Non specific urethritis persistent or recurrent NSU


Non-specific urethritis (NSU) has a very broad meaning. It used to apply to any urethritis, which is not gonococcal in origin (also referred to as non-gonococcal urethritis [NGU]). However, since chlamydia can now be diagnosed specifically, NSU, in these guidelines, refers to causes of urethritis where gonorrhoea and chlamydia have been excluded, and where there are > 5 WBC/HPF on microscopy.

It is assumed that the patient presenting with a discharge has already had treatment for gonorrhoea and/or chlamydia as per the management of discharge. If the patient is no longer symptomatic following treatment no further treatment is required at follow-up.

For the management of men with a discharge at first presentation, see Urethral discharge dysuria.

It is important that the partner is also tested and treated.

Clinical presentation
  • a clear or muco-purulent scanty to copious discharge from the penis, which can range from persistent to intermittent
  • pain on passing urine
  • Discomfort or irritation at the meatus.
  • non-compliance with treatment
  • reinfection – partners not investigated and/or treated
  • squeezing – ongoing mechanical irritation of the urethra
  • undetected trichomoniasis
  • azithromycin resistant strain of Mycoplasma genitalium, or possibly Ureaplasma urealyticum or Mycoplasma genitalium
  • other infective causes, e.g. HSV, adenovirus, meatal Candida.
  • Urethral culture or NAAT for Ureaplasma urealyticum and Mycoplasma genitalium. However, Ureaplasma can be found in 30 per cent of men as a commensal and therefore, may not be the cause of the symptoms.
  • Trichomonas vaginalis endourethral culture or NAAT where available
  • Herpes endourethral culture or NAAT.

Note: Tests should be done on a swab taken from the discharge or from FVU, not from a urethral swab taken in the absence of discharge.


Treatment depends upon what treatment has been given previously.

  • Doxycycline 100 mg orally, 12-hourly for 2 weeks


  • roxythromycin 300 mg orally, daily for 2 weeks


  • metronidazole 2 g orally, as a single dose


  • tinidazole 2 g orally, as a single dose.

Provide herpes treatment if appropriate.

Patients may require longer therapy.

Advise avoidance of alcohol with either metronidazole or tinidazole treatment.

Resistant Mycoplasma genitalium should be referred to a sexual health physician for review. 


Medicines in pregnancy.

Related links

Management of partners
Female sexual partners should be tested and treated for presumed cervicitis – the female equivalent of NSU. The term non-specific genital infection, which applies to both these conditions, is rarely used.
  • Patients need to be reviewed to ensure symptoms have resolved.
  • Review after treatment for clinical evidence of treatment success and test of cure culture of any causative organism.
  • If possible, also review partners' management if the index case remains symptomatic with no cause evident.
  • Consider referral to or review by a sexual health physician in persistent cases.

Until post-treatment review, ask patients to avoid:

  • sexual intercourse (even with a condom)
  • squeezing of the penis and self-examination.

Review one to two weeks after cessation of treatment:

  • assess resolution of signs and symptoms
  • review success of contact tracing.
Public health issues

This is not a notifiable disease.

Contact tracing and further counselling are important.

Always test for other STIs.