Avatar universal

Neg @ 6 Months, Any Benefit In a PCR Test?

Greetings Dr's,

I will keep this brief Dr's as it could be so long winded..

I had a HIV concern over an encounter with an ex, I have had around 18 tests (12 blood 6 insti) all 4th generation from 24 days post exposure right through to just past six months, I also had negtive HPB HPC too at six months.

I have not been tested for three months & have managed to get a grip on the anxiety (largely at least), I have had a few lingering concerns & I just wandered if there would be any benefit in a PCR RNA test??

Has there been cases where people have tested out to six months with 4th Gen tests & then positive to your knowledge?

There have been symptoms in all three people involved & although when you feel you have had risk "everything becomes a synptom"., I have managed to avoid getting to worried over reccorung oral thrush as I have conditions such as sinusitus.

I believe the "DUO" to be teh "Gold Standard" these days & even for three months to be Conservative, the odd "delayed" seroconversion memory from my "googling" time pops up so your advice would be appreciated.

Thanks ever so much Dr's,
5 Responses
300980 tn?1194929400
Welcome to the Forum.  From reading your question, my sense is that you have become well informed about HIV tests and what their various strengths and limitations are.  You are correct that globally the 4th generation tests, which detect both the HIV virus itself in the form of the HIV p24 antigen, and detect HIV antibodies in the same way that other antibody detection tests do, is the global "gold standard" for HIV diagnosis.  The 4th generation or so-called DUO tests provide definitive results at 4 weeks following a potential exposure because the p24 antigen test may be positive a week or two before antibodies are detectable.  Once antibodies are present, they remain positive throughout the course of the disease.

In your case, there is no benefit to PCR testing as the occasional benefit of a PCR test is that it may be positive a week or two before the p24 antigen.  The reason PCR testing is not routinely recommended at present by us or others is two-fold - the test has substantially more false positive results than the p24 antigen test and because of expense.  There is no late benefit of PCR as a diagnostic test for HIV.

If you have had so many negative tests, it is time for you to stop testing and focus on moving forward.  Most people with problems such as oral thrush or sinusitis have other explanations an a single HIV test eliminates HIV as a factor contributing to risk for such problems.   I hope you find my comments helpful.  EWH
Avatar universal
Thank you for your reply Dr.

It has been a long journey but what that has made me quite well informed & understnding of HIV.

In terms of the PCR test, my thought process took me there due to various symptoms in both my ex, my current girlfiend & myself, - putting symptoms asside over six months had passed & negative HEPB HEPC & HIV tests were abtained, I guess my only though trail is now that there is some kind of delayed Seroconversion to produce antibodies, I believe I am correct in saying that although the P24 part of the test is quite useful especially in early detection, it is not classed as diagnostic &can be nissed depending were you are within the window period. (Missed - undectable to my knowledge)

In terms of HEPB / C & or HIV, would you feel that adequate testing has taken place & that teh symptoms in anyone involved are irrelevant due to the siad negative tests?

I am not trying to get you to re-answer the same question more just a clarrficaiton on any risk or "delayed seroconversion" or if HEPC & HIV had been present in my ex could this make me potential "imuno silent" ?

Thanks in advance DR & having read your forum can I say that you really are very good at reassuring people, your words are no doubt very comforting and helpful to so many people.


300980 tn?1194929400
You are incorrect that the p24 test is not an accepted diagnostic test.  

Hepatitis C is not sexually transmitted to any meaningful extent.  It should not be considered an STD unless a person is engaged in rectal intercourse.

As for HIV, a negative hepatitis test is definitive at 6 months (an before)

Finally, both for you and for others, it is important to appreciate that the concept of :"delayed seroconversion" is an urban myth, promulgated on the internet which is not a realistic concern unless someone has taken anti-HIV medications or, perhaps, if they have a disease which causes life threatening immunosuppression.  Take care.  EWH
Avatar universal
Many Thanks again for your answer Dr, it is hellpful!

I appreciate the clarification on "delayed seroconversion" & the P24 anitgen being diagnostic

I guess like so many people on this forum it is easy to keep thinking "what if, but maybe..." etc...

I really appreciate your direct nature & quickness in response Dr, I will sleep easy again. :)

With Kind Regards,
300980 tn?1194929400
Glad to help. Take care. EWH

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