STIs
Mycoplasma genitalium PCR (swab)
PCR test for Mycoplasma genitalium in a self-collected vaginal swab; mainly useful when a male partner is being treated.
What it measures
Mycoplasma genitalium is a small bacterium that is transmitted through sex. In women, it has not been shown that the bacterium causes symptoms or complications such as inflammation of the womb and fallopian tubes; in men, it can cause inflammation of the urethra. More than 90 in 100 infections cause no symptoms, and some clear up on their own. The PCR looks for genetic material of the bacterium in material that you collect yourself from the vagina with a cotton swab.
- An infection with Mycoplasma genitalium of the vagina
- Whether you have the same infection as a male sexual partner who is being treated for Mycoplasma genitalium
Positive
A positive result means that the bacterium is present. According to Thuisarts and Soa Aids Nederland, treatment is usually not needed for women: the infection is not dangerous, probably has no effect on the chance of getting pregnant and often clears up on its own. Treatment is useful if a male sexual partner is being treated for Mycoplasma genitalium, so that you do not reinfect each other. The bacterium is often insensitive (resistant) to antibiotics: in Dutch research, 66 percent of the bacteria found had features of resistance to the first-choice drug and 9 percent to the second-choice drug. Unnecessary treatment increases that resistance.
Negative
A negative result means that the bacterium was not found in the vaginal swab. How long it takes after infection before the test becomes positive is not known; the LCI guideline (RIVM) calls the incubation period unclear. A negative result does not explain vaginal symptoms; other causes are more likely for those.
If your result is abnormal
With a positive result without symptoms, treatment is usually not needed. If a male sexual partner is being treated, the GP usually prescribes a course of antibiotics for both of you at the same time. Because this PCR does not determine resistance, the doctor requests a separate test for macrolide resistance if needed. Mycoplasma genitalium is not notifiable.
Reliability
The real-time PCR (NAAT) on first-void urine or a genital swab is the way to detect Mycoplasma genitalium. In people without symptoms, a positive result has no proven health benefit, and treatment without symptoms makes resistance increase. This test only shows whether the bacterium is present and does not determine resistance to antibiotics. With a positive result, the guideline often advises a separate test for macrolide resistance (insensitivity to the first-choice drug); the treating doctor requests this separately if needed.
Limitations
- The incubation period is unknown; shortly after a risk contact, the test can miss an infection.
- A positive result does not say whether the bacterium is the cause of symptoms; in women, a link with symptoms or complications has not been shown.
- With self-collection, too little material may end up on the swab, for example if it was not inserted far enough or for too short a time; this can give a falsely negative result.
- The result only applies to the vagina; the bacterium can also be in the anus, usually without symptoms.
How common is this
Because Mycoplasma genitalium is not routinely tested for, there are no current national figures. In general practice, the bacterium is found in about 4.5 percent of people tested. In a study at two large Centers for Sexual Health, this was 13.6 percent of women, 8.2 percent of heterosexual men and 20.1 percent of men who have sex with men, usually without symptoms.
Who is this useful for
In women, the result is mainly informative if a male sexual partner is being treated for Mycoplasma genitalium, or with symptoms together with a notification from a current partner. In women without symptoms, a positive result has no proven health benefit, and unnecessary treatment increases resistance. Vaginal symptoms more often fit chlamydia, gonorrhea or trichomonas.
Downsides and risks
- A positive result without symptoms can lead to treatment that is not medically needed and that increases the bacterium's resistance to antibiotics.
- A positive result can cause unnecessary worry or tension in a relationship, while the bacterium usually does no harm.
Sources
- RIVM-LCI-richtlijn Mycoplasma genitalium-infectie (2024)
- Multidisciplinaire Richtlijn Seksueel overdraagbare aandoeningen (2024), module C7 Mycoplasma genitalium-infectie
- Thuisarts.nl: Ik heb mycoplasma
- RIVM: Mycoplasma genitalium
- Soa Aids Nederland (professionals): Testen op mycoplasma (bijgewerkt 9 juli 2026)
- Medlab Stein, leistungsverzeichnis: Mycoplasma-genitalium-DNA
Always discuss an abnormal result with your GP. If a result is strongly abnormal, we try to reach you as soon as possible. Read your result yourself as well and contact your GP if in doubt. A test does not make a diagnosis. Read more about risks and results