By Rebecca Bowers

EXECUTIVE SUMMARY

The Food and Drug Administration has approved the first test to help with the diagnosis of Mycoplasma genitalium, a sexually transmitted infection.

  • In 2015, the infection was listed as a public health threat by the Centers for Disease Control and Prevention.
  • Mycoplasma genitalium causes urethritis in men and is associated with cervicitis, pelvic inflammatory disease, preterm birth, and spontaneous abortion in women.

The Food and Drug Administration (FDA) has approved the first test to help with the diagnosis of Mycoplasma genitalium, a sexually transmitted infection (STI). The infection is associated with non-gonococcal urethritis in men, as well as cervicitis and pelvic inflammatory disease in women. In 2015, the Centers for Disease Control and Prevention (CDC) listed M. genitalium as a public health threat.

Research findings indicate that the ribosomal ribonucleic acid-based M. genitalium assay demonstrated greater sensitivity than lab-developed or CE-marked DNA-based tests.1,2 The test can be performed using urine, urethral, penile meatal, endocervical, or vaginal swab samples.

In the past, M. genitalium has been difficult to diagnose, says Scott Gottlieb, MD, FDA commissioner. With more reliable detection of the infection, providers may be able to tailor treatment better and use medications that are most likely to be effective, he notes.

“In cases where M. genitalium is detected, doctors can consider forgoing use of antibiotics that are known to be ineffective against M. genitalium and choose a treatment more likely to be appropriate,” said Gottlieb in a press statement. “Having accurate and reliable tests to identify the specific bacteria that’s causing an infection can assist doctors in choosing the right treatment for the right infection, which can reduce overuse of antibiotics and help in the fight against antimicrobial resistance.”

Understand the Infection

First identified in 1980, M. genitalium is a bacterium that can infect the reproductive tract and is transmitted through sexual contact. Unlike most other bacteria, it is difficult to grow in culture, taking about six months to develop. Researchers were hampered in studying the epidemiology of M. genitalium infections until polymerase chain reaction tests were developed in the early 1990s. The bacteria’s genetic makeup leads to the development of antibiotic resistance; resistance rates are high, making treatment a challenge.

“Although M. genitalium is typically more common than gonorrhea, there is very little public awareness of this rising sexually transmitted infection, which can cause serious and potentially devastating health problems,” said Damon Getman, PhD, senior principal research scientist and director of research at Hologic, in a press statement.

The STI causes urethritis in men and is associated with cervicitis, pelvic inflammatory disease, preterm birth, and spontaneous abortion in women. According to the CDC’s 2015 guidelines, M. genitalium is responsible for approximately 15-20% of nongonococcal urethritis cases, 20-25% of nonchlamydial nongonococcal urethritis cases, and approximately 30% of cases of persistent or recurrent urethritis.3 In most settings, M. genitalium is more common than N. gonorrhoeae but less common than C. trachomatis.

Research indicates that a single 1-gram dose of azithromycin is significantly more effective than doxycycline against M. genitalium.3 However, resistance to azithromycin is increasing; the median cure rate for men and women is approximately 85%, but it was only 40% in the most recent trial.4 Cure rates for moxifloxacin range from 70-100%. Fluoroquinolones other than moxifloxacin are not recommended for the treatment of M. genitalium, according to the CDC. Recent research indicates treatment failure rates after treatment with azithromycin have increased because of the emergence of worldwide macrolide antimicrobial resistance in M. genitalium.5

Symptoms May Not Be Present

Detecting the presence of infection can be a challenge; about 40-75% of women and 70% of men are asymptomatic.6 Women may present with increased or altered vaginal discharge; urethritis that is acute, persistent, and recurrent; dysuria or urgency; occasional intermenstrual bleeding or post-coital bleeding; cervicitis; or lower abdominal pain. Men may have such symptoms as urethritis, dysuria, urethral discharge, and proctitis.6

Additional research is needed to identify new antibiotic targets, determine potential vaccine targets, and understand the lifecycle of M. genitalium in reproductive tract tissues.7

REFERENCES

  1. Unemo M, Salado-Rasmussen K, Hansen M, et al. Clinical and analytical evaluation of the new Aptima Mycoplasma genitalium assay, with data on M. genitalium prevalence and antimicrobial resistance in M. genitalium in Denmark, Norway and Sweden in 2016. Clin Microbiol Infect 2018;24:533-539.
  2. Le Roy C, Pereyre S, Henin N, Bebear C. French prospective clinical evaluation of the Aptima Mycoplasma genitalium CE-IVD assay and macrolide resistance detection using three distinct assays. J Clin Microbiol 2017;55:3194-3200.
  3. Workowski KA, Bolan GA; Centers for Disease Control and Prevention. Sexually transmitted diseases treatment guidelines, 2015. MMWR Recomm Rep 2015;64:1-137.
  4. Manhart LE, Gillespie CW, Lowens MS, et al. Standard treatment regimens for nongonococcal urethritis have similar but declining cure rates: A randomized controlled trial. Clin Infect Dis 2013;56:934-942.
  5. Murray GL, Bradshaw CS, Bissessor M, et al. Increasing macrolide and fluoroquinolone resistance in Mycoplasma genitalium. Emerg Infect Dis 2017;23:809-812.
  6. Sethi S, Zaman K, Jain N. Mycoplasma genitalium infections: Current treatment options and resistance issues. Infect Drug Resist 2017;10:283-292.
  7. Martin DH, Manhart LE, Workowski KA. Mycoplasma genitalium from basic science to public health: Summary of the results from a National Institute of Allergy and Infectious Diseases technical consultation and consensus recommendations for future research priorities. J Infect Dis 2017;216(suppl_2):S427-S430.