Conclusive

[Bubba34]

Dear Doc,

I have two Questions:  1.  Is a third generation antibody test along with a HIV RNA NAT test conclusive at 48.5 days?
I know this is short of 8 weeks by one week, but along with the NAT test I think it is OK.  2.  Is the HOME ACCESS test sold at the CVS pharmacy accurate and at what week would it be considered conclusive if so?

[Edward W Hook, MD]

At 6 weeks the antibody test picks 95%+ of infections and at 8 weeks virtually all are detectable.  7 weeks is somewhere in between- certainly tha vast majority.  

The perfromance of NAATs for diagnosis of HIV is not well studied as the perfomance of antibody tests are.  As I said, it is quite unlikely you are infected.  Can't be more specfic than that
.  EWH

[Bubba34]

Since I combined these two tests then, I shouldn't need further testing since my exposure was oral unprotected?  Also, at seven weeks what % does the antibody test pick up?  Also, is it possible to test positive after a seven week HIV NAT test when its window is 7 to 10 days?  Thanks

[Edward W Hook, MD]

Welcome to the Forum.  The data on test performance are the data we quote.  There are not good data on the additive performance of two tests in the manner that you describe.  When you combine tests such as an antibody test plus an HIV PCR test in the manner that you have, I'm certain that you increase sensitivity somewhat an thus your results are very likely to be conclusive.  

The Home Access test is FDA approved an has been rigorously tested in order to get that approval.  The Home Access test is an ELISA type test for HIV antibodies and it's performance is comparable to other ELISA-type antibody tests.  EWH