Mycoplasma genitalium is an important cause of nongonococcal urethritis, cervicitis, pelvic inflammatory disease, proctitis, and pharyngitis that is not caused by Chlamydia trachomatis. Diagnosis is by nucleic acid amplification testing. Treatment is with doxycycline and either azithromycin or moxifloxacin.. Diagnosis is by nucleic acid amplification testing. Treatment is with doxycycline and either azithromycin or moxifloxacin.
Mycoplasma genitalium (and related organisms M. hominis and Ureaplasma urealyticum) cause nongonococcal urethritis and other sexually transmitted infections including cervicitis and pelvic inflammatory disease (PID). These organisms also cause proctitis and pharyngitis, which may develop after rectal or orogenital sexual contact with an infected person.
M. genitalium is second to C. trachomatis as a cause of nongonococcal urethritis (see also Urogenital Chlamydial Infections). M. genitalium is the cause of approximately 15 to 20% cases of nongonococcal urethritis in men, and found in approximately 10 to 30% of women with cervicitis (1, 2).
(See also Overview of Sexually Transmitted Infections.)
General references
1. Workowski KA, Bachmann LH, Chan PA, et al. Sexually Transmitted Infections Treatment Guidelines, 2021. MMWR Recomm Rep. 2021;70(4):1-187. Published 2021 Jul 23. doi:10.15585/mmwr.rr7004a1. Erratum: Vol. 70, No. RR-4. MMWR Morb Mortal Wkly Rep. 2023;72(4):107-108. Published 2023 Jan 27. doi:10.15585/mmwr.mm7204a5
2. Obafemi OA, Rowan SE, Nishiyama M, Wendel KA. Mycoplasma genitalium: Key Information for the Primary Care Clinician. Med Clin North Am. 2024;108(2):297-310. doi:10.1016/j.mcna.2023.07.004
Symptoms and Signs of Urogenital Mycoplasmal Infections
Symptoms in men are similar to those of chlamydial urethritis: dysuria, discomfort in the urethra, and a clear to mucopurulent discharge. Also as with chlamydia, urethritis may be asymptomatic.
Symptoms in women may include those of urethritis (urethral irritation and discharge, dysuria, urinary frequency) as well as vaginal discharge, pelvic pain, and dyspareunia; cervicitis with yellow, mucopurulent exudate and cervical ectopy (expansion of the red endocervical epithelium onto the vaginal surfaces of the cervix); and pelvic inflammatory disease (lower abdominal discomfort, typically bilateral, and marked tenderness when the abdomen, adnexa, and cervix are palpated), which may potentially cause infertility.
Proctitis or pharyngitis may develop in men and women.
Diagnosis of Urogenital Mycoplasmal Infections
Nucleic acid amplification tests (NAATs)
Sometimes screening of sex partners
Diagnosis is by NAATs of urethral or vaginal discharge, urine (in males), or endocervical, rectal, pharyngeal, or urethral swabs. NAATs should include testing for markers of antibiotic resistance when available.
Microscopy is not helpful, and culture is too slow to be of practical use.
Because there is not enough evidence to support the benefit of routine testing and screening for mycoplasmas and because concern that overtreatment of mycoplasmas may worsen antibiotic resistance, testing is recommended only for patients with recurrent urethritis, proctitis, or cervicitis and for sex partners of patients with a known mycoplasmal sexually transmitted infection (1, 2). Testing may also be considered in patients with pelvic inflammatory disease.
Diagnosis references
1. Workowski KA, Bachmann LH, Chan PA, et al. Sexually Transmitted Infections Treatment Guidelines, 2021. MMWR Recomm Rep. 2021;70(4):1-187. Published 2021 Jul 23. doi:10.15585/mmwr.rr7004a1. Erratum: Vol. 70, No. RR-4. MMWR Morb Mortal Wkly Rep. 2023;72(4):107-108. Published 2023 Jan 27. doi:10.15585/mmwr.mm7204a5
2. Obafemi OA, Rowan SE, Nishiyama M, Wendel KA. Mycoplasma genitalium: Key Information for the Primary Care Clinician. Med Clin North Am. 2024;108(2):297-310. doi:10.1016/j.mcna.2023.07.004
Treatment of Urogenital Mycoplasmal Infections
Oral antibiotics
Treatment of sex partners
A 2-stage treatment regimen for sexually transmitted infections caused by M. genitalium is recommended, depending on the availability and result of macrolide-resistance testing (1):
If macrolide sensitive: Doxycycline 100 mg orally 2 times a day for 7 days, followed by azithromycin 1 g orally (initial dose), followed by 500 mg orally once/day for 3 additional days (2.5 g total)If macrolide sensitive: Doxycycline 100 mg orally 2 times a day for 7 days, followed by azithromycin 1 g orally (initial dose), followed by 500 mg orally once/day for 3 additional days (2.5 g total)
If macrolide resistant, or sensitivity testing is not available: Doxycycline 100 mg orally 2 times a day for 7 days, followed by moxifloxacin 400 mg orally once/day for 7 daysIf macrolide resistant, or sensitivity testing is not available: Doxycycline 100 mg orally 2 times a day for 7 days, followed by moxifloxacin 400 mg orally once/day for 7 days
Treatment in pregnant patients is individualized because both moxifloxacin and doxycycline are typically not recommended in pregnancy.
Sex partners should be tested and, if positive, treated (1). Treated patients should be re-tested if still symptomatic after 21 days of treatment.
Treatment reference
1. Workowski KA, Bachmann LH, Chan PA, et al. Sexually Transmitted Infections Treatment Guidelines, 2021. MMWR Recomm Rep. 2021;70(4):1-187. Published 2021 Jul 23. doi:10.15585/mmwr.rr7004a1. Erratum: Vol. 70, No. RR-4. MMWR Morb Mortal Wkly Rep. 2023;72(4):107-108. Published 2023 Jan 27. doi:10.15585/mmwr.mm7204a5
Drugs Mentioned In This Article
