Hi Dr. Daar,
If a person feels they were at some risk several years ago, lets say close to 10, but they kept putting testing off and tried to forget about it, but because they could never fully put it to rest and decide to finally get tested with a standard hiv elisa test, would going that many years make the antibodies undetectable or disappear and they would be a false negative? Seems silly the question but forgive me, I really would like to know and don't know who else to ask. Thanks for your reply in advance.
Hi L.K., Not a silly questions at all. In general once someone is infected they will have detectable antibodies by the standard HIV ELISA for life. In other words, the antibody test in the setting you describe should be very good at defining if someone is infected or not. If the test is negative and they have not been exposed in the last six months one can rest assured that they are not infected and will remain that way as long as they avoid future exposures.
The one setting where false negative antibody testing is a real concern is during the first weeks to months after infection. It is for this reasons that those exposed are recommended to have follow-up testing for up to 6 to 13 months after a specific exposure before they can be confident that they are truly negative.