Most patients come into an STD clinic with a short list of worries: chlamydia, gonorrhoea, syphilis, HIV. Mycoplasma genitalium (MG) rarely makes that list, because most people have never heard of it. That’s unfortunate, because it’s quietly common, often symptomless, and linked to real clinical problems when left untreated.
What the research confirmed
A University College London study reported by CNN in late 2015 confirmed what microbiologists had long suspected: MG is sexually transmissible. The bacterium had been known to researchers since the 1980s, but its role as a true STI — rather than a laboratory curiosity — had not been nailed down until large population studies in the UK linked infection clearly to sexual behaviour.
The infection is often silent: many carriers have no symptoms at all. When symptoms do appear, they’re easy to confuse with other infections — painful urination, cervical inflammation, unusual discharge. In men, MG is a recognised cause of non-gonococcal urethritis. In women, it’s been associated with cervicitis, pelvic inflammatory disease, and possibly complications in pregnancy and fertility.
Why this still matters in 2026
Since 2015, MG has become a bigger concern in clinical practice — particularly because it has developed significant resistance to azithromycin and the macrolide antibiotics that were historically first-line. Resistance rates of 30–60% are reported in some populations, which has pushed treatment toward moxifloxacin and guided therapy based on resistance testing.
For patients, the practical message hasn’t changed much:
- Routine STD screening doesn’t automatically include MG in many clinics. If you have persistent urinary symptoms or recurrent cervicitis that isn’t responding to standard treatment, it’s worth asking about MG testing specifically.
- Treatment has become more complicated — self-medicating with leftover antibiotics (including azithromycin) is especially unhelpful here, because it can drive resistance without clearing the infection.
- Partners should be treated, just as with other STIs, to prevent re-infection.
If you have symptoms you’re worried about, or have had a new partner and want a full screen, we can arrange appropriate testing. Confidential consultations are standard.