I once tested positive for HIV with the basic antibody test you mention - a pretty stunning result in view of my lifestyle. A followup Western blot test with hi

I once tested positive for HIV with the basic antibody test you mention - a pretty stunning result in view of my lifestyle. A followup Western blot test with higher accuracy confirmed I was not positive. The basic test is fast and cheap but if there are no more accurate tests to detect false positives, it's a dangerous thing to rely on. Same logic applies in other situations.