Order Guide: STI Testing

The following section outlines common incubation periods and appropriate early intervals for testing, and re-testing after treatment. If you get tested too early, a negative test result is not reliable and you may have repeat testing to ensure a valid result. Engaging in sexual activity if you are premature in testing may mean transmitting an STI unknowingly. We hope you use the guide below for choosing a time that is appropriate for you.
If you are providing a urine sample for STI testing, for improved detection, please provide the 1st catch (1st part of the stream) after holding your urine for 2 hours.
Please note that urine PCR testing for gonorrhea, chlamydia and trichomonas only tests for those organisms in the site tested (i.e. genital infection). These tests do not test for them in other areas like the throat or rectum. Special swabs are available for testing in these areas.

A window period represents the time after being exposed to an infection before a test can become positive. Testing too early can result in a false negative result. We recommend repeat testing after the window period has closed, and in the case of HIV after 12 weeks from the exposure to the individual.
Chlamydia
  • Window Period for testing: 7 – 14 days after exposure
  • Test of cure: repeat a test of cure 3 weeks after treatment to ensure clearance.
  • Resumption of sexual activity: you and your partner(s) should abstain from intercourse for 7 days after treatment is completed for all partners, and until all symptoms have resolved for all individuals.
  • Treatment:
    • 1st Line: Doxycycline 100mg tablets taken twice daily for 7 days (preferred)
    • 1st Line: Azithromycin 4 x 250mg tablets taken as a single dose (pregnancy)
Gonorrhea
  • Window Period for testing: 7 days – 14 days after exposure
  • Test of cure: repeat a test 3 weeks after treatment to ensure clearance
  • Resumption of sexual activity: you and your partner(s) should abstain from intercourse for 7 days after treatment is completed for all partners, and until all symptoms have resolved for all individuals.
  • Treatment:
    • 1st Line: Ceftriaxone 0.25g (Injection) + Azithromycin 4 x 250mg (pill) taken as a single dose (preferred)
    • 2nd Line: Cefixine 800mg (pill) + Azithromycin 4 x 250mg (pill) taken as a single dose
Trichomoniasis
  • Window Period for testing: 7 days – 30 days after exposure
  • Test of cure: repeat a test 3 months after treatment to ensure clearance.
  • Resumption of sexual activity: you and your partner(s) should abstain from intercourse for 7 days after treatment is completed for all partners, and until all symptoms have resolved for all individuals.
  • Treatment:
    • 1st line: Metronidazole 500mg tablet twice daily for 7 days
Syphilis
  • Window Period for testing: 30 days – 90 days after exposure
  • Test of cure: repeat a test at 12 weeks to ensure clearance.
  • Resumption of sexual activity: transmission only occurs when the infected individual has oral or skin lesions. We recommend a clearance of the infection and guidance from an infectious disease specialist before the resumption of sexual activity. All partners should be tested and seek medical care.
Rectal and Throat Gonorrhea and Chlamydia
  • Urine PCR testing specifically tests for exposure to gonorrhea and chlamydia in the urinary/vaginal tracts. It does NOT provide a diagnosis about oral or rectal gonorrhea.
  • Testing is recommended only for individuals who have had unprotected site exposure & have at least one of the following risk factors:
    • Gay, bisexual, or men who have sex with men, including trans-women
    • Engage in sex work or have had sexual contact with someone engaging in sex work
    • Known contact of those infected with chlamydia or gonorrhea
    • Signs or symptoms of rectal infection (constipation, anal discharge, urgency to have a bowel movement) following unprotected sex
    • Signs or symptoms of oral or pharyngeal infection (throat pain) following unprotected performative oral sex
HIV
Public Health Laboratories in canada use a 4th generation screening test which looks for p24 antigen (HIV protein) and antibodies. HIV can be detected in 50% of people by day 18, and 99% of people by day 44 (6.5 weeks). The p24 antigen is detectable in blood before HIV antibodies. Most people will get accurate results by 4 weeks after an exposure, but it is important to test again at the end of the window period to rule out an infection.
  • Window Period for testing: 14 days and 90 days
  • Confirmatory test: 12 weeks
Hepatitis B
  • Window Period for testing: 21 days – 42 days after exposure
  • Test of cure: while your immune system may clear Hepatitis B, your antibody test will remain positive for life. We advise you to seek treatment with an infectious disease specialist if you test positive for guidance regarding treatment options.
  • Resumption of sexual activity: we recommend guidance from an infectious disease specialist before resuming sexual activity. Factors include your partner(s) immunity status and your viral load.
Hepatitis C
· Window Period for testing: 60 days – 180 days after exposure
· Test of cure: while your immune system may clear Hepatitis C, your antibody test will remain positive for life. We advise you to seek treatment with an infectious disease specialist if you test positive for guidance regarding treatment options.
· Resumption of sexual activity: we recommend guidance from an infectious disease specialist before resuming sexual activity. Factors include your partner(s) immunity status and your viral load.
HIV
· Window Period for testing: 9 days – 12 weeks after exposure, depending on the test used by the laboratory. If you believed you were exposed to someone with HIV, we suggest seeking care with a health care provider for post-exposure prophylaxis (PEP) evaluation at an emergency room or walk-in clinic. We always recommend repeat testing for HIV at 12 weeks to confirm a negative result is a true negative test.
· Test of cure: HIV cannot be cured at present time, however, we recommend ongoing surveillance and treatment with an HIV specialist in your area.
Herpes
· Window Period for testing: 30 days – 180 weeks after exposure via blood testing; active genital or oral sores can be swabbed if you have an outbreak at a local walk-in clinic or urgent care center immediately.
· Test of cure: your antibody test will remain positive for life. If you are experiencing multiple recurrent outbreaks, you may qualify for suppressive therapy and we suggest seeking care with a local walk-in clinic or urgent care center.
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