The role of core groups in the emergence and dissemination of antimicrobial-resistant N gonorrhoeae

Effect of mass treatment on the long-term prevalence of gonorrhoea, chlamydia and syphilis-a systematic review

BACKGROUND

Selective mass treatment of STIs may lead to a durable reduction in the prevalence of STIs or a temporary reduction associated with an increased probability of antimicrobial resistance emerging.

METHODS

We searched PubMed and Google Scholar for studies evaluating the impact of mass STI treatment on the long-term prevalence of chlamydia, gonorrhoea, syphilis and chancroid. The primary outcomes were the long term (≥3 months post the intervention) impact of the intervention on prevalence/incidence of the STI and on antimicrobial resistance.

RESULTS

Our search yielded 269 studies, of which 4 met the inclusion criteria. With the exception of the Carletonville study, where this was not assessed, three of the four studies found that intensive STI treatment was associated with a reduced prevalence of the targeted STI during or immediately after the intervention. In all four studies, there was no evidence that the intense treatment had a long-term effect on prevalence. In the only study where this was assessed, the intensive use of penicillin to reduce gonococcal prevalence was associated with the emergence of reduced susceptibility to penicillin in N. gonorrhoeae.

CONCLUSION

The available evidence suggests that mass treatment of chlamydia, gonorrhoea and syphilis in high prevalence populations is only associated with a temporary reduction in the prevalence of these infections and may select for antimicrobial resistance.

Investigating the cause of increased tetracycline-resistant Neisseria gonorrhoeae in England, 2016-20

BACKGROUND

Antimicrobial resistance in Neisseria gonorrhoeae is a global public health concern. Tetracycline resistance (TetR) increased from 39.4% to 75.2% between 2016 and 2021 in N. gonorrhoeae isolates collected through national surveillance in England, despite the absence of use of tetracyclines for the treatment of gonorrhoea.

OBJECTIVES

We investigated whether there was correlation between bacterial sexually transmitted infection (STI) tests performed and treatment with antimicrobials, with increased TetR in N. gonorrhoeae.

METHODS

We examined correlations between bacterial STI tests, antimicrobial treatment and TetR in N. gonorrhoeae, using national surveillance data from three large sexual health services (SHS) in London during 2016-20. Doxycycline prescribing data and antibiograms of a non-STI pathogen from distinct patient groups (sexual health, obstetric and paediatric), at a large London hospital, were analysed to identify if doxycycline use in SHS was associated with resistance in a non-STI organism.

RESULTS

A substantial increase in TetR was observed, particularly in isolates from gay, bisexual and other MSM (GBMSM). Strong positive correlations were observed exclusively in GBMSM between N. gonorrhoeae TetR and both bacterial STI tests (r = 0.97, P = 0.01) and antimicrobial treatment (r = 0.87, P = 0.05). Doxycycline prescribing increased dramatically during the study period in SHS. Prevalence of TetR in Staphylococcus aureus was higher in isolates sourced from SHS attendees than those from other settings.

CONCLUSIONS

Frequent screening of GBMSM at higher risk of STIs, such as those on pre-exposure prophylaxis (PrEP) leading to/and increased use of doxycycline for the treatment of diagnosed infections, may account for the increase in TetR in N. gonorrhoeae.

Effect of screening for Neisseria gonorrhoeae and Chlamydia trachomatis on incidence of these infections in men who have sex with men and transgender women taking HIV pre-exposure prophylaxis (the Gonoscreen study): results from a randomised, multicentre, controlled trial

BACKGROUND

Guidelines recommend screening for Neisseria gonorrhoeae and Chlamydia trachomatis at three anatomical sites (urethra, anus, and pharynx) every 3 months (3 × 3) in men who have sex with men (MSM) and transgender women taking HIV pre-exposure prophylaxis (PrEP). We present the first randomised controlled trial to compare the effect of screening versus non-screening for N gonorrhoeae and C trachomatis on the incidence of these infections in MSM and transgender women taking PrEP.

METHODS

A multicentre, randomised, controlled trial of 3 × 3 screening for N gonorrhoeae and C trachomatis versus non-screening was done among MSM and transgender women taking PrEP in five HIV reference centers in Belgium. Participants attended the PrEP clinics quarterly for 12 months. N gonorrhoeae and C trachomatis was tested at each visit in both arms, but results were not provided to the non-screening arm, if asymptomatic. The primary outcome was incidence rate of N gonorrhoeae and C trachomatis infections in each arm, assessed in the per-protocol population. Non-inferiority of the non-screening arm was proven if the upper limit of the 95% CI of the incidence rate ratio (IRR) was lower than 1·25. This trial is registered with ClinicalTrials.gov, NCT04269434, and is completed.

FINDINGS

Between Sept 21, 2020, and June 4, 2021, 506 participants were randomly assigned to the 3 × 3 screening arm and 508 to the non-screening arm. The overall incidence rate of N gonorrhoeae and C trachomatis was 0·155 cases per 100 person-days (95% CI 0·128-0·186) in the 3 × 3 screening arm and 0·205 (95% CI 0·171-0·246) in the non-screening arm. The incidence rate was significantly higher in the non-screening arm (IRR 1·318, 95% CI 1·068-1·627). Participants in the non-screening arm had a higher incidence of C trachomatis infections and symptomatic C trachomatis infections. There were no significant differences in N gonorrhoeae infections. Participants in the non-screening arm consumed significantly fewer antimicrobial drugs. No serious adverse events were reported.

INTERPRETATION

We failed to show that non-screening for N gonorrhoeae and C trachomatis is non-inferior to 3 × 3 screening in MSM and transgender women taking PrEP in Belgium. However, screening was associated with higher antibiotic consumption and had no effect on the incidence of N gonorrhoeae. Further research is needed to assess the benefits and harms of N gonorrhoeae and C trachomatis screening in this population.

FUNDING

Belgian Health Care Knowledge Centre.

Antimicrobial Resistance and Molecular Typing of Neisseria gonorrhoeae Isolates From the Eastern Cape Province in South Africa

BACKGROUND

There is a paucity of Neisseria gonorrhoeae antimicrobial resistance data from resource-constrained settings because of the lack of diagnostic testing and limited scale of surveillance programs. This study aimed to determine the antimicrobial resistance profile of N. gonorrhoeae in the rural Eastern Cape province of South Africa.

METHODS

Specimens for N. gonorrhoeae culture were obtained from men with urethral discharge and women with vaginal discharge attending primary health care facilities. Direct inoculation of the agar plates was performed followed by culture and drug susceptibility testing using the Etest at the laboratory. Whole-genome sequencing of the isolates was performed to identify resistance-determining variants.

RESULTS

One hundred N. gonorrhoeae isolates were obtained. Most strains were nonsusceptible to ciprofloxacin (76%), tetracycline (75%), and penicillin G (72%). The gyrA S91F mutation was present in 68 of 72 ciprofloxacin-resistant isolates (94%), with concurrent parC mutations in 47 of 68 (69%); gyrA I250M was the only mutation in 4 other resistant strains. One azithromycin-resistant isolate was identified with a minimal inhibitory concentration (MIC) of 8.0 mg/L and the 23S rDNA gene mutation C2597T. The median MIC of cefixime was 0.016 mg/L (range, 0.016-0.064 mg/L), and that of ceftriaxone was 0.016 mg/L (range, 0.016 mg/L). Whole-genome sequencing showed 58 sequence types as revealed in N. gonorrhoeae sequence typing for antimicrobial resistance and 70 sequence types in N. gonorrhoeae multiantigen sequence typing.

CONCLUSIONS

This study confirmed high rates of N. gonorrhoeae antimicrobial resistance to ciprofloxacin, penicillin G, and tetracycline in our setting. The MICs of cephalosporins are reassuring for ceftriaxone use in syndromic treatment regimens, but the identification of azithromycin resistance warrants further attention.

Non-pathogenic Neisseria species of the oropharynx as a reservoir of antimicrobial resistance: a cross-sectional study

Commensal Neisseria species of the oropharynx represent a significant reservoir of antimicrobial resistance determinants that can be transferred to Neisseria gonorrhoeae. This aspect is particularly crucial in 'men having sex with men' (MSM), a key population in which pharyngeal co-colonization by N. gonorrhoeae and non-pathogenic Neisseria species is frequent and associated with the emergence of antimicrobial resistance. Here, we explored the antimicrobial susceptibility of a large panel of non-pathogenic Neisseria species isolated from the oropharynx of two populations: a group of MSM attending a 'sexually transmitted infection' clinic in Bologna (Italy) (n=108) and a group of males representing a 'general population' (n=119). We collected 246 strains, mainly belonging to N. subflava (60%) and N. flavescens (28%) species. Their antimicrobial susceptibility was evaluated assessing the minimum inhibitory concentrations (MICs) for azithromycin, ciprofloxacin, cefotaxime, and ceftriaxone using E-test strips. Overall, commensal Neisseria spp. showed high rates of resistance to azithromycin (90%; median MICs: 4.0 mg/L), and ciprofloxacin (58%; median MICs: 0.12 mg/L), whereas resistance to cephalosporins was far less common (<15%). Neisseria strains from MSM were found to have significantly higher MICs for azithromycin (p=0.0001) and ciprofloxacin (p<0.0001) compared to those from the general population. However, there was no significant difference in cephalosporin MICs between the two groups. The surveillance of the antimicrobial resistance of non-pathogenic Neisseria spp. could be instrumental in predicting the risk of the spread of multi-drug resistant gonorrhea. This information could be an early predictor of an excessive use of antimicrobials, paving the way to innovative screening and prevention policies.

Management of asymptomatic sexually transmitted infections in Europe: towards a differentiated, evidence-based approach

Most sexually transmitted infections (STIs) can be accurately diagnosed and treated during asymptomatic carriage. Widespread screening for these STIs is therefore assumed to be an effective way to reduce their prevalence and associated disease. In this review, we provide evidence that this is the case for HIV and syphilis. However, for other STIs such as Neisseria gonorrhoeae and Chlamydia trachomatis, our review reveals that the evidence that screening reduces infection prevalence and associated disease is weak. There is also growing evidence of harms from screening that might outweigh any benefits. The harms include the increased consumption of antimicrobials that follows frequent screening and increased detection of asymptomatic STIs in key populations, such as men who have sex with men taking HIV pre-exposure prophylaxis, and associated risk of antimicrobial resistance in target and non-target organisms. There may also be psycho-social harm associated with an STI diagnosis. We conclude that in the absence of symptoms, in high STI prevalence populations frequent STI screening should be limited to HIV and syphilis.

An open-label randomised controlled trial evaluating the efficacy of a meningococcal serogroup B (4CMenB) vaccine on Neisseria gonorrhoeae infection in gay and bisexual men: the MenGO study protocol

BACKGROUND

Gonorrhoea is an ongoing public health concern due to its rising incidence and the emergence of antibiotic resistance. There are an estimated 82 million new Neisseria gonorrhoeae infections each year, with several populations at higher risk for gonococcal infection, including gay and bisexual men (GBM). If left untreated, infection can lead to serious morbidity including infertility, sepsis and increased risk of HIV acquisition. Development of a gonorrhoea vaccine has been challenging, however there is observational evidence that serogroup B meningococcal vaccines, used to protect against the closely related bacteria Neisseria meningitidis, could provide cross-protection against N. gonorrhoeae.

METHODS

The MenGO (Meningococcal vaccine efficacy against Gonorrhoea) study is a phase III open-label randomised control trial in GBM to evaluate the efficacy of the four-component meningococcal serogroup B vaccine, 4CMenB, against gonorrhoea. A total of 130 GBM will be recruited at the Gold Coast Sexual Health Clinic, Australia, and randomised to either receive 2 doses of 4CMenB or no intervention. Participants will be followed up for 24 months with testing for N. gonorrhoeae and other sexually transmissible infections every three months. Demographics, sexual behaviour risk, antibiotic use, and blood samples for analysis of N. gonorrhoeae-specific immune responses, will be collected during the study. The primary outcome is the number of N. gonorrhoeae infections in participants over 2 years measured by nucleic acid amplification test (NAAT). Secondary outcomes are vaccine-induced N. gonorrhoeae-specific immune responses, and adverse events in trial participants.

DISCUSSION

This trial will determine if the 4CMenB vaccine is able to reduce N. gonorrhoeae infection. If shown to be effective, 4CMenB could be used in gonococcal prevention. Analysis of 4CMenB-induced immune responses will increase understanding of the type of immune response needed to prevent N. gonorrhoeae, which may enable identification of a potential correlate of protection to aid future gonorrhoea vaccine development.

TRIAL REGISTRATION

The trial has been registered on the Australian and New Zealand Clinical Trials Registry (ACTRN12619001478101) on 25 October 2019.

Community perspectives on ideal bacterial STI testing services for gay, bisexual, and other men who have sex with men in Toronto, Canada: a qualitative study

BACKGROUND

Innovation is needed to produce sustained improvements in bacterial sexually transmitted infections (STI) testing given suboptimal access and uptake among sexually active gay, bisexual or other men who have sex with men (GBM). Yet, the STI testing processes and technologies that best address local testing barriers among GBM in Toronto is unknown. We aimed to explore men's perspectives regarding STI testing services for GBM to identify and prioritize new STI testing interventions in Toronto, Ontario, Canada.

METHODS

We conducted four focus groups with twenty-seven GBM in 2017: two with cisgender men living with HIV, one with cisgender HIV-negative men, and one with transgender men. Twenty-seven men participated in the focus groups with 40% 18-30 years of age, 48% self-identifying as white, and the remainder self-identifying as Middle Eastern, Latino/Hispanic, Asian/Pacific Islander, South Asian, First Nations, African/Caribbean/Black, or mixed race. 59% of participants self-identified as living with HIV. Participants were asked about their STI testing experiences in Toronto, barriers and facilitators to testing, and ideal STI testing process. Focus groups were audio recorded, transcribed verbatim, and analyzed using thematic analysis.

RESULTS

Core concepts included how clinical context, bacterial STI testing delivery, and interactions with healthcare providers can create barriers and recommendations for ways to improve. Regarding clinical context, participants desired more clinics with accessible locations/hours; streamlined testing that minimized use of waiting rooms and wait times; and improved clinic ambience. Bacterial STI testing delivery recommendations included standardization to ensure consistency in sexual history intake, tests offered, follow-up and public health reporting between clinics. Men also recommended reducing the multistep process testing by offering components such as lab requisitions and results online. Participants also recommended interactions with healthcare providers be professional and non-judgmental, offer compassionate and competent care with destigmatizing and lesbian, gay, bisexual and trans (LGBT) affirming communication.

CONCLUSION

Concrete and practical solutions for improving existing sexual health services and facilitating optimal STI testing include streamlining testing options and providing patient-centred, LGBT-affirming care to enable optimal STI testing.

Cross-sectional assessment of determinants of STIs among men who have sex with men and transgender women in Kigali, Rwanda

BACKGROUND

STIs among men who have sex with men (MSM) and transgender women (TGW) continue to increase. In Rwanda, STI management relies on syndromic management with limited empirical data characterising the burden of specific STIs among MSM/TGW. This study evaluated the prevalence of syphilis, Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) and associated factors among MSM/TGW in Kigali.

METHODS

From March to August 2018, 737 MSM/TGW >18 years were enrolled using respondent-driven sampling (RDS). Structured interviews and HIV/STI screening were conducted. Syphilis was screened with rapid plasma reagin confirmed by Treponema pallidum hemagglutination assay. CT/NG were tested by Cepheid GeneXpert. RDS-adjusted multivariable Poisson regression models with robust variance estimation were used to evaluate factors associated with any STI, and determinants of urethral and rectal STIs separately.

RESULTS

Prevalence of any STI was 20% (RDS adjusted: 16.7% (95% CI: 13.2% to 20.2%)). Syphilis was 5.7% (RDS adjusted: 6.8% (95% CI: 4.3% to 9.4%)). CT was 9.1% (RDS adjusted: 6.1% (95% CI: 3.9% to 8.4%)) and NG was 8.8% (RDS adjusted: 7.1% (95% CI: 4.9% to 9.2%)). STIs were more common among older MSM and those with HIV (p<0.05). Of CT infections, 67% were urethral, 27% rectal and 6% were dual site. For NG infections, 52% were rectal, 29% urethral and 19% were dual site. Overall, 25.8% (23 of 89) of those with confirmed STI and returned for their results were symptomatic at time of testing.STI symptoms in the previous year (adjusted prevalence ratio (aPR): 1.94 (95% CI: 1.26 to 2.98)) were positively associated with any STI. Being circumcised was negatively associated with any STI (aPR: 0.47 (95% CI: 0.31 to 0.73)). HIV was positively associated with rectal STIs (aPR: 3.50 (95% CI: 1.09 to 11.21)) but negatively associated with urethral STIs.

CONCLUSION

MSM/TGW, especially those living with HIV, are at high risk of STIs in Rwanda with the vast majority being asymptomatic. These data suggest the potential utility of active STI surveillance strategies using highly sensitive laboratory methods among those at high risk given the anatomical distribution and limited symptomatology of STIs observed among Rwandan MSM/TGW.

Antimicrobial susceptibility of commensal Neisseria in a general population and men who have sex with men in Belgium

Non-pathogenic Neisseria are a reservoir of antimicrobial resistance genes for pathogenic Neisseria meningitidis and Neisseria gonorrhoeae. Men who have sex with men (MSM) are at risk of co-colonization with resistant non-pathogenic and pathogenic Neisseria. We assessed if the antimicrobial susceptibility of non-pathogenic Neisseria among MSM differs from a general population and if antimicrobial exposure impacts susceptibility. We recruited 96 participants at our center in Belgium: 32 employees, 32 MSM who did not use antibiotics in the previous 6 months, and 32 MSM who did. Oropharyngeal Neisseria were cultured and identified with MALDI-TOF–MS. Minimum inhibitory concentrations for azithromycin, ceftriaxone and ciprofloxacin were determined using E-tests^® and compared between groups with non-parametric tests. Non-pathogenic Neisseria from employees as well as MSM were remarkably resistant. Those from MSM were significantly less susceptible than employees to azithromycin and ciprofloxacin (p < 0.0001, p < 0.001), but not ceftriaxone (p = 0.3). Susceptibility did not differ significantly according to recent antimicrobial exposure in MSM. Surveilling antimicrobial susceptibility of non-pathogenic Neisseria may be a sensitive way to assess impact of antimicrobial exposure in a population. The high levels of antimicrobial resistance in this survey indicate that novel resistance determinants may be readily available for future transfer from non-pathogenic to pathogenic Neisseria.

The antimicrobial resistance landscape of Neisseria gonorrhoeae in New Zealand from November 2018 to March 2019 and the role of sexual orientation in transmission

The increasing use of culture independent diagnostic testing for the diagnosis of Neisseria gonorrhoeae infection has led to gaps in surveillance of antimicrobial resistance (AMR) rates due to limited availability of cultures. Our study reports the findings of a second national survey of N. gonorrhoeae in New Zealand, utilizing whole-genome sequencing (WGS) to study the population structure, prevalence of AMR, epidemiology and transmission of gonorrhoea isolates. We analysed 314 isolates and found a strong correlation between carriage of acquired resistance genes or chromosomal point mutations and phenotypic susceptibility testing results. Overall, the New Zealand rates of azithromycin resistance and decreased susceptibility to ceftriaxone remain lower than in most countries, which are part of the World Health Organization (WHO) Global Gonococcal Antimicrobial Surveillance Programme (GASP). The phylogeny provides evidence of a diverse population significantly associated with sexual behaviour groups. Transmission clustering with a ten single nucleotide polymorphism (SNP) cut-off identified 49 clusters, of which ten were solely associated with men who have sex with men (MSM), whereas remaining clusters included heterosexual patients, as well as MSM, suggesting that bridging of sexual networks is occurring. Utilizing pairwise SNP differences between isolates of the same sequence types we determined genetic variation for the three typing schemes used in this study [Multi locus sequence typing (MLST), multi-antigen sequence typing (NG-MAST), and sequence typing for antimicrobial resistance (NG-STAR)]. A median of 0.0 to 52.5 pairwise SNP differences within a single NG-STAR sequence type underlines previous findings of the superiority of the NG-STAR typing scheme in terms of genomic inherency. With our analysis incorporating epidemiological and genomic data, we were able to show a comprehensive overview of the N. gonorrhoeae population circulating in New Zealand, focussing on AMR and transmission within sexual networks. Regular surveillance studies to understand the origin, evolution and spread of AMR for gonorrhoea remain necessary to make informed decisions about public health guidelines, as the internationally rising rates of ceftriaxone and azithromycin resistance have already led to adaptation of current treatment guidelines in the UK and the USA, highlighting the importance of regular surveillance in individual countries.

Choosing New Therapies for Gonorrhoea: We Need to Consider the Impact on the Pan-Neisseria Genome. A Viewpoint

The development of new gonorrhoea treatment guidelines typically considers the resistance-inducing effect of the treatment only on Neisseria gonorrhoeae. Antimicrobial resistance in N. gonorrhoeae has, however, frequently first emerged in commensal Neisseria species and then been passed on to N. gonorrhoeae via transformation. This creates the rationale for considering the effect of gonococcal therapies on resistance in commensal Neisseria. We illustrate the benefits of this pan-Neisseria strategy by evaluating three contemporary treatment options for N. gonorrhoeae-ceftriaxone plus azithromycin, monotherapy with ceftriaxone and zoliflodacin.

First Case of High-Level Azithromycin-Resistant Neisseria gonorrhoeae in North Carolina

We report on the first high-level azithromycin-resistant Neisseria gonorrhoeae isolate (minimum inhibitory concentration, ≥256 μg/mL) in North Carolina isolated from a pharyngeal swab of a 33-year-old HIV-negative man who has sex with men. In addition, the isolate was found to be susceptible to cefixime, ceftriaxone, and penicillin and resistant to tetracycline. By whole-genome sequencing, the strain was assigned as MLST ST9363, NG-MAST ST5035, and a novel NG-STAR sequence type, ST1993.

WGS of Commensal Neisseria Reveals Acquisition of a New Ribosomal Protection Protein (MsrD) as a Possible Explanation for High Level Azithromycin Resistance in Belgium

In this study, we characterized all oropharyngeal and anorectal isolates of Neisseria spp. in a cohort of men who have sex with men. This resulted in a panel of pathogenic Neisseria (N. gonorrhoeae [n = 5] and N. meningitidis [n = 5]) and nonpathogenic Neisseria (N. subflava [n = 11], N. mucosa [n = 3] and N. oralis [n = 2]). A high proportion of strains in this panel were resistant to azithromycin (18/26) and ceftriaxone (3/26). Whole genome sequencing (WGS) of these strains identified numerous mutations that are known to confer reduced susceptibility to azithromycin and ceftriaxone in N. gonorrhoeae. The presence or absence of these known mutations did not explain the high level resistance to azithromycin (>256 mg/L) in the nonpathogenic isolates (8/16). After screening for antimicrobial resistance (AMR) genes, we found a ribosomal protection protein, Msr(D), in these highly azithromycin resistant nonpathogenic strains. The complete integration site originated from Streptococcus pneumoniae and is associated with high level resistance to azithromycin in many other bacterial species. This novel AMR resistance mechanism to azithromycin in nonpathogenic Neisseria could be a public health concern if it were to be transmitted to pathogenic Neisseria. This study demonstrates the utility of WGS-based surveillance of nonpathogenic Neisseria.

Antibacterial mouthwash to prevent sexually transmitted infections in men who have sex with men taking HIV pre-exposure prophylaxis (PReGo): a randomised, placebo-controlled, crossover trial

BACKGROUND

Bacterial sexually transmitted infections (STIs) are highly prevalent among men who have sex with men who use HIV pre-exposure prophylaxis (PrEP), which leads to antimicrobial consumption linked to the emergence of antimicrobial resistance. We aimed to assess use of an antiseptic mouthwash as an antibiotic sparing approach to prevent STIs.

METHODS

We invited people using PrEP who had an STI in the past 24 months to participate in this single-centre, randomised, double-blind, placebo-controlled, AB/BA crossover superiority trial at the Institute of Tropical Medicine in Antwerp, Belgium. Using block randomisation (block size eight), participants were assigned (1:1) to first receive Listerine Cool Mint or a placebo mouthwash. They were required to use the study mouthwashes daily and before and after sex for 3 months each and to ask their sexual partners to use the mouthwash before and after sex. Participants were screened every 3 months for syphilis, chlamydia, and gonorrhoea at the oropharynx, anorectum, and urethra. The primary outcome was combined incidence of these STIs during each 3-month period, assessed in the intention-to-treat population, which included all participants who completed at least the first 3-month period. Safety was assessed as a secondary outcome. This trial is registered with Clinicaltrials.gov, NCT03881007.

FINDINGS

Between April 2, 2019, and March 13, 2020, 343 participants were enrolled: 172 in the Listerine followed by placebo (Listerine-placebo) group and 171 in the placebo followed by Listerine (placebo-Listerine) group. The trial was terminated prematurely because of the COVID-19 pandemic. 151 participants completed the entire study, and 89 completed only the first 3-month period. 31 participants withdrew consent, ten were lost to follow-up, and one acquired HIV. In the Listerine-placebo group, the STI incidence rate was 140·4 per 100 person-years during the Listerine period, and 102·6 per 100 person-years during the placebo period. In the placebo-Listerine arm, the STI incidence rate was 133·9 per 100 person-years during the placebo period, and 147·5 per 100 person-years during the Listerine period. We did not find that Listerine significantly reduced STI incidence (IRR 1·17, 95% CI 0·84-1·64). Numbers of adverse events were not significantly higher than at baseline and were similar while using Listerine and placebo. Four serious adverse events (one HIV-infection, one severe depression, one Ludwig's angina, and one testicular carcinoma) were not considered to be related to use of mouthwash.

INTERPRETATION

Our findings do not support the use of Listerine Cool Mint as a way to prevent STI acquisition among high-risk populations.

FUNDING

Belgian Research Foundation - Flanders (FWO 121·00).

Impact of screening on the prevalence and incidence of Mycoplasma genitalium and its macrolide resistance in men who have sex with men living in Australia: A mathematical model

BACKGROUND

Mycoplasma genitalium (MG) causes a sexually transmitted infection (STI) with a rising rate of antimicrobial resistance. Currently, guidelines do not recommend screening asymptomatic men who have sex with men (MSM). We developed a mathematical model of MG transmission to examine the impact of various screening strategies on the incidence and prevalence of MG among MSM attending a sexual health clinic.

METHODS

A compartmental mathematical model of MG transmission among MSM was constructed and calibrated using data from the Melbourne Sexual Health center, where resistance-guided therapy provides high treatment effectiveness (92-95%). The model stratified men by symptom status, sexual risk behaviours and whether or not they had MG with macrolide resistance. We simulated the impact on endemic steady-state MG prevalence and incidence of the following screening scenarios, namely screening: 1) no MSM; 2) only symptomatic MSM (the current recommendation); 3) all symptomatic and high-risk asymptomatic MSM; and 4) all MSM. Our base case analysis assumed a treatment effectiveness of 92-95% using resistance-guided therapy. We also examined the impact of treatment effectiveness (i.e. the proportion of detected MG that were cured) and screening coverage (i.e. testing rate) on MG prevalence.

FINDINGS

The model predicts that the overall endemic MG prevalence is 9.1% (95% CI: 7.9-10.0) in the current situation where screening is only offered to symptomatic MSM (base-case). This would increase to 11·4% (95% confidence intervals (CI): 10.2-13.7) if no MSM are offered screening, but would decrease to 7.3% (95% CI: 5.7-8.4) if all symptomatic and high-risk asymptomatic MSM were offered screening and 6.4% (95% CI: 4.7-7·7) if all MSM were offered screening. Increasing coverage of MSM screening strategies shows a similar effect on decreasing endemic MG incidence. When evaluating the simultaneous impact of treatment effectiveness and screening coverage, we found that offering screening to more MSM may reduce the overall prevalence but leads to a higher proportion of macrolide-resistant MG, particularly when using treatment regimens with lower effectiveness.

INTERPRETATION

Based on the available treatment options, offering screening for MG to other MSM (beyond the currently recommended group of symptomatic MSM) could slightly reduce the prevalence and incidence of MG. However, further increasing screening coverage must be weighed against the impact of lower treatment effectiveness (i.e. when not using resistance-guided therapy), increasing the selection of macrolide resistance, and other negative consequences related to AMR and management (e.g. unnecessary psychological morbidity from infections that do not need treatment).

Population-Level Antimicrobial Consumption Is Associated With Decreased Antimicrobial Susceptibility in Neisseria gonorrhoeae in 24 European Countries: An Ecological Analysis

OBJECTIVES

There are substantial variations between different populations in the susceptibility of Neisseria gonorrhoeae to antimicrobials, and the reasons for this are largely unexplored. We aimed to assess whether the population-level consumption of antimicrobials is a contributory factor.

METHODS

Using antimicrobial susceptibility data from 24 countries in the European Gonococcal Antimicrobial Surveillance Programme and antimicrobial consumption data from the IQVIA MIDAS database, we built mixed-effects linear/logistic regression models with country-level cephalosporin, fluoroquinolone, and macrolide consumption (standard doses/1000 population/year) as the explanatory variables (from 2009 to 2015) and 1-year-lagged ceftriaxone, cefixime, azithromycin, and ciprofloxacin geometric mean minimum inhibitory concentrations (MICs) as the outcome variables (from 2010 to 2016).

RESULTS

Positive correlations were found between the consumption of cephalosporins and the geometric mean MICs of ceftriaxone and cefixime (P < .05 for both comparisons). Fluoroquinolone consumption was positively associated with the prevalence of resistance to ciprofloxacin (P < .05).

CONCLUSIONS

Differences in the population-level consumption of particular antimicrobials may contribute to variations in the level of antimicrobial resistance in N. gonorrhoeae in different settings. Further interventions to reduce misuse and overuse of antimicrobials in high-consumption populations and core groups are required.

Could Intensive Screening for Gonorrhea/Chlamydia in Preexposure Prophylaxis Cohorts Select for Resistance? Historical Lessons From a Mass Treatment Campaign in Greenland

INTRODUCTION

Neisseria gonorrhoeae has developed resistance to all classes of antimicrobials used against it. Current strategies to prevent the emergence of pan-resistance include increased gonorrhea screening in high-prevalence populations such as men who have sex with men taking HIV preexposure prophylaxis. By increasing antimicrobial exposure, others have argued that intensive screening may inadvertently promote the emergence of antimicrobial resistance.

AIM/METHODOLOGY

To contribute to this discussion, we conducted a historical review of the effect of a mass gonorrhea treatment campaign in Greenland from 1965 to 1968 on the incidence of gonorrhea and antimicrobial resistance. We conducted a literature review using PubMed and Google Scholar to find relevant studies. Data on the incidence of gonorrhea, antimicrobial susceptibility, and antimicrobials dispensed were extracted and analyzed.

RESULTS

Eight articles were found with relevant information. The cornerstone of the campaign involved the repeated treatment for all persons with a diagnosis of gonorrhea in the past 6 months as well as all remaining unmarried persons between 15 and 30 years of age. There was a small and temporary decline in the incidence of gonorrhea during the campaign. The campaign was, however, associated with an increase in the proportion of gonococci that were not susceptible to penicillin. Gonococcal incidence continued to climb after the campaign ended but did decline dramatically after reductions in risk behavior after the global AIDS epidemic.

DISCUSSIONS

The mass gonorrhea treatment campaign in Greenland was associated with only a temporary decline in the incidence of gonorrhea. It was, however, followed by an increase in penicillin nonsusceptibility. Intense gonorrhea screening and treatment strategies should be aware of the risk of inducing antimicrobial resistance.

Gonorrhoea treatment combined with population-level general cephalosporin and quinolone consumption may select for Neisseria gonorrhoeae antimicrobial resistance at the levels of NG-MAST genogroup: An ecological study in Europe

OBJECTIVES

The prevalence of Neisseria gonorrhoeae NG-MAST genogroup G1407, associated with decreased susceptibility to extended-spectrum cephalosporins and fluoroquinolone resistance, has declined in Europe and it switched from circulating predominantly in men who have sex with men (MSM) in 2009-2010 to heterosexuals in 2013. We hypothesise that changes to gonorrhoea treatment guidelines combined with differences in country-level consumption of cephalosporins and quinolones contributed to this shift.

METHODS

Linear regression was used to evaluate the association between changes in prevalence of G1407 between 2009-2010 and 2013 and country-level consumption of quinolones and cephalosporins in 2011/12 in 20 European countries.

RESULTS

Whilst the prevalence of G1407 declined between 2009-2010 and 2013 in the EU/EEA, its absolute prevalence increased by 10% or more in three countries. The national prevalence of G1407 in 2013 was positively associated with population-level general cephalosporin and quinolone consumption in the preceding 2 years. The association between the prevalence of G1407 and proportion of the national sample derived from MSM was non-significant in 2009-2010 and was negative in 2013.

CONCLUSIONS

Our results are broadly compatible with the hypothesis that changes in gonorrhoea therapy to the more efficacious ceftriaxone (plus azithromycin) from 2010 to 2011 onwards resulted in a reduced prevalence of the resistance-associated G1407 overall but in MSM in particular. High population-level consumption of quinolones and cephalosporins in certain countries then contributed to the selection of G1407 predominantly in heterosexuals in these countries.

Antimicrobial Resistance of Neisseria gonorrhoeae Isolates from High-Risk Men in Johannesburg, South Africa

Neisseria gonorrhoeae antimicrobial drug resistance has emerged worldwide; however, the situation in sub-Saharan Africa is not well documented. We investigated the molecular epidemiology and occurrence of antimicrobial resistance in Neisseria gonorrhoeae infections in two core transmission groups of men in Johannesburg, South Africa. We recruited men who have sex with men (MSM) presenting with urethral discharge and men with recurrent episodes of urethral discharge. Molecular testing and culture for N. gonorrhoeae were performed, followed by antimicrobial susceptibility testing. Whole-genome sequencing (WGS) was used to identify resistance-conferring mutations and to determine the genetic relatedness of the isolates. In all, 51 men were recruited; 42 (82%) had N. gonorrhoeae infections. Most gonococcal isolates were resistant to ciprofloxacin (78%) and tetracycline (74%); 33% were penicillin resistant. All gonococcal isolates were susceptible to cephalosporins and spectinomycin. Azithromycin resistance was observed in 4 (15%) isolates (epidemiological cutoff), all with mutations in the mtrR promoter region. Most of the isolates (19/27) harbored the gonococcal genetic island, which is associated with antimicrobial resistance. WGS revealed a diverse epidemic with mostly novel NG-STAR (70%) and NG-MAST (70%) sequence types. Thus, we demonstrate a high prevalence of antimicrobial resistance in Neisseria gonorrhoeae strains obtained from high-risk men in South Africa. The introduction of diagnostics and scale-up of surveillance are warranted to prevent the emergence of multidrug-resistant infections.

Epidemiology of gonorrhoea: a global perspective

Although understanding the local epidemiology of gonorrhoea is critical for local efforts, understanding the multinational epidemiology may support development of national and international prevention and control policies and strategies. In this paper, current epidemiology of gonorrhoea is reviewed through an international lens and with a focus on selected populations. The World Health Organization (WHO) estimates that ~87 million new gonococcal infections occurred among people aged 15-49 years in 2016. Gonorrhoea rates are rising in many countries. Gay, bisexual and other men who have sex with men, racial or ethnic minorities, Indigenous populations and sex workers appear to bear disproportionate burdens of gonorrhoea. International travel can facilitate spread of gonorrhoea, including resistant strains, across international borders. Critical gaps in epidemiological knowledge are highlighted, including data on gonorrhoea among transgender persons and the burden of extragenital gonorrhoea. Even as further data are gathered, action - informed by currently available data - is needed now to confront this growing international threat.

Screening for STIs in PrEP cohorts results in high levels of antimicrobial consumption

Screening for STIs in men who have sex with men receiving HIV pre-exposure prophylaxis resulted in high consumption of macrolides, extended spectrum cephalosporins, fluoroquinolones and tetracyclines. The consumption of macrolides was 52 times as high as that reported for community-level consumption in certain European countries.

Targeted surveillance strategies for efficient detection of novel antibiotic resistance variants

Genotype-based diagnostics for antibiotic resistance represent a promising alternative to empiric therapy, reducing inappropriate antibiotic use. However, because such assays infer resistance based on known genetic markers, their utility will wane with the emergence of novel resistance. Maintenance of these diagnostics will therefore require surveillance to ensure early detection of novel resistance variants, but efficient strategies to do so remain undefined. We evaluate the efficiency of targeted sampling approaches informed by patient and pathogen characteristics in detecting antibiotic resistance and diagnostic escape variants in Neisseria gonorrhoeae, a pathogen associated with a high burden of disease and antibiotic resistance and the development of genotype-based diagnostics. We show that patient characteristic-informed sampling is not a reliable strategy for efficient variant detection. In contrast, sampling informed by pathogen characteristics, such as genomic diversity and genomic background, is significantly more efficient than random sampling in identifying genetic variants associated with resistance and diagnostic escape.

Gonococcal resistance can be viewed productively as part of a syndemic of antimicrobial resistance: an ecological analysis of 30 European countries

BACKGROUND

It is unclear how important bystander selection is in the genesis of antimicrobial resistance (AMR) in Neisseria gonorrhoeae.

METHODS

We assessed bystander selection in a novel way. Mixed-effects linear regression was used to assess if country-level prevalence of gonococcal AMR in 30 European countries predicts homologous AMR in other bacteria. The data used was from the European Antimicrobial Resistance Surveillance Network.

RESULTS

The prevalence of gonococcal ciprofloxacin resistance was found to be positively associated with AMR prevalence in E. coli (coef. 0.52; P = 0.007), Acinetobacter spp. (coef. 0.13; P = 0.044) and Pseudomonas aeruginosa (coef. 0.36; P = 0.020) but not Klebsiella pneumoniae. Azithromycin resistance in N. gonorrhoeae was positively associated with macrolide resistance in Streptococcus pneumoniae (coef. 0.01; P = 0.018). No association was found for cephalosporins.

CONCLUSIONS

Gonococcal AMR is linked to that in other bacteria. This finding is likely explained by high antimicrobial consumption in affected populations and provides additional motivation for strengthening antimicrobial stewardship programs.

Long-distance truck drivers and the increasing risk of COVID-19 spread in Uganda

•

COVID-19 was first detected in Uganda in the third week of March 2020.

•

Although the number of COVID-19 cases has grown steadily, data have not been analyzed to determine whether a pattern in the nature of cases has emerged.

•

The first cases were detected among international arrivals and after that among their local contacts. However, in mid-April, a number of cases were detected among long-distance truck drivers arriving from the neighboring countries.

•

Among the 442 cases that have tested positive, a majority, 317 (71.8%) were truck drivers, 75 (16.9%) were community cases, and 50 (11.3%) were international arrivals.

•

A majority of the community cases have been linked to contact with long-distance truck drivers; interventions are urgently needed to protect long-distance truck drivers.

Objective

To examine the patterns of COVID-19 transmission in Uganda.

Methods

We reviewed ten weeks of press releases from the Uganda Ministry of Health from the day when the first case was announced, March 22, through May 29, 2020. We obtained the press releases from the MoH website and the Twitter handle (@MinofHealthUG). Data include the number of persons tested and the categories were classified as international arrivals, community members, and long-distance truck drivers.

Results

The first cases were international arrivals from Asia and Europe, and after that, community cases emerged. However, in the middle of April 2020, COVID-19 cases were detected among long-distance truck drivers. By May 29, 2020, 89, 224 persons had been tested; overall, 442 tested positive. Of those that tested positive, the majority, or 317 (71.8%) were truck drivers, 75 (16.9%) were community cases, and 50 (11.3%) were international arrivals. The majority of community cases have been linked to contact with truck drivers.

Conclusions

Truck drivers were the most frequently diagnosed category, and have become a core group for COVID-19 in Uganda. They have generated significant local transmission, which now threatens a full-blown epidemic unless strict controls are put in place.

Commensal Neisseria Are Shared between Sexual Partners: Implications for Gonococcal and Meningococcal Antimicrobial Resistance

Antimicrobial resistance in pathogenic Neisseria parallels reduced antimicrobial susceptibility in commensal Neisseria in certain populations, like men who have sex with men (MSM). Although this reduced susceptibility can be a consequence of frequent antimicrobial exposure at the individual level, we hypothesized that commensal Neisseria are transmitted between sexual partners. We used data from a 2014 microbiome study in which saliva and tongue swabs were taken from 21 couples (42 individuals). Samples were analyzed using 16S rRNA gene sequencing. We compared intimate partners with unrelated individuals and found that the oral Neisseria communities of intimate partners were more similar than those of unrelated individuals (average Morisita-Horn dissimilarity index for saliva samples: 0.54 versus 0.71, respectively (p = 0.005); and for tongue swabs: 0.42 versus 0.63, respectively (p = 0.006)). This similarity presumably results from transmission of oral Neisseria through intimate kissing. This finding suggests that intensive gonorrhea screening in MSM may, via increased antimicrobial exposure, promote, rather than prevent, the emergence and spread of antimicrobial resistance in Neisseria. Non-antibiotic strategies such as vaccines and oral antiseptics could prove more sustainable options to reduce gonococcal prevalence.

HIV-1 subtype variability and transmitted drug resistance in a culturally diverse population in Western Sydney, New South Wales, Australia

Background Transmitted human immunodeficiency virus type 1 (HIV-1) drug resistance (TDR) is an important contributor to antiretroviral treatment failure, and is associated with HIV-1 transmission among men who have sex with men (MSM), non-MSM clusters and individuals diagnosed with concurrent sexually transmissible infections (STI). Western Sydney has a culturally diverse population, with a high proportion of non-Australian-born individuals. This study describes the prevalence of TDR and non-B HIV-1 subtypes in a clinic-based population.

METHODS

A clinic database was examined for all newly diagnosed treatment-naïve HIV-1 patients and information on their HIV-1 resistance and subtype, demographics including country of birth and diagnosis of a bacterial sexually transmissible infection was collected.

RESULTS

Data were available from 74/79 individuals (62 cis-male, 16 cis-female and 1 transgender woman). Of the 74 genotypes, the prevalence of non-B subtypes and TDR was 43/74 (58%; 95%CI = 46.9-69.3) and 14/74 (19%; 95%CI = 10.0 to 27.8). It was also found that 30/79 (38%) had a concurrent bacterial STI. TDR was associated with subtype B infection (OR 3.53; 95%CI = 1.41-8.82; P = 0.007) and being born in Australia (OR 12.0; 95%CI = 2.45-58.86; P = 0.002).

CONCLUSION

The relative prevalence of non-B HIV-1 subtypes and TDR is higher in Western Sydney than in the rest of Australia. TDR is associated with subtype B HIV-1 and being Australian born, suggesting ongoing local transmission. This highlights the diversity of the HIV epidemic locally and the need for interventions to prevent ongoing HIV transmission.

Where have all the susceptible gonococci gone? A historical review of changes in MIC distribution over the past 75 years

BACKGROUND

Does the emergence of antimicrobial resistance in Neisseria gonorrhoeae include the erasure of highly susceptible strains or does it merely involve a stretching of the MIC distribution? If it was the former this would be important to know as it would increase the probability that the loss of susceptibility is irreversible.

METHODS

We conducted a historical analysis based on a literature review of changes of N. gonorrhoeae MIC distribution over the past 75 years for 3 antimicrobials (benzylpenicillin, ceftriaxone and azithromycin) in five countries (Denmark, Japan, South Africa, the United Kingdom and the United States).

RESULTS

Changes in MIC distribution were most marked for benzylpenicillin and showed evidence of a right shifting of MIC distribution that was associated with a reduction/elimination of susceptible strains in all countries. In the case of ceftriaxone and azithromycin, where only more recent data was available, right shifting was also found in all countries but the extent of right shifting varied and the evidence for the elimination of susceptible strains was more mixed.

CONCLUSIONS

The finding of right shifting of MIC distribution combined with reduction/elimination of susceptible strains is of concern since it suggests that this shifting may not be reversible. Since excess antimicrobial consumption is likely to be responsible for this right shifting, this insight provides additional impetus to promote antimicrobial stewardship.

Global geographic trends in antimicrobial resistance: the role of international travel

BACKGROUND

Rising antimicrobial resistance (AMR) is a threat to modern medicine, and increasing international mobility facilitates the spread of AMR. Infections with resistant organisms have higher morbidity and mortality, are costlier to treat, result in longer hospital stays and place a greater burden on health systems than infections caused by susceptible organisms. Here we review the role of travel in the international dissemination of AMR and consider actions at the levels of travelers, travel medicine practitioners and policymakers that would mitigate this threat.

RESULTS

Resistant pathogens do not recognize international borders; travelers to areas with high AMR prevalence are likely to be exposed to resistant bacteria and return to their home countries colonized. Medical tourists go between health facilities with drastically different rates of AMR, potentially transmitting highly resistant strains.Drug-resistant bacteria have been found in every continent; however, differences between countries in the prevalence of AMR depend on multiple factors. These include levels of antibiotic consumption (including inappropriate use), access to clean water, adequate sanitation, vaccination coverage, the availability of quality healthcare and access to high-quality medical products.

CONCLUSIONS

Travelers to areas with high levels of AMR should have vaccines up to date, be aware of ways of treating and preventing travelers' diarrhea (other than antibiotic use) and be informed on safe sexual practices. The healthcare systems of low- and middle-income countries require investment to reduce the transmission of resistant strains by improving access to clean water, sanitation facilities and vaccines. Efforts are needed to curb inappropriate antibiotic use worldwide. In addition, more surveillance is needed to understand the role of the movement of humans, livestock and food products in resistance transmission. The travel medicine community has a key role to play in advocating for the recognition of AMR as a priority on the international health agenda.

KEY POLICY RECOMMENDATIONS

AMR is a threat to modern medicine, and international travel plays a key role in the spread of highly resistant strains. It is essential that this is addressed at multiple levels. Individual travelers can reduce antibiotic consumption and the likelihood of infection. Travelers should have up-to-date vaccines and be informed on methods of preventing and treating travelers' diarrhea, other than use of antibiotics and on safe sexual practices, such as condom use. Healthcare facilities need to be aware of the travel history of patients to provide appropriate treatment to those who are at high risk of exposure and to prevent further spread. Internationally, in countries without reliable and universal access to clean water, sanitation and hygiene, investment is needed to reduce the emergence and spread of resistance and ensure the antimicrobials available are of assured quality. High-income countries must ensure their use of antimicrobials is appropriate to reduce selection for AMR. Surveillance across all countries is needed to monitor and respond to this emerging threat.

Is Screening for Chlamydia and Gonorrhea in Men Who Have Sex With Men Associated With Reduction of the Prevalence of these Infections? A Systematic Review of Observational Studies

BACKGROUND

Neisseria gonorrhoeae (gonorrhea) could become untreatable in the near future. Indeed, while the treatment of symptomatic gonorrhea in core groups, such men who have sex with men (MSM), is crucial for gonorrhea control programs, screening for and treating asymptomatic gonorrhea/Chlamydia trachomatis(chlamydia) in MSM may contribute to antibiotic resistance in gonorrhea. In this systematic review, we aim to assess if there is evidence that screening MSM for gonorrhea/chlamydia is associated with a decline in the prevalence of these infections.

METHODS

We conducted a systematic review in PubMed and Web of Science for relevant studies including uncontrolled observational studies and reported the results following the PRISMA guidelines. The change in estimated prevalences for chlamydia and gonorrhea across the different time points for 3 anatomical sites (oral, urethral and anal) were collected and examined.

RESULTS

Twelve studies met our entry criteria. We were able to statistically assess the change in prevalence in 10 of 12 studies. In 3 studies, there was a significant increase in chlamydia prevalence, whereas for gonorrhea, 2 studies reported a significant increase and 2 others a decrease. Our review provides little evidence that screening for gonorrhea and chlamydia in MSM has an effect on the prevalence of these infections. No evidence was found that more frequent screening reduces prevalence more effectively than annual screening.

CONCLUSIONS

Our study was not able to provide evidence that screening for chlamydia and gonorrhea lowers the prevalence of these infections in MSM. Randomized controlled trials are required to assess the risks and benefits of gonorrhea/chlamydia screening in high- and low-risk MSM.

Epidemiology, molecular characterisation and antimicrobial susceptibility of Neisseria gonorrhoeae isolates in Madrid, Spain, in 2016

With the aim to elucidate gonococcal antimicrobial resistance (AMR)–risk factors, we undertook a retrospective analysis of the molecular epidemiology and AMR of 104 Neisseria gonorrhoeae isolates from clinical samples (urethra, rectum, pharynx and cervix) of 94 individuals attending a sexually transmitted infection clinic in Madrid (Spain) from July to October 2016, and explored potential links with socio-demographic, behavioural and clinical factors of patients. Antimicrobial susceptibility was determined by E-tests, and isolates were characterised by N. gonorrhoeae multi-antigen sequence typing. Penicillin resistance was recorded for 15.4% of isolates, and most were susceptible to tetracycline, cefixime and azithromycin; a high incidence of ciprofloxacin resistance (~40%) was found. Isolates were grouped into 51 different sequence types (STs) and 10 genogroups (G), with G2400, ST5441, ST2318, ST12547 and G2992 being the most prevalent. A significant association (P = 0.015) was evident between HIV-positive MSM individuals and having a ciprofloxacin-resistant strain. Likewise, a strong association (P = 0.047) was found between patient age of MSM and carriage of isolates expressing decreased susceptibility to azithromycin. A decrease in the incidence of AMR gonococcal strains and a change in the strain populations previously reported from other parts of Spain were observed. Of note, the prevalent multi-drug resistant genogroup G1407 was represented by only three strains in our study, while the pan-susceptible clones such as ST5441, and ST2318, associated with extragenital body sites were the most prevalent.

The development of mouthwashes without anti-gonococcal activity for controlled clinical trials: an in vitro study

Background: The oropharynx plays a major role in the development and spread of antimicrobial resistant Neisseria gonorrhoeae among men who have sex with men. Trials are currently assessing the efficacy of bactericidal mouthwashes as possible therapeutic or preventive options against these pharyngeal gonococcal infections. Controlled clinical trials require the use of a placebo mouthwash without anti-gonococcal activity. So far, no such placebo mouthwash has been described. We describe the development of a mouthwash for this purpose.

Methods: The in vitro anti-gonococcal activity of Corsodyl®, Listerine Cool Mint®, Biotene®, phosphate buffered saline and six in-house placebo mouthwashes was evaluated. Three gonococcal isolates from patients with pharyngeal infection were exposed to the mouthwashes for a duration ranging from 30 seconds to 60 minutes. Isolates were then plated in duplicate onto blood agar (5% horse blood) and incubated for 24 hours (5-7% CO ₂, 35 ± 2°C). Growth of N. gonorrhoeae was scored on a five-point scale (0 = no growth, to 4 = confluent growth of colonies).

Results: Corsodyl® and Listerine Cool Mint® were bactericidal to all isolates. For the other mouthwashes, the median growth score after 60 minutes of exposure was 4 (interquartile range 4-4) for phosphate buffered saline; 1 (interquartile range 1-3) for Biotene®; and ranged between 0 and 2 for the in-house composed mouthwashes. An in-house composed mouthwash (Placebo 6) performed best, with a growth score of 2.5 (interquartile range 1-3).

Conclusions: All the evaluated potential placebo mouthwashes were bacteriostatic after gonococcal exposure of 30 to 60 minutes. In-house composed Placebo 6 showed less inhibition on gonococcal growth than Biotene® and the other in-house placebos and demonstrates, in our opinion, a good trade-off between anti-gonococcal properties and taste.

Conceptualizing Geosexual Archetypes: Mapping the Sexual Travels and Egocentric Sexual Networks of Gay and Bisexual Men in Toronto, Canada

Six geosexual archetypes were identified: hosters, house-callers, rovers, privates, travellers, and geoflexibles, each with different characteristic profiles. Prioritizing interventions to hosters, rovers, and geoflexibles may reduce sexually transmitted infection transmission.

Supplemental digital content is available in the text.

Background

There are complex, synergistic, and persistent sexually transmitted infection (STI) epidemics affecting gay, bisexual and other men who have sex with men (gbMSM) in every major urban centre across North America. We explored the spatial architecture of egocentric sexual networks for gbMSM in Toronto, Canada.

Methods

Our integrative mixed methods study included in-depth interviews with 31 gbMSM between May and July 2016. During interviews, participants mapped their egocentric sexual network for the preceding 3 months geographically. At the end, a self-administered survey was used to collect sociodemographic characteristics, online technology use, and STI testing and history.

Results

We identified 6 geosexual archetypes: hosters, house-callers, privates, rovers, travellers, and geoflexibles. Hosters always, or almost always (≥80%), hosted sex at their home. House-callers always, or almost always (≥80%), had sex at their partner’s home. Rovers always or almost always (≥80%) had sex at public venues (eg, bath houses, sex clubs) and other public spaces (eg, parks, cruising sites). Privates had sex in private—their own home or their partner's (part hoster, part house-caller). Travellers had sex away from their home, either at a partner’s home or some other venue or public space (part house-caller, part rover). Geoflexibles had sex in a variety of locations—their home, their partner’s home, or public venues. All hosters and rovers, and to a lesser extent, geoflexibles, reported a history of syphilis and human immunodeficiency virus.

Conclusions

Prioritizing interventions to hosters, rovers, and geoflexibles may have an important impact on reducing STI transmission.

Low gonorrhoea antimicrobial resistance and culture positivity rates in general practice: a pilot study

Objective

In the Netherlands, the Gonococcal Resistance to Antimicrobials Surveillance (GRAS) programme is carried out at Centres for Sexual Health (CSH), which provide care for sexual high-risk populations. However, half of gonorrhoea infections are diagnosed in general practice (GP). We performed a pilot study to explore expanding GRAS to GPs using laboratory-based surveillance. Additionally, antimicrobial resistance patterns of GP and CSH patients were compared.

Methods

Three laboratories from different regions were included, which all perform gonorrhoea diagnostics for GPs and used ESwab for patient sampling. Additional culturing for all GP patients with gonorrhoea took place from February to July 2018. After positive PCR-nucleic acid amplification test, residual ESwab material was used for culture. In positive cultures, susceptibility testing was performed for azithromycin, ciprofloxacin, cefotaxime and ceftriaxone using Etest.

Results

During the study period, 484 samples were put in culture. 16.5% of cultures were positive (n=80). Antimicrobial resistance levels were low, with 2.6% resistance to azithromycin, 21.5% to ciprofloxacin and 0.0% to cefotaxime and ceftriaxone. Resistance levels in CSH GRAS data (first half of 2018) were 19.2% for azithromycin, 31.5% for ciprofloxacin, 1.9% for cefotaxime and 0.0% for ceftriaxone.

Conclusions

Culture positivity rates for GP patients were low, probably due to long transportation times and awaiting PCR test results before attempting culture. Positivity rates might be improved by making changes in sampling and/or transportation methods, but that would require involvement of GPs and patients instead of keeping the surveillance lab based. Resistance levels appeared to be lower at GPs than at the CSH, indicating that resistance might emerge first in more high-risk populations. It is important to consider all potentially relevant patient populations when establishing a gonococcal antimicrobial resistance surveillance programme. However, based on the findings from this study the current GRAS programme will not be extended to GPs.

Effects of Sexual Network Connectivity and Antimicrobial Drug Use on Antimicrobial Resistance in Neisseria gonorrhoeae

Contemporary strategies to curtail the emergence of antimicrobial resistance in Neisseria gonorrhoeae include screening for and treating asymptomatic infections in high-prevalence populations in whom antimicrobial drug–resistant infections have typically emerged. We argue that antimicrobial resistance in these groups is driven by a combination of dense sexual network connectivity and antimicrobial drug exposure (for example, through screen-and-treat strategies for asymptomatic N. gonorrhoeae infection). Sexual network connectivity sustains a high-equilibrium prevalence of N. gonorrhoeae and increases likelihood of reinfection, whereas antimicrobial drug exposure results in selection pressure for reinfecting N. gonorrhoeae strains to acquire antimicrobial resistance genes from commensal pharyngeal or rectal flora. We propose study designs to test this hypothesis.

Screening is not associated with reduced incidence of gonorrhoea or chlamydia in men who have sex with men (MSM); an ecological study of 23 European countries

Background: Increasing rates of antimicrobial resistance has motivated a reassessment of if intensive screening for gonorrhoea and chlamydia is associated with a reduction in the prevalence of these infections in men who have sex with men (MSM).

Methods: Spearman’s correlation was used to evaluate the country-level correlation between the intensity of self-reported sexual transmitted infection (STI) screening in MSM (both anal and urethral screening, taken from a large internet survey of MSM) and the incidence (taken from ECDC surveillance figures) and prevalence (taken from a literature review of studies estimating prevalence in MSM attending STI clinics) of gonorrhoea and chlamydia.

Results: The intensity of both anal and genital screening was found to be positively associated with country level gonorrhoea incidence rates (rho 0.74; p=0.0004; rho=0.73; p=0.0004, respectively) and Ct incidence rates (rho 0.71; p=0.001; rho=0.78; p=0.0001, respectively). No associations were found between anal or genital screening intensity and Ng prevalence in clinic populations (Table 2).

Conclusions: We found no evidence of a negative association between screening intensity and the prevalence of gonorrhoea or chlamydia in MSM. Randomized controlled trials are urgently required to evaluate if the high antimicrobial exposure resulting from intensive screening programmes is justified.

Screening is not associated with reduced incidence of gonorrhoea or chlamydia in men who have sex with men (MSM); an ecological study of 23 European countries

Background: Increasing rates of antimicrobial resistance has motivated a reassessment of if intensive screening for gonorrhoea and chlamydia is associated with a reduction in the prevalence of these infections in men who have sex with men (MSM). Methods: Spearman's correlation was used to evaluate the country-level correlation between the intensity of self-reported sexual transmitted infection (STI) screening in MSM (both anal and urethral screening, taken from a large internet survey of MSM) and the incidence (taken from ECDC surveillance figures) and prevalence (taken from a literature review of studies estimating prevalence in MSM attending STI clinics) of gonorrhoea and chlamydia. Results: The intensity of both anal and genital screening was found to be positively associated with country level gonorrhoea incidence rates (rho 0.74; p=0.0004; rho=0.73; p=0.0004, respectively) and Ct incidence rates (rho 0.71; p=0.001; rho=0.78; p=0.0001, respectively). No associations were found between anal or genital screening intensity and Ng prevalence in clinic populations (Table 2). Conclusions: We found no evidence of a negative association between screening intensity and the prevalence of gonorrhoea or chlamydia in MSM. Randomized controlled trials are urgently required to evaluate if the high antimicrobial exposure resulting from intensive screening programmes is justified.

How actively should we screen for chlamydia and gonorrhoea in MSM and other high-ST-prevalence populations as we enter the era of increasingly untreatable infections? A viewpoint

A number of national and international organizations are advocating more intensive screening for Chlamydia trachomatis and Neisseria gonorrhoeae in high-prevalence populations as a way to reduce the prevalence of these infections. In this article, we review the available evidence and conclude that there is a paucity of evidence to support this approach. We further hypothesize that increasing screening intensity in high-prevalence populations will result in a considerable risk for the emergence of antimicrobial resistance in Neisseria gonorrhoeae and other pathobionts.

Antimicrobial Consumption and Susceptibility of Neisseria gonorrhoeae: A Global Ecological Analysis

Aims: The reasons why antimicrobial resistance in Neisseria gonorrhoeae has emerged explosively in certain populations but not others are poorly understood. We hypothesized that population level consumption of antimicrobials plays a role.

Methods: Using susceptibility data from the World Health Organizations Global Gonococcal Antimicrobial Surveillance Programme and antimicrobial consumption data from the IMS Health MIDAS database we built linear regression models with country-level cephalosporin, macrolide, and fluoroquinolone consumption (standard doses/1,000 population/year) as the explanatory variable and 1-year lagged ceftriaxone, azithromycin, and ciprofloxacin resistance as the outcome variables. These were performed at two time points 2008/2009 and 2013/2014.

Results: The association between antimicrobial resistance and consumption at the level of individual countries was positive in all six assessments. In four instances the positive associations were statistically significant (cephalosporins 2008: coefficient 0.0005 [95% confidence interval (CI) 0.0002–0.0007] and 2013: coefficient 0.0003 [95% CI 0.0002–0.0004]; macrolides 2013: coefficient 0.0005 [95% CI 0.00002–0.001]; fluoroquinolones 2013: coefficient 0.02 [95% CI 0.006–0.031]).

Conclusions: Differences in population level consumption of particular antimicrobials may play a role in explaining the variations in the emergence of antimicrobial resistance in N. gonorrhoeae.

Antibiotic resistance: a rundown of a global crisis

The advent of multidrug resistance among pathogenic bacteria is imperiling the worth of antibiotics, which have previously transformed medical sciences. The crisis of antimicrobial resistance has been ascribed to the misuse of these agents and due to unavailability of newer drugs attributable to exigent regulatory requirements and reduced financial inducements. Comprehensive efforts are needed to minimize the pace of resistance by studying emergent microorganisms, resistance mechanisms, and antimicrobial agents. Multidisciplinary approaches are required across health care settings as well as environment and agriculture sectors. Progressive alternate approaches including probiotics, antibodies, and vaccines have shown promising results in trials that suggest the role of these alternatives as preventive or adjunct therapies in future.

Identifying a sufficient core group for trachoma transmission

Background

In many infectious diseases, a core group of individuals plays a disproportionate role in transmission. If these individuals were effectively prevented from transmitting infection, for example with a perfect vaccine, then the disease would disappear in the remainder of the community. No vaccine has yet proven effective against the ocular strains of chlamydia that cause trachoma. However, repeated treatment with oral azithromycin may be able to prevent individuals from effectively transmitting trachoma.

Methodology/Principal findings

Here we assess several methods for identifying a core group for trachoma, assuming varying degrees of knowledge about the transmission process. We determine the minimal core group from a completely specified model, fitted to results from a large Ethiopian trial. We compare this benchmark to a core group that could actually be identified from information available to trachoma programs. For example, determined from the rate of return of infection in a community after mass treatments, or from the equilibrium prevalence of infection.

Conclusions/Significance

Sufficient groups are relatively easy for programs to identify, but will likely be larger than the theoretical minimum.

Public health programs can in theory target treatment to a core group of individuals responsible for a disproportionate amount of transmission. The smallest group of individuals who need to be vaccinated to eventually eliminate an infectious disease is easy to find in theory, but not in practice. While no vaccine has proven effective for trachoma, intensive periodic treatment may be able to effectively prevent individuals from transmitting infection. Here we use a variety of methods to find a core group for trachoma transmission, including methods that use information available to trachoma programs. We show that the rate that infection returns into a community after mass treatment, or the pre-treatment prevalence of an infectious disease should work, but will include more individuals than the theoretical minimum core group.

The role of sexual networks in studies of how BV and STIs increase the risk of subsequent reinfection

Prior studies have demonstrated that both bacterial vaginosis (BV) and sexually transmitted infections (STIs) are strong independent risk factors for subsequent STI. In observational studies of this biological enhancement (BE) hypothesis, it is important to adjust for the risk of STI exposure so that the independent effect of BE can be assessed. We sought to model if two markers of local sexual network (partner concurrency and cumulative number of STIs) represented residual confounding in the models of risk for subsequent infection in a study that screened 3620 women for STIs every 3 months for a year. Mixed-effects logistic regression was used to calculate the odds ratios for an incident diagnosis of Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis and BV following a diagnosis of any of these four at the prior visit, controlling for the cumulative number of STIs and partner concurrency variables. We found that partner concurrency and cumulative number of STIs were each associated with incident infection, and in general, controlling for these variables reduced the strength of the association between prior and incident infections. We conclude that the frequently found association between prior and incident STIs is associated with both BE and sexual network structure.

Identification of Novel Neisseria gonorrhoeae Lineages Harboring Resistance Plasmids in Coastal Kenya

Background

Africa has the highest incidence of gonorrhea in the world. However, little is known about gonococcal populations in this continent or mechanisms of antimicrobial resistance (AMR).

Methods

Whole-genome sequence data were analyzed from 103 Neisseria gonorrhoeae isolates from 73 patients, mainly men who have sex with men, from coastal Kenya. We annotated loci, defined the core genome, defined mechanisms of AMR, and performed phylogenetic analysis. For patients with multiple episodes of gonorrhea, we determined whether infections occurred with related strains.

Results

We identified 3 clusters of isolates that are phylogenetically distinct from isolates found elsewhere. Plasmids were virtually ubiquitous: pTetM and pblaTEM were found in 97%, and 55% of isolates, respectively. This was associated with high doxycycline use for undiagnosed sexually transmitted infections. Twenty-three percent of multiple episodes of gonorrhea in the same individual were caused by a related strain, suggesting inadequate treatment or reinfection.

Conclusions

The prevalence of plasmid-mediated AMR in Kenyan gonococci contrasts with that in wealthy countries, where AMR is largely chromosomally mediated. Antimicrobials have a profound effect on the maintenance of lineages harboring plasmids. Doxycycline can select for tetracycline and penicillin resistance, through plasmid cooperation. Understanding the mechanisms of AMR in high-risk groups is required to inform treatment strategies.

Genomic insights into the emergence and spread of antimicrobial-resistant bacterial pathogens

Whole-genome sequencing (WGS) has been vital for revealing the rapid temporal and spatial evolution of antimicrobial resistance (AMR) in bacterial pathogens. Some antimicrobialresistant pathogens have outpaced us, with untreatable infections appearing in hospitals and the community. However,WGS has additionally provided us with enough knowledge to initiate countermeasures. Although we cannot stop bacterial adaptation, the predictability of many evolutionary processes in AMR bacteria offers us an opportunity to channel them using new control strategies. Furthermore, by usingWGS for coordinating surveillance and to create a more fundamental understanding of the outcome of antimicrobial treatment and AMR mechanisms, we can use current and future antimicrobials more effectively and aim to extend their longevity.

Does gonorrhoea screening intensity play a role in the early selection of antimicrobial resistance in men who have sex with men (MSM)? A comparative study of Belgium and the United Kingdom

Background: It is unclear why antimicrobial resistance in Neisseriagonorrhoeae in the United Kingdom (UK) and the United States has tended to first appear in men who have sex with men (MSM). We hypothesize that increased exposure to antimicrobials from intensive STI screening programmes plays a role. Methods: We assess if there is a difference in the distribution of azithromycin, cefixime and ceftriaxone minimum inhibitory concentrations (MICs) between MSM and women in the United Kingdom (UK) where 70% of MSM report STI screening in the past year vs. Belgium where 9% report STI screening in the past year. Our hypothesis is that MICs of the MSM should be higher than those of the women in the UK but not Belgium. Data for the MICs were taken from the Gonococcal Resistance to Antimicrobials Surveillance Programme (GRASP) in the UK in 2010/2011 and 2014 and a similar national surveillance programme in Belgium in 2013/2014 (the first most complete available data). We used the Mann-Whitney test to compare the MIC distributions between MSM and women within each country Results: In the UK the MICs for all three antimicrobials were significantly higher in MSM than women at both time points (P all <0.0005). In Belgium only the MIC distribution for azithromycin was higher in MSM (P<0.0005). Conclusion: The findings for cefixime and ceftriaxone, but not azithromycin are compatible with our hypothesis that screening-intensity could contribute to the emergence of AMR. Numerous other interpretations of our results are discussed.