one encounter

[ineedpeaceofmind02]

hi,

i had a sexual encounter last night that has me a little concerned.  i had unprotected (vaginal) sex with a new girl i am seeing.  she said she has been tested somewhat recently and had no stds.  there were no signs of any stds or outbreaks present on her vagina or surrounding area (or anywhere on her body for that matter).  that being said, i am still a little concerned with hsv2 or any other std that cannot be "cured".  obviously, i probably should have just used a condom, but that being said, i have heard that your chances of getting an STD (even from someone who has one), are very slim if you have only had one sexual encounter with this person.  is this true?  i read somewhere that it is around a 1% chance just due to the statistics of you having only been with them once (or very few times, etc.).  now obviously, there is still a chance, but i would feel a lot better knowing that it is a small chance and that i don't have much to worry about unless i develop any symptoms.  am i correct that if any symptom of hsv2 were to appear, it would appear within 2 to 30 days after the sexual encounter?  also, if i dont have any symptoms, but wanted to be tested for hsv2 and other basic stds, a good time frame would be 1 to 3 months after the encounter?

assuming i dont develop any (visible) symptoms over the next month, do you think i should still get tested?  if so, what std's do you think i should get tested for?  i am a little stressed over this situation and would love to get some clarity and direction.

thanks,
worried forum writer

[Edward W Hook, MD]

No, in persons who do not have strong reasons for testing, such as symptoms, the probability of a falsely positive test is more likely to be the result of testing than to make a diagnosis of infection.  EWH

[ineedpeaceofmind02]

hi,

thank you for your response.  is the reason you recommend against a blood test for hsv2 in this situation (assuming no symptoms after 2 weeks) just due to the statistical unlikelyhood of me contracting it?


otherwise, i found your repsonse to be very clear and helpful.  thanks again!

[Edward W Hook, MD]

I accidentally cut off part of my opriginal response- here it is in full.  EWH

Welcome back to the Forum.  Before I address a question- I note that you seem to have a "habit" (if two questions qualifies), of coming into contact with partners and then having second thoughts/concerns about your exposures.  I would urge you to think this through in the future, having these sorts of "after the fact" concerns must be troublesome.  Now on to your questions:

The risk of any single sexual encounter with a new partner is low.  Few people have STDs and even when exposure to an infected partner, most exposures do not lead to infection. Thus if your partner had gonorrhea or chlamydial infection, your risk for infection would be about 20% (1 in 5) after a single exposure.  For other STDs, like herpes, if your partner was infected but was not having an active outbreak, the risk is lower, lower than 1 infection in 1000 exposures.  Thus the risk varies with different organisms and different sorts of exposures (females are more likely to become infected after contact with an infected male than a male is to get infected with an infected female partner).

To repeat, overall your risk from any single exposure, is low but not zero both because most people do not have infection and most exposures do not lead to transmission.  Most infections are transmitted by people who are not aware that they are infected whether because they are asymptomatic or have symptoms which they attribute to another, non-infectious cause.  Thus as a person who has had sex with a new partner, you qualify for "screening" (testing in the absence of symptoms) because you have had a new partner over a period of less than a year.  As a matter of personal protection, we recommend annual testing for anyone who has had new or  two or more sex partners in the past year (we consider this to be health maintenance- we also recommend you get your blood pressure and cholesterol checked regularly).

Finally, when you seek testing depends on what you are testing for.  You can get tested for the most common problems, gonorrhea and chlamydia at any time more than 3 days following your exposure.  On the other hand, we recommend against routine blood tests for herpes and would suggest you not worry unless you develop genital lesions in the two weeks after this exposure.  

I hope this helps.  For the future, my recommendation would be to use condoms. it really is the best and easiest way to go until you are in a stable relationship.   EWH

[Edward W Hook, MD]

The risk of any single sexual encounter with a new partner is low.  Few people have STDs and even when exposure to an infected partner, most exposures do not lead to infection. Thus if your partner had gonorrhea or chlamydial infection, your risk for infection would be about 20% (1 in 5) after a single exposure.  For other STDs, like herpes, if your partner was infected but was not having an active outbreak, the risk is lower, lower than 1 infection in 1000 exposures.  Thus the risk varies with different organisms and different sorts of exposures (females are more likely to become infected after contact with an infected male than a male is to get infected with an infected female partner).

To repeat, overall your risk from any single exposure, is low but not zero both because most people do not have infection and most exposures do not lead to transmission.  Most infections are transmitted by people who are not aware that they are infected whether because they are asymptomatic or have symptoms which they attribute to another, non-infectious cause.  Thus as a person who has had sex with a new partner, you qualify for "screening" (testing in the absence of symptoms) because you have had a new partner over a period of less than a year.  As a matter of personal protection, we recommend annual testing for anyone who has had new or  two or more sex partners in the past year (we consider this to be health maintenance- we also recommend you get your blood pressure and cholesterol checked regularly).

Finally, when you seek testing depends on what you are testing for.  You can get tested for the most common problems, gonorrhea and chlamydia at any time more than 3 days following your exposure.  On the other hand, we recommend against routine blood tests for herpes and would suggest you not worry unless you develop genital lesions in the two weeks after this exposure.  

I hope this helps.  For the future, my recommendation would be to use condoms. it really is the best and easiest way to go until you are in a stable relationship.   EWH