Pathophysiology
Urethritis is an inflammatory condition that can be either infectious or posttraumatic. Infections of the urinary tract are usually sexually transmitted and are categorized either as GU (ie, Neisseria gonorrhoeae-related infections) or NGU (e.g, resulting from Chlamydia trachomatis, Mycoplasma hominis, Ureaplasma urealyticum, Trichomonas vaginalis or Mycoplasma genitalium). (3)
A urethral smear with Gram-negative intracellular diplococci suggests gonococcal urethritis. Chlamydial infections account for 15%-40% of NGU cases, which are typically accompanied by gonococcal infection. In order to prevent complications and evaluate partners from chlamydial infections, especially in female partners, it is essential to document chlamydial infections.
Mycoplasma genitalium-induced urethritis has increased dramatically, becoming the second most common cause of non-genital urethritis, despite the absence of FDA-approved tests for detection.
Sexual transmission of this organism accounts for 15%-25% of NGU cases in the United States, and it should be suspected when recurrent or persistent urethritis occurs.
Patients who have unprotected oral sex are more likely to contract NGU caused by Haemophilus species. Among the uncommon infectious causes of urethritis are herpes simplex virus types 1 and 2, lymphogranuloma venereum, adenovirus, mycobacterial infection, syphilis, Corynebacterium, and other bacterial infections that are associated with cystitis (typically gram-negative rods) while the urethral stricture is present. (4)
Besides viral and streptococcal infections, anaerobic and meningococcal infections have also been reported as causes of urethritis. NGUs can still be infected with non-pathogenic organisms in 35% of cases, however.
In patients practicing intermittent catheterization and after instrumentation or foreign body insertion, post-traumatic urethritis can occur in 2%-20% of cases. Compared to silicone catheters, latex catheters are 10 times more likely to cause urethritis.
There are a number of infectious diseases related to urethritis, including:
- Iritis
- Proctitis
- Reactive arthritis
- Epididymitis
- Prostatitis
- Orchitis
- Otitis media
- Pneumonia
- Urinary tract infection