Non-Specific Urethritis (NSU)

Non-specific urethritis (NSU) is a sexually transmitted disease which causes inflammation of the urethra -- in NSU, no pathogen is identified.

Symptoms
The symptoms of urethritis can include pain or a burning sensation upon urination (dysuria), a white/cloudy discharge and a feeling that you need to pass urine frequently, however there are often no symptoms.

Causes
Urethritis can be caused by a number of organisms, including Neisseria gonorrheae, Chlamydia trachomatis, Ureaplasma urealyticum, Mycoplasma genitalium, Trichomonas vaginalis, Herpes simplex virus, and Candida albicans, and by a number of non-infectious causes, including urethral stricture, foreign bodies, trauma, Reiter's syndrome, and various autoimmune and allergic conditions.

Of these many causes, the vast preponderance of cases are due to either gonorrhea or chlamydia. It is currently estimated that 50% of non-gonoccocal urethritis cases are caused by chlamydia, with the remainder due to other causes.

Diagnosis
Historically, it has been easy to test for the presence of gonorrhea by viewing a Gram's stain of the urethral discharge under a microscope: the causative organism is distinctive in appearance. Thus, one of the major causes of urethritis can be identified by a simple common test, and the distinction between gonococcal and non-gonococcal urethritis arose historically for this reason.

Identifying chlamydia, the other major cause of urethritis, has required more sophisticated technology, but is now more widely available. These two tests combined identify the cause of most treatable forms of urethritis.

If tests for gonorrhea and chlamydia are negative, and the cause of the urethritis has not been otherwise identified, the term non-specific urethritis (NSU) is used.

Treatment
Treatment is based on the prescription and use of the proper antibiotics depending on the strain of the ureaplasma.

Because of its multi-causative nature, initial treatment strategies involve using a broad range antibiotic that is effective against chlamydia (such as doxycycline). It is imperative that both the patient and any sexual contacts are treated. Women who are infected with the organisms that cause non-gonococcal urethritis may develop pelvic inflammatory disease. If symptoms persist, follow-up with a urologist may be necessary to identify the cause.

If left untreated, complications can include epididymitis and infertility. Consistent and correct use of latex condoms during sexual activity greatly reduces the likelihood of infection.

Related topics
* Sexual Health Advice & Leaflets