I started a thread on a science forum else where on this Aids controversy and some useful things came out of it. The item I quoted for the purposes of that thread was one relating to concerns regarding the effectiveness of the ELISA test in Africa. A quote is in this thread also. A man named Tony replied thus: Tony wrote: "The one thing that I find interesting from the OP is the assertion that the only HIV test done in Africa is the ELISA screening. This test is not that accurate - anywhere from .5% to 1% false positives in some situations. I myself came up false positive when I gave blood once. Does anyone know if only ELISA is done in Africa?" A man named Fred (who seems well informed on this subject) replied thus: "That's a good point. The ELISA test is very sensitive for HIV but not very specific. Sensitivity and specificity are important parameters in testing. Sensitivity describes how well a test identifies subjects who have a condition, while specificity describes how well a test excludes subjects who do not have it. The combination of ELISA and Western Blot is both sensitive and specific. If someone is HIV infected, the test will almost always be positive or become positive over a short interval. Similarly, if someone does not have HIV, the combination will almost always correctly classify that person as negative. The Western Blotting test is itself both sensitive and specific, but it is probably too impractical for it to be used on everybody who is a candidate for screening. It is therefore reserved for those individuals who test positive with ELISA." This is useful piece of dialogue which covers the concerns (which appear to be genuine) with a relevant and informative reply. thoughts? The quote I posted previously suggested that in Africa they rely heavily on the ELISA test only, is this correct? Fred says that if a person tests positive with the ELISA they go on to have the other more reliable test. In Africa is this ALWAYS the case? Anyone know?