Incubation period
1 to 3 weeks.
When a test becomes reliable
About 2 to 3 weeks after exposure, with a PCR test.
Symptoms
- Frequently none
- Discharge from the penis or vagina
- Burning when passing urine
- Bleeding after sex, or between periods
- Discomfort low in the pelvis
Good to know
- It has one of the smallest genomes of any organism that can reproduce on its own, which is why it is studied as a model of the minimum a living cell needs
- It has no cell wall, so a whole family of antibiotics has nothing to attack
- Resistance is climbing fast enough that testing which drug will work is becoming standard practice
- Many laboratories still do not offer the test, so it is worth asking rather than assuming it was included
How it was discovered
It was isolated in 1980 by Joseph Tully and colleagues from two men with urethritis that no known organism explained. Proving it caused anything took another twenty years: it grows so slowly and so poorly in culture that studying it was nearly impossible until PCR made it possible to detect the organism without growing it at all.
Sources:
Last updated: September 2026
This page is general information, not a diagnosis and not medical advice. Symptoms overlap between infections, and many infections have none at all — only a test can tell. If you think you have been exposed, talk to a doctor.