There is no true difference, they are both antibody tests.
"Because it is less sensitive than a blood test, positive results must be confirmed by a traditional blood sample (ELISA plus WB)".
This doesn't make intuitive sense, since it is less sensitive than traditional blood tests. Intuitively, if the urine test comes up positive, then an ELISA or a rapid test would also be positive.
Greetings
I had protected sex, no oral play with a massage parlor worker 4 months back. This week my elisa test came back reactive while western blot test indicated negative result for hiv. I assume this is a false positive result for elisa. I also did 2 oraquick tests which were negative.
Do you think o am infected?
Because of this a second type of HIV test, the Western Blot, is performed on all samples that test positive for HIV antibodies using the ELISA test. The Western Blot test confirms if a sample is positive or negative. Very rarely, a result comes back ‘indeterminate’, meaning a person has just started to develop antibodies to HIV because it is so close to the time when they were infected.
Thank you doctor very much for your answer. You really helped me. In that article is also mentioned one other similar case but I think also two cases are very low number and the probability should be perhaps the same as you wrote.
I have few last questions related to this. I have read somewhere on web and here on medhelp that some older elisa antibody tests were less sensitive in detecting of "standard" group O. How sensitive are current elisa antibody tests in detecting this group?
Yes.. All a rapid test is, is a form of an ELISA test. Both check for antibodies, both are FDA approved and very reliable. Both on a positive result must be confirmed.
It's an ELISA test.
since here in Israel, the health department did not officially approved the rapid test (although it is FDA approved), we have to take regular ELISA test as well. in the test center they say that the time window of the rapid blood test is 3 months and the time window of the ELISA is 2 months. they suppose to call me in a few days if the result between the tests will be different.
I was very calm after my rapid test, but then remembered that 10.
I know you are not a doctor, but man, I would like to understand why a test that is made to be more sensitive than specific (ELISA) can be negative and a test that is suposed to be more specific and less sensitive can detect something that the ELISA could not...
If I had not made a ELISA before the WB, I think I would be scare to death by now...just as in the begining of this painful situation... And how can this WB detect a antibody to a antigen that simply does not exist (based on the PCR)?
I read slot on your advice on testing. I had a few unprotected encounters few years back. My question is regarding the 4th generation combo test. According to your advice it's 99%accurate at 4 weeks. But is it still accurate on or after 6 weeks? Since it detects mainly the p24 and it's only present in the beginning of the infectionnand the other part of the test is just like an elisa?
So in short less then a month or during ARS, PCR RNA tests is best (9 -11 days after the exposure) but after a month a PCR DNA test would be best, but at this point an Elisa test would work just as good and without the risk of false positive which would make most people here go crazy.
6. RNA PCR is for early detection, test at the 14 th day after the exposure backed up by an antibody test at the 12th week is good enough to rule out HIV.
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