What You Should Know About Mycoplasma Genitalium

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A study released in June 2007 found that infections caused by a bacterium called Mycoplasma genitalium seem to have surpassed gonorrhea in prevalence to become the third most common STD among young people in the United States. Among adolescents who participated in a nationwide health study, 4.2 percent were infected with chlamydia, 2.3 percent with trichomoniasis, 1.0 percent with M. genitalium, and 0.4 percent with gonorrhea.

Never heard of M. genitalium? You're not alone. Even some doctors weren't all that familiar with it. At least, they weren't until recently. Then, all of a sudden, "MG" was the newest STD on everyone's tongue. (Not literally. It only infects the genitals.)

What Is M. genitalium?

M. genitalium is a sexually transmitted bacterium. In men, it is probably the second most common cause of nongonococcal urethritis. In women, MG is commonly found in association with bacterial vaginosis; M. genitalium infections can also be associated with cervicitis and pelvic inflammatory disease. Most M. genitalium infections are asymptomatic. Doctors have not yet determined whether it is worthwhile to screen everyone for infection. Furthermore, as of 2015, there was not an FDA approved test for MG. There are tests that can be used in research settings and large medical centers. However, it is far more difficult to detect in most settings.


M. genitalium treatment is done with antibiotics. However, many antibiotics, such as penicillin, that work for other infections will not work on MG. That's because these antibiotics target the cell wall. MG doesn't have one. Furthermore, there are significant concerns about resistance developing to the antibiotics most often used for treatment.

That could make MG infections much more difficult to eliminate as time goes on, similar to what has happened with gonorrhea.

Long-Term Side Effects

M. genitalium has been associated with pelvic inflammatory disease in women. It has also been linked to endometritis (infection of the uterine lining) and preterm birth. As such, the long term consequences of infection with M. genitalium seem to be similar to those of infection with gonorrhea and chlamydia. This is not surprising since its early symptoms are also similar. It is not clear whether mycoplasma infection can lead to infertility in men.


Although studies aren't conclusive, it is likely that consistent condom use will significantly reduce your risk of M. genitalium infection. The only related study done to date found that consistent condom users had half the risk of infection as individuals who never used condoms.

Even if condoms turn out not to be fully effective at preventing the spread of M. genitalium, using them is still a good idea—they offer effective protection against other highly prevalent bacterial STDs, such as gonorrhea and chlamydia.


Anagrius C et al. "Mycoplasma Genitalium: Prevalence, Clinical Significance, and Transmission" Sex Transm Infect 2005; 81: 458-462

Centers for Disease Control. "2015 Sexually Transmitted Diseases Treatment Guidelines: Emerging Issues." http://www.cdc.gov/std/tg2015/emerging.htm.

Edwards RK et al. "Assessing the Relationship Between Preterm Delivery and Various Microorganisms Recovered From the Lower Genital Tract." J Matern Fetal Neonatal Med. 2006 Jun;19(6):357-63.

Haggerty CL et al. "Mycoplasma Genitalium Among Women With Nongonococcal, Nonchlamydial Pelvic Inflammatory Disease." Infect Dis Obstet Gynecol. 2006 Sep;14(3):30184

Manhart LE et al "Mycoplasma Genitalium Among Young Adults in the United States: An Emerging Sexually Transmitted Infection." Am J Public Health. 2007 Jun;97(6):1118-25.

Pingmin W, et al. "Prevalence Survey on Condom Use and Infection of Urogenital Mycoplasmas in Female Sex Workers in China" Contraception. 2005. 72:217– 220.

Svenstrup HF et al. "Mycoplasma Genitalium, Chlamydia Trachomatis, and Tubal Factor Infertility-A Prospective Study." Fertil Steril. 2007 Jun 2; [Epub ahead of print]

Tosh AK et al. "Mycoplasma Genitalium Among Adolescent Women and Their Partners." J Adolesc Health. 2007 May;40(5):412-7.