Considerations for Strengthening Surveillance of Neisseria gonorrhoeae Antimicrobial Resistance and Interpreting Surveillance Data

Surveillance systems to monitor antimicrobial resistance in Neisseria gonorrhoeae: a global, systematic review, 1 January 2012 to 27 September 2020

Background

Effective surveillance of antimicrobial resistance (AMR) in Neisseria gonorrhoeae is required for the early detection of resistant strains and to ensure that treatment guidelines are appropriate for the setting in which they are implemented. AMR in N. gonorrhoeae has been identified as a global health threat.

Aim

We performed a systematic review to identify and describe surveillance systems targeting AMR in N. gonorrhoeae.

Methods

We searched Medline, PubMed, Global Health, EMBASE, CINAHL, Web of Science and ProQuest databases and grey literature between 1 January 2012 and 27 September 2020. Surveillance systems were defined as the continuous, systematic collection, analysis and interpretation of N. gonorrhoeae resistance data. The key components of surveillance systems were extracted, categorised, described and summarised.

Results

We found 40 publications reporting on N. gonorrhoeae AMR surveillance systems in 27 countries and 10 multi-country or global surveillance reports. The proportion of countries with surveillance systems in each of the WHO's six regions ranged from one of 22 countries in the Eastern Mediterranean and five of 54 in Africa, to three of 11 countries in South East Asia. Only four countries report systems which are both comprehensive and national. We found no evidence of a current surveillance system in at least 148 countries. Coverage, representativeness, volume, clinical specimen source, type and epidemiological information vary substantially and limit interpretability and comparability of surveillance data for public health action.

Conclusion

Globally, surveillance for N. gonorrhoeae AMR is inadequate and leaves large populations vulnerable to a major public health threat.

Enhancing Gonococcal Antimicrobial Resistance Surveillance in Cisgender Women, Strengthening the US Response to Resistant Gonorrhea, 2018 to 2019

BACKGROUND

Cisgender women have been underrepresented in antibiotic-resistant gonorrhea (ARGC) surveillance systems. Three of 8 project sites (City of Milwaukee [MIL], Guilford County [GRB], Denver County [DEN]), funded under the Centers for Disease Control and Prevention's Strengthening the US Response to Resistant Gonorrhea (SURRG), focused efforts to better include cisgender women in ARGC surveillance.

METHODS

MIL, GRB, and DEN partnered with diverse health care settings and developed gonorrhea culture criteria to facilitate urogenital specimen collection in cisgender women and men. Regional laboratories within the Antibiotic Resistance Laboratory Network performed agar dilution antibiotic susceptibility testing (AST) of gonococcal isolates. Data from 2018 and 2019 were analyzed.

RESULTS

In SURRG, 90.5% (11,464 of 12,667) of the cisgender women from whom urogenital culture specimens were collected were from MIL, GRB, and DEN. Of women in SURRG whose gonococcal isolates underwent AST, 70% were from these 3 sites. In these 3 sites, a substantial proportion of cisgender women with positive urogenital cultures and AST were from health care settings other than sexually transmitted disease (STD) clinics (non-STD clinics; MIL, 56.0%; GRB, 80.4%; and DEN, 23.5%). Isolates with AST were obtained from 5.1%, 10.2%, and 2.4% of all diagnosed gonorrhea cases among cisgender women in MIL, GRB, and DEN, respectively, and were more often susceptible to all antibiotics than those from cisgender men from each of these sites.

CONCLUSIONS

With focused efforts and partnerships with non-STD clinics, 3 SURRG sites were able to include robust ARGC surveillance from cisgender women. These findings may guide further efforts to improve gender equity in ARGC surveillance.

Demographic and Epidemiological Characteristics Associated With Reduced Antimicrobial Susceptibility to Neisseria gonorrhoeae in the United States, Strengthening the US Response to Resistant Gonorrhea, 2018 to 2019

BACKGROUND

Jurisdictions participating in Strengthening the US Response to Resistant Gonorrhea (SURRG) implemented specimen collection for culture and antimicrobial susceptibility testing from a sample of persons of all genders (at multiple anatomic sites) attending sexually transmitted disease clinics and community clinics. We describe the percentage and characteristics of patients whose isolates demonstrated reduced susceptibility (RS) to azithromycin, ceftriaxone, or cefixime.

METHODS

We included patients from clinics that participated in SURRG whose isolates underwent antimicrobial susceptibility testing by Etest. We defined RS as azithromycin minimum inhibitory concentrations (MICs) ≥2 μg/mL (AZM-RS), ceftriaxone MICs ≥0.125 μg/mL (CRO-RS), or cefixime MICs ≥0.25 μg/mL (CFX-RS). Patients with repeated infections appeared >1 time in the data. We calculated the frequency and percentage of patients with an isolate demonstrating RS by epidemiological characteristics.

RESULTS

During the period 2018-2019, 10,013 patients from 8 jurisdictions provided 10,735 isolates. Among 10,013 patients, 11.0% (n = 1099) had ≥1 isolate with AZM-RS (range by jurisdiction, 2.5%-18.0%). Approximately 11.3% of 8771 of patients visiting sexually transmitted disease clinics and approximately 8.8% of 1242 patients visiting community clinics had an AZM-RS isolate. Nearly 6% of 1013 females had an AZM-RS isolate; among males, the percents of patients with an AZM-RS isolate were 17.7% among 4177 men who have sex only with men and 6.1% among 3581 men who have sex only with women. Few (0.4%) patients had isolates with CFX-RS (n = 40) or CRO-RS (n = 43).

CONCLUSIONS

Although infections with reduced cephalosporin susceptibility were rare, AZM-RS infections were prevalent in this sample of patients in multiple jurisdictions and across gender and gender of sex partner categories.

Doxycycline in the management of sexually transmitted infections

Doxycycline is a second-generation tetracycline, available worldwide for half a century. It is an inexpensive broad-spectrum antimicrobial agent largely used in the management of several bacterial infections, particularly involving intracellular pathogens, as well as in the treatment of acne or for the prophylaxis of malaria. Physicochemical characteristics of doxycycline (liposolubility) allow a high diffusion in the tissues and organs. It has high bioavailability and a long elimination half-life allowing oral administration of one or two daily doses. Over the last decade, the prevalence of bacterial sexually transmitted infections (STIs) (syphilis, chlamydiosis, gonorrhoea and Mycoplasma genitalium infections) has increased in most countries, mainly in MSM, many of whom are infected with HIV. In light of increasing prevalence of resistance towards first-line regimens of some STI agents and recently updated recommendations for STI management, doxycycline appears to be an attractive option compared with other available antibiotics for the treatment of some STIs due to its efficacy, good tolerability and oral administration. More recently, indications for doxycycline in STI prophylaxis have been evaluated. Considering the renewed interest of doxycycline in STI management, this review aims to update the pharmacology of, efficacy of, safety of and resistance to doxycycline in this context of use.

Estimating the fitness cost and benefit of cefixime resistance in Neisseria gonorrhoeae to inform prescription policy: A modelling study

BACKGROUND

Gonorrhoea is one of the most common bacterial sexually transmitted infections in England. Over 41,000 cases were recorded in 2015, more than half of which occurred in men who have sex with men (MSM). As the bacterium has developed resistance to each first-line antibiotic in turn, we need an improved understanding of fitness benefits and costs of antibiotic resistance to inform control policy and planning. Cefixime was recommended as a single-dose treatment for gonorrhoea from 2005 to 2010, during which time resistance increased, and subsequently declined.

METHODS AND FINDINGS

We developed a stochastic compartmental model representing the natural history and transmission of cefixime-sensitive and cefixime-resistant strains of Neisseria gonorrhoeae in MSM in England, which was applied to data on diagnoses and prescriptions between 2008 and 2015. We estimated that asymptomatic carriers play a crucial role in overall transmission dynamics, with 37% (95% credible interval CrI 24%-52%) of infections remaining asymptomatic and untreated, accounting for 89% (95% CrI 82%-93%) of onward transmission. The fitness cost of cefixime resistance in the absence of cefixime usage was estimated to be such that the number of secondary infections caused by resistant strains is only about half as much as for the susceptible strains, which is insufficient to maintain persistence. However, we estimated that treatment of cefixime-resistant strains with cefixime was unsuccessful in 83% (95% CrI 53%-99%) of cases, representing a fitness benefit of resistance. This benefit was large enough to counterbalance the fitness cost when 31% (95% CrI 26%-36%) of cases were treated with cefixime, and when more than 55% (95% CrI 44%-66%) of cases were treated with cefixime, the resistant strain had a net fitness advantage over the susceptible strain. Limitations include sparse data leading to large intervals on key model parameters and necessary assumptions in the modelling of a complex epidemiological process.

CONCLUSIONS

Our study provides, to our knowledge, the first estimates of the fitness cost and benefit associated with resistance of the gonococcus to a clinically relevant antibiotic. Our findings have important implications for antibiotic stewardship and public health policies and, in particular, suggest that a previously abandoned antibiotic could be used again to treat a minority of gonorrhoea cases without raising resistance levels.