I'm a 32 year old male. I had 3 sexual encounters with 3 different women this month. The first encounter was unprotected and was about a month ago. The second and third encounters were protected and were very recent, about 3-4 days ago.

So essentially 72 hours after my last sexual encounter, I developed a bad fever and a weird headache. It just aches when I laugh loudly, or cough, or when I move in certain positions. I think it is called a coughing headache or positional headache. I have no other symptoms besides this, no lesions, no irritiation, no sore throat, etc. The girl I had sex with is totally fine and doesn't have any symptoms.

Could this be some early symptoms of an STD?

I found that Herpes simplex encephalitis (HSE) presents with headache and fever and no lesions. So I was wondering if it's possible I have recently acquired HSV1 from kissing these girls (even though they did not have any sores I could see), and this fever and headache I have is related to early symptoms of Herpes Meningoencephalitis?

Thank you for the help

Based only on the title of your question, before reading anything else:  There are so many causes of fever and headache:  HIV may be among them, but no other STD would be a likely cause; and even among people at maximal risk of HIV, other causes of these symptoms are hundreds of times more common than is acute retroviral syndrome (ARS, i.e. initial HIV infection with symptoms. Further, with ARS these would rarely be the only symptoms.

Now I have read past the title and see HIV isn't necessarily your main concern. In any case, neither HIV nor any other STD causes such symptoms, certainly not within 72 hours. If I were a betting man, I would put my money on COVID, or other common viral infection (cold, influenza, etc). Maybe or maybe not from your sex partner -- it could be anyone you were near in the preceding few days (although 72 hours is very typical for COVID-19). Herpes encephalitis or meningitis? Exceedingly unlikely, although I cannot rule it out completely. (Herpes meningitis, often caused by HSV2, is a lot more common than encephalitis, and not nearly as dangerous.) But either of these is exceedingly unlikely in absence of other typical symptoms of a new HSV infection, i.e. oral or genital blisters, sores, etc. 

So my advice is first to test yourself for COVID, or see a doctor or pharmacist for it. If positive, your next step would be to seek treatment with Paxlovid. If your headache becomes more severe or your fever high, don't self test:  see a doctor. Conceivably you have something entirely different -- another viral infection or, conceivably, a more serious infection of some sort. Don't take this lightly -- but you can be quite confident no STI of any kind is responsible.

I hope these comments are helpful. Let me know if anything isn't clear.

HHH, MD

Regarding my symptoms, it's been quite strange. After 24 hours of my symptoms starting, the fever subsided and the headache prevailed. 48 hours later, the headache has also, for the most part, subsided. No other issues or symptoms have happened. I'm assuming I will be back to a 100% percent tomorrow.

I went to a clinic to get tested for COVID and I was negative. I don't think this was a flu or a cold either, since I had no symptoms besides a fever and a headache. So it is odd. From what I read, Herpes encephalitis can cause these symptoms without causing lesions, but it's too soon to tell without additonal symptoms. Meningistis might also cause these issues, but that would have to be HSV2 as you said, which I feel I don't have since I use protection 99% of the time.

I guess I have 2 questions at this point,

1) Since I'm slightly worried about Herpes encephalitis / meningitis, is there something I can look for in the coming days to completely rule out that possibility? Like when can I definitely assume this is not the case? I suppose if my symptoms are gone soon, I can rest easy that this was just some random infection? On the flip side, are there any warning signs I need to look out for and go to a doctor immediately?

2) Regarding HSV-1 in general, do you know any statistics on how easily it is transmitted from one person to another? I think HSV2 had a 10% per year of infecting someone in a relationship. I'm assuming HSV1 is much easier to transfer, which is why it's so much more common. Also, is there an accurate way of detecting HSV when you're asymptomatic? Maybe I'm freaking out over nothing when I already have it.

Thanks again for all the help!

1) Since you now feel healthy, you can safely be confident now that you don't have herpes encephalitis.

2) It's not so much that HSV1 is any "easier" to catch or transmit than HSV2, rather that different kinds of exposure are in play. In adults, most HSV1 is transmitted mouth to mouth by kissing or mouth to genital by oral sex. (By kissing, I mean sexual kissing -- open mouth etc, not a social kiss among friends, which probably is near zero risk.) However, in the absence of exposure to a person with an active, visible oral herpes outbreak, the risk of infection from any single kissing or oral sex exposure probably is under one chance in thousands.

Blood tests are available to detect antibody (indicating infection is present) against both HSV and HSV2. They are pretty accurate but not perfect. Up to 30% of people with HSV1 have negative blood tests, so a negative result doesn't rule it out. And since around 50% of adults in the US have HSV1 (mostly oral, not genital), even with a negative test result it's possible you have it. The HSV2 tests are better in that they rarely miss an infection, so a negative result is very good evidence someone isn't infected. However, care still is needed in interpreting results:  some positive results are false, depending on the strength of the positive result. Many people worried about herpes choose to be tested. If you decide to do so, I suggest using one of the Quest Laboratories outlets:  Quest routinely does the most standardized and best understood HSV antibody tests. Whatever lab and specific test you might have, make sure you only have an IgG antibody test; avoid those for IgM. (Too complex to explain here, but IgM antibody testing is so often inaccurate and misleading that it should be avoided at all costs, regardless of what a lab may try to sell you.) Finally, if there is any uncertainty about interpreting the test results when you get them, I would encourage you to post a new question on the forum; Terri Warren will be happy to help you understand the results.