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Avatar universal

hiv pcr dna why and why not?

I want someone to explain about the PCR - it may  NOT be a CDC approved diagnostic tool, ie it will will not show Antibodies , which provide the clinical definition of HIv + status - evidence of having contracted a virus (in essence having fought and defeated it, HIV being an exception amongst viruses as it is "unbeatable") .However, PCR DNA, testing for the actual genetic material of the virus in plasma  is used in blood donations and the porn industry - now we know the risks of the extremely promiscuous porn actors and we know the aftermath of the blood for haemophiliacs disaster in the UK some years ago.So why would they have this in place now, considering the expense of each test?Why is it that the PCR DNA test , which is widely used in the period of initial /acute infection, not a diagnostic tool? Why does therefore even exist? Why do some doctors say that at 4 weeks if you have both a neg pcr dna and and a neg anti 1/2 test then you cannot be infected? If teh PCR DNA test is not fit for purpose,is it reasonable to assume therefore that blood is still being passed on for medical prurposes and may be contaminated? From what i have read pcr dna is unpopular for 2 reasons -a) cost b) false positives - NOT because it cannot detect the presence of the genetic material of teh hiv virus. Can someone please explain because it is teh source of confusion for a lot of people on here?

(And this is not a MOVE ON question - i believe it will benefit all round)
16 Responses
Avatar universal
Move on. You just showed you didn't know what you are talking about in your first sentence. CDC? What do they have to do with test approvals? Nothing....
Avatar universal

No, but when you or anyone talk about the 3 month testing window (q"Your 3 month test will be conclusive"uq) you are talking about the CDC guidelines - these arent applied in Australia, France , many GUM clinics in UK and various other locations. There HAS to be reasons why sone tests exist and other tests are used and at what time frame and with what degree(s) of reliablity. There are doctors on the Ask a doctor forum who will disagree with what you consistently cite.
Teak you turn on anyone who questions the status quo ref testing as if theyre an AIDS denialist or have a psychiatric disorder.I am neither.
Why can you not answer my question? its a series of questions not a statement and a lot of people are confused (including me) about testing , test types, timeframes and frankly mate youre not doing anything to help. So dont insult me please with a one-liner.
So are you going to address some of my questions with some valid scientific evidence or are you going to ban me/time me out?
Avatar universal
You're wrong about the GUM clinic and the UK. They use the same guidelines as we use in the US.. No I don't turn on anything that is proven correct and you haven't proved your point and the point is that PCR-DNA test are NOT diagnostic tests they are monitoring tests for people that are infected with HIV to monitor their progression.
366749 tn?1544698865
Building on what Teak has said, yes PCR is not the test recommended for primary screening of the infection, but is a clinical tool for monitoring of the disease progression, and treatment efficacy done, along with other tests like CD4 counts etc. This is a test for those already infected.

Relatively higher probability of false positive, significantly high cost (in my country, it is 15-20 times higher than a simple ELISA anti body test) and other clinical reasons, antibody test still remain the top choice for primary diagnosis of the infection with a confirmation run by Western Blot.
480448 tn?1426952138
virus (in essence having fought and defeated it, HIV being an exception amongst viruses as it is "unbeatable"

Actually, this statement is incorrect.  Almost every virus in the world has no "cure".  There are treatments, and most viruses do not cause as serious complications, but HIV is not "the only virus without a cure", or "unbeatable"...not by far.

Example...common cold virus and influenza.  Both viruses, no cures.
Avatar universal
Sigh. I knew I shouldn't be watching this forum.

NAT/PCR IS used for diagnostic purposes for individuals at particular high risk (MSM with multiple partners) to detect early infection at certain clinics such as Dr. HHH's former clinic. It is tested on pooled samples first to save on costs.

PCR tests are used to diagnose the presence of a number of infectious organisms, including chlamydia and gonorrhea and are also used (as the OP correctly states) in diagnostic situations such as screening blood donations for HIV. Again, it is used on pooled blood samples to save on costs.

Of course it's a diagnostic test. It's just not recommended as the standard test for the vast majority of people who get tested for HIV (who are not at particularly high risk) because the cost and false positive issues already cited here do not justify it.

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366749 tn?1544698865
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