In an asymptomatic, non‑pregnant, immunocompetent adult without infertility, recent urologic instrumentation, or planned genital surgery, should a positive ureaplasma urealyticum or Mycoplasma hominis be treated?

Do Not Treat Asymptomatic Ureaplasma urealyticum or Mycoplasma hominis in Immunocompetent, Non-Pregnant Adults

In an asymptomatic, non-pregnant, immunocompetent adult without infertility concerns, recent urologic instrumentation, or planned genital surgery, you should NOT test for or treat positive Ureaplasma urealyticum or Mycoplasma hominis. 1, 2, 3, 4

Rationale for No Treatment

These Organisms Are Normal Genital Flora

• Asymptomatic carriage of U. urealyticum and M. hominis is extremely common, with colonization rates of 40-80% in sexually active adults 4
• The European STI Guidelines Editorial Board explicitly states there is no evidence that detecting and treating these organisms in asymptomatic individuals does more good than harm 4
• The CDC guidelines from 1998 and 2002 clearly state that specific diagnostic tests for U. urealyticum are not indicated because detection would not alter therapy in the absence of clinical urethritis 1, 3

No Evidence of Benefit, Clear Evidence of Harm

• The European Association of Urology guidelines state there is no evidence that treatment of genital tract infections without symptoms improves conception rates, even when organisms are detected 2
• Routine testing and treatment leads to unnecessary antimicrobial use, selection of antimicrobial resistance in these bacteria and other organisms, and substantial economic costs 4
• The commercialization of multiplex PCR assays that detect these organisms alongside true STIs has worsened inappropriate testing and treatment 4

When Testing and Treatment ARE Indicated

Symptomatic Urethritis

• Test only if the patient develops documented urethritis symptoms: mucopurulent/purulent urethral discharge, dysuria, or urethral pruritus 3
• Confirm objective signs of inflammation: ≥5 polymorphonuclear leukocytes per oil immersion field on urethral Gram stain, or ≥10 WBCs per high-power field in first-void urine 1, 3
• Critical caveat: Before attributing symptoms to U. urealyticum, you must first exclude Neisseria gonorrhoeae, Chlamydia trachomatis, Mycoplasma genitalium, and Trichomonas vaginalis 4

Before Urologic Procedures

• Screen for and treat asymptomatic bacteriuria (including these organisms) before urological procedures that breach the mucosa 1
• This is the only scenario where asymptomatic detection warrants treatment in non-pregnant patients 1

Pregnancy

• Screen for and treat asymptomatic bacteriuria in pregnant women, as U. urealyticum and M. hominis are associated with spontaneous abortion, preterm labor, and low birth weight 1, 5, 6
• Treatment in pregnancy has proven benefit for reducing pyelonephritis risk and adverse pregnancy outcomes 1, 5

Treatment Regimen (When Indicated)

First-Line Therapy

• Doxycycline 100 mg orally twice daily for 7 days 2
• This is the preferred regimen with uniform susceptibility demonstrated 5

Alternative for Compliance Concerns

• Azithromycin 1.0-1.5 g orally as a single dose 2
• Note: Resistance to azithromycin in M. hominis is common (66.7% in some studies) 7

Partner Management

• Sexual partners with last contact within 60 days must be evaluated and treated to prevent reinfection 2, 3
• This applies only when the index patient has symptomatic infection requiring treatment 3

Critical Pitfalls to Avoid

Do Not Screen Asymptomatic Patients

• Routine screening of asymptomatic men and women is explicitly not recommended by multiple guidelines 1, 2, 4
• The 2024 European Association of Urology guidelines give this a "Strong" recommendation against screening 1

Do Not Confuse Species

• Only U. urealyticum (not U. parvum) is associated with male infertility based on meta-analysis 2
• M. hominis alone is rarely pathogenic and was found in only 1 asymptomatic patient in a 2023 study 8

Do Not Treat Based on PCR Detection Alone

• If testing symptomatic patients, use quantitative species-specific molecular tests 4
• Only men with high U. urealyticum load should be considered for treatment 4
• Detection does not equal disease—the majority of colonized individuals never develop pathology 4

Do Not Assume Improved Fertility with Treatment

• The European Association of Urology emphasizes that randomized controlled trials with pregnancy and live birth as primary outcomes are needed 2
• Sperm parameter improvement does not equal fertility improvement—the critical outcome is live birth rate 2