I would be extremely grateful for your advice please. 

I am a 29yr old Male and had unprotected intercourse three times with a 30yr old Female friend back in November 2024. This was standard penile-vagina intercourse on each occasion and I also received oral sex from her.

We spoke about sexual partners and STI’s beforehand and she told me that she was clear. However, afterwards she revealed that her last STI checkup was in March 2024 and before our encounters she had a ‘friends with benefits’ in the UK on and off when she and this guy were ‘bored’. Unfortunately, I have no details about whether these encounters were protected (or what sexual activity they did i.e anal sex) and she has since blocked me because I started to ask questions like this, hence I am extremely anxious about what might be. 

HIV and Hepatitis B are my main concerns since these are tested for with my employment.

21 days after the final encounter I had a Qualitative HIV RNA PCR test. This returned ‘not detected’ for both HIV 1&2, which from reading other replies, means my results are 100% accurate and I am absolutely clear of HIV? (and this will not change).

Before the encounters I was not vaccinated against Hepatitis B (only A). However, I have since had TWO doses (my last being 9 February).

It is 104 days since the last encounter and I have had no symptoms such as rashes, pain when peeing or severe cough etc. 

Do you see any reason for worry or am I fine? Apologies, this whole ordeal has been incredibly stressful and something I will not allow to happen again.

Thank you

You describe a very low risk situation from the standpoint of all STIs, including HIV and hepatitis B virus (HBV). You don't say where you are, but if in North America or Europe, even if you were not vaccinated against HBV, it seems likely a 30 year old woman would have been immunized. Even if not, the chance of HBV from the events describe probably was under one chance in millions; HBV is very rarely sexually transmitted these days. Then one in millions guesstimate is even if you had not started your HBV vaccine series. In addition, substantial immunity is present within 2-3 weeks of the first dose.

The chance of HIV in this situation was even lower. It is the very rare sexually active female who has HIV; and if infected, the average transmission risk for unprotected vaginal sex is one chance in 2,500 for each sexual encounter. But anyway, the HIV RNA PCR tests are 100% conclusive any time 11 days or more after exposure -- so your negative test result proves you were not infected.

So honestly there is no scientific or practical basis for the level of stress and anxiety you report. I hope these comments help resolve them. Let me know if anything isn't clear.

HHH, MD

Apologies - my friend and I are from the UK. I learned that in the 90’s Hepatitis B vaccination was not compulsory for babies like it is now - only Hepatitis A doses were given. I did ask my friend after these events if she had been vaccinated against Hepatitis B, however she was unsure. I expect this means no.

I’m sorry if there has been any confusion - I had the first dose of the Hepatitis B vaccine last month (62 days AFTER this most recent exposure with her).

I’m sorry if my anxiety has come across in my post. I did ask my friend to have an STI check last month to put my mind at rest, but she became all defensive and refused (and has since ceased contact). I therefore wanted to get a scientific opinion from you or Dr Hook.

To summarise - I have nothing to worry about at all regarding HIV or Hepatitis B (or anything else) and I can move on with my life without concern?

I greatly appreciate your time.

I agree with your doctor about the spot  you noticed -- and syphilis cannot cause a visible skin abnormality sooner than 8-10 days after exposure. And if syphilis, it would be at a site of direct friction during sex, like your penis not the scrotum. (The organism usually must be massaged into tissues for infection to take hold.)

You definitely "...have nothing to worry about at all regarding HIV or Hepatitis B (or anything else) and I can move on with [your] life without concern."

Apologies - I see that you responded to my last message 17 hours ago, however I am unable to see said reply.

As mentioned in my last message, I desperately want to move on with my life and not have any lingering worry that my HIV or Hepatitis B blood test results will return positive when my work visa renews in September (I work overseas). Therefore, any concrete assurances you can offer would be greatly appreciated.

Thank you for taking the time to assist me and for your patience regarding my anxiety. 

Even with no vaccination at all, I would guess that not 10 cases of heterosexually transmitted HBV occur each year in the UK.