Gonorrhoea: a systematic review of prevalence reporting globally

Preliminary clinical performance of a Cas13a-based lateral flow assay for detecting Neisseria gonorrhoeae in urine specimens

Nucleic acid amplification testing (NAAT) for N. gonorrhoeae is unavailable in resource-limited settings. We previously developed a CRISPR-based lateral flow assay for detecting N. gonorrhoeae. We aimed to pair that assay with point-of-care DNA extraction, assess performance in clinical urine specimens, and optimize assay kinetics. We collected urine specimens among men presenting with urethritis enrolling in a clinical trial at the Massachusetts General Hospital Sexual Health Clinic. We assessed the quantified DNA yield of detergent-based extractions with and without heat. We selected one detergent for extracting all specimens, paired with isothermal recombinase polymerase amplification for 90 minutes and lateral flow Cas13a detection, interpreted via pixel intensity analysis. We also trained a smartphone-based machine-learning model on 1,008 images to classify lateral flow results. We used the model to interpret lateral flow results from the clinical specimens. We also tested a modified amplification chemistry with a second forward primer lacking the T7-promoter to accelerate reaction kinetics. Extraction with 0.02% Triton X resulted in an average DNA yield of 2.6 × 106 copies/µL (SD ± 6.7 × 105). We treated 40 urine specimens (n = 12 positive) with 0.02% Triton X, and using quantified pixel intensity analysis, the Cas13a-based assay correctly classified all specimens (100% agreement; 95% CI 91.2%-100%). The machine-learning model correctly classified 45/45 strips in the validation data set and all 40 lateral flow strips from clinical specimens. Including the second forward primer reduced incubation time to 60 minutes. Using point-of-care DNA extraction, our Cas13a-based lateral flow N. gonorrhoeae assay demonstrated promising performance among clinical urine specimens.IMPORTANCEUsing a CRISPR-based assay we previously developed for Neisseria gonorrhoeae detection, we developed new techniques to facilitate point-of-care use. We then demonstrated the promising performance of that assay in clinical specimens. Furthermore, we developed a smartphone-based machine learning application for assisting interpretation of lateral flow strip results. Such an assay has the potential to transform the care of sexually transmitted infections in low-resource settings where diagnostic tests are unavailable. A point-of-care pathogen-specific assay, paired with the connectivity offered by a smartphone application, can also support public health surveillance efforts in such areas.

Prevalence of chlamydia, gonorrhoea, and trichomoniasis among male and female general populations in sub-Saharan Africa from 2000-2024: A systematic review and meta-regression analysis

Background

Sub-Saharan Africa (SSA) has the highest sexually transmitted infection (STI) prevalence globally, but information about trends and geographic variation is limited by sparse aetiologic studies, particularly among men. This systematic review assessed chlamydia, gonorrhoea, and trichomoniasis prevalence by sex, sub-region, and year, and estimated male-to-female prevalence ratios for SSA.

Methods

We searched Embase, MEDLINE, Global Health, PubMed, and African Index Medicus for studies measuring STI prevalence among general populations from January 1, 2000, to September 17, 2024. We adjusted observations for diagnostic test performance and used log-binomial mixed-effects meta-regressions to estimate prevalence trends and sex-prevalence ratios.

Findings

Of 5202 records identified, we included 211 studies from 28 countries. In 2020, estimated prevalence among 15-49-year-olds in SSA for chlamydia was 6.6% (95%CI: 5.0-8.2%, n=169 observations) among females and 4.7% (3.4-6.1%, n=33) among males, gonorrhoea was 2.4% (1.4-3.3%, n=171) and 1.7% (0.7-2.6%, n=31), and trichomoniasis was 6.8% (3.6-9.9%, n=188) and 1.7% (0.7-2.7%, n=19). Male-to-female ratio estimates were 0.61 (0.53-0.71) for chlamydia, 0.81 (0.61-1.09) for gonorrhoea, and 0.23 (0.18-0.28) for trichomoniasis. From 2010-2020, chlamydia prevalence increased by 34.5% (11.1-62.9%) in SSA, while gonorrhoea and trichomoniasis trends were not statistically significant. Chlamydia and gonorrhoea prevalence were highest in Southern and Eastern Africa, whereas trichomoniasis was similar across sub-regions.

Interpretation

SSA has a high, geographically varied STI burden, with increasing prevalence of chlamydia. Region-specific sex-prevalence ratios differed from existing global ratios and should be considered in future burden estimates. Enhanced sex-stratified surveillance is crucial to guide national programmes and reduce STI prevalence in SSA.

Funding

Gates Foundation, Imperial College London, NIH, UKRI.

Gonorrhea cluster detection in Manitoba, Canada: Spatial, temporal, and spatio-temporal analysis

In Canada, Gonorrhea infection ranks as the second most prevalent sexually transmitted infection. In 2018, Manitoba reported an incidence rate three times greater than the national average. This study aims to investigate the spatial, temporal, and spatio-temporal patterns of Gonorrhea infection in Manitoba, using individual-level laboratory-confirmed administrative data provided by Manitoba Health from 2000 to 2016. Age and sex patterns indicate that females are affected by infections at younger ages compared to males. Moreover, there is an increase in repeated infections in 2016, accounting for 16% of the total infections. Spatial analysis at the 96 Manitoba regional health authority districts highlights significant positive spatial autocorrelation, demonstrating a clustered distribution of the infection. Northern districts of Manitoba and central Winnipeg were identified as significant clusters. Temporal analysis shows seasonal patterns, with higher infections in late summer and fall. Additionally, spatio-temporal analysis reveals clusters during high-risk periods, with the most likely cluster in the northern districts of Manitoba from January 2006 to June 2014, and a secondary cluster in central Winnipeg from June 2004 to November 2012. This study identifies that Gonorrhea infection transmission in Manitoba has temporal, spatial, and spatio-temporal variations. The findings provide vital insights for public health and Manitoba Health by revealing high-risk clusters and emphasizing the need for focused and localized prevention, control measures, and resource allocation.

Sexually transmitted infections among at-risk women in Ecuador: implications for global prevalence and testing practices for STIs detected only at the anorectum in female sex workers

OBJECTIVES

Anorectal sexually transmitted infections (STIs) such as Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG), present treatment challenges, potentially increase antibiotic resistance selection and if undetected may facilitate onward transmission. However, there are limited global prevalence data for anorectal STIs. We conducted a cross-sectional study to assess the prevalence and risk factors of non-viral genital and extragenital STIs in female sex workers (FSW) and female non-sex workers (NSW) in Ecuador.

METHODS

250 adult street and brothel FSWs and 250 NSWs, recruited from settlements in north-west Ecuador provided oropharyngeal and vulvo-vaginal swabs (VVS) as well as socio-demographic data. FSWs also provided anorectal swabs. PCR was used to detect CT, NG, Mycoplasma genitalium (MG) from all swabs and additionally Trichomonas vaginalis (TV) from VVS. Risk factors were analysed using logistic regression.

RESULTS

Prevalence of FSW vaginal, anorectal and oropharyngeal infection was 32.0% (95% CI 26.5% to 38.0%), 19.7% (95% CI 15.1% to 25.2%) and 3.2% (95% CI 1.6% to 6.2%), respectively, with most vaginal infections being TV (23.4%; 95% CI 18.5% to 29.2%). Overall FSW STI prevalence, at any anatomical site was 39.7% (95% CI 33.8% to 46.1%), with 12.1% (95% CI 8.5% to 16.9%) of infections detected only at the anorectum. Of all the CT and/or NG infections, 64.4% (95% CI 50.4% to 78.4%) were detected only at the anorectum. STI prevalence in NSWs in the vagina and oropharynx were 5.6% (95% CI 3.4% to 9.2%) and 0.8% (95% CI 0.2% to 2.9%), respectively, with most vaginal infections being MG (3.2%; 95% CI 1.6% to 6.2%). In multivariable analysis, risk factors among brothel-based FSWs for having an anorectal STI were vaginal CT, NG or MG (p<0.001), vaginal TV (p=0.029) and being 'in a relationship' (p=0.038).

CONCLUSIONS

High prevalence of CT and NG detected only at the anorectum in these FSWs indicate the possibility of missing significant infections if providing only genital testing and calls for greater research into the potential impact on global STI estimates if extragenital infections among at-risk women are not identified.

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.

Vaccine value profile for Neisseria gonorrhoeae

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

Global trends of antimicrobial resistance rates in Neisseria gonorrhoeae: a systematic review and meta-analysis

Background

Antimicrobial resistance (AMR) of Neisseria gonorrhoeae (NG) is a significant public health concern.

Objective

The objective of our study was to assess global AMR rates and test them both temporally and geographically.

Methods

We conducted a systematic search of relevant reports from international databases up to 2021. The R statistical package was used for all statistical analyses.

Results

A total of 225 articles were analyzed, and 432,880 NG isolates were examined. The weighted pooled resistance (WPR) rate of different antibiotics was as follows: ciprofloxacin, 51.6%; tetracycline, 45.4%; trimethoprim/sulfamethoxazole, 42.4%; chloramphenicol, 4.1%; kanamycin, 2.1%; gentamicin, 0.6%; and spectinomycin, 0.3%. The resistance to spectinomycin, gentamicin, and kanamycin decreased over time. Significant differences in antibiotic resistance rates were found between the countries.

Conclusion

Our findings reveal a continuous increase in resistance to some antibiotics (tetracycline and ciprofloxacin) historically used for gonorrhea, even after discontinuation. However, encouraging trends of decreasing resistance to spectinomycin, gentamicin, and kanamycin were observed. Continued global monitoring of AMR profiles in NG isolates is essential for informing appropriate treatment strategies and mitigating the threat of untreatable gonorrhea.

Antimicrobial treatment and resistance in sexually transmitted bacterial infections

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

Neisseria gonorrhea in Ethiopia, prevalence among STI suspected patients and its antimicrobial susceptibility: a systematic review and meta-analysis

Introduction

Neisseria gonorrhea (N. gonorrhea) represents a significant causative agent of sexually transmitted infections (STIs), posing considerable global health challenges. Despite the presence of diagnostic tools and empirically guided therapies, the escalating AMR of N. gonorrhea continues to pose a threat. This study aims to assess the prevalence of N. gonorrhea among STI suspected patients in Ethiopia and explore the patterns of AMR to common antimicrobials.

Methods

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we conducted a systematic review and meta-analysis. A thorough search of electronic databases from July 11 to July 24, 2023, identified 10 eligible studies. Data were extracted and analyzed using a random-effects model. Heterogeneity was assessed using the I2 statistic, and publication bias was evaluated through Egger's regression test and funnel plots.

Results

The overall pooled prevalence of N. gonorrhea among STI suspected patients in Ethiopia was 20% (95% confidence interval (CI): 8-30, I2 = 99.0%; p-value <0.001). Substantial regional variations were observed, with the highest prevalence in Addis Ababa (55, 95% CI: 45-65) and the lowest in the Southern Nations, Nationalities, and Peoples' Region (SNNPR) (4, 95% CI: 2-8). The pooled prevalence of AMR to ciprofloxacin, ceftriaxone, azithromycin, benzylpenicillin, tetracycline, and spectinomycin was 37, 9, 10, 79, 93, and 2%, respectively. Significant heterogeneity existed between studies (I2 = 99.0%; p value <0.001). Publication bias, identified through funnel plot examination and Egger's regression test (p < 0.001), execution of trim and fill analysis resulted in an adjusted pooled prevalence of (6.2, 95% CI: -6.8 to 19.3).

Conclusion

The prevalence of N. gonorrhea among STI suspected patients in Ethiopia is alarming, particularly in specific regions. The elevated AMR to ciprofloxacin underscores the immediate need for alternative treatment options and enhanced surveillance systems. Future initiatives should prioritize strengthening laboratory capacities and implementing targeted interventions to curtail N. gonorrhea transmission and prevent the emergence of AMR.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero, identifier CRD42023459698.

Improving gonorrhoea molecular diagnostics: Genome mining-based identification of identical multi-repeat sequences (IMRS) in Neisseria gonorrhoeae

Background

Curable sexually transmitted infections (STIs), such as Neisseria gonorrhoeae (N. gonorrhoeae), are a major cause of poor pregnancy outcomes. The infection is often asymptomatic in pregnant women, and a syndrome-based approach of testing leads to a missed diagnosis. Culture followed by microscopy is inadequate and time-consuming. The gold standard nucleic acid amplification tests require advanced infrastructure settings, whereas point-of-care tests are limited to immunoassays with sensitivities and specificities insufficient to accurately diagnose asymptomatic cases. This necessitates the development and validation of assays that are fit for purpose.

Methods

We identified new diagnostic target biomarker regions for N. gonorrhoeae using an algorithm for genome mining of identical multi-repeat sequences (IMRS). These were then developed as DNA amplification primers to design better diagnostic assays. To test the primer pair, genomic DNA was 10-fold serially diluted (100 pg/μL to 1 × 10-3 pg/μL) and used as DNA template for PCR reactions. The gold standard PCR using 16S rRNA primers was also run as a comparative test, and both assay products were resolved on 1% agarose gel.

Results

Our newly developed N. gonorrhoeae IMRS-PCR assay had an analytical sensitivity of 6 fg/μL representing better sensitivity than the 16S rRNA PCR assay with an analytical sensitivity of 4.3096 pg/μL. The assay was also successfully validated using clinical urethral swab samples. We further advanced this technique by developing an isothermal IMRS, which was both reliable and sensitive for detecting cultured N. gonorrhoeae isolates at a concentration of 38 ng/μL. Combining isothermal IMRS with a low-cost lateral flow assay, we were able to detect N. gonorrhoeae amplicons at a starting concentration of 100 pg/μL.

Conclusion

Therefore, there is a potential to implement this concept within miniaturized, isothermal, microfluidic platforms, and laboratory-on-a-chip diagnostic devices for highly reliable point-of-care testing.

Clinical Performance of Cas13a-based Point-of-Care Lateral Flow Assay for Detecting Neisseria gonorrhoeae

Background

Diagnosis of Neisseria (N.) gonorrhoeae is dependent on nucleic acid amplification testing (NAAT), which is not available in resource-limited settings where the prevalence of infection is highest. Recent advances in molecular diagnostics leveraging the high specificity of CRISPR enzymes can permit field-deployable, point-of-care lateral flow assays. We previously reported on the development and in vitro performance of a lateral flow assay for detecting N. gonorrhoeae. Here we aimed to pair that assay with point-of-care DNA extraction techniques and assess the performance on clinical urine specimens.

Methods

We collected an additional urine specimen among individuals enrolling in an ongoing clinical trial at the Massachusetts General Hospital Sexual Health Clinic who presented with symptoms of urethritis or cervicitis (urethral or vaginal discharge, dysuria, or dyspareunia). We then assessed thermal, detergent, and combination DNA extraction conditions, varying the duration of heat at 95°C and concentration of Triton X. We assessed the efficacy of the various DNA extraction methods by quantitative polymerase chain reaction (qPCR). Once an extraction method was selected, we incubated samples for 90 minutes to permit isothermal recombinase polymerase amplification. We then assessed the performance of lateral flow Cas13a-based detection using our previously designed porA probe and primer system for N. gonorrhoeae detection, comparing lateral flow results with NAAT results from clinical care.

Results

We assessed DNA extraction conditions on 3 clinical urine specimens. There was no consistent significant difference in copies per microliter of DNA obtained using more or less heat. On average, we noted that 0.02% triton combined with 5 minutes of heating to 95°C resulted in the highest DNA yield, however, 0.02% triton alone resulted in a quantity of DNA that was above the previously determined analytic sensitivity of the assay. Given that detergent-based extraction is more easily deployable, we selected that as our method for extraction. We treated 23 clinical specimens with 0.02% triton, which we added to the Cas13a detection system. We ran all lateral flow detections in duplicate. The Cas13a-based assay detected 8 of 8 (100%) positive specimens, and 0 of 15 negative specimens.

Conclusion

Using point-of-care DNA extraction, isothermal amplification, and Cas13a-based detection, our point-of-care lateral flow N. gonorrhoeae assay correctly identified 23 clinical urine specimens as either positive or negative. Further evaluation of this assay among larger samples and more diverse sample types is warranted.

The global burden of sexually transmitted infections

Understanding the global burden of sexually transmitted infections (STIs) is fundamental to being able to address and control these infections and the health harms they cause. The World Health Organization has renewed its global health sector strategy for the prevention and control of STIs. Reducing STIs remains an integral part of HIV prevention and of sexual and reproductive health programs. Data to measure and describe the global burden continue to improve, with systematic reviews and modeling providing global and regional data for the major STIs. Although substantial gaps remain, as many countries have limited data, the measures available demonstrate the scale of the problem for the main curable STIs, gonorrhea, chlamydia, syphilis, and trichomoniasis; the most common viral STIs, human papillomavirus and genital herpes; the interrelation between STIs and HIV; and the substantially unequal burden of these infections globally and among key populations. Regional and global trends in these infections are affected by population changes; the impact and availability of interventions, such as vaccination; changing behaviors that alter the dynamics of STI transmission; and the role of international travel in promulgating STIs in an increasingly interconnected world.

STI pathogens in the oropharynx: update on screening and treatment

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Ameliorating Gonorrhea: Recent Therapeutic Adaptations and Scope to Improve its Prevailing Condition

BACKGROUND

Gonorrhea is a sexually transmitted infection (STI) caused by the bacteria Neisseria gonorrhoeae. According to recent research, the prevalence of gonorrhea has been increasing in many parts of the world, with some areas reporting high rates of antibiotic resistance. In the United States, the Centers for Disease Control and Prevention (CDC) reported that the number of reported gonorrhea cases increased by 56% between 2015 and 2019. Globally, the World Health Organization (WHO) estimated that there were 87 million new cases of gonorrhea in 2016, with the highest burden of infection in low- and middle-income countries. Research has also shown that gonorrhea is becoming increasingly resistant to conventional antibiotics, increasing the prevalence of gonorrhea. This raises concerns and challenges in disease management.

OBJECTIVES

The present review gives updated insight on the current state of the disease, challenges, and shortcomings of existing approaches along with the modern and alternative direction like vaccine development, its challenges, and scope to confront the existing state of drug resistance and increased rate of incidence. Alternative strategies like immunotherapy and phage therapy along with recent antibiotics researched for the treatment of gonorrhea.

CONCLUSION

The review provides a thorough insight into the current state of the disease and various available methods used currently and recommended by WHO. To overcome disease prevalence, various alternate therapies are coming into the limelight. However, scientists and researchers show a lack of interest in the drug development and research of gonorrhea, due to less commercial scope, lack of funding, and limited scope in the scientific scenario. These hurdles need to be overcome to meet the WHO vision of reducing gonorrhea by 90% by 2030. So, there is a need to optimize the drug therapy (optimizing dosing schedule, and precision monitoring) to reduce the chance of drug resistance. Also, there is a wide scope for drug and therapeutic system development.

Use of genome sequencing to resolve differences in gradient diffusion and agar dilution antimicrobial susceptibility testing performance of Neisseria gonorrhoeae isolates in Alberta, Canada

Agar dilution is the gold standard method for phenotypic antimicrobial susceptibility testing (AST) for Neisseria gonorrhoeae. However, this method is laborious and requires expertise, so laboratories that perform N. gonorrhoeae AST may choose alternative methods such as disk diffusion and gradient diffusion. In this study, we retrospectively compare the performance of gradient diffusion to agar dilution for 2,394 unique N. gonorrhoeae isolates identified in Alberta from 2017 to 2020 against azithromycin, cefixime, ceftriaxone, ciprofloxacin, penicillin, and tetracycline. Genome sequencing was utilized to resolve discrepancies between AST methods, detect antimicrobial resistance markers, and identify trends between error rates and sequence types (STs) of isolates. Over 90% of N. gonorrhoeae isolates were susceptible to azithromycin, cefixime, and ceftriaxone, whereas decreased susceptibility was observed for ciprofloxacin, penicillin, and tetracycline. Categorical (CA) and essential agreement (EA) was poorest between the two methods for penicillin (CA: 86.02%; EA: 77.69%) and tetracycline (CA: 47.22%; EA: 55.96%); however, the low CA was primarily attributed to minor errors. Antimicrobial agents with errors outside of acceptable limits included azithromycin (very major error: 18.42%; major error: 7.73%) and tetracycline (very major error: 6.17%). Genome sequencing on a subset of isolates resolved 30.3% of the azithromycin major errors and confirmed the azithromycin or tetracycline very major errors. Significant associations between certain STs and error types for azithromycin and tetracycline were also identified. Overall, gradient diffusion compared well to agar dilution for cefixime, ceftriaxone, and ciprofloxacin, and genome sequencing was identified as a useful tool to arbitrate discrepant susceptibility testing results between gradient diffusion and agar dilution for N. gonorrhoeae.

Epidemiology and determinants of reemerging bacterial sexually transmitted infections (STIs) and emerging STIs in Europe

In this scoping review, we offer a comprehensive understanding of the current and recent epidemiology, challenges, and emerging issues related to bacterial sexually transmitted infections (STIs) in the WHO European Region. We endeavour in collating data from both EU/EEA and non- EU/EEA countries, thereby giving a complete picture of the region which highlights the higher notification rates in Northern and Western countries than other regions, likely due to differences in testing, access to testing, and surveillance capacity. We provide an up-to-date review on the current knowledge of determinants and persistent inequities in key populations as well as the use of molecular epidemiology for identifying transmission networks in gonorrhoea and syphilis, and detecting chlamydia mutations that evade molecular diagnosis. Finally, we explore the emerging STIs in the region and the evolving transmission routes of food and waterborne diseases into sexual transmission. Our findings call for harmonized STI surveillance systems, proactive strategies, and policies to address social factors, and staying vigilant for emerging STIs.

Development of Cas13a-based assays for Neisseria gonorrhoeae detection and gyrase A determination

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, the 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 the prevalence of infection 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. We designed and optimized RNA guides and primer sets for SHERLOCK assays capable of detecting N. gonorrhoeae via the porA gene and of predicting ciprofloxacin susceptibility via a single mutation in the gyrase A (gyrA) gene. We evaluated their performance using both synthetic DNA and purified N. gonorrhoeae isolates. For porA, we created both a fluorescence-based assay and lateral flow assay using a biotinylated fluorescein reporter. Both methods demonstrated sensitive detection of 14 N. gonorrhoeae isolates and no cross-reactivity with 3 non-gonococcal Neisseria isolates. For gyrA, 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 gyrA genotype predictions from the fluorescence-based assay with DNA sequencing, which showed 100% concordance for the isolates studied. We report the development of Cas13a-based SHERLOCK assays that detect N. gonorrhoeae and differentiate ciprofloxacin-resistant isolates from ciprofloxacin-susceptible isolates. IMPORTANCE Neisseria gonorrhoeae, the cause of gonorrhea, disproportionately affects resource-limited settings. Such areas, however, lack the technical capabilities for diagnosing the infection. The consequences of poor or absent diagnostics include increased disease morbidity, which, for gonorrhea, includes an increased risk for HIV infection, infertility, and neonatal blindness, as well as an overuse of antibiotics that contributes to the emergence of antibiotic resistance. We used a novel CRISPR-based technology to develop a rapid test that does not require laboratory infrastructure for both diagnosing gonorrhea and predicting whether ciprofloxacin can be used in its treatment, a one-time oral pill. With further development, that diagnostic test may be of use in low-resource settings.

Polyphenylene carboxymethylene (PPCM), the active component of the topical contraceptive Yaso-GEL, exhibits potent antimicrobial activity against Neisseria gonorrhoeae in preclinical studies

INTRODUCTION

Polyphenylene carboxymethylene (PPCM) is a condensation polymer that has both contraceptive and antimicrobial activity against several sexually transmitted viruses including HIV, herpes simplex virus, Ebola virus and SARS-CoV-2 in preclinical studies. PPCM, both as an active pharmaceutical ingredient (API) and in a vaginal gel formulation (Yaso-GEL), has an excellent safety profile. Here, we evaluated the efficacy of PPCM against Neisseria gonorrhoeae in vitro and in a gonorrhoea mouse model.

METHODS

The minimal inhibitory concentration (MIC) of PPCM was determined against 11 N. gonorrhoeae strains by agar dilution and a microtitre plate-based method. In vivo efficacy was tested in a murine model of N. gonorrhoeae genital tract infection by applying Yaso-GEL, PPCM incorporated in 2.7% hydroxyethylcellulose (HEC), or the HEC vehicle vaginally prior to challenge with N. gonorrhoeae. Vaginal swabs were quantitatively cultured over 5 days to assess efficacy.

RESULTS

PPCM MIC against N. gonorrhoeae ranged between 5-100 µg/mL (agar dilution) and 50-200 µg/mL (microtitre plate method). PPCM/HEC gel applied vaginally prior to bacterial challenge resulted in a concentration-dependent inhibition of infection. Yaso-GEL containing 4% PPCM prevented infection in 100% of mice. Incubation of N. gonorrhoeae with PPCM increased membrane permeability, suggesting PPCM directly compromises N. gonorrhoeae viability, which may be a mechanism by which PPCM inhibits N. gonorrhoeae infection.

CONCLUSIONS

Yaso-GEL containing the API PPCM showed significant activity against N. gonorrhoeae in vitro and in vivo in a female mouse model. These data support further development of Yaso-GEL as an inexpensive, non-hormonal and non-systemic product with both contraceptive and antimicrobial activity against gonorrhea and other common sexually transmitted infections (STIs). Such multipurpose prevention technology products are needed by women in all economic, social and cultural circumstances to prevent unintended pregnancy and STIs.

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.

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.

Enhancing Insights into Australia's Gonococcal Surveillance Programme through Stochastic Modelling

Continued surveillance of antimicrobial resistance is critical as a feedback mechanism for the generation of concerted public health action. A characteristic of importance in evaluating disease surveillance systems is representativeness. Scenario tree modelling offers an approach to quantify system representativeness. This paper utilises the modelling approach to assess the Australian Gonococcal Surveillance Programme's representativeness as a case study. The model was built by identifying the sequence of events necessary for surveillance output generation through expert consultation and literature review. A scenario tree model was developed encompassing 16 dichotomous branches representing individual system sub-components. Key classifications included biological sex, clinical symptom status, and location of healthcare service access. The expected sensitivities for gonococcal detection and antibiotic status ascertainment were 0.624 (95% CI; 0.524, 0.736) and 0.144 (95% CI; 0.106, 0.189), respectively. Detection capacity of the system was observed to be high overall. The stochastic modelling approach has highlighted the need to consider differential risk factors such as sex, health-seeking behaviours, and clinical behaviour in sample generation. Actionable points generated by this study include modification of clinician behaviour and supplementary systems to achieve a greater contextual understanding of the surveillance data generation process.

Comparison of the burden of self-reported bacterial sexually transmitted infections among men having sex with men across 68 countries on four continents

BACKGROUND

Men who have sex with men (MSM) are in general more vulnerable to sexually transmitted infections (STIs) than the heterosexual men population. However, surveillance data on STI diagnoses lack comparability across countries due to differential identification of MSM, diagnostic standards and methods, and screening guidelines for asymptomatic infections.

METHODS

We compared self-reported overall diagnostic rates for syphilis, gonorrhea, and chlamydia infections, and diagnostic rates for infections that were classified to be symptomatic in the previous 12 months from two online surveys. They had a shared methodology, were conducted in 68 countries across four continents between October 2017 and May 2018 and had 202,013 participants.

RESULTS

Using multivariable multilevel regression analysis, we identified age, settlement size, number of sexual partners, condom use for anal intercourse, testing frequency, sampling rectal mucosa for extragenital testing, HIV diagnosis, and pre-exposure prophylaxis use as individual-level explanatory variables. The national proportions of respondents screened and diagnosed who notified some or all of their sexual partners were used as country-level explanatory variables. Combined, these factors helped to explain differences in self-reported diagnosis rates between countries. The following differences were not explained by the above factors: self-reported syphilis diagnoses were higher in Latin America compared with Europe, Canada, Israel, Lebanon, and the Philippines (aORs 2.30 - 3.71 for symptomatic syphilis compared to Central-West Europe); self-reported gonorrhea diagnoses were lower in Eastern Europe and in Latin America compared with all other regions (aORs 0.17-0.55 and 0.34 - 0.62 for symptomatic gonorrhea compared to Central-West Europe); and self-reported chlamydia diagnoses were lower in Central East and Southeast Europe, South and Central America, and the Philippines (aORs 0.25 - 0.39 for symptomatic chlamydia for Latin American subregions compared to Central West Europe).

CONCLUSIONS

Possible reasons for differences in self-reported STI diagnosis prevalence likely include different background prevalence for syphilis and syndromic management without proper diagnosis, and different diagnostic approaches for gonorrhea and chlamydia.

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.

Assortative Sexual Mixing by Age, Region of Birth, and Time of Arrival in Male-Female Partnerships in Melbourne, Australia

BACKGROUND

Patterns of sexual mixing may be influenced by demographic factors where individuals show a preference for partners with particular traits and may have different levels of risk for HIV and sexually transmitted infection transmission. We aimed to explore age differences and mixing by region of birth among male-female partnerships.

METHODS

Male-female partnerships who presented to Melbourne Sexual Health Centre in Australia between 2015 and 2019 were investigated. Age and country of birth of sexual partners were collected. We calculated the age differences between partners and created tables demonstrating partnership mixing by age groups and by international region of birth.

RESULTS

A total of 2112 male-female partnerships (i.e., 4224 individuals) were included. The median age was 27 years (interquartile range, 23-31 years). Between men and women in partnerships, the median age difference was 1 year. Nearly half of all individuals (49.1% [2072 of 4224]) were in a partnership with another individual in the same 5-year interval age group as their own, and a majority of individuals (58.5% [2334 of 3988]) were in a partnership with another individual from the same region of birth when compared with other regions.

CONCLUSIONS

There is a strong assortative sexual mixing pattern by age and region of birth among male-female partnerships in Melbourne, Australia. These results may have applications in further research to understand sexually transmitted infection transmission among clients attending sexual health centers, particularly those born overseas.

Health inequalities in infectious diseases: a systematic overview of reviews

OBJECTIVES

The aim of this systematic overview of reviews was to synthesise available evidence on inequalities in infectious disease based on three dimensions of inequalities; inclusion health groups, protected characteristics and socioeconomic inequalities.

METHODS

We searched MEDLINE, Embase, Web of Science and OpenGrey databases in November 2021. We included reviews published from the year 2000 which examined inequalities in the incidence, prevalence or consequences of infectious diseases based on the dimensions of interest. Our search focused on tuberculosis, HIV, sexually transmitted infections, hepatitis C, vaccination and antimicrobial resistance. However, we also included eligible reviews of any other infectious diseases. We appraised the quality of reviews using the Assessment of Multiple Systematic Reviews V.2 (AMSTAR2) checklist. We conducted a narrative data synthesis.

RESULTS

We included 108 reviews in our synthesis covering all the dimensions of inequalities for most of the infectious disease topics of interest, however the quality and volume of review evidence and consistency of their findings varied. The existing literature reviews provide strong evidence that people in inclusion health groups and lower socioeconomic status are consistently at higher risk of infectious diseases, antimicrobial resistance and incomplete/delayed vaccination. In the protected characteristics dimension, ethnicity, and sexual orientation are important factors contributing to inequalities across the various infectious disease topics included in this overview of reviews.

CONCLUSION

We identified many reviews that provide evidence of various types of health inequalities in different infectious diseases, vaccination, and antimicrobial resistance. We also highlight areas where reviews may be lacking. The commonalities in the associations and their directions suggest it might be worth targeting interventions for some high risk-groups that may have benefits across multiple infectious disease outcomes rather than operating purely in infectious disease siloes.

Mechanisms of host manipulation by Neisseria gonorrhoeae

Neisseria gonorrhoeae (also known as gonococcus) has been causing gonorrhoea in humans since ancient Egyptian times. Today, global gonorrhoea infections are rising at an alarming rate, in concert with an increasing number of antimicrobial-resistant strains. The gonococcus has concurrently evolved several intricate mechanisms that promote pathogenesis by evading both host immunity and defeating common therapeutic interventions. Central to these adaptations is the ability of the gonococcus to manipulate various host microenvironments upon infection. For example, the gonococcus can survive within neutrophils through direct regulation of both the oxidative burst response and maturation of the phagosome; a concerning trait given the important role neutrophils have in defending against invading pathogens. Hence, a detailed understanding of how N. gonorrhoeae exploits the human host to establish and maintain infection is crucial for combating this pathogen. This review summarizes the mechanisms behind host manipulation, with a central focus on the exploitation of host epithelial cell signaling to promote colonization and invasion of the epithelial lining, the modulation of the host immune response to evade both innate and adaptive defenses, and the manipulation of host cell death pathways to both assist colonization and combat antimicrobial activities of innate immune cells. Collectively, these pathways act in concert to enable N. gonorrhoeae to colonize and invade a wide array of host tissues, both establishing and disseminating gonococcal infection.

The duration and body position during tongue-kissing among heterosexual men and women

Background

Emerging data suggest tongue-kissing may transmit gonorrhea. We aim to examine the duration or body position of heterosexual men and women during tongue-kissing (henceforth, known as kissing).

Methods

A cross-sectional survey among heterosexual men and women attending the Melbourne Sexual Health Centre in Australia between May 2019 and March 2020 collected data on the duration and body position (i.e., on top of or lying down underneath) of their most recent kissing partner in the past 3 months. Univariable and multivariable linear regressions were performed to examine the association between gender and kissing duration.

Results

Of 2,866 individuals, 93.6% (n = 2,683) had at least one kissing partner in the past 3 months, which included 1,342 (50.1%) men and 1,341 (49.9%) women, and 87.2% (n = 2,339) had sex with their opposite-gender kissing partner. The adjusted mean duration of kissing with the most recent opposite-gender kissing partner did not differ between men and women (12.2 vs. 11.5 min, p = 0.170). More men were on top of their most recent opposite-gender kissing partner compared to women (87.9 vs. 82.9%, p < 0.001). Men reported a longer kissing duration than women when they were on top of the opposite-gender kissing partner (8.3 vs. 7.4 min, p = 0.006). More women had same-gender kissing partners than men (9.6 vs. 2.8%, p < 0.001).

Conclusion

Men spending longer than women on top of their opposite-gender kissing partner suggests a potential alternative explanation for oropharyngeal gonorrhea being seen more commonly in women. Further research should investigate whether body positioning and duration of kissing influence the risk of gonorrhea transmission.

Current Resources for Evidence-Based Practice, March 2022

An extensive review of new resources to support the provision of evidence-based care for women and infants. The current column includes a discussion of systemic racism and its effect on maternal health in the United States and commentaries on reviews focused on barriers and facilitators to HPV vaccination and delayed cord clamping in preterm infants.

The Impact of Mouthwash on the Oropharyngeal Microbiota of Men Who Have Sex with Men: a Substudy of the OMEGA Trial

Mouthwash is a commonly used product and has been proposed as an alternative intervention to prevent gonorrhea transmission. However, the long-term effects of mouthwash on the oral microbiota are largely unknown. We investigated the impact of 12 weeks of daily mouthwash use on the oropharyngeal microbiota in a subset of men who have sex with men who participated in a randomized trial comparing the efficacy of two alcohol-free mouthwashes for the prevention of gonorrhea. We characterized the oropharyngeal microbiota using 16S rRNA gene sequencing of tonsillar fossae samples collected before and after 12 weeks of daily use of Listerine mouthwash or Biotène dry mouth oral rinse. Permutational multivariate analysis of variance (PERMANOVA) was used to assess differences in oropharyngeal microbiota composition following mouthwash use. Differential abundance testing was performed using ALDEx2, with false-discovery rate correction. A total of 306 samples from 153 men were analyzed (Listerine, n = 78 and Biotène, n = 75). There was no difference in the overall structure of the oropharyngeal microbiota following Listerine or Biotène use (PERMANOVA P = 0.413 and P = 0.331, respectively). Although no bacterial taxa were significantly differentially abundant following Listerine use, we observed a small but significant decrease in the abundance of both Streptococcus and Leptotrichia following Biotène use. Overall, our findings suggest that daily use of antiseptic mouthwash has minimal long-term effects on the composition of the oropharyngeal microbiota.

IMPORTANCE Given the role of the oral microbiota in human health, it is important to understand if and how external factors influence its composition. Mouthwash use is common in some populations, and the use of antiseptic mouthwash has been proposed as an alternative intervention to prevent gonorrhea transmission. However, the long-term effect of mouthwash use on the oral microbiota composition is largely unknown. We found that daily use of two different commercially available mouthwashes had limited long-term effects on the composition of the oropharyngeal microbiota over a 12-week period. The results from our study and prior studies highlight that different mouthwashes may differentially affect the oral microbiome composition and that further studies are needed to determine if mouthwash use induces short-term changes to the oral microbiota that may have detrimental effects.