Mycoplasma Genitalium: The Emerging STD in Southeast Asia | Dr Prevents

Some patients keep coming back.

They came in originally with classic STI symptoms — discharge, burning urination, the usual presentation. They tested positive for chlamydia. They took the standard antibiotic course. Symptoms improved for a few days, then crept back. They came in again. Tests were repeated. Sometimes still positive, sometimes negative for chlamydia but symptoms persisted. They got another antibiotic course. Sometimes a different one. Symptoms still wouldn’t resolve completely.

After the third or fourth round of this, with the patient understandably frustrated and the doctor increasingly suspicious that something else was going on, the conversation eventually turns to a less commonly tested organism: Mycoplasma genitalium.

If you’ve never heard of it, you’re in good company — most patients haven’t, and even some clinicians order standard STI panels that don’t include it. But Mycoplasma genitalium is now recognised as one of the more important and challenging STIs of our era, and it’s particularly relevant in Southeast Asia where antibiotic resistance patterns add another layer of complexity. This article walks through what it is, why it’s so often missed, and what proper testing and treatment actually involve.

What Mycoplasma Genitalium Is

Mycoplasma genitalium (often abbreviated M. genitalium or Mgen in clinical settings) is one of the smallest known free-living bacteria. It was first identified in the early 1980s but only relatively recently recognised as a meaningful sexually transmitted pathogen in its own right.

It’s transmitted through sexual contact — vaginal, anal, and oral. It primarily infects the urethra in men and the cervix in women, similar to chlamydia. Unlike chlamydia, which is a bacterium with a typical bacterial cell wall, Mycoplasma is unusual because it lacks a cell wall altogether. This is more than a microbiological curiosity — it directly affects which antibiotics work against it.

In Malaysia and across Southeast Asia, awareness of Mycoplasma genitalium has been growing, but routine testing isn’t yet universal. Many cases are missed simply because the test wasn’t ordered.

Why It Often Gets Missed

There are a few intersecting reasons Mycoplasma genitalium flies under the radar:
Standard STI panels don’t always include it.
Many basic STI panels in Malaysia test for chlamydia, gonorrhea, and trichomoniasis using combined PCR testing, plus separate tests for HIV, syphilis, and hepatitis. Mycoplasma genitalium typically requires a separate specific test that may not be included in the standard package. If you tested for “the usual stuff,” you may not have been tested for Mgen.
It causes the same symptoms as chlamydia.
Discharge, burning urination, mild pelvic pain in women, urethritis in men — Mycoplasma genitalium presents almost identically to chlamydia. Without specific testing, doctors often treat empirically as chlamydia, which doesn’t work for Mgen. The patient appears to “fail treatment” or develop “recurrent chlamydia” when actually the original organism was Mgen all along.
It often produces no symptoms.
Many people carrying Mycoplasma genitalium have no symptoms whatsoever. They unknowingly transmit it to partners, who may also be asymptomatic, and the cycle continues silently. Without specific testing, these silent carriers aren’t identified.
It’s a relatively newer addition to clinical awareness.
Although Mycoplasma genitalium has been known for decades, its full clinical significance has been clarified only in the past 10-15 years. Some practitioners trained in earlier eras may not routinely consider it. Public awareness is essentially zero.

Symptoms to Recognise

When Mycoplasma genitalium causes symptoms, they typically mimic chlamydia or gonorrhea but are often slightly milder.

In men.

Urethral discharge — typically clear or whitish, less commonly thick or yellow
Burning or stinging during urination
Sometimes itching at the tip of the penis
Sometimes mild discomfort in the testicles
Many men have no symptoms

In women.

Increased or unusual vaginal discharge
Bleeding between periods or after sex
Mild pelvic pain or discomfort
Painful urination
Pain during sex
Many women have no symptoms

The pattern that suggests Mycoplasma genitalium specifically.

Symptoms that don’t fully resolve after standard chlamydia treatment
“Recurrent chlamydia” diagnoses
Persistent urethritis without identifiable cause on standard testing
Persistent cervicitis or pelvic inflammatory disease that doesn’t respond to standard treatment

Why It's Worth Treating

Untreated Mycoplasma genitalium isn’t benign. Documented complications include:

Pelvic inflammatory disease in women.
Like chlamydia, Mycoplasma genitalium can spread upward from the cervix to cause PID. Long-term consequences mirror those of untreated chlamydia: fallopian tube scarring, ectopic pregnancy risk, and potentially fertility problems.

Persistent urethritis in men.
Mgen is one of the leading causes of non-gonococcal urethritis (NGU) — particularly persistent NGU that doesn’t respond to standard treatment. Some studies suggest links to epididymitis.

Pregnancy complications.
Some research suggests links between Mgen infection during pregnancy and outcomes including preterm labour and miscarriage, though this evidence is still evolving.

Increased HIV transmission risk.
Like other inflammatory STIs, untreated Mgen may increase susceptibility to HIV transmission during exposures.

Continued silent transmission.
Untreated carriers continue to transmit the infection to new partners. The silent transmission cycle is part of why Mgen is becoming more common globally.

Testing — Newer Technology, Better Detection

Modern Mycoplasma genitalium testing uses specific PCR-based methods:

PCR (NAAT) testing.
Detects Mycoplasma genitalium DNA directly in urine samples or genital swabs. Highly sensitive and specific. This is the standard approach where testing is available.

Where to get tested.
Specialised sexual health clinics like Dr Prevents typically include Mgen testing as part of comprehensive STI panels or as an add-on test. Routine testing isn’t yet universal, so it’s worth specifically asking whether Mgen is included in your panel.

Window period.
Reliable testing from about 1 to 2 weeks after exposure.

Resistance testing.
Increasingly important — some labs now offer testing not just for the presence of Mycoplasma genitalium but also for genetic markers of antibiotic resistance. Given the growing resistance issue (covered next), resistance-guided treatment is becoming the new standard.

The Antibiotic Resistance Problem

Here’s where Mycoplasma genitalium gets challenging. The bug is unusual — and increasingly, it’s becoming hard to treat.

Why standard antibiotics often don’t work.
Mycoplasma’s lack of a cell wall means several common antibiotic classes that target cell wall synthesis (like penicillins) don’t work against it at all. Treatment has historically relied on antibiotics that target other bacterial functions — primarily azithromycin and doxycycline.

Resistance to azithromycin is rising rapidly.
Globally, Mycoplasma genitalium resistance to azithromycin has increased dramatically over the past 20 years. In some regions, including parts of Asia, more than half of Mgen cases are now resistant to azithromycin. This makes empiric treatment with this antibiotic increasingly likely to fail.

Doxycycline alone has limited efficacy.
Doxycycline cures only about 30-40% of Mgen cases, making it inadequate as standalone treatment. Combination approaches are now standard.

Modern treatment approach.
Current best practice typically involves a sequential approach: doxycycline for 7 days first to reduce bacterial load, followed by either azithromycin or moxifloxacin depending on resistance status. Where resistance testing is available, treatment is guided by the specific resistance profile of the patient’s strain.

Moxifloxacin as a backup option.
Moxifloxacin (a fluoroquinolone antibiotic) works against most Mgen strains, including azithromycin-resistant ones. However, fluoroquinolone resistance is also emerging, and moxifloxacin has more potential side effects than first-line antibiotics. It’s typically reserved for resistant cases.

Test of cure is important.
Given the resistance landscape, follow-up testing 3 to 4 weeks after completing treatment is recommended to confirm cure. Persistent infection requires alternative treatment approaches.

If You've Had "Recurrent" Chlamydia

This pattern is worth flagging specifically. If you’ve been diagnosed with chlamydia, treated, and then either:

Tested positive for chlamydia again shortly after
Continued to have symptoms despite a negative repeat chlamydia test
Had urethral or cervical inflammation that didn’t fully resolve
Had treatment that initially helped but symptoms returned

…there’s a real possibility that Mycoplasma genitalium has been part or all of the picture from the beginning. Worth specifically asking about Mgen testing in this scenario.

Partner Notification and Treatment

If Mycoplasma genitalium is diagnosed, sexual partners need testing and (if positive) treatment to prevent the cycle of re-infection.

Identification timeline.

Partners from approximately the past 60 days are typically notified, similar to chlamydia partner management.

Treatment coordination.

Both partners should ideally be treated simultaneously, with abstinence from sex during treatment and for 7 days after both have completed therapy. This prevents the ping-pong reinfection that’s particularly common with Mgen.

Asymptomatic partners still need treatment if positive.

Partners often have no symptoms but can still carry and transmit the infection. Treatment is recommended for all positive partners regardless of symptom status.

Prevention Strategies

Mycoplasma genitalium prevention overlaps with prevention of other bacterial STIs:

Consistent condom use for vaginal, anal, and oral sex
Comprehensive STI testing including specific Mgen testing for sexually active adults with multiple or new partners
Pre-relationship testing for both partners (including Mgen testing)
Honest communication about sexual health history
Prompt testing if symptoms appear or if a partner is diagnosed
Test of cure follow-up after treatment to confirm clearance

Get Comprehensive Testing at Dr Prevents

If you’ve had persistent or recurrent symptoms after standard STI treatment, please come in for a more comprehensive evaluation including Mycoplasma genitalium testing. At Dr Prevents, our KL and Selangor clinics offer specific Mgen testing as part of comprehensive panels or as an add-on test for patients with persistent symptoms.

Many cases of “treatment failure” or “recurrent infection” turn out to be Mycoplasma genitalium that was never tested for in the first place. Identifying it correctly opens the door to treatment that actually works — even when standard chlamydia treatment hasn’t.

📞 Persistent symptoms deserve a thorough answer. Walk in today. 🩺