I took a 500mg Azith 16 days after exposure despite not having any noticeable symptoms or discharge. It has now been over 4 months since the initial exposure with no noticeable symptoms. 

However, within the last 3 weeks I’ve experienced more frequent urination which left a dull ache in my lower abdomen region. This happened to me twice and lasted for a few days. The first time I attributed to being overly caffeinated  and prior alcohol consumption causing an inflamed bladder. This most recent time happened very similarly with alcohol/caffeine and vaginal intercourse twice that same day which I imagine caused added pressure. These two episodes happened about 10-12 days apart. 

Outside of that, I have noticed no discharge or real pain upon urination or during. 

What is the likelihood or possibility of an STI like Chlamydia or Gonnorhea at this point? Thanks.

Having said that, why am I saying that it is unlikely you were/are infected:

1.  Most people do not have STIs, even persons with multiple partners and she indicated she did not. Presumably this was based on testing.

2.  Even if she was infected, most single exposures do not lead to infection (risk of infection is about 20% per episode).

3.  You remain essentially asymptomatic.  Urinary frequency is not a sign of STIs, unlike burning on urination or penile discharge.  Further, when STIs cause symptoms, they remain present or worsen- they do not come and go.

Bottom line, your risk of gonorrhea or chlamydial infection is low.  If you wish to be absolutely sure, testing with a urine test and a throat swab is highly reliable and easy to obtain.

Hope this perspective is helpful.  EWH

With that being said, how effective would a half dose be treating chalmydia? Azith at 1g is around 97% range from what I've read. Granted their probably isn't a significant amount of data for half doses since it is not the recommended approach but still wondering what the efficacy might be. 50-60% etc.

Secondly, you mentioned the risk being low which is sometimes hard to quantify. Provided the duration of time that has lapsed and the asymptomatic nature, have you seen anyone test positive after such time for chlamydia? I know you mentioned being absolutely sure, and realize that the only true way to do that is testing; but I'm wondering what you would do in this situation provided this use case? Would you hold off on testing until symptoms present? I've also read that the immune system can clear certain infections like (chalmydia) over time. 

I've read quite a bit on this forum and trust your opinions. However, provided the unique situation, azith half dose, and asymptomatic nature I figured I would ask. Thank you

Given all the things I mentioned, I’d estimate your risk of infection as just 1-2%.  Testing should not depend on the presence of symptoms but your comfort level of a 1-2% chance ( or lower ) of infection.  Personally, I’d probably not worry but everyone has their own level of comfort.  EWH 

The amount of stress and anxiety is honestly not worth it considering many times symptoms  can be asymptomatic and you are left wondering.

I want to thank you for your guidance and time. I’ve always practiced safe sex with condoms but had a momentary lapse of judgement. I’ve learned a lot about a variety of STI’s in this forum; and while I hope to never put myself at risk again, it will help me speak to it intelligently down the road. All the best.

Take care. EWH