Can Mycoplasma Genitalium Be Dormant or Silent?

Quick answer: Mycoplasma genitalium doesn't go truly "dormant" the way herpes does, but it can live in the body silently for months or even years without symptoms. During that time you may feel completely fine yet still carry — and pass on — the infection. Only a test can confirm it.

Can Mycoplasma Genitalium Be Dormant?

Patients ask me this a lot, usually worried an old infection is "hiding." The honest answer: sort of, but "dormant" isn't quite the right word. Some viruses, like herpes, genuinely hide in the body and reactivate. Mgen is a bacterium and doesn't have that kind of latency. What it does do is persist as a silent, asymptomatic infection — sitting in the urogenital tract, often for a long stretch, without causing anything you'd notice.

So it isn't "sleeping" in the technical sense, but the lived experience is similar: you can carry Mgen for months or years, feel nothing, and only find out through testing.

How Long Can It Stay Silent?

There's no fixed number, but the research suggests months to years is possible, and plenty of people never develop symptoms at all. Because it's left off many standard panels, a quiet infection can easily go unnoticed until it either causes a problem or turns up on a test that specifically looks for it.

Can a Silent Infection Still Cause Harm?

Yes — and this is the part I want patients to take seriously. Even without symptoms, Mgen can:

• Spread to partners — you're contagious whether or not you feel anything.

• Lead to complications — in women, cervicitis and pelvic inflammatory disease; in men, urethritis. These can surface even after a long quiet period.

Can It "Come Back" After Treatment?

Two things get mistaken for a comeback:

• Reinfection — from an untreated partner. Common, and preventable by treating partners together.

• Treatment failure — because Mgen is often resistant, a course may not fully clear it and symptoms return. A test of cure catches this. See our treatment guide.

When to Get Tested

• Persistent or recurring urinary or genital symptoms.

• A partner who tested positive.

• Symptoms that linger after treatment for another STI like chlamydia.

Frequently Asked Questions

Can you have mycoplasma genitalium for years without knowing?
Yes. It often causes no symptoms and can persist quietly for a long time, which is why testing is the only reliable way to find it.

Is it contagious with no symptoms?
Yes — you can pass it to partners even when you feel completely fine.

Does it go away on its own?
It tends to persist rather than clear, and it can cause complications, so it shouldn't be left untreated once found.

The Bottom Line

Mgen doesn't truly go dormant, but it can live silently for a long time — contagious and capable of causing harm even when you feel fine. If there's any chance you've been exposed, you can get tested rather than waiting for symptoms that may never come. Curious how it compares to a similar infection? See Mgen vs. chlamydia.

Last reviewed: September 2026

Medical review: This article is for informational purposes only and does not constitute medical advice. Consult a provider about testing and treatment. Guidance is based on the CDC 2021 STI Treatment Guidelines and CDC STI information.