Gonorrhea guide: Etiology and epidemiology

On this page

• Etiology
• Epidemiology
• Surveillance of antimicrobial resistance in gonorrhea
• References

Etiology

Neisseria gonorrhoeae is a Gram-negative diplococcus^{Footnote 1}. This highly infectious bacterium colonizes and infects genital mucosa and it may also infect extragenital sites, including the oropharyngeal, conjunctival and anorectal mucosae^{Footnote 2}.

N. gonorrhoeae can develop antimicrobial resistance (AMR) rapidly and has developed resistance to every class of antimicrobial used to treat it^{Footnote 3Footnote 4}; some of these antibiotics (sulphonamides, penicillins, tetracyclines) are ineffective and are no longer used.

Travel-related ceftriaxone-resistant gonorrhea isolates were reported in Canada in 2017^{Footnote 5} and 2018^{Footnote 6} and isolates with decreased susceptibility to cephalosporins (cefixime and ceftriaxone) continue to emerge. Resistance to azithromycin is increasing and treatment failures have been reported in Canada and around the world.

Epidemiology

Gonorrhea is the second most commonly reported sexually transmitted infection (STI) in Canada, with a gradual and steady increase in reported cases of gonorrhea since 2012^{Footnote 7}. Gonorrhea may be undiagnosed or unreported because gonorrheal infections are often asymptomatic^{Footnote 8}.

Between 2010 and 2019, the rate of gonorrhea was highest among males. The rate has been increasing fastest in males compared to females, widening the gap in rates between the sexes. In 2019, people less than 30 years old had the highest rates of infection. Over half (51.9%) of reported cases were identified in people under 30 years of age^{Footnote 7}.

More information

Local epidemiological information: Consult your public health unit.

National epidemiological information:

• Notifiable Diseases Online
• Canadian Communicable Disease report: Gonorrhea in Canada, 2010-2015^{Footnote 8}
• Report on Sexually Transmitted Infection Surveillance in Canada, 2019^{Footnote 7}

Global epidemiological information:  

• World Health Organization Report on global sexually transmitted infection surveillance

Surveillance of antimicrobial resistance in gonorrhea

Antimicrobial-resistant N. gonorrhoeae is a global public health challenge^{Footnote 3}. Surveillance of AMR in N. gonorrhoeae is crucial to monitor trends and inform efforts to prevent and control its spread.

In 2018, about 80% of cases were diagnosed using Nucleic Acid Amplification Testing (NAAT). As a result, fewer samples are available for susceptibility testing, making it difficult to generate an accurate picture of drug resistance^{Footnote 9}.

The Enhanced Surveillance of Antimicrobial-Resistant Gonorrhea (ESAG) program integrates epidemiologic and treatment failure data into existing laboratory-based monitoring of antimicrobial-resistant N. gonorrhoeae. ESAG information enables early identification of drug-resistant gonorrhea and assists in identifying appropriate and effective treatment, which helps prevent its spread.

In Canada, multidrug-resistant cases of gonorrhea have increased between 2015 and 2019. N. gonorrhoeae was shown to be resistant to ciprofloxacin, erythromycin, penicillin, and tetracycline^{Footnote 10}.

Gonococcal azithromycin resistance and decreased susceptibility to cephalosporins are on the rise in Canada. Treatment failures have also been reported with the use of third generation oral^{Footnote 10Footnote 11} and injectable cephalosporins. Cases of gonorrhea with high-level resistance to both ceftriaxone and azithromycin have been reported in Canada, the United Kingdom, Australia and Hawaii^{Footnote 5Footnote 6Footnote 12Footnote 13}.

References