Should a patient with urinary symptoms such as dysuria, frequency, or urgency, but with a negative urinalysis, undergo urine testing for sexually transmitted infections (STIs), including chlamydia and gonorrhea, especially if they are sexually active?

Should STI Testing Be Performed in Sexually Active Patients with Urinary Symptoms and Negative Urinalysis?

Yes, sexually active patients presenting with urinary symptoms (dysuria, frequency, urgency) and a negative urinalysis should undergo nucleic acid amplification testing (NAAT) for chlamydia and gonorrhea, as STIs frequently cause identical urinary symptoms and are commonly missed when providers focus solely on urinary tract infection diagnosis. 1, 2

The Critical Problem: STIs Masquerade as UTIs

The overlap between STI and UTI symptoms is substantial and clinically problematic:

• Sterile pyuria is present in 37% of women with confirmed STIs, and among those with pyuria, 74% have negative urine cultures 1
• 17-23% of women presenting with classic UTI symptoms (dysuria, frequency, urgency) actually have an STI rather than or in addition to a UTI 3, 2
• In emergency department studies, 37% of women diagnosed with UTI and treated empirically actually had an STI that went untreated 2
• Pyuria alone has only 41% positive predictive value for actual UTI when STIs are considered 2

When to Test for STIs in This Clinical Scenario

Test all sexually active patients under 25 years with urinary symptoms, regardless of urinalysis findings, as this age group has the highest STI prevalence 4

Test patients of any age with these risk factors since the last negative test:

• New sexual partner or more than one partner 4
• Partner with concurrent partners or known STI 4
• Inconsistent condom use outside mutually monogamous relationships 4
• Previous STI history 4
• Exchange of sex for money or drugs 4

Test when clinical features suggest STI over UTI:

• Absence of suprapubic tenderness (more typical of STI) 5
• Presence of any vaginal discharge or cervical findings on examination 3, 5
• Gradual symptom onset rather than acute (more typical of STI) 6
• Male partners with urethral symptoms 6

The Specific Testing Approach

Use nucleic acid amplification tests (NAATs) for both chlamydia and gonorrhea on the same specimen, as these have the highest sensitivity and specificity 4, 7

Specimen collection:

• For women: vaginal swab (preferred, can be self-collected) or first-catch urine 4, 7
• For men: first-catch urine or urethral swab 4, 7
• For men who have sex with men: test all exposure sites (urethra, rectum, pharynx) based on sexual practices 4, 7

Additional testing to consider:

• HIV and syphilis screening if not tested within the past year and sexually active 4, 7
• Trichomonas NAAT for women (not wet mount, which misses 30-40% of infections) 7, 8

Common Pitfalls to Avoid

Do not rely on urinalysis findings to rule out STI: 92% of women in one study had abnormal urinalysis findings, but this was not predictive of whether they had UTI versus STI 2

Do not assume negative nitrites exclude infection: Among STI-positive patients, 59% with positive nitrites actually had negative urine cultures, meaning the pyuria was from the STI, not a UTI 1

Do not skip testing based on absence of vaginal discharge: While vaginal discharge decreases UTI likelihood, many STIs (particularly chlamydia) cause urinary symptoms without discharge 6, 5

Do not treat empirically for UTI without culture in sexually active patients: This leads to overtreatment of UTI and undertreatment of STI, with 66% of empirically treated patients in one study having negative urine cultures 2

The Evidence for This Approach

The European Association of Urology guidelines emphasize that diagnosis of uncomplicated cystitis can be made on symptoms alone in low-risk women, but this explicitly excludes sexually active young women where STI prevalence is high 4

The U.S. Preventive Services Task Force strongly recommends annual screening for chlamydia and gonorrhea in all sexually active women under 25 years and older women with risk factors, which includes those presenting with any genitourinary symptoms 4

Multiple emergency department studies demonstrate that when providers diagnose UTI based on symptoms and urinalysis alone without considering STI, 37-64% of patients are inappropriately treated, receiving antibiotics for UTI they don't have while missing STIs that require different treatment 1, 2

Post-Test Management

If STI testing is positive: Treat according to CDC guidelines, notify and treat partners from the preceding 60 days, and retest at 3 months regardless of partner treatment due to 25-40% reinfection rates 4, 7, 8

If both urinalysis and STI testing are negative: Consider non-infectious causes including interstitial cystitis, chemical irritants, or Mycoplasma genitalium (requires specific testing) 6

If symptoms persist after negative testing and treatment: Perform urine culture if not already done, consider M. genitalium testing, and evaluate for non-infectious causes 4, 6