Canadian Guidelines on Sexually Transmitted Infections: Summary of Recommendations for Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and Syphilis
Tips for STI screening, treatment and follow-up
Reported cases of STI in Canada are increasing (2016)
121,244 cases of Chlamydia trachomatis (CT)
- 76% of cases are aged 15 to 29
- The highest increase in rates is in adults over 40
23,708 cases of Neisseria gonorrhoeae (NG)
- 57% of cases are aged 15 to 29
- The highest increase in rates is in adults over 30
3,829 cases of infectious Syphilis
- 92% of cases are men

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Organization: Public Health Agency of Canada
Published: 2019-02-20
Do you know if the person in front of you has ever been screened for sexually transmitted infections (STI)?
In 2018, over 60% of Canadians reported that they had never been screened for STI.
Normalize discussions about sexual health and offer STI screening to sexually active people as part of routine care.
STI screening provides an opportunity to discuss transmission, signs and symptoms, risk reduction and preventive measures.
Prenatal Screening
- Screen at first prenatal visit and repeat based on risk factors
- Consider repeat screening for syphilis in areas experiencing heterosexual outbreaks, regardless of risk factors
Risk Factor Screening
- ≥ 25 years old
- Offer screening and repeat screening based on risk factors
Annual Screening Footnote +
- < 25 years old
- Gay, bisexual, and other men who have sex with men (gbMSM) and transgender populations
More frequent STI screening may be appropriate for individuals with behavioural risk factors.
Behavioural risk factors for STI acquisition include but are not limited to: previous STI diagnosis, new sexual partner, multiple or anonymous sexual partners, sexual partner(s) having a STI, condomless sex and sex while under the influence of alcohol or drugs.
STI are often asymptomatic. Screen for one STI, screen for all!
Screening: Early STI detection in asymptomatic individualsFootnote †

Figure 1 - Text Equivalent
Image 1 depicts a flow chart of the different specimens and laboratory tests that may be used for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) screening. First void urine samples can be tested for CT and NG using Nucleic Acid Amplification Testing (NAAT). Urethral, vaginal or cervical swabs can be tested for CT and NG using NAAT and/or culture for NG. Rectal or pharyngeal swabs can be tested for CT and NG using NAAT, if available, and/or culture.
Tips
- Nucleic Acid Amplification Test (NAAT) is highly sensitive and the test of choice when screening asymptomatic individuals for CT and NG
- Preferred specimens for NAAT are first void urine or self-collected vaginal swab
- Collect pharyngeal and rectal specimens from individuals with a history of performing oral sex or having receptive anal intercourse, respectively
- Check with your laboratory for the availability of NAAT for rectal and pharyngeal specimens
- Collect specimens for both CT and NG due to high rates of co-infection
- When NG is suspected, collect specimens for NAAT AND culture
- Culture permits antimicrobial susceptibility testing to guide treatment
- Ideally, collect specimens prior to empirical/epidemiological treatment

Figure 2 - Text Equivalent
Image 2 depicts the flow chart of syphilis screening using blood samples. Laboratories will use blood samples to perform syphilis serology using an algorithm combining non-treponemal and treponemal tests.
Tips
- Testing algorithms may vary by province and territory
Offer HIV testing when screening for other STIFootnote †
Early diagnosis and treatment lead to better health outcomes
Chlamydia trachomatis (CT) | Neisseria gonorrhoeae (NG) | Syphilis |
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OR
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For anogenital and pharyngeal infections
OR For anogenital infections
Note: Cefixime is considered alternate treatment in gbMSM |
For infectious syphilis (primary, secondary and early latent)
For late latent syphilis
|
Tips
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Tips
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Chlamydia trachomatis (CT) | Neisseria gonorrhoeae (NG) | Syphilis |
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TOC using NAAT 3 - 4 weeks after the completion of treatment is recommended only when:
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Routine TOC is recommended:
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Indications for post-treatment monitoring and follow-up serology:
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Tips
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Tips
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Consult the Canadian Guidelines on Sexually Transmitted Infections for more detailed information.
Recommendations do not supersede any provincial/territorial legislative, regulatory, policy and practice requirements or professional guidelines that govern the practice of health professionals in their respective jurisdictions, whose recommendations may differ due to local epidemiology or context.
Additional info:
- Canadian Guidelines on Sexually Transmitted Infections (PHAC)
- HIV Fact Sheet: Screening and Testing (PHAC)
- Discussing sexual health, harm reduction and STBBIs: A guide for service providers (CPHA)
- Reducing stigma and discrimination through the protection of privacy and confidentiality (CPHA)
Learn more: visit Canada.ca and search Sexual Health or download the Canadian STI guidelines mobile application.
Footnotes
- Footnote 1
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Offer more frequent screening based on risk factors
- Footnote 2
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For HIV specific guidance consult the HIV Factsheet: Screening and Testing available on Canada.ca
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