I was recently the victim of a sexual assault. I did not know this person and am worried about possible HIV infection due to the unknown history of the person who assaulted me. About 2 weeks post exposure I had a sore throat with no other symptoms that lasted about 2 weeks. I also had muscle pain in my legs that took a few weeks to resolve. My PCP thinks my symptoms were a combination of a viral infection and anxiety. I had a 4th generation antigen/antibody HIV test 25 days post exposure that came back negative. I also had a rapid antibody test at 32 days post exposure and a 3rd generation HIV antibody only test at 35 days post exposure that all came back negative. My Dr will not let me test again until I am 3 months post exposure. I do plan on completing this test as advised by my PCP. However, I am wondering how reliable these results are so that I may have peace of mind in the meantime. Any help would be greatly appreciated. Thank you.

You can be almost completely confident that you did not acquire HIV from the assault. There are multiple reasons that I say this, the most important one will be the last.  Here they are:

1.  Most people do not have HIV and of those who are infected, most are on therapy which reduces or even prevents transmission.

2.  Most exposures to persons with untreated HIV do not acquire infection.  Fewer than 1 person in 1000 exposed to an untreated infected person will acquire the infection.  In other words, even if your partner had HIV, there is a 99.9% chance that you were not infected.

3.  Most importantly, at 4 weeks results of 4th generation HIV tests are more than 99% conclusive.  We have never seen a person who had a negative test at 4 weeks go on to become positive.  FYI, results of 4th generation tests for HIV are entirely conclusive at 6 weeks following exposure.

I hope this information is helpful and reassuring.  If there are further questions, please use your up to two follow-ups for clarification.  EWH