The azithromycin regimen you describe has not bee studied against chlamydia, but almost certainly it would be just as effective as single dose treatment, probably even more effective. The treatment is effective in eradicating chlamydia within a few days. There is no drug in the world that alters the effectiveness of azithromycin against chlamydia. Your minor symptoms do not suggest chlamydia or any STD.
Many things can cause vaginal area itch and discharge. If your partner's symptoms persist or recur, she should see her provider about them. But you can be sure that if she has chlamydia or some other STD as the cause, it didn't come from your sexual adventure 3+ weeks ago.
Good luck-- HHH, MD
Thank you very much for your quick and timely response! I just want to clarify a statment you made. You said that my partner could not have contracted and STD from me due to my encounter. I had unprotected intercourse with my partner 8 days after my encounter with the stranger and before I becan my z pak treatment. 6-7 days after that is when she began experiencing the vaginal itch and discharge. Wouldn't these things be connected? If you do not mind explaining futhur I would appreciate it.
If you had sex with your regular partner after your casual exposure and before you were treated, you could have transmitted chlamydia to her. Vulvar itching doesn't suggest chlamydia, but a discharge might. The combination of both symptoms suggest yeast or herpes as possibilities. Most likely you weren't infected with anything and her symptoms were coincidental. But to be safe she should be examined and tested for chlamydia and other common STDs, even if her symptoms are resolved and do not return.
I am not trying to get around anything and pardon me if that is what my question sounded like. As I stated, I understand that many, maybe even most, people are infected and never show signs. My question was even if one is infected, if symptoms have not occured, how long after exposure can one assume symptoms will not occur. 14 days, 21, 30, years?