Chlamydia, gonorrhoea, trichomoniasis and syphilis: global prevalence and incidence estimates, 2016

The First Reported Case of Ocular Syphilis in an Iranian Patient

Purpose

To report the first case of ocular syphilis in an Iranian patient and discuss its diagnostic challenges.

Case Report

A man in his mid-70s presented with progressive bilateral visual and auditory decline. He had previously lived in a Southeast Asian country for 10 years. Prior steroid therapies entailed no inflammation subsidence. His visual acuity at presentation was light perception OU. Funduscopic findings included severe vitritis, severe optic atrophy, diffuse retinal vascular occlusion, and diffuse retinal atrophy OU. Angiography demonstrated diffuse areas of retinal and choriocapillaris atrophy with no active choroiditis. Scaly cutaneous lesions were noted on his palms and soles - atypical findings of secondary syphilis. Serum analysis revealed an underlying syphilis infection. The cerebrospinal fluid sample was reactive to anti-syphilis antibodies, securing a neurosyphilis diagnosis. Two weeks of antibiotic therapy resulted in cutaneous lesions resolution and relative visual improvement despite extensive baseline retinal atrophic damage.

Conclusion

Ocular syphilis can mimic numerous ocular inflammatory scenarios. In cases of ocular inflammation that is unresponsive to steroids, reconsidering alternative diagnoses, especially infections with the highest clinical relevance, is necessary. We stress the importance of acquiring patients' sexual history, regardless of cultural barriers and the rarity of the entity in some regions.

Activity of compounds derived from benzofuroxan in Trichomonasvaginalis

Trichomoniasis is a sexually transmitted infection caused by the protozoan Trichomonas vaginalis. Currently, trichomoniasis is treated with the class of nitroimidazoles, namely, metronidazole; however, resistant isolates and strains have been reported. The compounds derived from benzofuroxan are biologically active heterocycles. This study evaluated the in vitro antiparasitic activity of these compounds in trophozoites of T. vaginalis and determined the mean inhibitory concentration (IC50), minimum inhibitory concentration (MIC), mortality curve, and cytotoxicity. The compounds were named EH1, EH2, EH3, and EA2 and tested in various concentrations: 100 to 15 μM (EH1 and EH2); 100 to 5 μM (EH3); and 100 to 25 μM (EA2), respectively. The greatest efficacy was observed in the highest concentrations in 24 h, with inhibition of approximately 100% of trophozoites. Compounds EH2 and EH3 had the lowest MIC: EH2 (35 μM) and EH3 (45 μM), with IC50 of 11.33 μM and 6.83 μM, respectively. Compound EA2 was effective at the highest concentrations. The activity of the compounds in T. vaginalis started in the first hour of incubation with 90% inhibition; after 12 h, inhibition >95% was observed. Compound EH1 showed the lowest activity, with the highest activity between 12 and 24 h after incubation. These results demonstrate that benzofuroxan derivatives are promising compounds for the in vitro treatment of T. vaginalis.

Trichomonas vaginalis adherence phenotypes and extracellular vesicles impact parasite survival in a novel in vivo model of pathogenesis

Trichomonas vaginalis is a human infective parasite responsible for trichomoniasis-the most common, non-viral, sexually transmitted infection worldwide. T. vaginalis resides exclusively in the urogenital tract of both men and women. In women, T. vaginalis has been found colonizing the cervix and vaginal tract while in men it has been identified in the upper and lower urogenital tract and in secreted fluids such as semen, urethral discharge, urine, and prostatic fluid. Despite the over 270 million cases of trichomoniasis annually worldwide, T. vaginalis continues to be a highly neglected organism and thus poorly studied. Here we have developed a male mouse model for studying T. vaginalis pathogenesis in vivo by delivering parasites into the murine urogenital tract (MUT) via transurethral catheterization. Parasite burden was assessed ex-vivo using a nanoluciferase-based gene expression assay which allowed quantification of parasites pre- and post-inoculation. Using this model and read-out approach, we show that T. vaginalis can be found within MUT tissue up to 72 hrs post-inoculation. Furthermore, we also demonstrate that parasites that exhibit increased parasite adherence in vitro also have higher parasite burden in mice in vivo. These data provide evidence that parasite adherence to host cells aids in parasite persistence in vivo and molecular determinants found to correlate with host cell adherence in vitro are applicable to infection in vivo. Finally, we show that co-inoculation of T. vaginalis extracellular vesicles (TvEVs) and parasites results in higher parasite burden in vivo. These findings confirm our previous in vitro-based predictions that TvEVs assist the parasite in colonizing the host. The establishment of this pathogenesis model for T. vaginalis sets the stage for identifying and examining parasite factors that contribute to and influence infection outcomes.

Feasibility of using volatile urine fingerprints for the differentiation of sexually transmitted infections

Sexually transmitted infections (STIs) are a public health problem worldwide, and current diagnostic methods have certain limitations. In recent years, volatile organic compounds (VOCs) have been studied as an alternative diagnostic method. Due to this, this study aimed to detect, in vaginal swabs and urine samples, VOCs emitted by highly prevalent STIs-causing bacteria (Chlamydia trachomatis, Mycoplasma genitalium, and Neisseria gonorrhoeae) to identify potential biomarkers that allow the detection of these STIs. VOCs detected in urine samples showed a better differentiation of patients with STIs due to C. trachomatis from those not infected, with 2,6-dimethyl-4-heptanone as the volatile compound most related to the presence of this bacterium. Among the VOCs most related to M. genitalium in urine, 4-methyltetradecane and 2-methylpentadecane stood out, while 3,4,4-trimethyl-2-cyclohexen-1-one was the VOC most closely related to N. gonorrhoeae infection. Moreover, C12 alcohols were the main VOC family associated with positive samples in all three bacteria, which could indicate the presence of aldehyde reductases in their metabolism. In contrast, alcohols such as 3-methyl-1-heptanol and 1-octanol, as well as dimethyl esters, were more associated with negative samples and may be useful in ruling out an STI caused by one of these three bacteria. In short, the VOCs identified as potential biomarkers in patients with infection by C. trachomatis, M. genitalium, or N. gonorrhoeae could be used in the early diagnosis of these STIs, quickly interrupting the chain of transmission, especially interesting in asymptomatic patients. KEY POINTS: • Sexually transmitted infections are a serious public health problem worldwide. • The study of VOCs in multiple infections is increasing in recent years. • The identification of volatile biomarkers could allow new diagnostic methods.

Exploring causal mechanisms and essential factors in the prevention and control of chlamydia in Guangdong, Southern China: a study protocol

BACKGROUND

Chlamydia Trachomatis (CT) is among the most prevalent sexually transmitted diseases (STDs) globally. According to the World Health Organization, more than 131 million people get infected with CT annually. CT is usually transmitted via sexual contact or perinatal exposure and can result in severe long-term complications. In developing nations, particularly, the prevention and control of CT is challenging. Hence, this study will explore the feedback mechanisms of chlamydia prevention and control, as well as identify the essential factors affecting the control and prevention of this infection in China.

METHODS

Our study will employ a mixed-methods research design that encompasses both qualitative and quantitative methods. Firstly, we will develop a causal loop diagram (CLD) based on the literature review and optimize it via in-depth interviews with stakeholders. Additionally, we will utilize a quantitative method called MICMAC(Impact Matrix Cross-Reference Multiplication Applied to a Classification tool) to obtain consensus among different stakeholders and pinpoint the key information. Next, the CLD will be transformed into a system dynamics model (SDM) to evaluate the feedback mechanisms within the CLD. The causality in the CLD will be modeled using mathematical equations, which facilitate the transformation into an SDM. As such, we will be able to analyze the dynamic behavior of the system and its response to different decisions.

DISCUSSION

Our study offers a systematic perspective on the control and prevention of chlamydia infection through system dynamics modeling, examining the dynamic properties and background factors of the system. The creation of the CLD affords stakeholders the chance to comprehend the functionality of their relationships and improve cooperation. Consequently, by evaluating the outcomes of these simulations, it will be possible to analyze and determine potential interventions and their effects on chlamydia infections. This modeling approach can help us gain insight into the dynamic characteristics of the system, evaluate the potential outcomes of different decisions, and design control strategies to either stabilize the system or adjust its behavior.

Evolutionary conservation of Trichomonas-mycoplasma symbiosis across the host species barrier

Introduction

The protozoan parasite Trichomonas vaginalis is the most common cellular sexually transmitted disease in humans, and the closely related species Trichomonas gallinae is an avian parasite of ecological and economic importance. Phylogenetic evidence suggests T. vaginalis arose during bird to human transmission of a T. gallinae-like ancestor. Trichomonas vaginalis shares a strong clinical association with the independent sexually transmitted pathogen Metamycoplasma (formerly Mycoplasma) hominis, and the uncultured bacterium "Candidatus Malacoplasma (formerly Mycoplasma) girerdii," with the latter association being an order of magnitude stronger. Both bacterial species have been shown to profoundly influence T. vaginalis growth, energy production and virulence-associated mechanisms.

Methods

Evidence for a novel Malacoplasma sp. was discovered by in vivo Illumina metatranscriptomics sequencing of the T. gallinae-infected pigeon mouth. We leveraged published 16S rDNA profiling data from digestive tract of 12 healthy and 24 T. gallinae-infected pigeons to investigate association between the novel Malacoplasma sp. and T. gallinae. We utilised Illumina metagenomics sequencing targeted to pigeon oral and crop samples infected with the novel Malacoplasma sp. to generate its full-length genome sequence. Sequence similarity network analysis was used to compare annotated proteins from the novel Malacoplasma sp. with a range of other related species.

Results

Here we present evidence for a novel Malacoplasma species, related to "Ca. M. girerdii," that is strongly associated with T. gallinae in the upper digestive tract of domestic pigeons. Analysis of the genome sequence revealed gene features apparently specific to a Trichomonas-symbiotic Malacoplasma lineage.

Discussion

These data support a model of long-term association between Trichomonas and Malacoplasma spp. that has been conserved across diversification of the Trichomonas lineage and the host species barrier from birds to human.

When Bacteria and Viruses Collide: A Tale of Chlamydia trachomatis and Sexually Transmitted Viruses

The global incidence of sexually transmitted infections (STIs) remains high, with the World Health Organization (WHO) estimating that over 1 million people acquire STIs daily. STIs can lead to infertility, pregnancy complications, and cancers. Co-infections with multiple pathogens are prevalent among individuals with an STI and can lead to heightened infectivity and more severe clinical manifestations. Chlamydia trachomatis (CT) is the most reported bacterial STI worldwide in both men and women, and several studies have demonstrated co-infection of CT with viral and other bacterial STIs. CT is a gram-negative bacterium with a unique biphasic developmental cycle including infectious extracellular elementary bodies (EBs) and metabolically active intracellular reticulate bodies (RBs). The intracellular form of this organism, RBs, has evolved mechanisms to persist for long periods within host epithelial cells in a viable but non-cultivable state. The co-infections of CT with the most frequently reported sexually transmitted viruses: human immunodeficiency virus (HIV), human papillomavirus (HPV), and herpes simplex virus (HSV) have been investigated through in vitro and in vivo studies. These research studies have made significant strides in unraveling the intricate interactions between CT, these viral STIs, and their eukaryotic host. In this review, we present an overview of the epidemiology of these co-infections, while specifically delineating the underlying mechanisms by which CT influences the transmission and infection dynamics of HIV and HSV. Furthermore, we explore the intricate relationship between CT and HPV infection, with a particular emphasis on the heightened risk of cervical cancer. By consolidating the current body of knowledge, we provide valuable insights into the complex dynamics and implications of co-infection involving CT and sexually transmitted viruses.

Syphilis and the host: multi-omic analysis of host cellular responses to Treponema pallidum provides novel insight into syphilis pathogenesis

Introduction

Syphilis is a chronic, multi-stage infection caused by the extracellular bacterium Treponema pallidum ssp. pallidum. Treponema pallidum widely disseminates through the vasculature, crosses endothelial, blood-brain and placental barriers, and establishes systemic infection. Although the capacity of T. pallidum to traverse the endothelium is well-described, the response of endothelial cells to T. pallidum exposure, and the contribution of this response to treponemal traversal, is poorly understood.

Methods

To address this knowledge gap, we used quantitative proteomics and cytokine profiling to characterize endothelial responses to T. pallidum.

Results

Proteomic analyses detected altered host pathways controlling extracellular matrix organization, necroptosis and cell death, and innate immune signaling. Cytokine analyses of endothelial cells exposed to T. pallidum revealed increased secretion of interleukin (IL)-6, IL-8, and vascular endothelial growth factor (VEGF), and decreased secretion of monocyte chemoattractant protein-1 (MCP-1).

Discussion

This study provides insight into the molecular basis of syphilis disease symptoms and the enhanced susceptibility of individuals infected with syphilis to HIV co-infection. These investigations also enhance understanding of the host response to T. pallidum exposure and the pathogenic strategies used by T. pallidum to disseminate and persist within the host. Furthermore, our findings highlight the critical need for inclusion of appropriate controls when conducting T. pallidum-host cell interactions using in vitro- and in vivo-grown T. pallidum.

Genetic Variability of the Internal Transcribed Spacer and Pyruvate:Ferredoxin Oxidoreductase Partial Gene of Trichomonas vaginalis from Female Patients

In the present study, we evaluated the genetic variability of the internal transcribed spacer (ITS) region and the pyruvate:ferredoxin oxidoreductase (pfor) A gene of Trichomonas vaginalis from female patients and its possible implications in the host-parasite relationship. Phylogenetic and genetics of populations analyses were performed by analyzing sequences of the ITS region and partial pfor A gene of clinical samples with T. vaginalis, as previously documented. Alignments of protein sequences and prediction of three-dimensional structure were also performed. Although no correlation between the main clinical characteristics of the samples and the results of phylogeny was found, a median-joining analysis of ITS haplotypes showed two main clusters. Also, pfor A, due to its phylogenetic divergence, could be used as a marker to confirm the genus and species of trichomonads. Alignment of protein sequences and prediction of three-dimensional structure showed that PFOR A had a highly conserved structure with two synonymous mutations in the PFOR domain, substituting a V for a G or a S for a P. Our results suggest that the role of genetic variability of PFOR and ITS may not be significant in the symptomatology of this pathogen; however, their utility as genus and species markers in trichomonads is promising.

A riboside hydrolase that salvages both nucleobases and nicotinamide in the auxotrophic parasite Trichomonas vaginalis

Pathogenic parasites of the Trichomonas genus are causative agents of sexually transmitted diseases affecting millions of individuals worldwide and whose outcome may include stillbirths and enhanced cancer risks and susceptibility to HIV infection. Trichomonas vaginalis relies on imported purine and pyrimidine nucleosides and nucleobases for survival, since it lacks the enzymatic activities necessary for de novo biosynthesis. Here we show that T. vaginalis additionally lacks homologues of the bacterial or mammalian enzymes required for the synthesis of the nicotinamide ring, a crucial component in the redox cofactors NAD+ and NADP. Moreover, we show that a yet fully uncharacterized T. vaginalis protein homologous to bacterial and protozoan nucleoside hydrolases is active as a pyrimidine nucleosidase but shows the highest specificity toward the NAD+ metabolite nicotinamide riboside. Crystal structures of the trichomonal riboside hydrolase in different states reveals novel intermediates along the nucleoside hydrolase-catalyzed hydrolytic reaction, including an unexpected asymmetry in the homotetrameric assembly. The active site structure explains the broad specificity toward different ribosides and offers precise insights for the engineering of specific inhibitors that may simultaneously target different essential pathways in the parasite.

Integrated microscale immiscible phase extraction and isothermal amplification for colorimetric detection of Neisseria gonorrhoeae

Gonorrhea is the second most common sexually transmitted infection (STI) with around 87 million cases worldwide estimated in 2016 by the World Health Organization. With over half of the cases being asymptomatic, potential life-threatening complications and increasing numbers of drug-resistant strains, routine monitoring of prevalence and incidence of infections are key preventive measures. Whilst gold standard qPCR tests have excellent accuracy, they are neither affordable nor accessible in low-resource settings. In this study, we developed a lab-on-a-chip platform based on microscale immiscible filtration to extract, concentrate and purify Neisseria gonorrhoeae DNA with an integrated detection assay based on colorimetric isothermal amplification. The platform was capable of detecting as low as 500 copies/mL from spiked synthetic urine and showed no cross-reactivity when challenged with DNAs from other common STIs. The credit card-size device allows DNA extraction and purification without power or centrifuges, and the detection reaction only needs a low-tech block heater, providing a straightforward and visual positive/negative result within 1 h. These advantages offer great potential for accurate, affordable and accessible monitoring of gonorrhea infection in resource-poor settings.

The potential impact of a vaccine on Neisseria gonorrhoeae prevalence among heterosexuals living in a high prevalence setting

BACKGROUND

Treatment of Neisseria gonorrhoeae is under threat with the emergence and spread of antimicrobial resistance. Thus, there is a growing interest in the development of a gonorrhoea vaccine. We used mathematical modelling to assess the impact of a hypothetical vaccine in controlling gonorrhoea among heterosexuals living in a setting of relatively high N. gonorrhoeae prevalence (∼3 %).

METHODS

We developed a mathematical model of N. gonorrhoeae transmission among 15-49-year-old heterosexuals, stratified by age and sex, and calibrated to prevalence and sexual behaviour data from South Africa as an example of a high prevalence setting for which we have data available. Using this model, we assessed the potential impact of a vaccine on N. gonorrhoeae prevalence in the entire population. We considered gonorrhoea vaccines having differing impacts on N. gonorrhoeae infection and transmission and offered to different age-groups.

RESULTS

The model predicts that N. gonorrhoeae prevalence can be reduced by ∼50 % in 10 years following introduction of a vaccine if annual vaccination uptake is 10 %, vaccine efficacy against acquisition of infection is 25 % and duration of protection is 5 years, with vaccination available to the entire population of 15-49-year-olds. If only 15-24-year-olds are vaccinated, the predicted reduction in prevalence in the entire population is 25 % with equivalent vaccine characteristics and uptake. Although predicted reductions in prevalence for vaccination programmes targeting only high-activity individuals and the entire population are similar over the same period, vaccinating only high-activity individuals is more efficient as the cumulative number of vaccinations needed to reduce prevalence in the entire population by 50 % is ∼3 times lower for this programme.

CONCLUSION

Provision of a gonorrhoea vaccine could lead to substantial reductions in N. gonorrhoeae prevalence in a high prevalence heterosexual setting, even with moderate annual vaccination uptake of a vaccine with partial efficacy.

Mycoplasma hominis and Candidatus Mycoplasma girerdii in Trichomonas vaginalis: Peaceful Cohabitants or Contentious Roommates?

Trichomonas vaginalis is a pathogenic protozoan diffused worldwide capable of infecting the urogenital tract in humans, causing trichomoniasis. One of its most intriguing aspects is the ability to establish a close relationship with endosymbiotic microorganisms: the unique association of T. vaginalis with the bacterium Mycoplasma hominis represents, to date, the only example of an endosymbiosis involving two true human pathogens. Since its discovery, several aspects of the symbiosis between T. vaginalis and M. hominis have been characterized, demonstrating that the presence of the intracellular guest strongly influences the pathogenic characteristics of the protozoon, making it more aggressive towards host cells and capable of stimulating a stronger proinflammatory response. The recent description of a further symbiont of the protozoon, the newly discovered non-cultivable mycoplasma Candidatus Mycoplasma girerdii, makes the picture even more complex. This review provides an overview of the main aspects of this complex microbial consortium, with particular emphasis on its effect on protozoan pathobiology and on the interplays among the symbionts.

Structural elucidation of recombinant Trichomonas vaginalis 20S proteasome bound to covalent inhibitors

Proteasomes are essential for protein homeostasis in mammalian cells1-4 and in protozoan parasites such as Trichomonas vaginalis (Tv).5 Tv and other protozoan 20S proteasomes have been validated as druggable targets.6-8 However, in the case of Tv 20S proteasome (Tv20S), biochemical and structural studies were impeded by low yields and purity of the native proteasome. We successfully made recombinant Tv20S by expressing all seven α and seven β subunits together with the Ump-1 chaperone in insect cells. We isolated recombinant proteasome and showed that it was biochemically indistinguishable from the native enzyme. We confirmed that the recombinant Tv20S is inhibited by the natural product marizomib (MZB)9 and the recently developed peptide inhibitor carmaphycin-17 (CP-17)8,10. Specifically, MZB binds to the β1, β2 and β5 subunits, while CP-17 binds the β2 and β5 subunits. Next, we obtained cryo-EM structures of Tv20S in complex with these covalent inhibitors at 2.8Å resolution. The structures revealed the overall fold of the Tv20S and the binding mode of MZB and CP-17. Our work explains the low specificity of MZB and higher specificity of CP-17 towards Tv20S as compared to human proteasome and provides the platform for the development of Tv20S inhibitors for treatment of trichomoniasis.

Extra Virgin Olive Oil-Based Formulations: A "Green" Strategy against Chlamydia trachomatis

In recent decades, antibiotic misuse has emerged as an important risk factor for the appearance of multi-drug-resistant bacteria, and, recently, antimicrobial resistance has also been described in Chlamydia trachomatis as the leading cause of bacterial sexually transmitted diseases worldwide. Herein, we investigated, for the first time, the antibacterial activity against C. trachomatis of a polyphenolic extract of extra virgin olive oil (EVOO), alongside purified oleocanthal and oleacein, two of its main components, in natural deep eutectic solvent (NaDES), a biocompatible solvent. The anti-chlamydial activity of olive-oil polyphenols (OOPs) was tested in the different phases of chlamydial developmental cycle by using an in vitro infection model. Transmission and scanning electron microscopy analysis were performed for investigating potential alterations of adhesion and invasion, as well as morphology, of chlamydial elementary bodies (EBs) to host cells. The main result of our study is the anti-bacterial activity of OOPs towards C. trachomatis EBs down to a total polyphenol concentration of 1.7 μg/mL, as shown by a statistically significant decrease (93.53%) of the total number of chlamydial-inclusion-forming units (p < 0.0001). Transmission and scanning electron microscopy analysis supported its anti-chlamydial effect, suggesting that OOP might damage the chlamydial outer layers, impairing their structural integrity and hindering EB capability to infect the host cell. In conclusion, OOPs may represent an interesting alternative therapeutic option toward C. trachomatis, although further studies are necessary for exploring its clinical applications.

[Epidemiological situation of post-pandemic sexually transmitted infections in Catalonia, Spain]

BACKGROUND

The growing trend of STIs in recent years was altered after the outbreak of the SARS-CoV-2 pandemic.

OBJECTIVES

Describe the impact of the SARS-CoV-2 pandemic on STI declarations received during the pre-pandemic to pandemic period and estimate the number of STI cases expected for the pandemic period.

MATERIAL AND METHODS

Descriptive analysis of STI declarations received during the pre-pandemic (2018-2019) and pandemic (2020-2021) periods. The influence of the number of positive cases of SARS-CoV-2 with the number of positive cases of STIs during the months of the pandemic was studied using a correlation model. Using the Holt-Wilson time series model, an estimate was made of the number of STI cases expected for the pandemic period.

RESULTS

The global incidence rate for all STIs in 2020 decreased by 18.3% compared to 2019. Chlamydia and syphilis presented a greater reduction in their incidence from 2019 to 2020 of 22.7% and 20.9%, respectively and 9.5% and 2.5% for gonorrhea and LGV. Estimates showed that in 2020 there would have been 44.6% more STIs than those declared. The proportions according to sex, country of birth and sexual orientation changed significantly in chlamydia and gonorrhea.

CONCLUSIONS

The measures adopted for the prevention of SARS-CoV-2 infections were able to achieve an initial decrease in STI cases in 2020, however, this change was not maintained during 2021, which ended with higher incidences recorded to date.

Genomic surveillance and antimicrobial resistance determinants in Neisseria gonorrhoeae isolates from Uganda, Malawi and South Africa, 2015-20

OBJECTIVES

Global antimicrobial resistance (AMR) surveillance in Neisseria gonorrhoeae is essential. In 2017-18, only five (10.6%) countries in the WHO African Region reported to the WHO Global Gonococcal Antimicrobial Surveillance Programme (WHO GASP). Genomics enhances our understanding of gonococcal populations nationally and internationally, including AMR strain transmission; however, genomic studies from Africa are extremely scarce. We describe the gonococcal genomic lineages/sublineages, including AMR determinants, and baseline genomic diversity among strains in Uganda, Malawi and South Africa, 2015-20, and compare with sequences from Kenya and Burkina Faso.

METHODS

Gonococcal isolates cultured in Uganda (n = 433), Malawi (n = 154) and South Africa (n = 99) in 2015-20 were genome-sequenced. MICs were determined using ETEST. Sequences of isolates from Kenya (n = 159), Burkina Faso (n = 52) and the 2016 WHO reference strains (n = 14) were included in the analysis.

RESULTS

Resistance to ciprofloxacin was high in all countries (57.1%-100%). All isolates were susceptible to ceftriaxone, cefixime and spectinomycin, and 99.9% were susceptible to azithromycin. AMR determinants for ciprofloxacin, benzylpenicillin and tetracycline were common, but rare for cephalosporins and azithromycin. Most isolates belonged to the more antimicrobial-susceptible lineage B (n = 780) compared with the AMR lineage A (n = 141), and limited geographical phylogenomic signal was observed.

CONCLUSIONS

We report the first multi-country gonococcal genomic comparison from Africa, which will support the WHO GASP and WHO enhanced GASP (EGASP). The high prevalence of resistance to ciprofloxacin (and empirical use continues), tetracycline and benzylpenicillin, and the emerging resistance determinants for azithromycin show it is imperative to strengthen the gonococcal AMR surveillance, ideally including genomics, in African countries.

Facilitators and Barriers for Chlamydia and Gonorrhea Testing in Female Sex Workers: A Scoping Review

We conducted a scoping review to examine the barriers and facilitators accessing Chlamydia trachomatis and Neisseria gonorrhoeae testing among female sex workers. A literature search was conducted in Embase, Medline, and Web of Science for studies published from the date of creation of database to 17 March 2023, without restrictions for publication date. We used thematic synthesis to identify common affecting factors across included studies and then linked them into categories of the socioecological framework. Among the 14 articles included, 3 utilized qualitative methods, 7 utilized quantitative surveys, 2 were mixed methods, and 2 were randomized controlled trials. Several important affecting factors stood out during this review, including stigma and discrimination, as well as social support at the societal level, and financial costs at the service level. This review suggested that interventions on addressing societal- and service-level determinants are needed, which includes reducing stigma and discrimination toward sex work and cost for facility testing, as well as increasing social support and community engagement.

Towards the prevention of sexually transmitted infections (STIs): Healthcare-seeking behaviour of women with STIs or STI symptoms in sub-Saharan Africa

OBJECTIVE

Sexually transmitted infections (STIs) constitute major public health problems because of their prevalence and contribution to mortality and morbidity worldwide. Healthcare seeking for STIs plays a significant role in the global prevention of STIs. We examined the prevalence and factors associated with healthcare seeking for STIs or STI symptoms among women in sub-Saharan Africa (SSA).

METHODS

Data on 38 394 women of reproductive age from the most recent Demographic and Health Surveys of 28 countries in SSA were analysed. Percentages were used to summarise the prevalence of healthcare seeking for STIs or STIs symptoms. The factors associated with healthcare seeking for STIs or STI symptoms were examined using multilevel binary logistic regression analysis. We presented the results using adjusted odds ratios (aORs) with 95% confidence intervals (CIs).

RESULTS

Overall, the proportion of women with STIs or STI symptoms who sought healthcare was 66.1%, with the highest and lowest proportion found in Liberia (85.6%) and Ethiopia (37.9%) respectively. The likelihood of seeking healthcare for STIs or STI symptoms increased with increasing wealth quintile and level of education. Working women, older women, cohabiting women, women with comprehensive HIV/AIDS knowledge, women exposed to mass media, those who had no barrier to healthcare access, and those covered by health insurance had greater odds of seeking treatment for STIs or STI symptoms. On the contrary, the odds of seeking treatment for STIs or STI symptoms was lower among married women and women who lived in rural areas.

CONCLUSION

The findings of the study call for strengthening of policies, programmes, and interventions geared towards improving thehealthcare-seeking behaviour of women with STIs, taking into consideration the factors identified in this study.

Analysis and prediction of the incidence and prevalence trends of gonorrhea in China

To understand the epidemiological trend of gonorrhea in China from 2004 to 2021, predict the prevalence of the disease, and provide basic theory and data support for monitoring and managing gonorrhea. Gonorrhea incidence data in China from 2004 to 2021 were collected through the China Public Health Science Data Center and National Administration of Disease Prevention and Control, and the incidence and epidemiological characteristics were analyzed. Statistical analysis was performed using Joinpoint and autoregressive integrated moving average (ARIMA) models. A linear correlation model was used to analyze the correlation between gross domestic product (GDP) and the incidence rate. From 2004 to 2021, a total of 2,289,435 cases of gonorrhea were reported in China, with an average reported incidence rate of 9.46/100,000 people and a downward followed by an upward trend. Individuals with gonorrhea were primarily 20-30 y of age, with 1,034,847 cases (53.38%) from 2004 to 2018. The trend of increasing incidence was most obvious in the 10-20 age group (5,811 cases in 2004 to 12,752 cases in 2018, AAPC = 6.1, P < .001). The incidence of gonorrhea in China was negatively correlated with GDP from 2004 to 2021 (r = -0.547, P = .019). The correlation coefficient between the average incidence growth rate of each region from 2012 to 2018 and the average growth rate of regional GDP was 0.673 (P < .01). The root mean square error (RMSE) of the ARIMA model was 4.89%, showing powerful performance. There would be 97,910 gonorrhea cases in 2023 as predicted by the model.

Evaluation of Chlamydia trachomatis Genotypes in Endocervical Specimens by Sequence Analysis of ompA Gene among Women in Tehran

Tehran's actual prevalence of Chlamydia trachomatis (CT) and its genotypes are still unclear. Molecular typing of CT strains can provide essential epidemiological knowledge and contribute to improved control measures. In this study, we aimed to determine the prevalence of CT and its genotypes in the endocervical infections of females who attended the gynecology and infertility clinics in Tehran. A total of 291 women were tested for chlamydial infection by in-house PCR using specific primers for the CT cryptic plasmid. Nested PCR for amplification of the ompA gene in positive samples was carried out, genotyping was performed by sequencing this gene, and further phylogenetic analysis was conducted. Sexual infection by CT was observed in 10.3% (30/291) of the subjects, and the mean age of patients was 30.4. The ompA gene was sequenced in 27 samples, revealing E genotypes 40.7%, (n = 11), F 25.9%, (n = 7), G 18.5%, (n = 5), D 11.1%, (n = 3), and K 3.7%, (n = 1). This study emphasizes the importance of the diversity among CT genotypes in our studied population and the need for wide-screening the neglected bacterial infection among women in Tehran.

Epidemiological Overview of Urogenital Gonorrhea in Mexico (2003-2020)

In Mexico, urogenital gonorrhea (UG) is one of the main sexually transmitted diseases notifiable by health systems around the world. Epidemiological data on sexually transmitted infections (STIs) in Mexico indicated that UG was "under control" until 2017. However, international epidemiological reports indicate the increase in incidence due to several factors, including an increase during the first year of the COVID-19 pandemic. These factors suggest that this phenomenon may occur in developing countries, including Mexico. Therefore, the aim of this study was to analyze national surveillance data on UG from 2003-2019 and the first year of the COVID-19 pandemic. An epidemiological study of cases and incidence of UG (2003-2020) was performed in the annual reports issued by the General Directorate Epidemiology in Mexico. Cases and incidence were classified and analyzed by year, sex, age group, and seasons (by temperature). Distribution of UG was carried out using heat maps for the whole country. Ultimately, a seasonal and correlation analysis was performed for UG cases versus temperature. The results showed that the distribution of cases and incidence by sex showed that there was no variation over 14 years. From 2016 onward, a significant increase in UG was observed before the pandemic. During the first year of the pandemic, a significant increase was observed in females aged 24-44 years. A heterogeneous distribution of UG was identified; however, border states were ranked among the top states with elevated incidences and cases. Lastly, the occurrence of UG was associated with temperature, related to summer. The information presented is intended to be useful to promote prevention and to contribute to visualize the distribution of UG over the last 18 years for decision making, and to show one of the consequences of the collapse of epidemiological surveillance of UG during the first year of the COVID-19 pandemic.

TRiCit: A High-Throughput Approach to Detect Trichomonas vaginalis from ITS1 Amplicon Sequencing

Trichomoniasis, caused by Trichomonas vaginalis (TV), is the most common non-viral sexually transmitted infection (STI) worldwide, affecting over 174 million people annually and is frequently associated with reproductive co-morbidities. However, its detection can be time-consuming, subjective, and expensive for large cohort studies. This case-control study, conducted at the Mount Sinai Adolescent Health Center in New York City, involved 36 women with prevalent TV infections and 36 controls. The objective was to examine Internal Transcribed Spacer region-1 (ITS1) amplicon-derived communities for the detection of prevalent TV infections with the same precision as clinical microscopy and the independent amplification of the TV-specific TVK3/7 gene. DNA was isolated from clinician-collected cervicovaginal samples and amplified using ITS1 primers in a research laboratory. Results were compared to microscopic wet-mount TV detection of concurrently collected cervicovaginal samples and confirmed against TV-specific TVK3/7 gene PCR. The area under the receiver operating characteristics curve (AUC) for diagnosing TV using ITS1 communities was 0.92. ITS1 amplicons displayed an intra-class correlation coefficient (ICC) of 0.96 (95% CI: 0.93-0.98) compared to TVK3/7 PCR fragment testing. TV cases showed an increased risk of bacterial vaginosis (BV) compared to the TV-negative controls (OR = 8.67, 95% CI: 2.24-48.54, p-value = 0.0011), with no significant differences regarding genital yeast or chlamydia infections. This study presents a bioinformatics approach to ITS1 amplicon next-generation sequencing that is capable of detecting prevalent TV infections. This approach enables high-throughput testing for TV in stored DNA from large-scale epidemiological studies.

Syphilis

Syphilis is a sexually and vertically transmitted bacterial infection caused by the bacterium Treponema pallidum. Its prevalence is high in low-income and middle-income countries, and its incidence has increased in high-income countries in the last few decades among men who have sex with men. Syphilis is a major cause of adverse pregnancy outcomes in low-income and middle-income countries. Clinical features include a primary chancre at the point of inoculation, followed weeks later by the rash of secondary syphilis, a latent period, and in some cases, involvement of the eyes, CNS, and cardiovascular systems. It is diagnosed serologically. A single intramuscular dose of long-acting benzathine penicillin is recommended for people who have had syphilis for less than 1 year and longer courses for people with late latent syphilis. Control strategies include screening and treatment of all pregnant women, and targeted interventions for groups at high risk. Vaccine development, research on antibiotic prophylaxis, and digital messaging as prevention strategies are ongoing.

Evaluating the global, regional, and national impact of syphilis: results from the global burden of disease study 2019

Syphilis is a global public health concern. This study aimed to assess the global and regional burden of syphilis from 1990 to 2019. Disease burden was evaluated using disability-adjusted life-years (DALYs) and prevalence. Data were extracted from the 2019 global burden of disease Study, an open database available for download. Age-standardized rates (ASR) and estimated annual percentage changes (EAPC) were calculated to evaluate the syphilis burden over time. In 2019, the total number of prevalent cases of syphilis was 49.71 million worldwide. The ASR of prevalence was stable from 1990 to 2019 with an EAPC of 0.00 (95% CI - 0.10-0.11). The number of DALYs caused by syphilis was 7.36 million in 2019, reflecting a reduction of 16.38% compared with that in 1990 (8.80 million). The ASR of DALYs exhibited a decreasing trend from 1990 to 2019 (EAPC =  - 1.01; 95% CI - 1.19 to - 0.84), with the highest rates observed in the younger age group (< 14 years old). In 2019, the highest ASR of DALYs was found in low sociodemographic index (SDI) regions (239.21/100,000), and the lowest in high SDI regions (3.14/100,000). Generally, the ASR of DALYs decreased as the SDI increased. The top three countries with the highest ASR of DALYs for syphilis were the Solomon Islands, Equatorial Guinea, and Liberia. While the global prevalence of syphilis remained persistently high from 1990 to 2019, there has been a recent decrease in the ASR of DALYs. Increased attention should be dedicated to younger populations and regions characterized by low SDIs.

Prevalence of five treatable sexually transmitted infections among women in Lower River region of The Gambia

BACKGROUND

The prevalence of sexually transmitted infections (STIs) in sub-Saharan Africa is poorly described. We aimed to determine the prevalence of five treatable STIs (Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, Mycoplasma genitalium, Treponema pallidum) in a sample of Gambian women from the general population.

METHODS

Archived specimens from 420 women aged 15 - 69 years living in The Gambia enrolled in a clinical trial of human papilloma virus vaccine schedules were tested in this study. Urine samples were tested for C. trachomatis, N. gonorrhoeae, T. vaginalis and M. genitalium using a commercially available, open-platform multiplex PCR kit. A fragment of the ompA gene was amplified from C. trachomatis-positive samples and sequenced. Serum samples were tested for T. pallidum using the Chembio DPP Syphilis Screen and Confirm test.

RESULTS

Overall, 41/420 (9.8%) women tested positive for at least one STI. 32 (7.6%), 9 (2.1%), 1 (0.2%), 1 (0.2%) and 0 (0.0%) tested positive for T. vaginalis, C. trachomatis, N gonorrhoeae, M. genitalium and T. pallidum, respectively. ompA gene sequence was available from five C. trachomatis infections: four were genovar D,one was genovar G and one was genovar F.

CONCLUSIONS

STIs are endemic in The Gambia. Monitoring systems should be established.

Analysis of Structure-Activity Relationships of Novel Inhibitors of the Macrophage Infectivity Potentiator (Mip) Proteins of Neisseria meningitidis, Neisseria gonorrhoeae, and Burkholderia pseudomallei

The macrophage infectivity potentiator (Mip) protein is a promising target for developing new drugs to combat antimicrobial resistance. New rapamycin-derived Mip inhibitors have been designed that may be able to combine two binding modes to inhibit the Mip protein of Burkholderia pseudomallei (BpMip). These novel compounds are characterized by an additional substituent in the middle chain linking the lateral pyridine to the pipecoline moiety, constituting different stereoisomers. These compounds demonstrated high affinity for the BpMip protein in the nanomolar range and high anti-enzymatic activity and ultimately resulted in significantly reduced cytotoxicity of B. pseudomallei in macrophages. They also displayed strong anti-enzymatic activity against the Mip proteins of Neisseria meningitidis and Neisseria gonorrhoeae and substantially improved the ability of macrophages to kill the bacteria. Hence, the new Mip inhibitors are promising, non-cytotoxic candidates for further testing against a broad spectrum of pathogens and infectious diseases.

Are sexually transmitted infections associated with male infertility? A systematic review and in-depth evaluation of the evidence and mechanisms of action of 11 pathogens

Purpose

To systematically review the evidence on the association between sexually transmitted infections (STIs) and male infertility. We sought to answer two questions: Are STIs significantly associated with detrimental changes in semen parameters?; and, is the prevalence of STIs significantly higher in infertile than fertile men?

Materials and methods

PubMed, Scopus and Google Scholar databases were searched (inceptionMarch 2023) following the PRISMA guidelines. Identified original studies in English on the association between STIs and male infertility were included. Data was tabulated/described by pathogen, mechanisms of action, number of studies and their level of evidence.

Results

Seventy out of 903 originally retrieved articles were included in this review. For the detrimental changes in semen parameters (first question), the evidence seems equivocal based on the nearly equal number of studies and similar levels of evidence. The only exception was for Ureaplasma, where the number of studies and levels of evidence supported an association with male infertility. Pertaining to a significantly higher prevalence of STI among infertile compared to fertile men (second question), evidence was insufficient to support/deny a significant association. The two exceptions were Ureaplasma and Mycoplasma, where the number of studies and evidence levels were in favour of an association with male infertility.

Conclusions

Generally, the relationship between STIs and male infertility remains to be uncovered. Our appraisal of the overall state of this relationship shows that the evidence base leaves much to be desired. The exceptions are Ureaplasma and Mycoplasma, where the evidence convincingly suggests their associations with infertility in men.

The impact of COVID-19 pandemic on technologic and process innovation in point-of-care diagnostics for sexually transmitted infections

The STI diagnostic landscape of FDA cleared tests for use at point-of-care (POC), as well as those emergency use authorized for COVID-19 are reviewed; some of these COVID-19 diagnostics may have platform potential as STI diagnostics. Finally, process innovation is described with self-collection and hub-and-spoke mail-in to reference lab models. Movement of Clinical Laboratory Improvement Amendments (CLIA)-waived POC tests to over-the-counter formats will make tests more accessible to consumers. Together with public health messaging, these measures could accelerate STI and COVID-19 syndemic diagnostic solutions.

Evaluation of the AIX1000 Automated Rapid Plasma Reagin Assay in a High-Prevalence Setting

BACKGROUND

Manually performed nontreponemal assays, such as rapid plasma reagin (RPR), are labor intensive and time consuming. Recently, commercial automated RPR assays gained attention. The aim of this study was to compare the qualitative and quantitative performance of the AIX1000 (RPR-A; Gold Standard Diagnostics) to a manual RPR test (RPR-M; Becton Dickinson Macrovue) within a high-prevalence setting.

METHODS

A retrospective panel of 223 samples was selected for comparison between RPR-A and RPR-M, including 24 samples from patients with known syphilis stages and 57 samples from 11 patients in follow-up. In addition, 127 samples obtained during routine syphilis diagnosis with RPR-M were analyzed prospectively with AIX1000.

RESULTS

Overall qualitative concordance (percent agreement) between both assays was 92.0% in the retrospective and 89.0% in the prospective panel. Of 32 discordances, 28 were explained by a treated syphilis infection still positive in one assay and already negative in the other. One sample was false positive with RPR-A, 1 infection remained undetected by RPR-M, and 2 remained undetected by RPR-A. A hook effect was apparent on the AIX1000 at RPR-A titers from 1:32 onward; however, no infections were missed. Accepting a ±1 titer difference, quantitative concordance between both assays reached 73.1% and 98.4% for the retrospective and prospective panels, respectively, with an upper limit of reactivity for RPR-A at 1:256.

CONCLUSIONS

The AIX1000 showed a similar performance to Macrovue RPR with the exception of a negative deviation for high-titer samples. Within the reverse algorithm used in our high-prevalence setting, AIX1000's main advantage is automation.

Whole genome analysis and antimicrobial resistance of Neisseria gonorrhoeae isolates from Ghana

Introduction

Gonorrhoea is a major public health concern. With the global emergence and spread of resistance to last-line antibiotic treatment options, gonorrhoea threatens to be untreatable in the future. Therefore, this study performed whole genome characterization of Neisseria gonorrhoeae collected in Ghana to identify lineages of circulating strains as well as their phenotypic and genotypic antimicrobial resistance (AMR) profiles.

Methods

Whole genome sequencing (WGS) was performed on 56 isolates using both the Oxford Nanopore MinION and Illumina MiSeq sequencing platforms. The Comprehensive Antimicrobial Resistance Database (CARD) and PUBMLST.org/neisseria databases were used to catalogue chromosomal and plasmid genes implicated in AMR. The core genome multi-locus sequence typing (cgMLST) approach was used for comparative genomics analysis.

Results and Discussion

In vitro resistance measured by the E-test method revealed 100%, 91.0% and 85.7% resistance to tetracycline, penicillin and ciprofloxacin, respectively. A total of 22 sequence types (STs) were identified by multilocus sequence typing (MLST), with ST-14422 (n = 10), ST-1927 (n = 8) and ST-11210 (n = 7) being the most prevalent. Six novel STs were also identified (ST-15634, 15636-15639 and 15641). All isolates harboured chromosomal AMR determinants that confer resistance to beta-lactam antimicrobials and tetracycline. A single cefixime-resistant strain, that belongs to N. gonorrhoeae multiantigen sequence type (NG-MAST) ST1407, a type associated with widespread cephalosporin resistance was identified. Neisseria gonorrhoeae Sequence Typing for Antimicrobial Resistance (NG-STAR), identified 29 unique sequence types, with ST-464 (n = 8) and the novel ST-3366 (n = 8) being the most prevalent. Notably, 20 of the 29 STs were novel, indicative of the unique nature of molecular AMR determinants in the Ghanaian strains. Plasmids were highly prevalent: pTetM and pblaTEM were found in 96% and 92% of isolates, respectively. The TEM-135 allele, which is an amino acid change away from producing a stable extended-spectrum β-lactamase that could result in complete cephalosporin resistance, was identified in 28.5% of the isolates. Using WGS, we characterized N. gonorrhoeae strains from Ghana, giving a snapshot of the current state of gonococcal AMR in the country and highlighting the need for constant genomic surveillance.

Prevalence of sexually transmissible infections in adolescents treated in a family planning outpatient clinic for adolescents in the western Amazon

Sexually transmitted infections (STIs) are among the most common public health problems worldwide, especially among adolescents and young adults, who account for almost 50% of all STI patients. Studies on the subject in the western Amazon are limited. This study aimed to evaluate the prevalence of STIs (chlamydia, gonorrhea, trichomoniasis, herpes simplex virus, syphilis, human immunodeficiency virus [HIV], hepatitis B, and hepatitis C) in adolescents treated at a family planning outpatient clinic in the western Amazon: Porto Velho, Rondônia, Brazil. A total of 196 adolescents were enrolled. During the gynecological examination, endocervical samples were collected to test for four STIs (chlamydia, gonorrhea, trichomoniasis, and herpes simplex virus), and blood samples were collected for the detection of HIV, syphilis, and hepatitis B and C. The mean age was 17.3 ± 1.5 years, the age at sexarche was 14.4 ± 1.6 years, and 54.6% of participants had their first sexual intercourse at 14 years or younger. Only 1.0% of the adolescents used condoms in all sexual relations, and 19.9% had casual partner(s) in the last year. In the evaluation of prevalence, we found that 32% of the adolescents had at least one STI, with the most prevalent being chlamydia (23%), followed by trichomoniasis (5.6%), herpes simplex (4.6%), and gonorrhea (3.1%). No positive cases of hepatitis B, hepatitis C, or HIV were detected, but 1% of the adolescents tested positive for syphilis. These indicators will support more effective health care strategies aimed at improving the quality of life of populations in this region of the western Amazon. In conclusion, our findings demonstrated high rates of STIs in the studied patients, reinforcing the need to expand epidemiological studies to implement more appropriate public policies and intervention strategies to prevent STIs in adolescents and other vulnerable populations in the western Amazon.

Social Pressure from a Core Group can Cause Self-Sustained Oscillations in an Epidemic Model

Let the individuals of a population be divided into two groups with different personal habits. The core group is associated with health risk behaviors; the non-core group avoids unhealthy activities. Assume that the infected individuals of the core group can spread a contagious disease to the whole population. Also, assume that cure does not confer immunity. Here, an epidemiological model written as a set of ordinary differential equations is proposed to investigate the infection propagation in this population. In the model, migrations between these two groups are allowed; however, the transitions from the non-core group into the core group prevail. These migrations can be either spontaneous or stimulated by social pressure. It is analytically shown that, in the scenario of spontaneous migration, the disease is either naturally eradicated or chronically persists at a constant level. In the scenario of stimulated migration, in addition to eradication and constant persistence, self-sustained oscillations in the number of sick individuals can also be found. These analytical results are illustrated by numerical simulations and discussed from a public health perspective.

Pay-it-forward gonorrhea and chlamydia testing among men who have sex with men and male STD patients in China: the PIONEER pragmatic, cluster randomized controlled trial protocol

BACKGROUND

Gonorrhea and chlamydia are the most common sexually transmitted diseases (STDs) among men who have sex with men (MSM) in China. Previous studies have shown pay-it-forward (PIF) interventions to be associated with a substantial increase in gonorrhea and chlamydia test uptake compared to standard-of-care. We propose a 'pay-it-forward' gonorrhea and chlamydia testing randomized controlled trial (PIONEER). The trial would evaluate the effectiveness of two pay-it-forward strategies in promoting testing uptake compared to the standard of care (in which men pay for their tests out-of-pocket) among MSM and male STD patients in China.

METHODS

PIONEER will be a three-armed, pragmatic cluster randomized controlled trial (RCT), conducted across 12 clinics (six MSM-led and six public STD clinics) to compare the effectiveness of three implementation strategies. Each facility will be randomized to a standard pay-it-forward intervention of gonorrhea/ chlamydia testing with minimal encouragement for testing, a community-engaged pay-it-forward arm, or a control arm where men pay for their tests out-of-pockets. The primary outcome will be dual gonorrhea/chlamydia test uptake. Secondary outcomes will include syphilis testing, amount donated in pay-it-forward, number of positive gonorrhea and chlamydia tests, and measures of antimicrobial resistance. A sequential transformative mixed methods design will be used to evaluate the implementation process in type 2 effectiveness-implementation hybrid design. Data sources will include survey on acceptability, and feelings and attitudes towards the interventions among participants; testing and treatment uptake data from clinic records, WeChat records, and qualitative data to gain insights into men's perceptions and attitudes towards the pay-it-forward, mechanisms driving uptake, and donating behaviors. Implementers and organizers will be interviewed about fidelity and adherence to protocol, sustainability of pay-it-forward intervention, and barriers and facilitators of implementing the intervention.

DISCUSSION

PIONEER will substantially increase gonorrhea/chlamydia testing among MSM in China, providing an innovative and new financial mechanism to sustain STD screening among sexual minorities in low- and middle-income countries. This study will answer compelling scientific questions about how best to implement pay-it-forward and the individual and organizational characteristics that moderate it.

TRIAL REGISTRATION

The study with identification number NCT05723263 has been registered on clinicaltrials.gov/.

Prevalence, Associated Factors, and Appropriateness of Empirical Treatment of Trichomoniasis, Bacterial Vaginosis, and Vulvovaginal Candidiasis among Women with Vaginitis

Trichomoniasis (TV), bacterial vaginosis (BV), and vulvovaginal candidiasis (VVC) are the most common causes of vaginitis. This study investigated the prevalence of these diagnoses, their associated factors, and the appropriateness of the empirical treatment. From March 25, 2019, to June 17, 2022, 429 women with symptoms or signs of vaginitis were enrolled in a hospital in northern Taiwan with 438 episodes of vaginitis. Vaginal swabs were collected for Gram's staining, in vitro cultures for Trichomonas vaginalis, bacteria, and yeasts, and multiplex PCR assay for TV, BV, and VVC. Their empirical treatments were recorded. Factors associated with different etiologies of vaginitis were sought in multivariable logistic regression models. The prevalence of TV, BV, and VVC were 2.1%, 22.8%, and 21.7%, respectively, while coinfections of BV and VVC, TV and BV, TV and VVC, and triple infection occurred in 5.0%, 0.2%, 0.2%, and 0.7%, respectively. Multivariable analyses revealed that having multiple sexual partners was associated with TV and BV (adjusted odds ratio [aOR] 9.756 and 3.246, respectively), while menopausal women were less likely to have VVC (aOR 0.184). Moreover, dysuria was associated with TV (aOR 4.981), vaginal itch and pelvic pain with VVC (aOR 3.223 and 0.425, respectively), and discharge pH > 4.5 with BV (aOR 1.767). Other clinical symptoms and pelvic examination features had limited value for differential diagnosis. Among the 78 empirical antifungal and metronidazole prescriptions, 55.2% were ineffective or unnecessary. Our study highlights the importance to integrate appropriate diagnostic tools into the clinical care of women with vaginitis. IMPORTANCE Vaginal complaints are widespread among women and are associated with emotional, physical, and economic burdens with challenges in their diagnosis and management. In this survey, we identified that 40% of vaginitis in Taiwan was caused by either trichomoniasis, bacterial vaginosis, vulvovaginal candidiasis, or a combination of these infections. Our data suggested that typical physical findings appeared infrequently among women with these infections and their empirical treatments were frequently inappropriate. Our findings highlighted the importance of integrating proper diagnostic tools into clinical practice to improve the diagnosis and management of vaginitis, as recommended by national and international guidelines.

Hormonal steroids bind the Neisseria gonorrhoeae multidrug resistance regulator, MtrR, to induce a multidrug binding efflux pump and stress-response sigma factor

Overexpression of the multidrug efflux pump MtrCDE, a critical factor of multidrug-resistance in Neisseria gonorrhoeae , the causative agent of gonorrheae, is repressed by the transcriptional regulator, MtrR (multiple transferable resistance repressor). Here, we report the results from a series of in vitro experiments to identify innate, human inducers of MtrR and to understand the biochemical and structural mechanisms of the gene regulatory function of MtrR. Isothermal titration calorimetry experiments reveal that MtrR binds the hormonal steroids progesterone, β-estradiol, and testosterone, all of which are present at significant concentrations at urogenital infection sites as well as ethinyl estrogen, a component of some birth control pills. Binding of these steroids results in decreased affinity of MtrR for cognate DNA, as demonstrated by fluorescence polarization-based assays. The crystal structures of MtrR bound to each steroid provided insight into the flexibility of the binding pocket, elucidated specific residue-ligand interactions, and revealed the conformational consequences of the induction mechanism of MtrR. Three residues, D171, W136 and R176 are key to the specific binding of these gonadal steroids. These studies provide a molecular understanding of the transcriptional regulation by MtrR that promotes N. gonorrhoeae survival in its human host.

Usability of a novel lateral flow assay for the point-of-care detection of Neisseria gonorrhoeae: A qualitative time-series assessment among healthcare workers in South Africa

Accurate and user-friendly rapid point-of-care diagnostic tests (POCT) are needed to optimize treatment of Neisseria gonorrhoeae, especially in low-resource settings where syndromic management is the standard of care for sexually transmitted infections. This study aimed to assess the acceptability and usability of a novel lateral flow assay and portable reader for the point-of-care detection of N. gonorrhoeae infection (NG-LFA). This mixed-methods study was conducted as part of a diagnostic performance and usability evaluation of a prototype NG-LFA for detection of N. gonorrhoeae in symptomatic men and women at primary healthcare facilities in the Buffalo City Metro, South Africa. The Standardized System Usability Scale (SUS) was administered, and in-depth interviews were conducted among healthcare professionals (HCPs) and fieldworkers (FWs) at pre-implementation, initial use and 3- and 6-month study implementation to assess user expectations, practical experience, and future implementation considerations for the NG-LFA. Data collection and analysis was guided by the Health Technology Adoption Framework, including new health technology attributes, learnability, satisfaction, and suitability. The framework was adapted to include perceived durability. A total of 21 HCPs and FWs were trained on the NG-LFA use. SUS scores showed good to excellent acceptability ranging from 78.8-90.6 mean scores between HCPs and FWs across study time points. All transcripts were coded using Dedoose and qualitative findings were organized by learnability, satisfaction, suitability, and durability domains. Usability themes are described for each time point. Initial insecurity dissipated and specimen processing dexterity with novel POCT technology was perfected over time especially amongst FWs through practical learning and easy-to-use instructions (learnability). Participants experienced both positive and negative test results, yielding perceived accuracy and minimal testing challenges overall (satisfaction). By 3- and 6-month use, both HCPs and FWs found the NG-LFA convenient to use in primary health care facilities often faced with space constraints and outlined perceived benefits for patients (suitability and durability). Findings show that the NG-LFA device is acceptable and usable even amongst paraprofessionals. High SUS scores and qualitative findings demonstrate high learnability, ease-of-use and suitability that provide valuable information for first-step scale-up requirements at primary healthcare level. Minor prototype adjustments would enhance robustness and durability aspects.

Burden of Disease of Gonorrhoea in Latin America: Systematic Review and Meta-analysis

INTRODUCTION

Neisseria gonorrhoeae causes gonorrhoea, a globally neglected but increasing disease. This systematic review and meta-analysis reviewed the epidemiology and economic burden of gonorrhoea in Latin America and the Caribbean (LAC).

METHODS

We searched PubMed, EMBase, Cochrane Library, EconLIT, CINAHL, CRD, LILACS, Global Health, Global Dissertations and Theses, SciELO, Web of Science databases, countries' ministries of health, and the IHME's Global Burden of Disease databases. Studies published in the last 10 years (20 years for economic studies) were included if conducted in any LAC country, without language restrictions. The main outcome measures were incidence/prevalence, proportion of co-infections, case fatality rates, specific mortality/hospitalisation rates, direct/indirect costs, and impact of gonorrhoea on quality of life. To assess evidence quality, we used a checklist developed by the US National Heart, Lung, and Blood Institute for observational studies and trial control arms, the Cochrane Effective Practice Organization of Care Group tool for randomised controlled trials, and the CICERO checklist for economic studies.

RESULTS

We identified 1290 articles; 115 included epidemiological studies and one included an economic study. Ministry of health data from Argentina, Brazil, Chile, Colombia, Mexico, and Uruguay were identified. Gonorrhoea prevalence was 1.46% (95% confidence interval [CI] 1.00-2.00%) from 48 studies and 5.68% (95% CI 4.23-7.32%) from 58 studies for non-high-risk and high-risk populations, respectively. Cumulative incidence for the high-risk population was 2.05 cases per 100 persons/year. Few published studies were rated as "good" in the risk of bias assessments. Variations in the methodology of the sources and limited information found in the countries' surveillance systems hinder the comparison of data.

CONCLUSION

The burden of gonorrhoea in LAC is not negligible. Our results provide public health and clinical decision support to assess potential interventions to prevent gonorrhoea.

TRIAL REGISTRATION

The protocol is registered on PROSPERO (CRD42021253342). The study was funded by GlaxoSmithKline Biologicals SA (GSK study identifier VEO-000025).

In Vitro Testing of Trichomonas vaginalis Drug Susceptibility: Evaluation of Minimal Lethal Concentrations for Metronidazole and Tinidazole That Correspond With Treatment Failure

BACKGROUND

The only drugs approved by the US Food and Drug Administration for oral treatment of trichomoniasis belong to the 5-nitroimidazole group. Most individuals infected with Trichomonas vaginalis can be cured with a standard treatment of metronidazole or tinidazole, but it is estimated that more than 159,000 people fail treatment each year. Although a minimal lethal concentration (MLC) corresponding to treatment failure has been reported for metronidazole, the MLC for tinidazole associated with treatment failure has not been determined. We conducted a study using T. vaginalis isolates from women with reported treatment success or failure to determine these values.

METHODS

We measured MLCs of 47 isolates obtained from women who had failed metronidazole treatment, 33 isolates from women who had failed tinidazole treatment, and 48 isolates from women successfully cured with metronidazole. The cutoff was calculated as the 95th percentile of MLCs of susceptible isolates for each drug.

RESULTS

Our data confirmed that the MLC previously associated with metronidazole treatment failure is ≥50 μg/mL and identified the MLC associated with tinidazole treatment failure as ≥6.3 μg/mL. For metronidazole, the agreement between laboratory result and treatment outcome was 93.7%; for tinidazole, this agreement was 88.9%.

CONCLUSIONS

The T. vaginalis susceptibility assay is useful for determining whether 5-nitroimidazole treatment failure in persons with trichomoniasis can be attributed to drug resistance. These results are useful for establishing interpretive guidance of test results, and MLC levels can help guide appropriate patient treatment.

Antimicrobial resistance of Neisseria gonorrhoeae in Latin American countries: a systematic review

BACKGROUND

Detailed information is needed on the dynamic pattern of antimicrobial resistance (AMR) in Neisseria gonorrhoeae in Latin America and the Caribbean (LAC).

OBJECTIVES

To conduct a systematic review of AMR in N. gonorrhoeae in LAC.

METHODS

Electronic searches without language restrictions were conducted in PubMed, Embase, Cochrane Library, EconLIT, Cumulative Index of Nursing and Allied Health Literature, Centre for Reviews and Dissemination, and Latin American and Caribbean Literature in Health Sciences. Studies were eligible if published between 1 January 2011 and 13 February 2021, conducted in any LAC country (regardless of age, sex and population) and measured frequency and/or patterns of AMR to any antimicrobial in N. gonorrhoeae. The WHO Global Gonococcal Antimicrobial Surveillance Programme (WHO-GASP) for LAC countries and Latin American AMR SurveillanceNetwork databases were searched. AMR study quality was evaluated according to WHO recommendations.

RESULTS

AMR data for 38, 417 isolates collected in 1990-2018 were included from 31 publications, reporting data from Argentina, Brazil, Colombia, Peru, Uruguay, Venezuela and WHO-GASP. Resistance to extended-spectrum cephalosporins was infrequent (0.09%-8.5%). Resistance to azithromycin was up to 32% in the published studies and up to 61% in WHO-GASP. Resistance to penicillin, tetracycline and ciprofloxacin was high (17.6%-98%, 20.7%-90% and 5.9%-89%, respectively). Resistance to gentamicin was not reported, and resistance to spectinomycin was reported in one study.

CONCLUSIONS

This review provides data on resistance to azithromycin, potentially important given its use as first-line empirical treatment, and indicates the need for improved surveillance of gonococcal AMR in LAC. Trial registration: Registered in PROSPERO, CRD42021253342.

Progress towards triple elimination of mother-to-child transmission of HIV, hepatitis B and syphilis in Pacific Island Countries and Territories: a systematic review

The diverse geographic, demographic, and societal factors in the Pacific Island Countries and Territories (PICTs) have contributed to unique epidemiological patterns of HIV, syphilis, and hepatitis B. Transmission can be during pregnancy, at the time of birth or via breastfeeding for HIV, and can have long-term adverse outcomes. Given the similarities in prevention of mother-to-child transmission of these infections, coordinated interventions for triple elimination are used. This systematic review has evaluated the peer-reviewed literature, grey literature, and global databases to assess the availability of data to report against elimination targets in the WHO Regional Framework for the Triple Elimination of Mother-to-Child Transmission of HIV, Hepatitis B and Syphilis in Asia and the Pacific 2018-2030. The secondary objective is to report on progress towards these targets. The findings show that none of the PICTs are on track to achieve triple elimination by 2030. Amongst the limited publicly available indicator data, there is suboptimal coverage for most indicators. It is important that there is an increase in availability of and access to antenatal care, testing, and treatment for pregnant women. Increased efforts are needed to collect data on key indicators and integrate reporting into existing systems to avoid extra burden.

Funding

Leila Bell was supported by an Australian Government Research Training Program (RTP) Scholarship, Australia. Funding sources had no role in paper design, data collection, data analysis, interpretation, or writing of the paper.

A large screen identifies beta-lactam antibiotics which can be repurposed to target the syphilis agent

Syphilis, caused by the spirochete Treponema pallidum subsp. pallidum (hereafter called T. pallidum), is re-emerging as a worldwide sexually transmitted infection. A single intramuscular dose of benzathine penicillin G is the preferred syphilis treatment option. Both supply shortage concerns and the potential for acquired antibiotic resistance further the need to broaden the repertoire of syphilis therapeutics. We reasoned that other β-lactams may be equally or more effective at targeting the disease-causing agent, Treponema pallidum, but have yet to be discovered due to a previous lack of a continuous in vitro culture system. Recent technical advances with respect to in vitro T. pallidum propagation allowed us to conduct a high-throughput screen of almost 100 β-lactams. Using several molecular and cellular approaches that we developed or adapted, we identified and confirmed the efficacy of several β-lactams that were similar to or outperformed the current standard, benzathine penicillin G. These options are either currently used to treat bacterial infections or are synthetic derivatives of naturally occurring compounds. Our studies not only identified additional potential therapeutics in the resolution of syphilis, but provide techniques to study the complex biology of T. pallidum-a spirochete that has plagued human health for centuries.

Vertebrate and Invertebrate Animal and New In Vitro Models for Studying Neisseria Biology

The history of Neisseria research has involved the use of a wide variety of vertebrate and invertebrate animal models, from insects to humans. In this review, we itemise these models and describe how they have made significant contributions to understanding the pathophysiology of Neisseria infections and to the development and testing of vaccines and antimicrobials. We also look ahead, briefly, to their potential replacement by complex in vitro cellular models.

Point-of-care detection of Neisseria gonorrhoeae based on RPA-CRISPR/Cas12a

Gonorrhea, caused by Neisseria gonorrhoeae (N. gonorrhoeae), is a persistent global public health threat. The development of low-cost, point-of-care testing is crucial for gonorrhea control, especially in regions with limited medical facilities. In this study, we integrated CRISPR/Cas12a reaction with recombinase polymerase amplification (RPA) to provide a simple and adaptable molecular detection method for N. gonorrhoeae. The RPA-Cas12a-based detection system developed in this study enables rapid detection of N. gonorrhoeae within 1 h without the use of specialized equipment. This method is highly specific for identifying N. gonorrhoeae without cross-reactivity with other prevalent pathogens. Furthermore, in the evaluation of 24 clinical samples, the detection system demonstrates a 100% concordance rate with traditional culture, which is being used clinically as a reference method. Overall, the RPA-Cas12a-based N. gonorrhoeae detection has the advantages of rapidity, portability, low-cost, no special equipment required, and strong operability, and has a high potential for application as a self-testing and point-of-care diagnosis, which is critical for the clinical management of gonorrhea in developing countries lacking medical equipment.

Development of Cas13a-based Assays for Neisseria gonorrhoeae Detection and Gyrase A Determination

Background

Neisseria gonorrhoeae is one of the most common bacterial sexually transmitted infections. The emergence of antimicrobial-resistant N. gonorrhoeae is an urgent public health threat. Currently, diagnosis of N. gonorrhoeae infection requires expensive laboratory infrastructure, while antimicrobial susceptibility determination requires bacterial culture, both of which are infeasible in low-resource areas where prevalence is highest. Recent advances in molecular diagnostics, such as Specific High-sensitivity Enzymatic Reporter unLOCKing (SHERLOCK) using CRISPR-Cas13a and isothermal amplification, have the potential to provide low-cost detection of pathogen and antimicrobial resistance.

Methods and Results

We designed and optimized RNA guides and primer-sets for SHERLOCK assays capable of detecting N. gonorrhoeae via the por A gene and of predicting ciprofloxacin susceptibility via a single mutation in the gyrase A ( gyr A) gene. We evaluated their performance using both synthetic DNA and purified N. gonorrhoeae isolates. For por A, we created both a fluorescence-based assay and lateral flow assay using a biotinylated FAM reporter. Both methods demonstrated sensitive detection of 14 N. gonorrhoeae isolates and no cross-reactivity with 3 non-gonococcal Neisseria isolates. For gyr A, we created a fluorescence-based assay that correctly distinguished between 20 purified N. gonorrhoeae isolates with phenotypic ciprofloxacin resistance and 3 with phenotypic susceptibility. We confirmed the gyr A genotype predictions from the fluorescence-based assay with DNA sequencing, which showed 100% concordance for the isolates studied.

Conclusion

We report the development of Cas13a-based SHERLOCK assays that detect N. gonorrhoeae and differentiate ciprofloxacin-resistant isolates from ciprofloxacin-susceptible isolates.

Persistence of obligate intracellular pathogens: alternative strategies to overcome host-specific stresses

In adapting to the intracellular niche, obligate intracellular bacteria usually undergo a reduction of genome size by eliminating genes not needed for intracellular survival. These losses can include, for example, genes involved in nutrient anabolic pathways or in stress response. Living inside a host cell offers a stable environment where intracellular bacteria can limit their exposure to extracellular effectors of the immune system and modulate or outright inhibit intracellular defense mechanisms. However, highlighting an area of vulnerability, these pathogens are dependent on the host cell for nutrients and are very sensitive to conditions that limit nutrient availability. Persistence is a common response shared by evolutionarily divergent bacteria to survive adverse conditions like nutrient deprivation. Development of persistence usually compromises successful antibiotic therapy of bacterial infections and is associated with chronic infections and long-term sequelae for the patients. During persistence, obligate intracellular pathogens are viable but not growing inside their host cell. They can survive for a long period of time such that, when the inducing stress is removed, reactivation of their growth cycles resumes. Given their reduced coding capacity, intracellular bacteria have adapted different response mechanisms. This review gives an overview of the strategies used by the obligate intracellular bacteria, where known, which, unlike model organisms such as E. coli, often lack toxin-antitoxin systems and the stringent response that have been linked to a persister phenotype and amino acid starvation states, respectively.

Peptidases Are Potential Targets of Copper(II)-1,10-Phenanthroline-5,6-dione Complex, a Promising and Potent New Drug against Trichomonas vaginalis

Trichomonas vaginalis is responsible for 156 million new cases per year worldwide. When present asymptomatically, the parasite can lead to serious complications, such as development of cervical and prostate cancer. As infection increases the acquisition and transmission of HIV, the control of trichomoniasis represents an important niche for the discovery and development of new antiparasitic molecules. This urogenital parasite synthesizes several molecules that allow the establishment and pathogenesis of infection. Among them, peptidases occupy key roles as virulence factors, and the inhibition of these enzymes has become an important mechanism for modulating pathogenesis. Based on these premises, our group recently reported the potent anti-T. vaginalis action of the metal-based complex [Cu(phendione)₃](ClO₄)₂.4H₂O (Cu-phendione). In the present study, we evaluated the influence of Cu-phendione on the modulation of proteolytic activities produced by T. vaginalis by biochemical and molecular approaches. Cu-phendione showed strong inhibitory potential against T. vaginalis peptidases, especially cysteine- and metallo-type peptidases. The latter revealed a more prominent effect at both the post-transcriptional and post-translational levels. Molecular Docking analysis confirmed the interaction of Cu-phendione, with high binding energy (-9.7 and -10.7 kcal·mol^-1, respectively) at the active site of both TvMP50 and TvGP63 metallopeptidases. In addition, Cu-phendione significantly reduced trophozoite-mediated cytolysis in human vaginal (HMVII) and monkey kidney (VERO) epithelial cell lineages. These results highlight the antiparasitic potential of Cu-phendione by interaction with important T. vaginalis virulence factors.