Is Ureaplasma considered a sexually transmitted infection (STI)?

Ureaplasma as a Sexually Transmitted Infection

Ureaplasma is not considered a true sexually transmitted infection (STI) despite being sexually transmissible, as it is frequently found as a commensal organism in sexually active individuals without causing symptoms or disease. 1

Classification and Clinical Significance

• Ureaplasma species (including U. urealyticum and U. parvum) are classified as "equivocal pathogens" rather than definitive STIs, unlike established pathogens such as Chlamydia trachomatis, Neisseria gonorrhoeae, and Mycoplasma genitalium 1, 2
• Testing and treatment for Ureaplasma is not routinely recommended because of its high prevalence as a colonizer in asymptomatic, sexually active individuals 1, 3
• The Infectious Diseases Society of America (IDSA) specifically states that "culture or NAATs for Ureaplasma is not recommended because of the high prevalence of colonization in asymptomatic, sexually active people" 1

Epidemiology and Prevalence

• Ureaplasma species are commonly found in the genital tract of sexually active individuals, with prevalence rates of 15.7% for U. urealyticum and 28.2% for U. parvum in general population studies 2
• Unlike traditional STIs, Ureaplasma colonization often occurs without symptoms or clinical disease 3
• Ureaplasma can be detected in both men and women, though it is more frequently isolated from the vaginal fluid than from the male urethra 4

Clinical Implications

• While Ureaplasma can be associated with certain clinical conditions, its mere presence does not indicate disease or need for treatment 3
• Unlike established STIs such as Chlamydia trachomatis and Neisseria gonorrhoeae, Ureaplasma species have not been consistently linked to specific genital symptoms or clinical signs in non-pregnant women 3
• In a comprehensive study of non-pregnant women, Ureaplasma species were not associated with specific symptoms or signs after adjusting for true STIs and other vaginal conditions 3

Testing Considerations

• Multiplex PCR assays often include Ureaplasma detection alongside true STI pathogens, which has led to increased detection and potentially unnecessary treatment 2, 5
• The inclusion of Ureaplasma in these panels has contributed to confusion about its clinical significance 1, 2
• Despite technological advances allowing for easy detection, current guidelines do not support routine testing for Ureaplasma 1

Treatment Approach

• If treatment is deemed necessary based on clinical judgment (not merely positive test results), the CDC recommends:
  • Doxycycline 100 mg orally twice daily for 7 days as first-line treatment 6, 7
  • Alternative regimens include azithromycin 1 g orally in a single dose or erythromycin base 500 mg orally four times a day for 7 days 6, 7
• Treatment should be considered only when Ureaplasma is detected in the context of specific clinical syndromes where other causes have been ruled out 1, 6

Common Pitfalls in Management

• Overtreatment of asymptomatic individuals based solely on positive test results contributes to antimicrobial resistance 2
• More than half of patients with detected Ureaplasma receive antibiotics despite lack of evidence supporting this practice 2
• Focusing on Ureaplasma may delay diagnosis and treatment of true pathogens causing similar symptoms 3
• The presence of Ureaplasma should not automatically trigger partner treatment, as is standard practice with confirmed STIs 1, 3

In conclusion, while Ureaplasma can be transmitted sexually, current evidence and guidelines do not support classifying it as a true STI that requires routine testing and treatment in asymptomatic individuals. Its presence should be interpreted in the context of clinical presentation and after excluding established pathogens.