Is Ureaplasma a Sexually Transmitted Disease?
Ureaplasma is sexually transmitted and can cause disease in specific contexts, but it exists in a gray zone—it is not classified as a traditional STD like gonorrhea or chlamydia because it frequently colonizes healthy individuals without causing symptoms. 1
Understanding Ureaplasma's Ambiguous Status
Ureaplasma occupies a controversial position in sexual health because:
Ureaplasma urealyticum and Ureaplasma parvum are implicated as causes of nongonococcal urethritis (NGU) in some studies, but the CDC guidelines explicitly state that specific diagnostic tests for these organisms are not routinely indicated because detection is difficult and would not alter standard therapy. 1
These organisms can be isolated with considerable frequency from the urogenital tract of both symptomatic and asymptomatic individuals, making it the most prevalent genital organism detected in both men and women. 2, 3
The key distinction is that Ureaplasma is sexually transmitted (meaning it spreads through sexual contact) but is not always disease-causing—it becomes pathogenic only under specific risk conditions. 4, 5
When Ureaplasma Actually Causes Disease
The evidence shows Ureaplasma acts as a pathogen in these specific scenarios:
U. urealyticum (but not U. parvum) is significantly associated with NGU among men with fewer lifetime sexual partners (<5-10 partners), suggesting that lack of adaptive immunity allows clinical manifestation. 5
Both species are associated with urogenital inflammation, elevated semen levels of TNF, IL-1β, and IL-6, and increased leukocyte counts including CD4/CD8 T lymphocytes and neutrophils. 6
U. urealyticum (specifically, not U. parvum) is associated with male infertility based on meta-analysis evidence from the European Association of Urology. 7
Infection rates increase in the presence of other STDs—trichomoniasis increases colonization with Mycoplasma hominis, and cervical infections with gonorrhea or chlamydia raise the incidence of genital mycoplasmas. 3
Clinical Management Approach
The CDC recommends treating Ureaplasma only when patients have documented urethritis symptoms (mucopurulent discharge, dysuria, urethral pruritis) or objective signs (>5 WBCs per oil immersion field on Gram stain, positive leukocyte esterase, or >10 WBCs per high-power field on first-void urine). 1
Treatment Protocol When Indicated:
- First-line: Doxycycline 100 mg orally twice daily for 7 days 8, 9
- Alternative: Azithromycin 1 g orally as single dose (for compliance concerns) 8, 9
- Second alternative: Erythromycin base 500 mg orally four times daily for 7 days 8, 9
Partner Management:
- Sexual partners require evaluation and treatment, with treatment indicated for partners with last sexual contact within 30 days of symptom onset for symptomatic patients or within 60 days of diagnosis for asymptomatic patients. 8, 9
- Both patients and partners must abstain from sexual intercourse for 7 days after single-dose therapy or until completion of 7-day regimen. 8
Critical Pitfalls to Avoid
Do not routinely screen asymptomatic individuals for Ureaplasma—there is no evidence that treatment of genital tract infections without symptoms improves conception rates, even when organisms are detected. 7
Do not treat based on positive Ureaplasma testing alone without documented urethritis symptoms or objective signs of inflammation. 9, 7
Do not confuse U. urealyticum with U. parvum—only U. urealyticum is associated with infertility and has stronger pathogenic evidence. 7, 5
Do not assume that treating asymptomatic Ureaplasma colonization in infertility workups will improve pregnancy outcomes—randomized controlled trials with live birth as primary outcomes are needed to establish this benefit. 7