Chlamydia & Gonorrhoeae Test

Chlamydia and gonorrhea are the two most frequently reported bacterial sexually transmitted infections, and the majority of people who carry them have no idea. Between 86% and 93% of urogenital gonorrhea infections in women produce no symptoms. Chlamydia is similarly silent. Left undetected, both infections can quietly cause lasting damage to your reproductive tract, and the only way to know for certain whether you are carrying either one is to test.

This test uses a technology called NAAT (nucleic acid amplification testing), which searches your sample for tiny fragments of RNA specific to Chlamydia trachomatis and Neisseria gonorrhoeae. It does not measure a protein or a hormone that rises and falls on a spectrum. It answers a binary question: are these bacteria present in your body right now, yes or no? That simplicity is its strength. With sensitivity above 90% and specificity above 98%, it is the most accurate method available for detecting these infections.

Why These Infections Matter

The danger of chlamydia and gonorrhea is not the infection itself, which is easily treated with antibiotics. The danger is what happens when infections go undetected. Weeks or months of silent bacterial activity can trigger inflammation in the reproductive tract, leading to scarring that blocks fallopian tubes, disrupts fertility, or increases the risk of a pregnancy implanting outside the uterus (ectopic pregnancy).

These are not rare outcomes. The research paints a clear picture of what untreated infection costs.

Pelvic Inflammatory Disease

Pelvic inflammatory disease (PID) occurs when bacteria spread from the cervix into the uterus, fallopian tubes, or surrounding tissue. It is the most direct complication of untreated chlamydia and gonorrhea, and it can cause chronic pelvic pain, scarring, and infertility.

Sources: Alexiou et al. (2024), Reekie et al. (2018), Gardella et al. (2024).

What this means for you: gonorrhea appears to carry a substantially higher PID risk than chlamydia alone. But the key takeaway is that both infections, when left untreated, create a measurable increase in the chance of serious reproductive harm. Screening catches the infection before the damage starts.

Fertility and Ectopic Pregnancy

The long-term reproductive consequences extend well beyond PID. In the Dutch cohort that tracked 5,704 women for up to 14 years, women with prior chlamydia infection were about 2.75 times as likely to develop tubal factor infertility (scarring that blocks the fallopian tubes) and about 1.84 times as likely to have an ectopic pregnancy compared to women who had never been infected.

In the US veterans cohort, a positive chlamydia or gonorrhea test was associated with about 1.11 times the risk of infertility and about 1.14 times the risk of ectopic pregnancy. Women with repeat positive tests had even higher risks. These numbers reinforce a straightforward conclusion: detecting and treating the infection early is the most direct way to protect future fertility.

How the Test Works

This is a combined NAAT that screens for both Chlamydia trachomatis and Neisseria gonorrhoeae in a single test. The lab amplifies bacterial RNA from your sample, making it possible to detect even very small amounts of these organisms. Results are reported as "detected" or "not detected" for each pathogen. There is no scale, no reference range, and no gray zone in most cases.

Preferred specimen types differ by sex. For women, a vaginal swab (either self-collected or clinician-collected) is the most sensitive option. For men, a urine sample works well. For anyone who has had oral or anal sexual contact, throat and rectal swabs are recommended in addition to the standard specimen, because infection at these sites is common and almost always asymptomatic.

When Results Can Be Misleading

While this test is highly accurate, a few situations can produce results that do not reflect your true infection status.

• Testing too soon after treatment: The test detects bacterial RNA, including fragments from dead bacteria. If you retest within about three weeks of completing treatment for chlamydia, residual RNA can trigger a positive result even though the infection has been cleared. For gonorrhea, most people clear detectable RNA within 2 to 3 days, with over 95% clearing by 12 days.
• Low-positive signal values: Some samples produce a weak positive signal that sits near the threshold between positive and negative. One study found that only about 81% of low-positive chlamydia samples and 33% of low-positive gonorrhea samples retested as positive. If your result falls in this zone, your lab or clinician may recommend confirmatory testing.
• Throat swabs for gonorrhea: The throat naturally harbors bacteria closely related to Neisseria gonorrhoeae. Certain test platforms can mistake these harmless relatives for the real thing. Cross-reactivity rates on older test platforms ran as high as 11 to 14%, though newer assays have reduced this to 1 to 2%.
• Urine samples during pregnancy: Substances in urine, including certain crystals and proteins, can interfere with the amplification process and produce false-negative results. Inhibition rates in pregnant women reached about 10% in one study, compared to about 3% in non-pregnant women.

Understanding Your Result

This test does not use traditional reference ranges with optimal, borderline, and elevated tiers. It reports a simple binary: detected or not detected.

Any detection means treatment is needed. There is no concept of a "mild" or "borderline" positive for a bacterial infection. The test identifies the presence of the organism, and antibiotics clear it.

Why Repeat Screening Matters More Than a Single Test

A negative result today does not guarantee you are protected next month. These infections can be acquired at any point of sexual contact, and re-infection after successful treatment is common. In the US veterans cohort, women with more than one positive test over the follow-up period had higher risks of PID and infertility than those with a single positive test.

Current guidelines recommend annual screening for all sexually active women aged 25 and under, and for older women with risk factors such as new or multiple sexual partners. Men who have sex with men should be screened at least annually at all sites of exposure (urogenital, rectal, and pharyngeal), and every 3 to 6 months if they have multiple partners or use pre-exposure prophylaxis for HIV.

If you test positive and complete treatment, you should be rescreened about 3 months later to catch reinfection, which is common. A single negative test is reassuring for that moment in time, but regular rescreening is the only way to catch new infections before they cause harm. For anyone who is sexually active with more than one partner, think of this test as part of a routine check, not a one-time event.