Cost-effectiveness of testing for Mycoplasma genitalium among men who have sex with men in Australia

OBJECTIVES

Mycoplasma genitalium (MG) disproportionately affects men who have sex with men (MSM). We determined the cost-effectiveness of different testing strategies for MG in MSM, taking a healthcare provider perspective.

METHODS

We used inputs from a dynamic transmission model of MG among MSM living in Australia in a decision tree model to evaluate the impact of four testing scenarios on MG incidence: (1) no one tested; (2) symptomatic MSM; (3) symptomatic and high-risk asymptomatic MSM; (4) all MSM. We calculated the incremental cost-effectiveness ratios (ICERs) using a willingness-to-pay threshold of $A30 000 per quality-adjusted life year (QALY) gained. We explored the impact of adding an antimicrobial resistance (AMR) tax (ie, additional cost per antibiotic consumed) to identify the threshold, whereby any testing for MG is no longer cost-effective.

RESULTS

Testing only symptomatic MSM is the most cost-effective (ICER $3677 per QALY gained) approach. Offering testing to all MSM is dominated (ie, higher costs and lower QALYs gained compared with other strategies). When the AMR tax per antibiotic given was above $150, any testing for MG was no longer cost-effective.

CONCLUSION

Testing only symptomatic MSM is the most cost-effective option, even when the potential costs associated with AMR are accounted for (up to $150 additional cost per antibiotic given). For pathogens like MG, where there are anticipated future costs related to AMR, we recommend models that test the impact of incorporating an AMR tax as they can change the results and conclusions of cost-effectiveness studies.

Prevalence of Mycoplasma genitalium infection among HIV PrEP users: a systematic review and meta-analysis

OBJECTIVES

To summarise the prevalence of Mycoplasma genitalium (MG) and antibiotic-resistant MG infection among HIV pre-exposure prophylaxis (PrEP) users.

METHODS

We searched MEDLINE, Embase, Web of Science and Global Index Medicus up to 30 September 2022. We included studies reporting the prevalence of MG and/or antibiotic-resistant MG infection among PrEP users. Two reviewers independently searched for studies and extracted data. A systematic review with random-effects meta-analysis was performed to quantitatively summarise the results of included studies. The critical appraisal of included studies was conducted with the Joanna Briggs Institute checklist for prevalence studies and the quality of evidence was assessed with Grading of Recommendations Assessment, Development and Evaluation (GRADE).

RESULTS

A total of 15 studies were included in the systematic review, with 2341 individuals taking PrEP. Studies were conducted in high-income level countries between 2014 and 2019. Median age of participants varied from 23.5 to 40 years. The majority were men (85%) and among them, 93% were men who have sex with men. To identify MG, urine samples were analysed in 14 studies, rectal or anal swabs in 12 studies, oral or pharyngeal swabs in 9 studies, and urethral or vaginal in 3 studies. The pooled point prevalence of MG among PrEP users was 16.7% (95% CI 13.6% to 20.3%; 95% prediction interval (95% PI) 8.2% to 31.1%). The pooled point prevalence of macrolide-resistant infections was 82.6% (95% CI 70.1% to 90.6%; 95% PI 4.7% to 99.8%) and the prevalence of fluoroquinolone-resistant infections was 14.3% (95% CI 1.8% to 42.8%). Individuals taking PrEP have a higher chance of being infected with MG compared with those not taking PrEP (OR 2.30; 95% CI 1.6 to 3.4). The quality of evidence was very low to moderate.

CONCLUSION

We observed a high prevalence of MG and its macrolide resistance among PrEP users, highlighting the need to reinforce prevention strategies against sexually transmitted infections in this population.

PROSPERO REGISTRATION NUMBER

CRD42022310597.

Novel use of oral chloramphenicol for treatment-resistant Mycoplasma genitalium

We describe the novel use of oral chloramphenicol for treatment-resistant Mycoplasma genitalium (M. genitalium) infection in a 20-year-old heterosexual cisgender male presenting with recurrent symptomatic non-gonococcal urethritis. M. genitalium urethritis is an increasingly common clinical conundrum in sexual health clinics and in cases of second-line treatment failure (such as moxifloxacin), UK and international guidelines struggle to make recommendations for third-line treatments. As shown in our case, the evidence base for third-line treatments is lacking, with poor success rates, and may be poorly tolerated. Here we demonstrate the novel use of a well-tolerated oral antimicrobial, chloramphenicol, resulting in rapid microbiological and clinical cure in treatment-resistant M. genitalium urethritis.

Rapid accurate point-of-care tests combining diagnostics and antimicrobial resistance prediction for Neisseria gonorrhoeae and Mycoplasma genitalium

In addition to inadequate access to early diagnosis and treatment with antimicrobial agents for patients and sexual contacts, management and control of STIs is significantly challenged by emergence and spread of antimicrobial resistance (AMR), particularly for STIs such as Neisseria gonorrhoeae and Mycoplasma genitalium This is further compounded by use of nucleic acid amplification techniques for diagnosis, resulting in reduced phenotypic AMR testing for N. gonorrhoeae and absence or suboptimal AMR surveillance for guiding treatment of both STIs in many settings. Rapid accurate point-of-care (POC) tests for diagnosis of all STIs would be valuable but to significantly impact treatment precision and management of N. gonorrhoeae and M. genitalium infections, combinations of rapid POC diagnostic and AMR testing (POC-AMR) will likely be required. This strategy would combat STI burden and AMR emergence and spread by enabling diagnosis and individualised treatment at the first healthcare visit, potentially reducing selection pressure on recommended antimicrobials, reducing transmission of resistant strains and providing means for AMR surveillance. Microfluidic and nanotechnology platforms under development for rapid detection of STIs provide a basis to also develop molecular rapid POC-AMR prediction. A number of prototypic devices are in the pipeline but none as yet approved for routine use. However, particularly for N. gonorrhoeae, more knowledge is required to assess which antimicrobials lend themselves to a genotypic POC-AMR approach, in relation to genotypic-phenotypic associations and potential impact clinically and epidemiologically. Key for successful deployment will include also understanding cost-effectiveness, cost-consequences and acceptability for key stakeholders.

Antimicrobial susceptibility in Neisseria gonorrhoeae isolates from five sentinel surveillance sites in Zimbabwe, 2015-2016

OBJECTIVES

Gonorrhoea and antimicrobial resistance (AMR) in Neisseria gonorrhoeae are major public health concerns worldwide. Enhanced AMR surveillance for gonococci is essential globally. In Zimbabwe, very limited gonococcal AMR data were reported. Our aims were to (i) implement quality-assured gonococcal AMR surveillance in Zimbabwe and (ii) investigate gonococcal AMR at five health centres in 2015-2016.

METHODS

Gonococcal isolates from 104 men with urethral discharge were tested for susceptibility to kanamycin, ceftriaxone, cefixime, ciprofloxacin and azithromycin using Etest.

RESULTS

All isolates (102 possible to test) were susceptible to ceftriaxone and cefixime. The level of resistance (intermediate resistance) to kanamycin and ciprofloxacin was 2.0% (2.0%) and 18.6% (27.5%), respectively. The two kanamycin-resistant isolates (R≥128 mg/L) had a kanamycin minimum inhibitory concentration (MIC) of >256 mg/L. The ciprofloxacin resistance ranged from 9.5% to 30.8% in the five sentinel sites. Only 10 (9.6%) of the isolates were tested for susceptibility to azithromycin and 1 (10.0%) was resistant (MIC=4 mg/L).

CONCLUSIONS

The emergence of multidrug-resistant gonorrhoea internationally is a major public health concern and gonococcal AMR surveillance is crucial globally. In Zimbabwe, gonococcal AMR surveillance has now been implemented and quality assured according to WHO standards. The results of this first surveillance will be used to directly inform revisions of the national treatment guidelines. It is imperative to further strengthen the surveillance of gonococcal AMR, and ideally also treatment failures, in Zimbabwe and most countries in the WHO African region, which requires continuous national and international support, including technical support, and political and financial commitment.

Rapid identification and antimicrobial susceptibility testing of positive blood cultures using MALDI-TOF MS and a modification of the standardised disc diffusion test: a pilot study

AIMS

In an era when clinical microbiology laboratories are under increasing financial pressure, there is a need for inexpensive, yet effective, rapid microbiology tests. The aim of this study was to evaluate a novel modification of standard methodology for the identification and antimicrobial susceptibility testing (AST) of pathogens in positive blood cultures, reducing the turnaround time of laboratory results by 24 h.

METHODS

277 positive blood cultures had a Gram stain performed and were subcultured and incubated at 37°C in a CO2 atmosphere for 4-6 h. Identification of the visible growth was performed using matrix-assisted laser desorption time of flight mass spectrometry (MALDI-TOF MS). Taking a modified approach to the Clinical and Laboratory Standards Institute-standardised AST methodology, an inoculum density of 0.5 McFarland was prepared from the early growth for disc diffusion testing. The standard AST method was also performed on the 18-24 h culture.

RESULTS

96% (n=73/76) of gram-negative organisms were correctly identified by MALDI-TOF MS. Comparative analysis of the rapid and standard AST results showed an overall interpretive category error rate of 7.7% (6.7% minor errors, 0.6% major errors and 0.4% very major errors). 100% of Staphylococcus aureus (n=41) and enterococcus isolates (n=9) were correctly identified after 4-6 h incubation. The overall AST categorical agreement was also 100% for these isolates.

CONCLUSIONS

An incubation of 4-6 h directly from positive blood cultures allowed for both a rapid species identification and an antimicrobial susceptibility result approximately 24 h earlier than is possible using standard methodology.

Epidemiological typing of Neisseria gonorrhoeae and detection of markers associated with antimicrobial resistance directly from urine samples using next generation sequencing

OBJECTIVES

To investigate the potential for next generation sequencing (NGS) to be used directly on clinical specimens that have tested positive for Neisseria gonorrhoeae by nucleic acid amplification testing (NAAT), to generate information on epidemiological genotyping and antimicrobial resistance (AMR) markers.

METHODS

DNA was extracted from 13 N. gonorrhoeae NAAT-positive urine specimens, enriched for microbial DNA and sequenced using the Ion Torrent PGM workflow. Sequences that aligned to the human genome were filtered out and the remaining sequences were de novo assembled. The resulting contigs were searched for regions of interest using Ridom SeqSphere. MLST and NG-MAST alleles were assigned according to the schemes at PubMLST.org and NG-MAST.net, respectively.

RESULTS

In total, 11 of the 13 samples tested generated a sufficient number of N. gonorrhoeae sequence reads to provide full coverage of the genome at a depth of 6-130×. Complete MLST and NG-MAST sequence types could be generated for each of these samples. The presence of 10 different AMR markers was investigated, and both previously reported and novel mutations were identified in genes associated with reduced susceptibility to several antimicrobials.

CONCLUSIONS

We found that sequencing the entire genome of N. gonorrhoeae directly from clinical samples is possible using NGS, and that multiple levels of N. gonorrhoeae typing information can be generated. As NAAT only testing becomes more common, this method could be used to detect both known and novel mutations associated with AMR and to generate genotyping information, supporting AMR and epidemiological surveillance in the absence of culturing.

An outbreak of high-level azithromycin resistant Neisseria gonorrhoeae in England

OBJECTIVES

To investigate a potential outbreak of high-level azithromycin resistant (HL-AziR) gonococcal infections diagnosed in eight patients attending a sexual health clinic in Leeds, North England, between November 2014 and March 2015.

METHODS

Eight cases of infection with gonococci exhibiting azithromycin minimum inhibitory concentrations (MICs) ≥256 mg/L were identified from patients in Leeds as part of the routine service provided by the Sexually Transmitted Bacteria Reference Unit. All patient records were reviewed to collate epidemiological and clinical information including evaluation of patient management. Whole-genome sequencing (WGS) was performed on seven gonococcal isolates to determine Neisseria gonorrhoeae multiantigen sequence type (NG-MAST), WGS comparison and mutations in the 23S rRNA genes.

RESULTS

All patients were heterosexual (five male, three female) from a range of ethnic backgrounds and from the Leeds area. Three patients were linked by partner notification. All patients were infected at genital sites and two women had pharyngeal infection also. Six patients received the recommended first-line therapy for uncomplicated gonorrhoea, one was treated for pelvic inflammatory disease and one received spectinomycin followed later by ciprofloxacin. Test of cure was achieved in seven patients and confirmed successful eradication. All seven isolates sequenced were identical by NG-MAST and WGS comparison, and contained an A2143G mutation in all four 23S rRNA alleles.

CONCLUSIONS

Epidemiological and microbiological investigations confirm that an outbreak of a gonococcal strain showing HL-AziR is ongoing in the North of England. Every effort should be made to identify and curtail dissemination of this strain as it presents a significant threat to the current recommended front-line dual therapy.

u-CARE: user-friendly Comprehensive Antibiotic resistance Repository of Escherichia coli

BACKGROUND AND AIMS

Despite medical advancements, Escherichia coli-associated infections remain a major public health concern and although an abundant information about E. coli and its antibiotic resistance mechanisms is available, no effective tool exists that integrates gene and genomic data in context to drug resistance, thus raising a need to develop a repository that facilitates integration and assimilation of factors governing drug resistance in E. coli.

DESCRIPTIONS

User-friendly Comprehensive Antibiotic resistance Repository of Escherichia coli (u-CARE) is a manually curated catalogue of 52 antibiotics with reported resistance, 107 genes, transcription factors and single nucleotide polymorphism (SNPs) involved in multiple drug resistance of this pathogen. Each gene page provides detailed information about its resistance mechanisms, while antibiotic page consists of summary, chemical description and structural descriptors with links to external public databases like GO, CDD, DEG, Ecocyc, KEGG, Drug Bank, PubChem and UniProt. Moreover, the database integrates this reductive information to holistic data such as strain-specific and segment-specific pathogenic islands and operons. In addition, the database offers rich user interface for the visualisation and retrieval of information using various search criteria such as sequence, keyword, image and class search.

CONCLUSIONS

u-CARE is aimed to cater to the needs of researchers working in the field of antimicrobial drug resistance with minimal knowledge of bioinformatics. This database is also intended as a guide book to medical practitioners to avoid use of antibiotics against which resistance has already been reported in E. coli. The database is available from: http://www.e-bioinformatics.net/ucare.

Targeting core groups for gonorrhoea control: feasibility and impact

OBJECTIVE

We aimed to outline why core groups should be targeted in Neisseria gonorrhoeae control and suggest several important and timely interventions to target core groups while highly resistant strains are spreading.

METHODS

Core group definition, feasibility and impact of gonorrhoea core group interventions as well as gonorrhoea resistance development have been reviewed in the paper.

RESULTS

Core group interventions have proven effective in gonorrhoea control in the past but are compromised by the spread of highly resistant strains.

CONCLUSIONS

Worldwide functional Gonorrhoea Antimicrobial Surveillance Program, better screening and better treatment programmes are needed. Prevention through condom promotion aimed at core groups remains essential. More specific treatment guidance for low-income and middle-income countries without resistance data is required in the meantime to achieve a better use of antibiotics.

Revised simulation model does not predict rebound in gonorrhoea prevalence where core groups are treated in the presence of antimicrobial resistance

OBJECTIVES

To determine the effects of using discrete versus continuous quantities of people in a compartmental model examining the contribution of antimicrobial resistance (AMR) to rebound in the prevalence of gonorrhoea.

METHODS

A previously published transmission model was reconfigured to represent the occurrence of gonorrhoea in discrete persons, rather than allowing fractions of infected individuals during simulations.

RESULTS

In the revised model, prevalence only rebounded under scenarios reproduced from the original paper when AMR occurrence was increased by 10(5) times. In such situations, treatment of high-risk individuals yielded outcomes very similar to those resulting from treatment of low-risk and intermediate-risk individuals. Otherwise, in contrast with the original model, prevalence was the lowest when the high-risk group was treated, supporting the current policy of targeting treatment to high-risk groups.

CONCLUSIONS

Simulation models can be highly sensitive to structural features. Small differences in structure and parameters can substantially influence predicted outcomes and policy prescriptions, and must be carefully considered.

Gonococcal antimicrobial resistance: perspectives from the African region

Many countries in Africa have weak surveillance systems for data collection of sexually transmitted infections, and hardly any programmes for gonococcal antimicrobial susceptibility assessment. The widespread adoption of the syndromic approach to the diagnosis and management of sexually transmitted infections has also meant that the collection of a genital specimen for laboratory analysis is no longer routinely done when patients present with genital complaints, and clinical staff and laboratory technicians have lost the skill to collect genital specimens and processing them for culture and antimicrobial susceptibility testing. Following reports of gonococcal antimicrobial resistance to quinolones, WHO urged countries to monitor gonococcal antimicrobial resistance in a more systematic and regular manner. Although the response in Africa has been slow to take off, a number of studies have been conducted in a few countries and plans for implementation are in place in others. However, the number of isolates studied has been small in nearly all the countries except one, and the barriers to scaling up gonococcal antimicrobial resistance surveys seem overwhelming. In spite of the studies being few and of small sample sizes, enough information can be discerned to indicate that quinolones can no longer be a medicine of choice for the treatment of gonorrhoea in Africa and the threat of antimicrobial resistance developing in Neisseria gonorrhoeae to third-generation cephalosporins is real and imminent.

Moving forward in tackling antimicrobial resistance: WHO actions

Although the key focus of this supplement is related to antimicrobial resistance (AMR) in a sexually transmitted infection, Neisseria gonorrhoeae, the purpose of this article is to highlight the wider public health impact of AMR and the need for different disciplines of health to coordinate and collaborate in their selection and use of antimicrobial agents. AMR is being detected in health areas ranging from simple drugs used to treat common bacterial infections to the complex formulations used to treat tuberculosis, malaria and HIV infection, and on all continents. Tackling and containing AMR present an ordeal to international and national health authorities on many fronts. In June 2012, WHO launched the WHO Global Action Plan to Control the Spread and Impact of Antimicrobial Resistance in Neisseria gonorrhoeae with a vision to enhance the global response to the prevention, diagnosis and control of N gonorrhoeae infection and mitigate the health impact of AMR through enhanced, sustained, evidence-based and collaborative multisectoral action. This global action plan is positioned within a long-standing commitment of WHO to the issue of AMR with the launch of the Global Strategy on AMR in 2001 and World Health Day on AMR in 2011.

Antimicrobial resistance monitoring in Neisseria gonorrhoeae and strategic use of funds from the Global Fund to set up a systematic Moroccan gonococcal antimicrobial surveillance programme

OBJECTIVES

The aims of this study were to assess antimicrobial resistance in Neisseria gonorrhoeae infections and update the treatment in the national guidelines for the syndromic management of sexually transmitted infections in Morocco.

METHODS

171 men complaining of urethral discharge were recruited from basic health services during 2009. Urethral swab samples were collected and N gonorrhoeae identification was performed by culture. Antimicrobial susceptibility testing was performed using the Etest method and the antimicrobial agents tested were ciprofloxacin, penicillin, spectinomycin, tetracycline, ceftriaxone and cefixime.

RESULTS

A total of 72 isolates were examined. Significant resistance to tetracycline (92.8%) and ciprofloxacin (86.8%), which was used as first-line treatment in gonococcal infections, was noted. No resistance to spectinomycin, ceftriaxone or cefixime was detected in all the isolates.

CONCLUSIONS

Following these results the Ministry of Health of Morocco replaced ciprofloxacin and introduced ceftriaxone 250 mg as a single dose in the treatment of gonococcal infections. Using funds from the Global Fund to Fight AIDS, Tuberculosis and Malaria (the Global Fund), a surveillance programme was set up for antimicrobial resistance testing in N gonorrhoeae.