasing in prevalence but its pathophysiology remains incompletely understood. This study assessed for CNS-specific immune responses during neurosyphilis compared to syphilis without neurosyphilis and compared these immune profiles to those observed in other neuroinflammatory diseases.

METHODS

Participants with syphilis were categorized as having neurosyphilis if their cerebrospinal fluid (CSF)-venereal disease research laboratory (VDRL) test was reactive and as having syphilis without neurosyphilis if they had a non-reactive CSF-VDRL test and a white blood cell count <5/μL. Neurosyphilis and syphilis without neurosyphilis participants were matched by rapid plasma reagin titer and HIV status. CSF and plasma were assayed for markers of neuronal injury and glial and immune cell activation. Bulk RNA sequencing was performed on CSF cells, with results stratified by the presence of neurological symptoms.

FINDINGS

CSF neopterin and five CSF chemokines had levels significantly higher in individuals with neurosyphilis compared to those with syphilis without neurosyphilis, but no markers of neuronal injury or astrocyte activation were significantly elevated. The CSF transcriptome in neurosyphilis was characterized by genes involved in microglial activation and lipid metabolism and did not differ in asymptomatic versus symptomatic neurosyphilis cases.

CONCLUSIONS

The CNS immune response observed in neurosyphilis was comparable to other neuroinflammatory diseases and was present in individuals with neurosyphilis regardless of neurological symptoms, yet there was minimal evidence for neuronal or astrocyte injury. These findings support the need for larger studies of the CSF inflammatory response in asymptomatic neurosyphilis.

FUNDING

This work was funded by the National Institutes of Health, grants K23MH118999 (S.F.F.) and R01NS082120 (C.M.M.).

COVID-19 impact on blood donor characteristics and seroprevalence of transfusion-transmitted infections in southern Thailand between 2018 and 2022

Blood safety is a critical aspect of healthcare systems worldwide involving rigorous screening, testing, and processing protocols to minimize the risk of transfusion-transmitted infections (TTIs). The present study offers a comprehensive assessment of the prevalence of hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV), and syphilis among blood donors in southern Thailand. It explores the consequences of the COVID-19 pandemic on the blood transfusion service, donor characteristics, and the prevalence of TTIs. A retrospective analysis of 65,511 blood donors between 2018 and 2022 was conducted at Songklanagarind Hospital, Thailand. The socio-demographic characteristics of the donors were examined using the Chi-square test to assess the relationship between TTIs serological positivity and donor characteristics. The donors were divided into pre-COVID-19 (2018-2019) and during COVID-19 (2020-2022) groups to evaluate the impacts of COVID-19. The study found that HBV had the highest overall prevalence at 243 per hundred thousand (pht), followed by syphilis (118 pht), HCV (32 pht), and HIV (31 pht) over a five-year period of study. After COVID-19, the prevalence of HBV decreased by 21.8%; HCV decreased by 2.1%; HIV increased by 36.4%; and syphilis increased by 9.2%. The socio-demographic characteristics and TTIs prevalence were significantly altered over time. This study provides insights into blood donor characteristics and TTIs prevalence in southern Thailand, highlighting the understanding of the impact of COVID-19 on the spread of TTIs.

Clinical features-based machine learning models to separate sexually transmitted infections from other skin diagnoses

INTRODUCTION

Many sexual health services are overwhelmed and cannot cater for all the individuals who present with sexually transmitted infections (STIs). Digital health software that separates STIs from non-STIs could improve the efficiency of clinical services. We developed and evaluated a machine learning model that predicts whether patients have an STI based on their clinical features.

METHODS

We manually extracted 25 demographic features and clinical features from 1315 clinical records in the electronic health record system at Melbourne Sexual Health Center. We examined 16 machine learning models to predict a binary outcome of an STI or a non-STI diagnosis. We evaluated the models' performance with the area under the ROC curve (AUC), accuracy and F1-scores.

RESULTS

Our study included 1315 consultations, of which 36.8% (484/1315) were diagnosed with STIs and 63.2% (831/1315) had non-STI conditions. The study population predominantly consisted of heterosexual men (49.5%, 651/1315), followed by gay, bisexual and other men who have sex with men (GBMSM) (25.7%), women (21.6%) and unknown gender (3.2%). The median age was 31 years (intra-quartile range (IQR) 26-39). The top 5 performing models were CatBoost (AUC 0.912), Random Forest (AUC 0.917), LightGBM (AUC 0.907), Gradient Boosting (AUC 0.905) and XGBoost (AUC 0.900). The best model, CatBoost, achieved an accuracy of 0.837, sensitivity of 0.776, specificity of 0.831, precision of 0.782 and F1-score of 0.778. The key important features were lesion duration, type of skin lesions, age, gender, history of skin disorders, number of lesions, dysuria duration, anorectal pain and itchiness.

CONCLUSIONS

Our best model demonstrates a reasonable performance in distinguishing STIs from non-STIs. However, to be clinically useful, more detailed information such as clinical images, may be required to reach sufficient accuracy.

Factors associated with hepatitis A susceptibility among men who have sex with men using HIV pre-exposure prophylaxis in Northeastern Brazil: A cross-sectional study

Hepatitis A virus (HAV) infection has disproportionately affected more men who have sex with men (MSM), occurring in outbreaks, despite being vaccine-preventable. We determined the prevalence and factors associated with HAV susceptibility among cisgender MSM on HIV pre-exposure prophylaxis (PrEP) in Northeastern Brazil. From September 30, 2021 to June 19, 2023, 282 cisgender MSM receiving HIV PrEP were enrolled into this cross-sectional study. Sociodemographic and clinical information were collected. Blood samples were collected for screening of sexually transmitted infections (STIs) and serum samples were tested for IgM and total anti-HAV antibodies. Non-reactive results for total anti-HAV antibodies were found in 106 of 282 (37.6%) participants. Factors associated with HAV susceptibility included age <30 years (prevalence ratio [PR]: 2.02; 95% confidence interval [95% CI]: 1.61-2.53), having health insurance (PR: 1.39; 95% CI: 1.19-1.64), sex only with cisgender men (PR: 1.52; 95% CI: 1.23-1.89), non-steady partner (PR: 1.20; 95% CI: 1.01-1.43) and no lifetime history of STIs (PR: 1.25; 95% CI: 1.03-1.53). Identifying clinical correlates of HAV susceptibility in key populations is a fundamental step towards development of public policy focused on prevention, especially following the recent hepatitis A outbreak in Brazil.

Sero-prevalence of syphilis and associated risk factors among pregnant women attending antenatal care at an urban-poor health centre in Kampala, Uganda: a cross-sectional study

Introduction

syphilis and its outcomes remain a healthcare system burden with adverse consequences such as stillbirths, neonatal deaths and spontaneous abortions among others. The situation might have worsened because the COVID-19 pandemic has caused a major attention drift from other diseases. Additionally, much as testing for syphilis is a routine practice among pregnant mothers, its proportion is not known in urban health care setting. A study to determine the prevalence of syphilis among pregnant mothers in an urban poor setting is warranted.

Methods

a cross-sectional study was conducted among pregnant women who attended antenatal care at Kawaala Health Centre IV in Kampala Capital City between December 2019 to March 2020. Informed consent was sought from study participants prior to data collection using structured questionnaires. Whole blood was collected and tested using SD Bioline HIV/syphilis duo rapid test kit (SD Standard Diagnostics, INC, Korea). Data analysis was done using STATA 14.2.

Results

one thousand one hundred and sixty-nine pregnant women participated in the study, with a mean age of 25 years. About 27% of them had completed only primary-level education. Approximately 6% of the participants were HIV seropositive. The prevalence of syphilis was 5.9% (69/1169). HIV positivity (aOR: 4.13, 95%CI: 2.05-8.34), elevated blood pressure (aOR: 2.84, 95%CI: 1.42-5.69), and status of previous pregnancy (aOR: 0.21, 95%CI: 0.05-0.89) were significant predictors of the risk of syphilis among pregnant women in this setting.

Conclusion

the prevalence of syphilis among pregnant women in urban poor settings is not low and so must not be underestimated. The potential drivers of syphilis among pregnant women are HIV, elevated blood pressure, and status of previous pregnancy. There should be increased awareness about routine syphilis testing among pregnant mothers attending antenatal care.

Antibiotic overuse, poor antimicrobial stewardship, and low specificity of syndromic case management in a cross section of men with urethral discharge syndrome in Kampala, Uganda

OBJECTIVE

High prevalence of sexually transmitted infections (STIs) combined with poor antimicrobial stewardship are drivers of STI antimicrobial resistance (AMR) especially in resource-limited settings where syndromic case management (SCM) is the norm. We characterized patterns of antibiotic use prior to clinic attendance and study enrollment in Ugandan men with urethral discharge syndrome (UDS), evaluated in-clinic prescribing, and the performance characteristics of SCM.

METHODS

Participants were recruited from government clinics participating in an existing gonococcal surveillance program in Kampala, Uganda. Questionnaires including antimicrobial use prior to attendance, prior episodes of UDS, penile swabs, and blood samples were collected. Bivariable and multivariable logistic regression models were used to estimate odds ratios (OR) for preselected factors likely to be associated with antibiotic use. In-clinic antibiotic treatment data were extracted from clinical notes, and the performance of SCM against laboratory-based STI diagnoses was evaluated.

FINDINGS

Between October 2019 and November 2020, 100(40%) of 250 men with UDS reported taking antibiotics in the 14days prior to attending the clinic. Of these 210(84%) had at least one curable STI and 20% had a reactive point-of-care HIV test. Multivariable analysis demonstrated significant associations between recent antimicrobial use and duration of UDS symptoms <6 days (OR 2.98(95%CI 1.07,8.36), p = 0.038), and sex with women only (OR 0.08(95%CI 0.01,0.82),p = 0.038). The sensitivity of SCM ranged from 80.0% to 94.4%; specificity was low between 5.6% and 33.1%. The positive predictive value of SCM ranged from 2.4(95%CI 0.7,6.0) for trichomoniasis to 63.4(95%CI 56.5,69.9) for gonorrhea.

CONCLUSION

Pre-enrollment antibiotic use was common in this population at high risk of STI and HIV. Combined with the poor specificity of SCM for male UDS, extensive antibiotic use is a likely driver of STI-AMR in Ugandan men. Interventions to improve antimicrobial stewardship and deliver affordable diagnostics to augment SCM and decrease overtreatment of STI syndromes are required.

Neisseria gonorrhoeae vaccines: a contemporary overview

Neisseria gonorrhoeae infection is an important public health issue, with an annual global incidence of 87 million. N. gonorrhoeae infection causes significant morbidity and can have serious long-term impacts on reproductive and neonatal health and may rarely cause life-threatening disease. Global rates of N. gonorrhoeae infection have increased over the past 20 years. Importantly, rates of antimicrobial resistance to key antimicrobials also continue to increase, with the United States Centers for Disease Control and Prevention identifying drug-resistant N. gonorrhoeae as an urgent threat to public health. This review summarizes the current evidence for N. gonorrhoeae vaccines, including historical clinical trials, key N. gonorrhoeae vaccine preclinical studies, and studies of the impact of Neisseria meningitidis vaccines on N. gonorrhoeae infection. A comprehensive survey of potential vaccine antigens, including those identified through traditional vaccine immunogenicity approaches, as well as those identified using more contemporary reverse vaccinology approaches, are also described. Finally, the potential epidemiological impacts of a N. gonorrhoeae vaccine and research priorities for further vaccine development are described.

Syphilis Prevalence Among People Living With and Without HIV in Sub-Saharan Africa: A Systematic Review and Meta-Analysis

BACKGROUND

Syphilis is a curable sexually transmitted infection that, untreated, is associated with significant morbidity and mortality. In people living with HIV (PLWH), syphilis carries greater risks of disease progression. We estimated syphilis prevalence among PLWH in the general population in sub-Saharan Africa and compared the prevalence among PLWH and without HIV.

METHODS

We searched for studies published January 1, 2011, to March 28, 2022, reporting syphilis prevalence among PLWH in sub-Saharan Africa (PROSPERO No. CRD42020167328). We excluded studies in high-risk subpopulations. We estimated pooled syphilis prevalence among PLWH using random-effects modeling and compared the prevalence with people without HIV when included in the same study. We examined influences of region, study setting, and test type in subgroup analyses.

RESULTS

We identified 926 studies; 53 were included in the meta-analysis. Pooled syphilis prevalence among PLWH was 7.3% (95% confidence interval [CI], 6.3%-8.5%). Prevalence differed by region: 3.1% (95% CI, 2.2%-4.0%) in Southern, 5.5% (95% CI, 2.3%-9.3%) in West/Central, and 10.5% (95% CI, 8.0%-13.1%) in Eastern Africa. Prevalence also differed by study setting: 13.8% (95% CI, 5.7%-23.0%) in sexual and reproductive health/sexually transmitted infection care, 8.7% (95% CI, 5.0%-12.8%) in HIV care, 7.1% (95% CI, 5.8%-8.5%) in antenatal care, and 3.8% (95% CI, 2.0%-5.8%) in household/community-based settings. Syphilis prevalence was higher among PLWH than without HIV (relative risk, 3.5; 95% CI, 2.8-4.5).

CONCLUSIONS

Syphilis is highly prevalent among PLWH in sub-Saharan Africa and is more common among PLWH than without HIV. Integration of syphilis screening and management into HIV care may reduce complications of HIV-syphilis coinfection among PLWH in sub-Saharan Africa.