URETHRITIS

 

Urethritis is a commonly occurring sexually transmitted disease. Two separate clinical entities, Gonococcal urethritis (GU) and Non-gonococcal urethritis (NGU) are recognised. Urethritis is readily treatable with a short course of antibiotics. The complications of urethritis include urethral stricture disease and infertility for female sexual contacts.

 

Gonococcal urethritis (GU) caused by Neisseria gonorrhoeae is the commonest clinical infection of the urethra. Nongonococcal urethritis (NGU) is caused by a variety of organisms, Chlamydia trachomatis being the most prevalent. Accurate diagnosis of the cause of urethritis requires the taking of a urethral swab. Urethral swabbing should be done at least an hour but preferably four hours after the last micturition, to ensure that the organism cultured originates from the urethra and not the bladder. As many as 40% of men with GU will also have Chlamydial urethritis, therefore treatment of urethritis should cover both GU and NGU. Intramuscular ceftriaxone (125 mg) or oral fluoroquinolone (500 mg ciprofloxacin or 400 mg ofloxacin) will eradicate gonococcal urethritis. Azithromycin (1 g per os) or doxycycline (100 mg BD per os) is given to eradicate nongonococcal pathogens. Identification and treatment of sexual partners is important, since these may continue to be carriers of the disease and cause reinfection of the patient. Pelvic inflammatory disease and infertility are possible consequences for female sexual partners. Urethral stricture disease is a possible long-term complication of urethritis in men. The use of condoms during intercourse is a successful way of preventing urethritis and other sexually transmitted diseases.  

 

Urethritis caused by Neisseria gonorrhoeae (GU) is the commonest clinical infection of the urethra. N. gonorrhoeae is an intracellular gram-negative diplococcus. The incubation period is 3-10 days but may be as short as 12 hours or as long as 3 months. The clinical picture is usually a complaint of urethral burning during micturition coupled with a purulent urethral discharge. The chance of contracting GU after a single sexual exposure with a carrier is 17%. Up to 40-60% of carriers of the disease may be asymptomatic. Without treatment, GU is usually self-limiting, taking as long as 6 weeks to clear up.

 

Nongonococcal urethritis (NGU) is caused by a variety of organisms, Chlamydia trachomatis being the most prevalent (30-50% of NGU). The incubation period is usually 1-5 weeks and clinical findings are urethral burning on micturition (though a constant urethral itch may be the only symptom) and a scant, watery urethral discharge, though it may be thick and purulent. Other culprits are Ureaplasma urealyticum (20-50% of NGU), Mycoplasma hominis, Mycoplasma genitalum, Trichomonas vaginalis, Herpes simples and human papillomavirus (HPV). Diagnosis of NGU requires the demonstration of urethritis and exclusion of infection with N. gonorrhoeae. As many as 40% of men with GU will also have Chlamydial urethritis, therefore treatment of urethritis should cover both GU and NGU.

 

Accurate diagnosis of the cause of urethritis requires the taking of a urethral swab. Urethral swabbing should be done at least an hour but preferably four hours after the last micturition, to ensure that the organism cultured originates from the urethra and not the bladder. For N. gonorrhoeae, a calcium alginate swab is inserted 2-4 cm in the urethra and gently rotated, and then plated onto Thayer-Martin or New York culture medium. Cotton swabs should be avoided because of their bactericidal effect. The same swab specimen can be used for Gram staining, which is 99% specific and 95% sensitive for the diagnosis of GU. This high accuracy makes serologic and fluorescent antibody testing unnecessary, though it is available. An endo-urethral swab taken 2-4 mm inside the urethra is used for culture of Chlamydia. Culture medium is not freely available everywhere, and direct fluorescent antibody (DFA) testing or enzyme immunoassay (EIA) may be used to detect the organism. Specific diagnostic tests are not freely available for other causes of NGU.

Treatment of urethritis is aimed against both GU and NGU, since co-infection is not uncommon. N. gonorrhoeae used to be sensitive to penicillin, but plasmid-carried resistance against penicillin is now widespread, and a single dose of intramuscular ceftriaxone (125 mg) or oral fluoroquinolone (500 mg ciprofloxacin or 400 mg ofloxacin) is the preferred treatment. Along with this, azithromycin (1 g per os) or doxycycline (100 mg twice daily per os) is given to eradicate nongonococcal pathogens. Persistence of infection may indicate tetracycline resistant Chlamydia or Ureaplasma infection, and erythromycin 500 mg 4 times per day per os for 7 days can be given. Persistent itch, burning or a clear discharge in the absence of pus cells on microscopy does not indicate treatment failure, since these findings may be evident for a few days after eradicating the infection.

 

In addition to treating the patient, identification and treatment of their sexual partners is important, since these may continue to be carriers of the disease and cause reinfection of the patient. Pelvic inflammatory disease and infertility are possible consequences for female sexual partners that are infected by their male counterparts. Urethral stricture disease is a possible long-term complication of urethritis in men. HIV-testing should be considered in men diagnosed with urethritis and urethritis-related urethral stricture disease. The use of condoms during intercourse is a successful way of preventing urethritis and other sexually transmitted diseases.  

 

Dr AM Naudè

Department of Urology, University of Stellenbosch and Tygerberg Hospital

Email: amn@sun.ac.za

September 2004

 

REFERENCES

1.        Foo C, Browne R, Boag F. Retrospective review of the correlation of symptoms, signs and microscopy with the diagnosis of Chlamydia trachomatis in men. Int J STD AIDS, 15: 319, 2004

2.        Kodner C. Sexually transmitted infections in men. Prim Care, 30: 173, 2003

3.        McSorley J, Gilson R. Sexual disease in male patients. Practitioner, 246: 802, 807, 2002

4.        Molodysky E. Urethritis and cervicitis. Aust Fam Physician, 28: 333, 1999

 

Note:

Contact INFOMED at the Tygerberg Campus Library at mailto:infomed@sun.ac.za  to request one of the above references

© StellMed Updates,Faculty of Health Sciences,Stellenbosch University. All Articles are Peer Reviewed.