65 days ago I had brief unprotected sex with a high-end (expensive) CSW that I had been meeting with for several months.  It lasted about 2 minutes, at which point I stopped, washed off, and put on a condom in order to resume.  We discussed it afterward.  The CSW told me she had been tested within the previous 2 weeks and was negative.  I have had no symptoms whatsoever, but I recently started seeing a woman and want to make sure I'm being completely safe before resuming unprotected sex with anyone.  From what I read it seems like there's very little chance of gonorrhea, since there have been no symptoms.  Syphilis seems pretty improbable.  I'm less sure about chlamydia, which seems to very often exhibit no symptoms.  I've read female to male transmission might range anywhere from 5% to 20%.   Is testing necessary in this situation? 

Welcome to the forum. Thanks for your question.---

Thanks Doctor.  I think that covers everything.  The reference to 5% to 20% was the range of what I have seen described as the chance of transmission of chlamydia from female in a one off sexual encounter.  I think the NYC STD Center's website says it's 4.5%, and I have seen as high as 20% elsewhere.

Thanks for clarifying. Those indeed are good estimates for chlamydia. Your risk is a lot lower than that, considering the low chance your CSW partner has it and your lack of symptoms. (That in itsself doesn't rule it out, but helps:  probably around half to two thirds of men with urethral infection have symptoms.)---

Doctor Handsfield:

Just a brief follow up.  After sending you the additional information below, I drove to the collection center where I submitted my blood and urine. The woman who collected my samples went over the result with me and assured me there was no way she could have put the urine into a grey top tube. She showed me the packet containing the vial and pipette that she uses to collect and submit urine samples for STI tests and explained her collection procedure to me.  The vial comes with the pipette in the same package.  Grey top tubes are much smaller and have a sort of rubber end that is injected into - she couldn't imagine even trying to put urine into a grey top tube.   Indeed, she said she has never had an occasion to use a grey top tube in the 8 months she has worked there.  They are going to call the lab in Washington to see if they can get an explanation for the reference to a grey top tube on my test result page.  They think the lab may have a photo of the specimen as well.

You needn't have gone to all that trouble. I'm not a labatory expert, but I'm pretty sure that if a sample is in a container that actually would interfere with testing, the lab would have not run the test and would have contacted you to request a new specimen. I'm sur eyou can rely on the negative results, especially since you were really just confirming a virtually zero chance of infection. In fact, if you'd had a positive result, I would have suspected it to be false! (Or that there was something wrong with your exposure history.)---