Hi there. It is not an std and not something your wife has to tell you. :>) All women get things like UTI's, yeast infections and bacterial infections. Both yeast and bacterial infections (and uti's) are something that can happen all on their own and once there, can pass back and forth between man and woman very normally. They don't cause issues in men like they do women. She doesn't have an std most likely but the things that every woman I know personally has had at one time or another. I had a yeast infection and didn't chit chat about that with my hubby. Not sexy dinner conversation. I just treated it and moved on. So, please don't make this something to cause marital woes over. If you do, that's precisely why your wife doesn't talk to you about things like this.
And years ago, I had a bacterial vaginal infection. It is hard to get rid of. I took medicine for it and it came back. The doctor gave me pills then for my husband and myself both to take at the same time. Never did he accuse me of cheating or did I accuse him of cheating because I know that BV happens and we passed it back and forth. VERY common.
So, keep that in mind and do not overreact. be supportive to her. good luck
Cipro is usually prescribed for something like a uti and the Diflucan can be given with it to keep a woman from getting a yeast infection. The combination of these 2 meds are very common and don't immediately convey an std. If she already has a yeast infection then ues wear a condom. I would ask her what the doctor prescribed her the meds for and go from there. Usually for stds stronger antibiotics are given and usually not Cipro from what I've read