Non-Sexually Transmitted Causes of Urethritis
Yes, urethritis can be caused by non-sexually transmitted factors, though sexually transmitted infections remain the most common etiology. While the CDC guidelines emphasize that N. gonorrhoeae and C. trachomatis are the principal bacterial pathogens of proven clinical importance 1, multiple non-STI causes are recognized.
Non-STI Causes of Urethritis
Infectious Non-STI Causes
- Enteric organisms (particularly E. coli) can cause urethritis in men aged >35 years, especially those with recent urinary tract instrumentation, surgery, or anatomical abnormalities of the urinary tract 1
- Adenovirus and herpes simplex virus are less common viral pathogens that can cause urethritis 2
- Streptococcus urinalis has been recently identified as a potential causative organism in male urethritis, representing an emerging non-STI pathogen 3
Non-Infectious Causes
- Chemical irritants and exposure to irritating substances can cause urethritis 1
- Frequent douching has been implicated as a potential cause of urethritis-like inflammation 1
- Trauma from urinary tract procedures or instrumentation can lead to urethritis 1
Clinical Context and Diagnostic Approach
Age-Related Patterns
- Men under 35 years: Urethritis is most often caused by STIs (C. trachomatis or N. gonorrhoeae) 1
- Men over 35 years: Non-sexually transmitted epididymitis associated with urinary tract infections from Gram-negative enteric organisms occurs more frequently 1
When to Suspect Non-STI Urethritis
Consider non-STI causes when:
- The patient has recent urologic instrumentation or surgery 1
- There are known anatomical abnormalities of the urinary tract 1
- The patient is older (>35 years) with risk factors for urinary tract infections 1
- Standard STI testing is negative but objective signs of urethritis persist 4
Important Clinical Caveat
Despite the existence of non-STI causes, the CDC recommends that all patients with urethritis should be tested for both N. gonorrhoeae and C. trachomatis 4, as these remain the most common and clinically important pathogens. The etiology of most cases of nonchlamydial, nongonococcal urethritis remains unknown even after extensive evaluation 1.
Diagnostic Confirmation Required
Urethritis should be confirmed by at least one of the following before treatment 4:
- Mucopurulent or purulent urethral discharge
- Positive leukocyte esterase test on first-void urine
- ≥10 WBC per high-power field on microscopic examination of first-void urine sediment
In approximately 50% of men with chronic nonbacterial prostatitis/chronic pelvic pain syndrome, urethral inflammation is present without any identifiable microbial pathogens 1, highlighting that a substantial proportion of urethritis cases have no identifiable infectious cause despite thorough evaluation.