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Avatar universal

Different opinions of HIV test time period

Hello,

I am a gay men living in Ottawa, Canada.  First of all, I had a contact with a guy on 19th of July, 2010.  I performed protected anal sex and an oral sex without a protection which is why I am worried.  Besides, he had several purple dots on this body which I am not sure whether it is related to HIV infection, but I asked and he said that it is bad reaction to the flu shot.  He, if that is true, is military personnel, but not a soldier.

Ok, so his purple dots made me worried about HIV infection along with unprotected oral sex.  Therefore, I went to the city's sexual health clinic in Ottawa where it is believed to be the best for STD/HIV test or consultation in the city.  I had rapid HIV test and it was "negative".  That was yesterday, 31st of Aug.  Although, the public nurse said that HIV test has to be done after 3 months of "Window period".  I have read couple posts here and many doctors already have said that it can be detected after 3-4 weeks.  So yes, since 19th of July it has been a month.  So I believed that it is accurate result until she said "3 month window period".

I want to know what is correct and what is not or at least whether I should be relieved or not.  Also, please, I would like to know the main causes of HIV infection, really.  I am tired of inaccurate information on the Internet.
3 Responses
300980 tn?1194933000
MEDICAL PROFESSIONAL
Welcome to our Forum.  My response to your question has several elements and will address not only the timing of test results for HIV but also an apparent misperception about the risk associated with your sexual activities.  Let's deal with your risk first.  

Your rectal exposure was protected and when condoms are used correctly and consistently they prevent STD and HIV transmission, thus your rectal exposure does not represent a risk for infection.  As for oral sex, the quoted figure for HIV risk, if one has oral sex with an infected partner is less than 1 in 10,000 and, in my estimation that is too high. Some experts state there is no risk at all from oral sex.  Neither of us on this site have ever seen or reading the medical literature of a convincing instance in which HIV was passed by oral sex.  Thus the nature of the exposures you describe is very, very low, if not no risk for HIV.

Secondly, we get many questions about the meaning of HIV test results at different time points.  This is now confused by the availability of a variety of different types of tests.  The traditional and most widely used tests for HIV are tests for antibodies to HIV which are available both as so-called "rapid" or point of care tests which can be done in the clinic and laboratory based antibody tests. For all practical purposes both of these types of test perform comparably and provide accurate information on the presence or absence of HIV infection in virtually everyone at 8 weeks following exposure.  The recommendations for testing at 3 and even 6 months are the result of two factors- data from older tests no longer used (you really do not need to worry about which generation of tests you were tested with, at this time virtually all tests are far more sensitive that they were even 2-3 years ago when the 3 month recommendation was made) and secondly, the fact that some, mostly governmental agencies which have to provide recommendations for virtually everyone without the sort of interactions such as those you get with your doctor or on personalized sites such as this one, feel the cannot "afford" to be wrong and therefore make recommendations and guidelines which leave most people unnecessarily nervous for 4-6 weeks longer than the 6-8 weeks it takes virtually everyone to develop HIV antibodies.  

In addition, there are so-called "combo" or DUO tests which test both for HIV antibodies and for the HIV p24 antigen. These tests, which are more expensive than the standard antibody test, provide accurate information on risk of HIV infection at 4 weeks following exposure.  

Finally, there are PCR-type tests which some labs recommend for HIV testing.  In general we do not recommend HIV PCR tests for HIV diagnosis.  The problems with these tests are: that they have a higher false positive rate than antibody tests, that the time course by which they become positive in infected persons, while certainly sooner than the antibody tests, is not well characterized; and that they tend to be expensive.  They are becoming more widely used but at the present time are not sufficient for a definitive diagnosis of HIV and while a negative test is somewhat helpful information in many situations, it is not sufficiently well characterized to be definitive.  

In your own case, given the sorts of exposure you describe, I suspect you have no reason for concern and have little reason for further testing.  I hope these comments are helpful to you.  EWH
Avatar universal
Thank you very much for your help, doctor.

But I need to clear something first. (Sorry if I didn't understand clearly.) So you are saying that, in my case, the testing in a month following the exposure is reliable? If then, I really don't have to worry about.

Some are saying that the negative result can be changed within 6months if the person was exposed to HIV infection. Because it takes some time for HIV virus to take over the whole blood steam to HIV positive... Is that true?
300980 tn?1194933000
MEDICAL PROFESSIONAL
I mentioned several different types of tests.   You need to know which test is being used to test you .  The combination p24 antigen/HIV antibody test gives you reliable results 1 month after exposure.

Please re-read my answer.  It does not take 6 months to get a definitve test result for HIV.  EWH
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