Welcome to the STD forum. I'll try to help.
If the information you give about your extramarital encounters is correct -- protected vaginal sex, with no vaginal penetration before the condom was put on -- and if you indeed had two negative tests for chlamydia after those encounters, then it is exceedingly unlikely that you infected your wife with chlamydia.
Probably one of two things is going on here. First, her test was falsely positive. The chance of this is higher with some tests than others. If she had a NAAT, e.g. Aptima and other brands, then false positive results are rare; it's more likely if she had a DNA probe test.
Second, she has had other sex partners and was infected in that way. You know her and I don't, so you're a better judge of this chance than I am. But I will point out that when one member of a partnership finds a need for extramarital sex, it's not uncommon that the other partner has done the same.
A third but very unlikely possibility is that your wife has been infected for many years. However, carriage of chlamydia for more than 4 years has never been reported.
To your specific questions:
1) I agree that getting infected in this circumstance is low.
2) Comments on this and the HIV forum have frequently pointed out that HIV is relatively uncommon in CSWs. But many have chlamydia and other STDs; you have never seen Dr. Hook or me make a generalization that non-HIV STDs are rare in CSWs.
3) Correct: gonorrhea happens fairly commonly after oral sex, chlamydia rarely if ever.
4) I agree; it is unlikely you had two false negative chlamydia tests. That, combined with the protected vaginal sex plus low risk of oral sex, is why I believe you were not infected and did not transmit chlamydia to your wife.
I agree with your plan to await your wife's repeat test before discussing this with her. If positive, it would make sense for you to be retested yet again. If either of you is positive, you will need to discuss your risks -- but be prepared for the possibility she'll need do do the same.
I hope this helps. I'll be happy to comment further if you can find out what kinds of tests your wife had (both times) and her follow-up test result.
Regards-- HHH, MD
If your wife hasn't had other partners, then I would tend to favor the false positive test explanation. However, as I said, that depends in part on exactly what tests were done, both on you and her.
Anything beyond this would be speculation. We'll just have to awiat her follow-up test resutls.
Dear Dr. Handsfield,
Thank you for your response. While I know I should wait until her second test result before posting again, I am getting quite anxious waiting until next week.
I am quite positive that she has had no other sex partners. My history as described previously is also true, and I can't recall any condom complications. With these facts, how likely is it that her first test be a false positive? Conversely, how likely is it that I got chlamydia from two relatively low-risk encounters and my two previous STD tests miss it?
I know there is no certainty in this, but I am hoping that some tangible probabilities would relieve my anxieties until next week.
Thank you and regards,