Clarification

[Rogersj]

Hello Doctors,

I am in a long term relationship and have recently stupidly strayed. I have tested negative for all the standard STIs but am concerned about Mycoplasma Genitalium. Having researched your site I appreciate that many STD experts doubt the importance of MG but the fact that it's debated and seems to be unknown is for me a cause of concern in itself - eg. I'd rather not put my partners health risk at all.

I have decided to test privately in London for this bacteria both urethral and throat samples but would really appreciate your guidance on the below questions:

- Much of what I've read on the internet says that the 'Incubation period' for Mycoplasma Genitalium is unknown with reference being made to 'some researchers believe 60 days +'. However, the clinics that test for the infection give a 'window period' of 2-3 weeks for testing. Can you confirm my understanding that reference to 'incubation periods' simply means the time it takes for symptoms to appear rather than when it is safe to test accurately and that the 'window period' of 2-3 weeks for accurate testing is correct?

- Some clinics take urine samples and others urethral swabs - is there any meaningful difference between the accuracy of the two as long as they are PCR tests?

- Finally, I've read that cotton swabs shouldn't be used in the throat as it would mean PCR would not detect the bacteria and they need to be a different material. Is it safe for me to assume that private clinics in London will use swabs of the correct material?

Thanks for your help.

[Rogersj]

Thanks a lot Doctor. Have a good rest of the day.

[Edward W Hook, MD]

Yes, that is what I said.  It is normal in the male urethra.  EWH

[Rogersj]

Thanks Doctor. Appreciate the quick response. Just to end this question, you mention that UU is likely to come back, so even if a test shows negative it can grow back naturally anyway?

[Edward W Hook, MD]

For PCR testing there is no significant difference between testing using urine versus a swab.

There are no useful data on what you refer to as an incubation period since the infection can be asymptomatic.  Testing could certainly be performed with accuracy at any time more than two weeks after exposure.

Testing for ureaplasma was a waste of time.  Ureaplasmas are part of the organisms found normally I the genital tract.  Treatment might make it go away for a while but it will be back.  Doxycycline does suppress M. genitalium so, if you choose to test, I'd suggest you wait two weeks before testing. EWH

[Rogersj]

Thanks Doctor but just to confirm I've not yet been tested at all but am planning on being so privately.

It would be appreciated if you could answer my questions re. urine Vs. swab accuracy - eg. is there any meaningful difference in accuracy as some clinics carry out a urine test for mycoplasma genitalium and others a swab test for the bacteria.

Also, If my understanding is correct that the window period for testing is 2-3 weeks and that when reference is made to 'incubation periods' this is something different and related to the onset of symptoms.

Finally, something I didn't mention previously, I have tested for ureaplasma recently by urine sample (home test from an online kit) and have finished my doxycline course yesterday. If is it safe to test for mycoplasma genitalium immediately (ie, tomorrow) or could bacteria be 'suppressed' by the doxycline so as not to show up on a test but still be there or is it the case that if no infection is found you can assume you're clear of infection - eg. no need to wait several weeks to test?

Thanks Doctor

[Edward W Hook, MD]

Welcome to our Forum.  I'll try to help.  Thanks for looking into the topic of M. genitalium to help refine your questions.  You are correct, this organism is the topic of increasing research and it's role as an STI pathogen is not clear.  When it causes infection in men however, M. genitalium causes detectable signs of inflammation which should have been detected when you were examined.  If testing for M. genitalium was not performed, you still would have been given a diagnosis of non-specific urethritis (NSU- here in the U.S. we call it NGU [nongonococcal urethritis]) and treated.  You can resolve you continuing concerns about M. genitalium by contacting the clinic you were seen at and asking if you were tested for M. genitalium or NSU.  If you were and either was not present you can move forward without further concern.

As for you concerns about improper testing, I would not be concerned.  If e tests were done, they would have been done correctly and were the specimens inadequate, the lab would have informed the clinic so further testing could be carried out.

My advice would be assume that you were properly evaluated.  I would also suggest staying off of the Internet for more information.  The statements there are often misleading, taken out of context, or even just wrong.  EWH