It is logical that duration of intercourse influences transmission of most STDs. But there are no precise data and I can't say how much your risk was reduced because of the brevity of your exposure.
HHH, MD
say hypothetically that there were one or two unprotected penis to vagina insertions, by how much would the chance of contracting herpes go up. Does the length of time have any effect on decreasing the risk. Thanks again
thanks so much, you are truly providing a great service for people and helping them calm their fears and anxiety...you read so much stuff on the internet that freaks the hell out of you and gets everyone worked up...thanks again
The risk of herpes from the exposure you describe must be very low. In monogamous couples in which one person has herpes and the other doesn't, who have sex an average of 3 times a week, and who do not use condoms, only about 3% of the uninfected partners acquire herpes per year. Now translate that to your exposure. Probably too low a risk to measure, even if your partner has genital herpes.
The risk of STD transmission from any single exposure varies from one STD to another. If a woman has gonorrhea, her male partner has around a 20% chance of catching it for each episode of unprotected vaginal intercourse. For gonorrhea transmission in the male-to-female direction, the risk is around 50% per unprotected exposure--which is more than twice the risk of female-to-male. The risk for chlamydia transmission in either direction may be somewhat lower, but the difference for male-female vs female-male holds up. It also holds for herpes and HIV. Probably not much difference, though, for HPV infection.
Both men and women in noncommitted relationships should use condoms. I know, you have heard it before--but it's true.
Good luck-- HHH, MD