How reliable for HIV are ELISA test and a western blot?

Very. But that assumes that sufficient time has elapsed from the time you were infected until you were tested. It may take up to several months before antibody testing becomes positive, but generally most will appear by 4-6 wks.

Related Questions

How reliable is a HIV ELISA test vs a western blot?

HIV testing. Elisa assay is quite sensitive (will detect antibodies best) but the western blot is more specific and confirm the results of the elisa if it was positive, as being either truly positive or false-positive. There are several other circumstances in which conditions other than HIV will produce a positive elisa assay. If there are symptoms and too early for antibody test, then PCR for RNA is best. Read more...

Should I get an ELISA or western blot test if my hiv1&2 rapid tests come out negative? Hiv rapid is reliable?

PCR. The reason i would urge you to get the pricey pcr is that is is clear that you are worried, and it is costing you emotional energy. Pcr is the gold standard and will give you the right answer before either of the others. I hope things turn out well, but having HIV is no longer a death sentence. Good luck, live and love responsibly, and keep taking a proactive approach to your health. Read more...

Is an HIV ELISA test always done with an western blot test?

No. In general, the elisa is done first, and the lab then does a western blot if the elisa is positive. However, it is possible to order just the western blot, in which case the elisa usually isn't done. Read more...

So there are no tests other than ELISA and western blot that would detect HIV if a person is sure of an encounter with an hiv+ person?

Repeat testing. It may take up to 6mos after an exposure to HIV for the elisa & western blots to turn positive. If you were exposed to HIV & had negative tests, it is recommended that you get retested in 6 months. If positive, your doctor will perform more detailed studies, like viral load & cd4 counts. Not all exposures result in HIV infection, however you should use precautions to protect yourself & others. Read more...
Others, but why?? The conventional method in the US is to perform an HIV screen followed by an HIV western blot. Both test for antibodies against HIV. Other methods such as p24 antigenemia assay and by rt-PCR are very expensive and are not typically used for diagnosis. However, your question likely has very specific issues best addressed by your physician and not in this venue. Read more...
Yes-but why? Note-a single encounter via unprotected sex with an HIV + person doesn't mean you are infected. It depends on several factors (discussed elsewhere). The HIV screen by elisa , confirmed by western blot is 97-99% sensitive/ specific. Though there is a window period where neither test works, it is recommended that one is tested every 3 mo if sexually active, especially with known risk of exposure. Read more...

When tested for hiv, how should a strongly positive ELISA test (index above 7) and a negative western blot be interpreted? What additional testing is required?

Indetermined. Western blot is the confirmatory test if elisa is positive. I will repeat test in 4-6 weeks. In general if HIV test is negative and concerned about HIV then i will repeat it in 3 & 6 months. If negative after 6 months, then you dont have HIV infection, assuming you are not having possible exposure (i.e., sex, drug use, etc). If in doubt, then see id doctor. Read more...
Likely negative. This is probably a negative test. If the results haven't changed in a month, then you're definitely not infected. If you don't want to wait that long, you could get a viral load test. An undetectable viral load would be highly reassuring, but i'd still repeat the serology. Read more...

With todays ultra sensitive modern ELISA tests, what use is the western blot for hiv? A few months ago I received a weakly reactive cmia HIV ag/ab test, a 4th generation HIV combo test, and this was followed by a negative western blot and a negative p24 t

It . It seems very unlikely that the cmia HIV ag/ab test is indicative of true infection with only a weak reaction and 2 negative western blots and p24 antigens and 2 other negative antibody screens.7 months after exposure. The only way this could be is if you had acquired a strain of HIV that only the cmia HIV ag/ab test could detect. This seems highly unlikely. A cross reacting substance in your blood that this test reacts weakly to is much more likely. The only further test to confirm this that is easy to get is the pcr however. Read more...
False-positives. Screening tests are designed to be highly sensitive so they don't miss anyone with the disease. However, they can be so sensitive that they occasionally give a false-positive result. That is, the test appears positive for someone without the disease. The western blot, being time consuming and extra cost, is only used to make sure a positive is really a positive. Talk with your doc for more info. Read more...

I just read that they do a confirmatory test called a western blot after the ELISA HIV test. Why?

Confirm the results. Hiv elisa test is a screening test and has a few false positive resuilts. Western blot test looks for and confirms that HIV genetic material is in the sample. Read more...

2 false pos ELISA HIV tests, all 1 1/2 years post exposure. Neg western blot, ifa, naat and 2 neg oraquick home tests. What is my HIV status? Help!

Likely negative. There is typically a "window" of 3-6 months after exposure where you could be HIV positive but test negative. Since you didn't get your testing until well after that, i'd say the confirmatory tests (western blot, ifa) are what you should go by. The elisa is very sensitive and can have false positives- that's why we rely on the confirmatory tests. I would consider your status to be negative. Read more...