Screen by exposure site, not just urine. Self-collected vaginal, rectal and pharyngeal swabs are as sensitive as clinician-collected ones — urine alone misses most pharyngeal and rectal infections in men who have sex with men and sex workers.
Who to screen & how often
- Men who have sex with men: at least annually, 3-monthly if on PrEP or with multiple partners.
- Sex workers: 3-monthly comprehensive screening.
- Pregnancy: HIV, syphilis and hepatitis B at booking; chlamydia if under 30; repeat syphilis at 28 and 36 weeks if risk continues.
- Aboriginal and Torres Strait Islander people aged 15–29: annually in high-prevalence regions.
- Symptomatic patients or known contacts: test promptly, and consider same-day empirical treatment if the contact is high-risk.
Specimen collection
- First-pass urine for chlamydia/gonorrhoea NAAT in people with a penis; self-collected vaginal swab in people with a vagina.
- Self-collected vaginal, rectal and pharyngeal swabs have equal sensitivity to clinician-collected swabs.
- Serology: syphilis (RPR plus a treponemal test), HIV 4th-generation, hepatitis B and C — often from one blood draw; add hepatitis A serology if at risk.
- Throat and rectal swabs are essential in men who have sex with men and sex workers — urine/urethral testing alone misses a large share of infections at these sites.
Test window periods
- Chlamydia/gonorrhoea NAAT: reliable from 2 weeks post-exposure — consider empirical treatment first if a high-risk contact presents earlier.
- Syphilis serology: reliable from 4 weeks; repeat at 12 weeks if exposure was recent; repeat 3 months after treatment to confirm response.
- HIV 4th-generation: reliable from 45 days.
- Hepatitis C antibody: reliable from 12 weeks — use HCV RNA PCR earlier if acute infection is suspected.
Testing access & resources. No referral is required to request STI testing. Full testing algorithms and the standard asymptomatic check-up are at sti.guidelines.org.au (ASHM). Melbourne Sexual Health Centre (03) 9341 6200 for clinician advice.
Safety
- Test all exposed sites — urine alone will miss most pharyngeal and rectal infections in MSM and sex workers.
- Don't wait for serology to turn positive before treating a high-risk symptomatic contact — treat empirically if the picture fits.
- Confirm the window period before reassuring a recently-exposed patient — testing too early can give a false negative.
Red flags / refer
- A pregnant patient with a new STI diagnosis or reactive serology → urgent specialist/obstetric input.
- Suspected disseminated gonococcal infection, neurosyphilis, or diagnostic uncertainty → sexual health physician or infectious diseases.
- Recurrent or unclear results despite correct window-period testing → sexual health clinic referral.
ID-03 v1.0 · Reviewed Jun 2026 · Review Jun 2027
For health-professional use. Framework: ASHM/Australian STI Management Guidelines (sti.guidelines.org.au). Companion sheet: ID-03B STI Treatment & Partner Notification.
