What Is a Ureaplasma Spp. NAA Test?

A Ureaplasma spp. NAA test checks a urine or genital swab sample for the genetic material of ureaplasma, a tiny bacterium of the genital and urinary tract. Unlike a chlamydia test, a positive result doesn’t settle much on its own, because ureaplasma is commonly found in healthy sexually active adults who have no disease.¹ Your doctor treats the result as one clue, weighed alongside your symptoms and situation, not as a diagnosis by itself.

How the Ureaplasma DNA Test Works

NAA stands for nucleic acid amplification. The lab makes millions of copies of a stretch of the bacterium’s DNA until it’s abundant enough to detect, so even a very small amount of ureaplasma in a sample can be picked up.² The “spp.” on your order means the test looks for the ureaplasma group as a whole, which in people mainly means two species, Ureaplasma urealyticum and Ureaplasma parvum.³ Some versions report which of the two species is present, and that is the preferred approach.⁴

The older method, culture, grows the bacteria from the sample and can take two to five days.⁵ DNA tests usually return results within about 24 hours.⁶ In direct comparisons the DNA test caught about 95% of infections found either way, while culture missed more.⁷ Culture also can’t tell the two species apart, and it can be spoiled when other bacteria overgrow the sample.⁸

On your report, the result line usually reads “detected” or “not detected.” Some reports list U. urealyticum and U. parvum separately. “Not detected” means no ureaplasma DNA was found in that sample.

This test also differs from a standard STI panel. Ureaplasma is often ordered separately or as part of a broader mycoplasma panel. A negative routine STI screen doesn’t mean ureaplasma was checked.

What the Sample Collection Involves

The test can be run on first-void urine, which is the first part of the stream, or on vaginal, cervical, or urethral swabs.⁹ For symptoms at other sites, doctors can test rectal or throat swabs, sometimes alongside other STI tests from the same sample.¹⁰ In rare cases, such as joint infection in people with weak immune systems, joint fluid can be tested.¹¹

For a first-void urine sample, not urinating for about an hour or more beforehand is commonly advised, so enough bacteria collect in the urethra. You catch the first part of the stream, not a midstream sample as with other urine tests. Labs vary, so follow your clinic’s own timing instructions.

Swabs are quick. Vaginal swabs are often self-collected. Cervical swabs are taken during a speculum exam, much like a Pap test. A urethral swab in men can sting briefly.

What a Positive Result Means

Estimates of how many sexually active people carry ureaplasma without symptoms range widely, from about 1 in 10 to 8 in 10.¹² A positive in someone without symptoms is therefore often just a normal resident.

Species and amount matter more than a simple yes or no. Some DNA tests also estimate how much bacteria is in the sample, called the bacterial load, which culture cannot do.¹³ Men with unexplained urethritis had higher loads of U. urealyticum than men without it, but U. parvum loads didn’t differ.¹⁴ Women with cervical inflammation and no other cause had higher loads of both species than women without it.¹⁵ Still, no agreed cutoff exists for how much ureaplasma counts as clinically meaningful.¹⁶

A positive doesn’t prove ureaplasma caused your symptoms. It isn’t treated the same way as a positive chlamydia test. If you have symptoms, ask whether other causes were tested and ruled out.

Why Doctors Order the Test

Major US and international guidelines don’t recommend testing people without symptoms for ureaplasma.¹⁷¹⁸ Testing is usually driven by symptoms, a doctor’s judgment, pregnancy, or recurring unexplained urinary or genital symptoms.¹⁹

Doctors may test men with nongonococcal urethritis, which is inflammation of the tube carrying urine that isn’t caused by gonorrhea.²⁰ Pooled data found U. urealyticum more often in these men than in men without symptoms, about 18% versus 14%.²¹ U. parvum wasn’t linked to urethritis and is not thought to cause it.²²²³

For women, evidence that ureaplasma causes cervicitis, pelvic infection, infertility, or genital discomfort is limited and conflicting.²⁴ In pregnancy, though, testing positive has been linked to roughly 2 to 3 times higher odds of preterm birth, early waters breaking, and infection of the membranes around the baby.²⁵ It has also been linked to a lung disease in premature babies.²⁶²⁷ And women with repeated miscarriages carried ureaplasma more often than other women, about 16% versus 10%.²⁸

These pregnancy links come from studies comparing groups, so ureaplasma may be a marker rather than the trigger. That’s why doctors don’t test or treat every pregnant woman. Women with a history of preterm birth or miscarriage are more likely to be offered testing.

Treatment After a Positive Test

Ureaplasma has no cell wall, so penicillins and cephalosporins don’t work against it.²⁹ Ureaplasma may also explain urethritis that didn’t respond to a penicillin-type drug, so tell your doctor which antibiotics you already took. It does respond to tetracyclines like doxycycline, macrolides like azithromycin or erythromycin, and quinolones.³⁰ In one group of women with repeated miscarriage, over 95% cleared ureaplasma after treatment, and 76% then had a live birth.³¹

Resistance shapes the choice. Resistance to quinolones such as levofloxacin is common in some regions, around half to over 80% of samples in Chinese studies.³²³³ Resistance to erythromycin stayed low, under 6%.³⁴³⁵ About 1 in 5 samples from infertile men resisted tetracycline.³⁶ If symptoms persist after one antibiotic, a different class may be tried.

If you’re treated for symptoms, doctors may suggest a partner be evaluated, and you should avoid sex until treatment is finished. A repeat test is sometimes used to confirm clearance, especially in pregnancy planning. Treating carriers without symptoms is generally not recommended.

Other Infections Tested Alongside Ureaplasma

Ureaplasma can show up alongside chlamydia, Mycoplasma genitalium, and Mycoplasma hominis in the same person.³⁷ In pregnant women carrying ureaplasma, nearly 8 in 10 also had Gardnerella, a bacterium tied to bacterial vaginosis.³⁸

Mycoplasma genitalium matters more. It is a better-established cause of urethritis and cervicitis, and a panel may report it right next to ureaplasma. A positive for it is usually treated even if ureaplasma is ignored.