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HIV Exposure & Tests
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HIV Exposure & Tests

Hello:

Due to my own carelessness (assuming badly) & the lady's own desire, I ended up having unprotected vaginal sex (5 minutes, I ejaculated in her) with a married lady at a swinger party 11 days ago.  I can't find anything about the lady's HIV status.  Below are relevant facts.

The lady (& her hubby) are Caucasian (I'm Asian male).  She does not appear to do/ like other risky sex acts (like anal or double penetration or rough sex).  However, she does like to do unprotected vaginal sex with another man while her husband watches (and then they have sex with each other afterward).  I found out after the fact that before me she did this with 5 other men that night.

My questions:

1.  Since she had other men's semen inside her (and assuming she is HIV negative but one of the men is positive), how likely could I catch HIV via another man's semen touching my urethia while I was inside her?

2.  I really like to get tested ASAP because I hate waiting, but I'm still under PEP.  If I get tested at the 14 or 21 days (after possible exposure), would the test result be Totally inaccurate?  Is there any test, like PCR/ NAT, that would provide accurate result?  I really do not want to wait until 60 days, but is this the only way due to my PEP treatment?

3.  I know viral load of the infected source can impact transmission probability.  Looking at this article (link: http://en.wikipedia.org/wiki/File:Hiv-timecourse.png), it seems to indicate that the viral load of the infected person is really low if the infection just occured (like in week 1).  Is this accurate in your view?

4.  I saw the various probability data on this forum, but female to male transmission can still happen via vaginal sex.  What are the top transmission routes during straight (and only) vaginal sex?  Could the HIV come into me via my urethia? Or is it thru the lining of my urethia?  Does my ejaculation inside her increases the risk?

Many thanks.
Tags: HIV exposure test vaginal
300980_tn?1194933000
Welcome back to the Forum.  Your questions deal with a situation for which there are no scientific data, that is, assuming your partner or one of her earlier partners had HIV, how likely is it to become infected with HIV (or for that matter, any other STD) when your partner is not infected but has the genital secretions of other, possibly infected persons in her vagina?.  As I understand it, you are already taking PEP so I will answer your questions  assuming this and acknowledging that if your partner or one of her other partners had HIV, you might have been exposed.  My guess is that this remains a rather inefficient means of transmitting HIV and that your risk is no higher, and perhaps lower than if your partner herself was infected.

To address your questions:
1.  See above.  Presumably HIV is transmitted through heterosexual intercourse through introduction of infected secretions into the urethra during sex.  If your partner's own secretions were infected the risk is about 1 infection per 1000 exposures.  If it is another person's secretions mixed with hers, some dilution may occur and HIV loses its viability and therefore infectiousness with time so, if anything, the risk would be lower.  All of this is, of course conjecture- there are no direct scientific data to refer to.

2.  You have no choice but to wait.  Whether testing for antibodies of viral nucleic acids (PCR) the PEP would make the data interpretable.   You need to wait until you have finished PEP.

3.  I would not assume that if a partner was  early in the course of infection that they are less infectious. You are correct that the higher the viral load the more likely infection is.  Viral load increases rapidly following infection, starting at very low levels (most sexually transmitted HIV infections are started by a single virus) and then increasing rapidly over less than a week to extraordinarily high levels.  The onset of viral replication typically is not detected for a few days.  

4.  Ejaculation is not known to impact transmission rates (again, no data).  The average risk for infection through penile-vaginal intercourse is about 1 infection in 1000.  Obviously averages are composite figures but again, there are no data on the highest possible transmission rate and trying to figure them out makes little sense.  If the odds are 1 in 1000 and you’re the one, then your transmission rate was 100%.

Sorry I don't have more answers.  Your questions are sort of "what if" questions for which there are no good answers.  Take your PEP now that you have started it and then follow-p as instructed by your doctor.  EWH
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Avatar_n_tn
Hi Doc:

Thanks for your reply.  If god forbids my PEP is not working, would the PCR or antibody test detects HIV infection at the 14 or 21 days mark?

There seems to be some disagreement on when one must start PEP for it to work.  Most seem to think it's within 72 hours post exposure, but state of New York is saying starting PEP after 36 hours post exposure generally does not work.  What is your view?

Many Thanks.  
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300980_tn?1194933000
If your PEP were not working there are no scientific data to tell us how soon a PCR test might be positive.  Sorry.  I would not think a 14 day test would be sufficient however.

The data are clear that the sooner PEP is started the better, thus 36 hours is better than 72 but I still go with the 72 hour time frame in my own practice.  EWH
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Avatar_n_tn
Hello:

Thank you for your reply.  

I am thinking about getting tested (for all other STDs) at the 14 days mark?  Would that be too early (for STDs other than HIV)?  Would my current PEP impact the accuracy for test of other STDs?

Would you say the HIV risk profile of the particular lady I was with (multiple partner unprotected vaginal sex) is higher than CSW?  Would you have ordered PEP for me given my situation (described in first part of the thread)?

If my partner has multiple STDs but I'm totally clean, would the fact that my partner has other STDs + HIV increase the probability of HIV transmission to me than if my partner only has HIV?

Many thanks again.
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300980_tn?1194933000
1.  You can get tested for the most common STDs (gonorrhea, chlamydia, NGU) at any time more than two days after your exposure.  Herpes and syphilis typically present with lesions at the site of exposure 14 (Herpes) to 21 (syphilis) days after exposure.  Blood tests for syphilis are typically definitive at about 30 days following exposure.  We do not recommend blood tests for HSV in your situation and in the absence of lesions or known exposure to lesions- too many false positve test results.  PEP will not effect your testing for other STDs.

2.  Some swingers clubs require members to test.  If you do not know about your partner's (or her partners') prior exposures both inside and outside the club, this was a rather high risk exposure, simply on the basis of numbers alone.  CSWs risk varies and trying to determine where your risk if relative to other high risk situation is not a practical thing to do.  

The choice of PEP is a personal decision but I probably would not have recommended it.  I would need more information and further discussion (which we cannot do here) to give such advice.  This is something that a clinician and patient should discuss between themselves.  

3.   The presence of virtually any other STD in a partner, if that partner also has HIV, increases the risk of HIV transmittion by about 30% compared to exposure to a HIV infected partner who does not have other STDs.  

EWH
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