Persistent or recurrent NGU is urethritis that comes back or never fully clears after a first round of antibiotics. The usual culprits are an untreated partner who reinfects you, or a harder-to-kill organism like Mycoplasma genitalium. The fix is to re-confirm the inflammation is real, test for resistant bugs, treat both you and your partner, and use condoms.
with the right treatment
testing, not symptoms, decides
| Item | Value |
|---|---|
| Curable? | yes — with the right treatment |
| Tested by | NAAT / lab |
| Often | no symptoms |
| If you may have it | get tested — testing, not symptoms, decides |
The essentials
NGU (nongonococcal urethritis) is inflammation of the urethra that isn't caused by gonorrhea. It's a syndrome rather than a single infection, so it sometimes refuses to go away. Several different organisms can produce identical symptoms: Chlamydia trachomatis, Mycoplasma genitalium, sometimes Trichomonas vaginalis, herpes simplex virus, or adenovirus. In about half of cases no organism is ever identified CDC, 2021. You can read more about what drives it on our page covering ngu causes.
"Persistent" means symptoms that never resolved after a full, correctly taken course of treatment. "Recurrent" means symptoms that cleared and then returned. The two most common reasons are the same ones a clinician thinks about first: you were reinfected by an untreated partner, or your infection was caused by an organism the first antibiotic doesn't reliably cure. M. genitalium is the classic example. It's slow-growing, often doesn't respond fully to a standard course, and has developed resistance to several drugs.
Symptoms of persistent or recurrent NGU
The symptoms look the same the second time around as the first. NGU mainly presents in people with a penis, and some infections cause no symptoms at all, which is part of why reinfection cycles are so easy to miss.
- Urethral discharge, which can be mucoid (thin and cloudy) or purulent (thick and pus-like).
- Painful or burning urination (dysuria), often described as stinging at the tip.
- Urethral itching or irritation inside the penis between urinations.
If your symptoms resolved and then came back weeks later, think reinfection, most often from a partner who was never treated. If they never really went away, the question becomes whether the original diagnosis was right, whether you finished the medication, or whether a resistant organism is in play. A clinician needs to distinguish between true ongoing infection and lingering inflammation that takes time to settle even after the bug is gone.
How persistent NGU is tested
The first job is to confirm there's still real urethritis and not just anxiety about a symptom that's fading. Treating someone who no longer has objective inflammation just exposes them to antibiotics for nothing. Diagnosis requires objective evidence: a Gram stain showing at least two white blood cells per oil-immersion field with no gonococci, or a positive leukocyte esterase test or at least ten white blood cells per high-power field on a first-void urine sample.
On top of that, you get a NAAT (nucleic acid amplification test) for chlamydia and gonorrhea, and in persistent cases, testing for M. genitalium specifically. That last test changes management, because a positive result points to a different drug entirely. Where available, resistance or macrolide-mutation testing for M. genitalium helps guide which antibiotic will work.
In practice this is straightforward. Most of these tests come from a urine cup, a self-collected swab, or a quick exam, with results usually back in a few days. You don't need anything elaborate, and it's free or low-cost at health departments, Planned Parenthood, and Title X clinics. If you're unsure how soon a test will be accurate after a new exposure, see our guide on when to test after exposure, or just go ahead and get tested.
Treatment for persistent or recurrent NGU
For a first episode of NGU, the recommended treatment is doxycycline 100 mg orally twice daily for seven days, chosen over single-dose azithromycin because it produces better outcomes and less resistance. A single 1 g dose of azithromycin is the alternative. When NGU persists or recurs, the approach changes: a clinician re-confirms urethritis and tests for M. genitalium. If that's positive, the regimen is doxycycline followed by moxifloxacin 400 mg once daily for seven days. The order matters because doxycycline lowers the organism load first and moxifloxacin clears what remains.
Whatever course you're given, finish all of it even once you feel better. Stopping early is one of the most common reasons NGU bounces back, and it breeds the resistant infections that are so hard to treat the next time. For the full breakdown of drugs and dosing, see our dedicated page on ngu treatment.
| Scenario | What the clinician does | Typical regimen |
|---|---|---|
| First episode NGU | Confirm urethritis, NAAT for chlamydia & gonorrhea | Doxycycline 100 mg twice daily for 7 days (azithromycin 1 g single dose is the alternative) |
| Persistent / recurrent NGU | Re-confirm urethritis, test for M. genitalium | If M. genitalium positive: doxycycline followed by moxifloxacin 400 mg daily for 7 days |
| Reinfection suspected | Treat the partner; retreat the patient for the same organism | Match the regimen to the confirmed organism |
The single biggest treatment mistake in recurrent NGU has nothing to do with the pills. It's an untreated partner. If your partner was never evaluated and treated, you'll keep passing the same infection back and forth no matter how perfect your own course was. Always ask whether your partner needs treating.
Preventing reinfection
Recurrent NGU is mostly about breaking the reinfection cycle. Refer all sex partners from the prior 60 days for evaluation, testing, and presumptive treatment effective against chlamydia, and avoid sex with those partners until everyone has completed treatment. Skip this step and you end up on a second and third round of antibiotics for what is really the same untreated source.
- Use condoms every time, which lowers risk for the sexually transmitted causes of NGU.
- Make sure recent partners are evaluated and treated so you don't reinfect each other.
- Test routinely, since some of these infections cause no symptoms and circulate silently.
- Wait until both you and your partner have finished treatment before having sex again.
When to see a clinician
See a clinician if your symptoms didn't clear after finishing a full course of antibiotics, if they cleared and came back, or if you have ongoing discharge, burning, or urethral irritation. Bring details: what you were treated with, whether you took every dose, and whether your partner was treated. That history lets the clinician decide whether you're dealing with reinfection, a resistant organism, or residual inflammation, and steers them toward the right test rather than just repeating the same drug.
A persistent NGU diagnosis is common and treatable. Clinics handle it daily. Needing a second round of testing or a different antibiotic says nothing about you as a person; it's a sign the infection was a tougher type or that the chain of transmission wasn't fully broken the first time.