Gonococcal Antimicrobial Surveillance Program of Canada (GASP-Canada): Overview:

GASP-Canada is a national surveillance initiative and has operated since 1985. The program is led by the National Microbiology Laboratory (NML). Provinces and territories submit Neisseria gonorrhoeae cultures to the NML for antimicrobial susceptibility testing. Monitoring antimicrobial resistance trends helps us develop treatment guidelines. It also ensures up-to-date treatments are being used for gonorrhea infections nationwide.

Why we monitor AMR in gonorrhea

N. gonorrhoeae is the bacterium that causes gonorrhea. It is the second most common bacterial sexually transmitted infection (STI) in Canada. N. gonorrhoeae can infect the:

• urogenital tract (such as the penis, urethra and vagina)
• throat
• rectum
• bloodstream and joints (if untreated)

The Canadian Notifiable Diseases Surveillance System (CNDSS) reports on gonorrhea. The incidence of gonorrhea more than doubled since 2013. Incidence rose from 40.56 cases per 100,000 people in 2013 to 92.34 in 2022. N. gonorrhoeae has evolved over time to become resistant to multiple antimicrobials, including those used for treatment.

Between 2023 and 2024, 9 cases of ceftriaxone-resistant N. gonorrhoeae were identified. This is a significant rise since only 5 cases were reported between 2017 and 2021. The growing prevalence of ceftriaxone-resistant strains is a serious threat. Ceftriaxone is the only remaining empiric treatment for gonorrhea infections.

GASP-Canada partners

Some provincial and territorial partners do their own AMR testing. These partners send N. gonorrhoeae cultures with antimicrobial resistance or reduced susceptibility to the NML. Some of these regions also provide data for their susceptible cultures. This contributes to the annual, national AMR analysis.

Provinces and territories that do not perform their own AMR testing send all of their N. gonorrhoeae cultures to the NML for testing.

Figure 1. Number of N. gonorrhoeae cultures from each province or territory represented in GASP-Canada in 2022 2021 2020 2019 2018

Methods

Antimicrobial susceptibility tests are performed on all N. gonorrhoeae cultures sent to the NML. Testing is done using either whole genome sequencing^{Footnote 1}, agar dilution method^{Footnote 2}, or both. Resistance breakpoints for these antimicrobials are interpreted using:

• Clinical and Laboratory Standards Institute (CLSI) guidelines (penicillin, tetracycline, azithromycin, ciprofloxacin)
• World Health Organization (WHO) guidelines for decreased susceptibility for ceftriaxone and cefixime
• Tang et al^{Footnote 3} breakpoints for resistance to ceftriaxone and cefixime

GASP-Canada antimicrobial resistance

Molecular genotyping of N. gonorrhoeae cultures is done using whole genome sequencing methods and determined using:

• multi-antigen sequence typing (NG-MAST)^{Footnote 4}
• sequence typing for antimicrobial resistance (NG-STAR)^{Footnote 5}

GASP-Canada molecular typing for N. gonorrhoeae

Policies for culturing suspected gonorrhea infections differ between regions and NML receives isolates and associated data from provinces and territories at their discretion. Interpretation of results is limited not only by the number of the cultures tested but by the source of the cultures, as bias may be introduced based on the risk group of the client.

Enhanced surveillance of N. gonorrhoeae

The Enhanced Surveillance of Antimicrobial Resistant Gonorrhea (ESAG) program uses GASP-Canada's laboratory data. It integrates that data with epidemiological and clinical data from participating areas. The program provides a detailed understanding of AMR trends across Canada.

ESAG Health Infobase dashboard

Contact us

For more information on GASP-Canada or how to participate, contact: nml.strepsti-lnm.strepits@phac-aspc.gc.ca

Recent GASP-Canada publications

• Antimicrobial susceptibilities of Neisseria gonorrhoeae in Canada, 2022
• Antimicrobial susceptibilities of Neisseria gonorrhoeae in Canada, 2021
• Increasing Azithromycin Resistance in Neisseria gonorrhoeae Due to NG-MAST 12302 Clonal Spread in Canada, 2015 to 2018
• Disseminated Gonococcal Infections in Manitoba, Canada: 2013 to 2020
• Antimicrobial susceptibilities of Neisseria gonorrhoeae, 2020
• Equations to predict antimicrobial minimum inhibitory concentrations in Neisseria gonorrhoeae using molecular antimicrobial resistance determinants

References