worried about possible contraction...

So I'll my my story and brief and to the point as possible.  I'll first start off by saying I'm a 21 year old, heterosexual male who hasn't led a very risky life in terms of HIV exposure until recently.  I began dating a girl in the beginning of December and we started having unprotected sex.  I dated her for a little over a month and we probably engaged in the act a dozen or so times.  However here's where I'm concerned...  At the end of the relationship we had anal sex twice very briefly (again unprotected).  Now considering I'm a worrisome type of person anyway, I couldn't help but start thinking that my possibility of contracting HIV just skyrocketed.  It's been 8 weeks since our first sexual encounter and I haven't had any symptoms.  I did come down with Strep Throat at the end of December (a month into our relationship) but didn't think anything of it at the time considering I'm very prone to getting Strep (I get it once a year right around the winter time) however the more I began to read about HIV the more I thought that perhaps that was a possible sign.

I am going to get tested however in the meantime I'm going crazy and am in a panic.  So I guess the question is, what are the odds that I could have HIV?  And if there's any other question I'm leaving out that someone feels they need to address, by all means, inform me.  Thanks for your time in advance.

[wondering1122]

A little research could answer all of your questions.

You did partake in actions that can cause the transmission of HIV. However HIV from a woman to a man is much harder than from a man to a woman. The odds of getting HIV from unprotected sex are around 1 in 2000. So even if she did have HIV you probably didn't get it. Lastly, there have been numerous studies that show that HIV is most likely spread during the acute phase. In fact some believe this is how 90+% of new cases are created. Unless she recently contracted HIV your chances of getting it are extremely low. There are tons of studies about magnetic couples that have unprotected sex hundreds of times and never pass on the virus.

Lastly, a prerequisite of getting HIV is that she has to have it. The chances of her having it are extremely low. Depending on how sexually active she is, who her partners were, etc, are all factors on how risky she was.

What you did was nothing out of the norm and you are more likely to get hit by a car tomorrow than have HIV right now.

If it eases your mind try calling her up and simply asking her if she's ever been tested. She might think you are dumb or she might talk to you about it. Maybe she would even be willing to get tested for you. Who knows.

Regardless you should not be worrying, I know it's easier said than done, but unless you had unprotected anal sex with a gay man you really don't have a reason to worry.

Just go get tested right now. There are tests that are free and the results are instant.

[strata]

Your post implies that you MIGHT not know how HIV is transmitted, based on the fact that you considered the insertive anal sex to be 'risky' but that you seemed unconcerned about the insertive vaginal sex.

Transmission of HIV requires one partner to be infected with the HIV virus. HIV/AIDS is not 'created' by the act of anal sex. (No one laugh. We've all seen this question several times on thebody.com and other sites).

IF your girlfriend was infected with HIV, you had roughly the SAME chance of contracting HIV from both the vaginal and anal sex.

The per-act transmission rate for HIV for insertive vaginal with a KNOWN HIV+ woman is roughly 5/10,000.

The per-act transmission rate for HIV for insertive analk with a KNOWN HIV+ person is roughly 6.5/10,000.

In any case, you and your girlfriend do not appear to be from high risk groups, so chances are good that neither of you are infected with HIV.

If you're still concerned, get a routine HIV antibody test at least 6 weeks following exposure. Some authorities recommend waiting until 3 months (13 weeks), but this is not usually necessary, especially for people who are not in statistically high hrisk groups (gay men and IV drug users).

In the future, it's good to get tested together with a partner if you plan to have unprotected sex. At the very least, you ought to discuss your HIV and STD status before having unprotected sex, and, if you engage in unprotected sex with multiple partners, you ought to have routine (1-4 times/year) HIV and STD testing.

But you are very likely HIV- based on the exposures you describe.

[frankyboy3]

"The per-act transmission rate for HIV for insertive vaginal with a KNOWN HIV+ woman is roughly 5/10,000."

Ive often heard stats like this quoted.  Can someone enlighten me as the medical reason why?  I spoke to a doctor and she said that even a man who has unprotected sex with a known HIV+ female, the risk of infection is roughly 1 in a 1000.  But I forgot to ask why...

Is it as simple as "fluid mainly goes from the man to the woman, not the other way around?"  or is there more to it?

[WorriedT]

The stats are based on studies of couples, one HIV+, one HIV- and the rate of transmission in these couples. There is one very well controlled, blinded Ugandan study that showed over 4 years with an average of 100 unprotected heterosexual encounters per year in a stable monogomaous relationship, about 25% of seroconversions were detected. This works out at about 1 in 1600.

With respect to the biological reasons why, the first thing to understand is that HIV finds most things a barrier to infection as it can only infect certain types of cells. If there is open damage to skin or mucous membranes (eg. sores), then that increases risk. In a totally healthy setting, it is believed HIV can only infect through the thinnest of mucous membranes. These areas are much smaller in men than in women, thus there is more risk of transmitting male to female, than female to male.

I think that's the current understanding, but other posters may have more information...

[strata]

WorriedT is correct.

If you'd like to know more of the 'why', you can read some of the scientific studies. Here's a link to CDC study; Table 1 of the study (at the end) contains the estimated per-act transmission rates and study references for each. Figure 1 contains a decision diagram for whether an exposure is 'high risk' or not (i.e., whether PEP would be recommended).

http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5402a1.htm

The reference for insertive vaginal sex comes from:

European Study Group on Heterosexual Transmission of HIV. Comparison of female to male and male to female transmission of HIV in 563 stable couples. BMJ 1992;304:809--13.