Hi, if your in a trusting relationship you can rule out gono and chlamydia. Sounds like a simple UTI. If its not cleared then best to see your doc again.
Wouldn't the Zithromax have cleared Chlam or Gono by day 11?
It could be a strain of a UTI you two passed back and forth!? Sometimes Chlam and Gono take more than a week to be accurately detected so the accuracy may depend on when you got tested. I am having a similar issue right now and trying Cranberry extract (on top of many other vitamins I take) plus I am going to take 3 raw cloves of garlic a day (every 6 hours) for the next 3 days and see if that does anything. In doing a little research on garlic it seems to work for many people. Luck for your wife she can use it as a suppository for a couple of hours a day as well (look it up!). Anyway best of luck and keep us posted.