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Confused and worried!
Apr 24, 2001

Dear Dr. Feinberg,

I've posed questions on this web site on a couple of occasions earlier but nobody responded. I trust you will help me out this time.

I went in for an HIV antibody test 90 days after possible exposure. The result came back reactive on the Elisa but non-reactive on the Western Blot. They asked me to take another test 6 weeks later to confirm my status.

Here are my questions in the light of this.

1. Is the HIV antibody produced by the human body unique or is it one that is generic and produced in response to a number of other viral/bacterial infections(I had a rash on my face, and some inflammation on my penis when I went in for the test)? If the latter is true what are those viruses/bacteria or infections?

2. What is the difference between the Elisa and the Western Blot tests that they both produce different results?

3. Is a reactive Elisa and a non-reactive western blot a cause for concern? What are the chances of the western blot getting reactive 6 weeks later?

I had a very low risk exposure. No sex, no needles. But some contact with an object that had some(very little - I mean the female played with herself but did not secrete) infected vaginal secretion that was dry but not too long after it was deposited. My skin was broken. I feel weak and look very thin and I've been stressed to the max.

Hoping to hear from you. Thanks for your time.

Response from Dr. Feinberg

The ELISA test looks for antibodies that react with any part of the virus. Sometimes antibodies directed against a part of one virus or bacterium will cross-react (turn positive) with a different organism because of some similarity between them. The Western Blot looks directly for specific proteins (antigens) that are part of HIV rather than looking for antibodies, which are the body's reaction to HIV. Because antibodies can sometimes cross-react, it is possible to have a false-positive antibody test. If you are really HIV-infected, then the viral antigens will be present (positive Western Blot). So these 2 tests can give different results because they are looking for different substances. A positive ELISA and a negative Western Blot means that you are not HIV-infected, that is, there is no evidence of the virus itself in your body.

when does herpes strikes...

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