What’s actually included in a full STI screen (and what’s left out)?

“Full STI screen” sounds like it should mean testing for everything. In practice it means something more specific: a well-chosen set of tests that catches the infections that matter most, done in a way that’s accurate and worthwhile. Just as telling is what a screen deliberately leaves out — and there are good reasons for that. Here’s exactly what a standard Australian STI screen includes, what it doesn’t, and how to know which tests you actually need.

What is a full STI screen?

A standard STI screen is the set of tests recommended for someone with no symptoms who wants to check their sexual health. It’s built around a simple principle: test for the infections that are common enough, serious enough, and treatable enough that finding them clearly helps. That’s why a screen isn’t an endless list — adding tests for rare or hard-to-interpret infections can create more confusion and worry than benefit. A good screen is targeted, not exhaustive.

It’s worth knowing that “full” can mean slightly different things depending on your situation. The core screen is the same for most people, but some groups need a few extra tests, and we’ll come to those below.

The standard screen: what’s tested

For most people, a standard asymptomatic screen in Australia covers five infections, through a combination of a blood test and a urine sample or swab.

The blood test checks for:

• HIV — using a combined antigen/antibody test
• syphilis — a bacterial infection that’s rising in Australia and easily missed without a blood test
• hepatitis B — a viral infection that can affect the liver.

The urine sample or swab checks for:

• chlamydia — Australia’s most commonly notified STI
• gonorrhoea — often silent, and increasingly resistant to antibiotics.

Chlamydia and gonorrhoea are detected with a NAAT (a sensitive DNA-based test), the same technology used for most modern STI testing. If you want to understand how those two compare, our guide to chlamydia vs gonorrhoea breaks it down. This five-infection core is what most people mean by a “full” screen, and it’s what our STI test covers.

How the samples are collected

Testing is more straightforward — and more private — than many people expect. There’s no need for an uncomfortable physical examination when you have no symptoms.

• Urine test: for chlamydia and gonorrhoea, men and women can often use a first-pass urine sample (the first part of the stream).
• Self-collected swab: women can take a quick vaginal swab themselves, which is as accurate as a clinician-taken one.
• Blood test: a single blood sample covers HIV, syphilis and hepatitis B.

For some people, swabs from the throat or rectum are added, because chlamydia and gonorrhoea can be carried at those sites without symptoms. More on who needs that below.

What’s left out of a standard screen, and why

This is where people are often surprised. Several well-known infections are not part of a routine screen — and in each case that’s a deliberate, evidence-based choice, not an oversight.

Mgen (Mycoplasma genitalium)

Mgen is common and behaves a lot like chlamydia, but guidelines specifically recommend against screening people with no symptoms. The main reason is antibiotic resistance: testing and treating silent infections would drive resistance without a clear benefit. It’s tested only when there are symptoms or a partner’s diagnosis. We cover this fully in what is Mgen.

Trichomoniasis (trich)

Trich is the world’s most common curable STI, but in most of urban Australia it’s genuinely uncommon. When an infection is rare in the general population, screening everyone turns up very few true cases and more false alarms, so testing is targeted to symptoms and higher-prevalence groups. See what is trich for the detail.

Herpes (HSV)

Many people assume a screen includes herpes. It usually doesn’t — and that catches people off guard. A herpes blood test is not recommended for people without symptoms, because it can’t tell you where an infection is or when you got it, it produces a meaningful number of false positives, and a positive result rarely changes what you’d do — while causing real distress. Herpes is best tested when there’s an active sore, by swabbing it directly. If that’s you, see our herpes test.

HPV and genital warts

There’s no routine STI-screen test for HPV in the general population. Most HPV clears on its own, and there’s no useful “do I have it” test for people without symptoms. The oncogenic (cancer-causing) types are managed separately through cervical screening for people with a cervix, and visible warts are diagnosed by simply looking, not by a lab test.

Tests some people need on top of the standard screen

The core screen suits most people, but a genuinely “full” check-up is the one matched to your risk. Depending on your circumstances, a Specialist GP may recommend adding:

• Throat and rectal swabs — for anyone having oral or anal sex, since chlamydia and gonorrhoea are often carried silently at those sites. This is routine for gay and bisexual men.
• Hepatitis C — recommended for people who inject drugs, some men who have sex with men, and others with specific risk factors.
• More frequent testing — every 3 months rather than annually for people with higher exposure, such as those on HIV PrEP or with multiple partners.
• Trichomoniasis — in communities where it’s more common, or when there are symptoms.

Pregnancy also changes the picture: testing is recommended in pregnancy because some infections can affect the baby, as we explain in chlamydia and pregnancy.

Timing and window periods

One thing a screen can’t do is detect an infection you caught yesterday. Every test has a window period — the gap between exposure and when a test can reliably pick the infection up. Chlamydia and gonorrhoea can usually be detected within about two weeks, while HIV and syphilis can take longer, up to around six to twelve weeks for full reassurance.

In practice this means two things. If you’ve had a recent risk, a screen still makes sense now, but you may be advised to repeat one or two tests a few weeks later to be sure. And a clear result reflects your exposures up to the window period — not necessarily the encounter last weekend. If you have symptoms, don’t wait for a window period; get seen promptly, and read what to do if you have an STI.

How to get a screen

A standard screen is quick, confidential and, through Clinic365, bulk-billed. You can do it by telehealth from anywhere in Australia: a Specialist GP checks what you need, arranges the pathology, and you attend a local collection centre (or use a self-collection option) before getting your results by SMS. If anything comes back positive, treatment and partner notification are handled discreetly.

The takeaway: a “full” STI screen isn’t about testing for every infection that exists — it’s about testing for the right ones, in the right way, for you. For most people that’s the standard five, with a few additions based on your history. If you’re unsure what applies to you, that’s exactly the kind of thing a Specialist GP can sort out in a few minutes.