Mycoplasma genitalium (or Mgen) is a sexually transmitted bacterium that can cause reproductive tract infections of the penile urethra or cervix. Mgen causes symptomatic and asymptomatic urethritis. It may also play a role in cervicitis, pelvic inflammatory disease (PID), preterm delivery, spontaneous abortion, and infertility.

People who are sexually active can get mycoplasma genitalium (Mgen), a curable sexually transmitted disease (STD). This fact sheet answers general questions about Mgen.

What is Mycoplasma genitalium?

Mycoplasma genitalium (or Mgen) is an STD that can cause infection among people of any gender. Mgen can infect the cervix (opening to the uterus), inside the penis (the urethra), or the rectum.

How is Mgen spread?

You can get Mgen by having vaginal or anal sex without a condom with someone who has the infection. Researchers are still determining whether sex partners can spread Mgen through oral sex.

A person with Mgen can pass the infection to someone even when they have no signs or symptoms.

How can I reduce my risk of getting Mgen?

The only way to completely avoid STDs such as Mgen is to not have vaginal or anal sex.

If you are sexually active, the following things can help lower your chances of getting Mgen:

• Being in a long-term mutually monogamous relationship with a partner who does not have Mgen; and
• Using condoms the right way every time you have vaginal or anal sex.

How do I know if I have Mgen?

People with Mgen often have no symptoms.

Someone with symptoms may notice:

• Vaginal discharge;
• A burning sensation when peeing;
• Discharge from the penis.

See your healthcare provider if you notice any of these symptoms.

You should also see a provider if your partner has an STD or symptoms of one. Symptoms of an STD can include an unusual sore, a smelly discharge, burning when peeing, pain/bleeding after sex, and bleeding between periods.

How will my healthcare provider know if I have Mgen?

Laboratory tests can diagnose Mgen. Your healthcare provider may ask you to provide a urine sample for testing. In some cases, they may use (or ask you to use) a swab to get a sample from the vagina or cervix.

Is there a cure for Mgen?

Yes, the right treatment with antibiotics can cure Mgen. It is important that you take all of the medicine your healthcare provider gives you to treat the infection. Do not share medicine for Mgen with anyone. Your sex partner(s) should also see a healthcare provider who can test and treat them if needed. When taken properly, treatment will stop the infection and can decrease your chances of having problems later. Although medicine will stop the infection, it will not undo any permanent damage caused by the disease.

It is becoming harder to treat some Mgen infections, as drug-resistant strains of Mgen are increasing. Return to a healthcare provider if your symptoms continue for more than a few days after completing treatment.

When can I have sex again after my Mgen treatment?

Wait until you and your sex partner(s) complete treatment and symptoms are gone before you have sex again.

If you were treated for Mgen in the past, you can still get it again. This can happen if you have vaginal or anal sex without a condom with a person who has Mgen.

What happens if I don’t get treated?

Left untreated, Mgen can cause serious and permanent health problems in women, including pelvic inflammatory disease (PID). Some of the complications of PID are:

• Formation of scar tissue that blocks fallopian tubes;
• Ectopic pregnancy (pregnancy outside the uterus);
• Infertility (not being able to get pregnant); and
• Long-term pelvic/abdominal pain.

For people who are already pregnant, Mgen may be associated with preterm (early) delivery or pregnancy loss.

We do not know if men develop long-term health problems from Mgen.

The 2017-2018 National Health and Nutrition Examination Survey estimates overall prevalence of urogenital Mgen to be 1.7% among people aged 14-59 years in the United States. The survey reported similar prevalence between males at 1.8% and females at 1.7%.

Reported estimates of Mgen prevalence among clinic-based populations are higher. Among men presenting with urethritis in select STI clinics, 28.7% were positive for Mgen. Among women presenting in an STI clinic in Seattle, 26% had an Mgen infection. A large U.S. prospective multicenter study of a nucleic acid amplification diagnostic test for Mgen including male and female patients seeking care in diverse geographic regions found overall prevalence to be 10.3%. In this study, Mgen was more common among people ages 15 to 24 years than in people ages 35 to 39 years. The risk for Mgen was higher in Black participants than White participants and higher in non-Hispanic than in Hispanic participants. A meta-analysis of Mgen prevalence among gay, bisexual, and other men who have sex with men (MSM) found that urethral (5.0%) and rectal (6.2%) Mgen infections were more common than pharyngeal infections (1.0%).

Mgen spreads through vaginal and anal sex without a condom with someone who has the infection. Researchers are still determining whether sex partners can spread Mgen through oral sex. People treated for Mgen can get reinfected.

Mgen causes symptomatic and asymptomatic urethritis among men.

When present, the typical symptoms of Mgen- urethritis include:

• dysuria,
• urethral pruritus, and
• purulent or mucopurulent urethral discharge.

On examination, urethral discharge is often present. However, the discharge may not be grossly evident, and urethral milking (placing pressure along the length of the penis to express discharge) may be necessary for detection.

Among women, Mgen may cause cervicitis and PID, though individuals with cervicitis due to Mgen often are asymptomatic.

When present, symptoms associated with Mgen cervicitis include:

• vaginal discharge,
• vaginal itching,
• dysuria, and
• pelvic discomfort.

Clinical findings associated with cervicitis include purulent or mucopurulent cervical discharge and cervical friability. Vaginal wet smear or cervical fluid Gram stain may show elevated numbers of polymorphonuclear leukocyte cells.

Symptoms of PID due to Mgen may include:

• mild to severe pelvic pain,
• abdominal pain,
• abnormal vaginal discharge, and/or
• bleeding.

Research shows that 1%-26% of MSM and 3% of women have rectal infections of Mgen. Rectal infections often are asymptomatic, but not always.

Similarly, people may have asymptomatic Mgen in the pharynx. However, no evidence exists of it causing oropharyngeal symptoms or systemic disease. At this time, more research is needed to determine whether oral sex can spread Mgen.

Mgen is consistently associated with urethritis in cisgender males. However, there is not enough data to implicate Mgen infection with adverse reproductive sequelae (e.g., epididymitis, prostatitis, or infertility). The consequences of asymptomatic infection with Mgen among cisgender men are unknown.

While Mgen is associated with cases of PID, there are conflicting data regarding the strength of the association. There are no clinical trials examining treatment of Mgen and prevention of PID. In vitro inoculation of Mgen into fallopian tube tissue causes damage to cilia, and Mgen is more common among cisgender women with infertility. However, data are conflicting regarding the association between Mgen and tubal factor infertility. Data are also limited regarding the association of Mgen with ectopic pregnancy or preterm delivery.

Nucleic acid amplification testing (NAAT) is the preferred method of detection for Mgen. Currently there are two FDA-approved NAATs.

To diagnose Mgen in men using NAAT, urine samples are the optimal specimen. For females, urine or cervical/vaginal swab samples are acceptable, but the preferred specimen types are vaginal swabs. Several commercial laboratories in the U.S. have laboratory-developed tests which also utilize nucleic acid amplification. There are not published data on the sensitivity and specificity of these tests compared to FDA-approved NAATs.

Mgen is an extremely slow growing organism. Culture can take up to six months and only a few research settings in the U.S. have the technical capability to culture Mgen.

People with recurrent urethritis and cervicitis resulting from treatment failure of initial therapy should receive Mgen testing. Also consider testing people with PID.

CDC does not recommend screening for Mgen in people who are asymptomatic. However, sex partners of patients with symptomatic Mgen infection should receive testing. Those with positive test results should receive treatment with antibiotics to possibly reduce the risk for reinfection. If testing the partner is not possible, healthcare providers should prescribe treatment to the partner with the same antibiotics that were prescribed to the patient.

The recommended treatment for all cases of Mgen is a two-step therapy with doxycycline, followed by an additional agent (either moxifloxacin or azithromycin). Although cure rates with doxycycline monotherapy are low, using doxycycline as the initial agent may lower Mgen organism load and facilitate organism clearance.

Mgen treatment failures can occur when using doxycycline, azithromycin, and moxifloxacin. Microbiologic cure rates are poor with either doxycycline or azithromycin monotherapy (~50% or less). Microbiologic cure rates for moxifloxacin were initially high (close to 100%) but have declined to 89% in studies conducted from 2010-2017.