the 6 month rule? How accurate is a PCR?

Hello and welcome to E health forum.

Though a few virions can become dormant, it is highly unlikely that all the virions will become dormant. Even if a few virions initiate the disease process, they will be detected by the body's immune system and antibodies will be produced to them, and will be detected in the serum.

If you had an infective exposure, then there is a 90% chance that you develop the antibodies to HIV within 12 weeks of exposure.

The infective dose will not affect the test results in any way.

Please understand that tests for HIV (ELISA) detect the presence of antibodies to HIV, which usually present within 4 - 12 weeks of exposure, depending on the severity of exposure (Probable no of virions that might have entered the blood stream).

Hence once antibodies are synthesized by the body, they remain in considerable amounts as long as viremia is present.

Hence the chances of very sensitive tests (like ELISA) giving a negative result, in presence of antibodies to HIV, is very negligible.

if antibodies are present - the test is positive, if they are absent - the test is negative. It is as simple as that.

There is no reason to doubt test results if they are done at the correct interval.

In your case, since the tests results at 8 months have been negative, it is certain that you do not have HIV infection.

I hope this helps.