Mitigating the emergence and spread of multidrug- and extensively drug-resistant gonorrhea: is there sufficient support in resource-poor settings in Africa?

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.

Establishment of a Gonococcal Antimicrobial Surveillance Programme, in Accordance With World Health Organization Standards, in Côte d'Ivoire, Western Africa, 2014-2017

BACKGROUND

Antimicrobial resistance (AMR) in Neisseria gonorrhoeae is compromising the treatment of gonorrhea globally. Recent AMR data are extremely limited in Africa, and mainly totally lacking in Western Africa, including Côte d'Ivoire. This study (i) established a quality-assured gonococcal antimicrobial surveillance program, according to World Health Organization quality criteria, (ii) investigated the AMR to 8 therapeutic antimicrobials in gonococcal isolates from 2014 to 2017, and (iii) provided evidence for updating the National Sexually Transmitted Disease Syndromic Management Guidelines in Côte d'Ivoire.

METHODS

During 2014 to 2017, gonococcal isolates were obtained from sexually active symptomatic or asymptomatic males and females in 14 sites in Côte d'Ivoire. It was a special focus on symptomatic males, and their sexual partners, due to the higher culture positivity rates in symptomatic males. Patient metadata were collected, including age, gender, sexual orientation, and symptoms. Minimum inhibitory concentrations of 8 antimicrobials were determined by Etest and interpreted using European Committee on Antimicrobial Susceptibility Testing breakpoints. β-lactamase production was detected using cefinase disks.

RESULTS

The level of resistance, examining 212 gonococcal isolates, was as follows: 84.9% to tetracycline, 68.9% to benzylpenicillin, 62.7% to ciprofloxacin, 6.1% to azithromycin, and 1.4% to gentamicin. All isolates were susceptible to ceftriaxone, cefixime and spectinomycin.

CONCLUSIONS

We provide the first gonococcal AMR data, quality assured according to World Health Organization standards, from Côte d'Ivoire since more than 20 years. The high ciprofloxacin resistance, which informed a revision of the national syndromic management guideline during study, and relatively high resistance to azithromycin demand an improved gonococcal antimicrobial surveillance program and increased awareness when prescribing treatment in Côte d'Ivoire.

Antimicrobial resistance (AMR) and molecular characterization of Neisseria gonorrhoeae in Ghana, 2012-2015

Neisseria gonorrhoeae antimicrobial resistance (AMR) surveillance is essential for tracking the emergence and spread of AMR strains in local, national and international populations. This is crucial for developing or refining treatment guidelines. N. gonorrhoeae multiantigen sequence typing (NG-MAST) is beneficial for describing the molecular epidemiology of gonococci at national and international levels. Elucidation of AMR determinants to β-lactam drugs, is a means of monitoring the development of resistance. In Ghana, little is known about the current gonococcal AMR prevalence and no characterization of gonococcal isolates has been previously performed. In this study, gonococcal isolates (n = 44) collected from five health facilities in Ghana from 2012 to 2015, were examined using AMR testing, NG-MAST and sequencing of penA. High rates of resistance were identified to tetracycline (100%), benzylpenicillin (90.9%), and ciprofloxacin (81.8%). One isolate had a high cefixime MIC (0.75 μg/ml). Twenty-eight NG-MAST sequence types (STs) were identified, seventeen of which were novel. The isolate with the high cefixime MIC contained a mosaic penA-34 allele and belonged to NG-MAST ST1407, an internationally spreading multidrug-resistant clone that has accounted for most cefixime resistance in many countries. In conclusion, AMR testing, NG-MAST, and sequencing of the AMR determinant penA, revealed high rates of resistance to tetracycline, benzylpenicillin, and ciprofloxacin; as well as a highly diverse population of N. gonorrhoeae in Ghana. It is imperative to continue with enhanced AMR surveillance and to understand the molecular epidemiology of gonococcal strains circulating in Ghana and other African countries.

Antimicrobial Susceptibility of Neisseria gonorrhoeae Isolates in Yaoundé, Cameroon From 2009 to 2014

We investigated the antimicrobial resistance in gonococci 2009 to 2014 in Yaoundé, Cameroon, and recommend revisions of the Cameroonian treatment guideline. We observed a high resistance to ciprofloxacin (17.6%) but no ceftriaxone resistance. Ceftriaxone should replace ciprofloxacin as the recommended first-line treatment for urethral/vaginal discharge. Enhanced resistance surveillance in Africa is essential.

Antibiotic resistance and NG-MAST sequence types of Neisseria gonorrhoeae isolates in Poland compared to the world

Gonorrhoea is one of the most common sexually transmitted infections and in 2012, the World Health Organization estimated about 78 million of new global urogenital cases among adults per year. The main concern during the latest decade has been the emergence and spread of multidrug-resistant strains of Neisseria gonorrhoeae. Resistance has emerged internationally to the extended-spectrum cephalosporins, ceftriaxone and cefixime, which are the last remaining options for empiric first-line monotherapy of gonorrhoea. In Poland, the levels of resistance to ciprofloxacin, benzylpenicillin and tetracycline are high, and the prevalence of azithromycin resistance has increased. However, no resistance to ceftriaxone has been identified. The currently spread multidrug-resistant strains frequently represent epidemic clones. The present paper reviews and describes the antimicrobial resistance and N. gonorrhoeae multiantigen sequence typing (NG-MAST) sequence types of N. gonorrhoeae strains spreading in Poland compared to the world.

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.

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.