Hello from JustAnswer. This is Dr. Love and I will be glad to assist you today.
He can certainly be tested, but the problem is that it likely will be unclear what it will mean.
There are blood tests that can identify antibodies to HSV1 and/or HSV2. HSV1 typically causes oral herpes, but can be spread to the genitals by oral sex. HSV2 typically causes genital herpes, but can be spread to the mouth by oral sex.
The majority of people will test positive for antibodies for HSV1, because most people have been infected at some time in their life, frequently when a young child. Many of these people do not remember ever having symptoms of oral herpes. If he is tested and is found to be positive for HSV1, which is the most likely finding, it is impossible to know whether it is from the usual oral infection or from a genital infection from oral sex.
If he has symptoms in a specific location, then the positive blood test would suggest that there is an infection at that location. But in someone with no symptoms, the blood test will not be able to differentiate whether he has an oral infection or a genital infection.
The only value of the test would be if he is negative for both types of HSV, in which case it can be said that he is not infected in either location. But since the majority of people are positive, the blood test may not be able to provide the answer that you are seeking.
If I can provide any additional information, please let me know.
Please let me know if I can provide any further assistance.
I am sorry for the delay, but I had stepped away from the computer.
The blood tests would be able to say whether he has previously been infected with HSV1, HSV2, both, or nether. But in someone with no symptoms, if either HSV1 or HSV2 is positive, it will not be able to say the location of the infection.
If your concern is only about HSV2, then this encounter entailed minimal risk, since the greater risk would be the transmission of HSV1 to the genitals via oral sex. Certainly, the prostitute is at risk for a genital HSV2 infection, but it would typically be a genital infection and would not have been transmitted from this encounter of oral sex. However, if either you or he was ever sexually active engaging in penile-vaginal sex before your current relationship, then either of you could have gotten infected with HSV2, and the only way to be certain that either of you are not infected would be to check a blood test.
If both of you have never engaged in penile-vaginal sex before your current relationship, then there is no reason to be concerned about having HSV2 from this single encounter.
However, that is a different issue than concern over whether he may have gotten infected during this encounter of oral sex with a prostitute, in which the risk is a genital infection of HSV1. If he is negative for both HSV1 and HSV2, then this would be excluded, but it is statistically more likely that he will be positive for HSV1, because most people are positive, and the blood tests will not help you if that happens.
Absolutely. If he engaged in penile-vaginal sex, then there would be a risk for HSV2 infection.
It is worth noting that it does not need to be unprotected penile-vaginal sex. While condoms are very good at preventing STDs transmitted by body fluids, such as HIV, gonorrhea, and chlamydia, condoms only offer modest protection against transmission of HSV2. HSV2 is transmitted by skin-to-skin contact, and there is a significant amount of genital skin that is not covered by a condom. In clinical studies, condoms only offer about 50% protection. You will note that my comment above about the risk involved in either of you engaging in penile-vaginal sex before this relationship did not say that the risk was involved in unprotected sex. The risk is present if either of you engaged in penile-vaginal sex before this relationship.
However, the risk for HSV2 would be greater if there had been a penile-vaginal sexual encounter with a prostitute, because a prostitute would be more likely to be infected with HSV2.