What is the treatment for a urinary tract STI (Sexually Transmitted Infection)?

Treatment for Ureaplasma STI

For Ureaplasma urethritis, treat with doxycycline 100 mg orally twice daily for 7 days, or azithromycin 1 g orally as a single dose if compliance is a concern. 1, 2

Understanding Ureaplasma in the Context of Urethritis

Ureaplasma urealyticum causes 20-40% of nongonococcal urethritis (NGU) cases, though it's important to note that asymptomatic carriage is extremely common (40-80% of detected cases may represent colonization rather than true infection). 3, 4 The CDC guidelines frame Ureaplasma as part of the broader NGU syndrome rather than requiring species-specific testing in most cases. 3

A critical caveat: Routine testing specifically for Ureaplasma is NOT recommended. 4 You should first exclude traditional STI pathogens (N. gonorrhoeae, C. trachomatis, M. genitalium, and T. vaginalis) before considering Ureaplasma as the causative agent. 4 Most symptomatic urethritis should be treated empirically as NGU without species-specific testing. 3

First-Line Treatment Regimens

Preferred Options:

• Doxycycline 100 mg orally twice daily for 7 days 3, 1, 2
• Azithromycin 1 g orally as a single dose - particularly advantageous when compliance is questionable or directly observed therapy is needed 3, 1, 2

The 1998 CDC guidelines (the most recent comprehensive STD treatment guidelines in the evidence provided) elevated azithromycin to equal status with doxycycline, emphasizing the compliance advantage of single-dose therapy. 3

Alternative Regimens (if doxycycline/azithromycin cannot be used):

• Erythromycin base 500 mg orally four times daily for 7 days 3, 1, 2
• Erythromycin ethylsuccinate 800 mg orally four times daily for 7 days 3, 1, 2
• Ofloxacin 300 mg orally twice daily for 7 days 3, 2
• Levofloxacin 500 mg orally once daily for 7 days 1, 2

For patients who cannot tolerate high-dose erythromycin:

• Erythromycin base 250 mg orally four times daily for 14 days 3
• Erythromycin ethylsuccinate 400 mg orally four times daily for 14 days 3

Management of Persistent or Recurrent Symptoms

Do not re-treat based on symptoms alone - you must document objective signs of urethritis (≥5 WBCs per oil immersion field on urethral smear, mucopurulent discharge, or ≥10 WBCs per high-power field on first-void urine) before initiating additional antimicrobial therapy. 3, 2

Re-treatment Algorithm:

1. If non-compliant with initial treatment or re-exposed to untreated partner: Re-treat with the same initial regimen 3, 2

2. If compliant and partner treated: Consider treatment failure

   • After doxycycline failure: Azithromycin 500 mg on day 1, then 250 mg daily for 4 days 2
   • After azithromycin failure: Moxifloxacin 400 mg orally once daily for 7-14 days 2
   • The 1993 guidelines recommend extended erythromycin (500 mg four times daily for 14 days) to cover tetracycline-resistant U. urealyticum 3

3. If symptoms persist after multiple regimens: Perform wet mount and culture for T. vaginalis 3

Partner Management

All sexual partners within the preceding 60 days must be evaluated and treated. 1, 2 For symptomatic patients, treat partners with last sexual contact within 30 days of symptom onset. 1

Both patient and partners must abstain from sexual intercourse for 7 days after single-dose therapy (azithromycin) or until completion of the 7-day regimen, provided symptoms have resolved. 3, 1, 2

Test of Cure Recommendations

Test of cure is NOT routinely recommended after completing doxycycline or azithromycin treatment. 2 Only retest if:

• Symptoms persist after treatment 2
• Reinfection is suspected 2
• Therapeutic compliance is questionable 2
• Erythromycin was used (due to lower efficacy) 2

If performing test of cure, wait at least 3 weeks after completion of therapy. 2

Critical Clinical Pitfalls

Beware of sterile pyuria in the setting of STIs. In women with confirmed STIs who have pyuria, 74% have sterile urine cultures. 5 This leads to substantial overtreatment with UTI antibiotics when the actual problem is an STI. 5 The overlap in symptoms between UTIs and STIs (dysuria, frequency, urgency) makes clinical differentiation challenging. 6, 5

Do not rely on pyuria or positive nitrite alone to diagnose UTI in patients with suspected STI. Nitrite-positive urines in STI patients are actually 18% more likely to be associated with negative urine cultures. 5 Always perform pelvic examination and cervical cultures when STI is in the differential. 5

Avoid the multiplex PCR trap. Many commercial assays detect Ureaplasma alongside traditional STI pathogens, leading to overdiagnosis and overtreatment of colonization rather than true infection. 4 This contributes to antimicrobial resistance and unnecessary healthcare costs. 4