[Question #3561] HIV Group P and N

37 months ago
Dear Doctors, 

I’m really happy to find an expert website because I have been seeking an understanding and explanation of a few things that confuse me and honestly not many doctors also don’t  seem to know these details. I request your expert explanation so that I can understand the following - 
1.) I studied the Abbott Architect manual for CMIA test and it clearly mentions the test checks for HIV 1 Group M and O and HIV2. If the manufacturers themselves have written this so clearly what if someone is infected by Group P or group N of HIV1? The test will miss this infection ?
2.) Now if someone tests early we can find P24 antigen. Is P24 produced by the body irrespective of the group of HIV1 by all 4 groups M,N,O and P. ....I know HIV 2 infection there is no p24.? If you say yes that p24 is produced by all types of HIV1 irrespective of the group then early detection testing is good but what if someone tests after P24 is gone? And if you 
3.) if someone wanted to make sure that they were not infected with HIV 1 Group P and Group N then which test do you suggest that they take. I understand these are rare but to exclude their possibility what test to take?
4.) For HIV2 is the duo sufficient for all types and subtypes? Is there is possibility that the test misses a few types and subtypes of HIV2?
5.) now, regarding the PCR testing. Can this test detect all types of HIV1 infection with regards to the types including group P, O and N. 

Last I would also request if you can help me understand why is it that labs or testing services conduct one test say at 12 weeks and if it’s negative tell the individual who is testing that he is conclusively negative whereas there may be a chance of the individual being infected with a group of HIV1 subtype that the test does not detect? Isn’t that dangerous because that individual can pass on the infection to his wife or girl friend or anyone else? 
I just want to understand how does this work and why is it that tests don’t check the rare types? 
37 months ago
Sorry - in question no.2 to complete if p24 is not produced by all types and subtypes then isn’t there a chance for the test to miss? 

I have read your older posts and I know you have said the HIV tests are among one of the most accurate tests for any medical condition. It’s just that I want to understand this and request if you can please explain.
37 months ago
Sorry. I have broken the question in too many parts. Also, one last question

6.) I came across a article online which said that a person was infected with  CRF01_AE (subtype E )  But the tests could not detect this and that person got negative in two tests. His exposure was in Thailand but he tested in India? How does this happen? 
Edward W. Hook M.D.
Edward W. Hook M.D.
37 months ago
Welcome to our Forum. Before I answer your specific questions, I will give you several pieces of more general advice which I think will also answer your questions.  My fist comment is that I need to urge you to stay of the internet regarding information on HIV.  Much of what is there is incorrect, out of date, or taken out of context and will mislead you.  Second,  concerns about various HIV types are misplaced.  Current HIV tests, detect all HIV types.  Earlier concerns about type O were addressed soon after they were recognized and since then HIV tests can be used with confidence irrespective of the type of infection one is worried about. 

In answer to your specific questions:
1.) I studied the Abbott Architect manual for CMIA test and it clearly mentions the test checks for HIV 1 Group M and O and HIV2. If the manufacturers themselves have written this so clearly what if someone is infected by Group P or group N of HIV1? The test will miss this infection ?
The test results from the Architect should be believed for all HIV types.

2.) Now if someone tests early we can find P24 antigen. Is P24 produced by the body irrespective of the group of HIV1 by all 4 groups M,N,O and P. ....I know HIV 2 infection there is no p24.? If you say yes that p24 is produced by all types of HIV1 irrespective of the group then early detection testing is good but what if someone tests after P24 is gone? And if you 
All HIV-1 types produce p24 antigen which is similar and would be detected by current tests.  The p24 antigen is not produced by the infected person, it is a part of the HIV virus.  Once the p24 antigen can no longer be detected, infected persons reliably have antibodies to HIV which would be detected by current tests.

3.) if someone wanted to make sure that they were not infected with HIV 1 Group P and Group N then which test do you suggest that they take. I understand these are rare but to exclude their possibility what test to take?
See above.  Standard tests will detect all HIV types.

4.) For HIV2 is the duo sufficient for all types and subtypes? Is there is possibility that the test misses a few types and subtypes of HIV2?
The combination tests detect antibodies to HIV 2 reliably at any time more than 6-8 weeks after exposure.  I say 6-8 weeks because we know these tests are reliable for all HIV-1 types at 6 weeks but there are SO FEW HIV-2 infections that the data are limited.

5.) now, regarding the PCR testing. Can this test detect all types of HIV1 infection with regards to the types including group P, O and N. 
Yes

6. I came across a article online which said that a person was infected with  CRF01_AE (subtype E )  But the tests could not detect this and that person got negative in two tests. His exposure was in Thailand but he tested in India? How does this happen? 
I am not aware of this report or the circumstances.  Please see my earlier note about the internet.  EWH
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37 months ago
Thank you so much for replying doctor. 

What I understand from you is that current tests detect all HIV types and subtypes, which now makes me wonder why is the manual by Abbott saying only M and O for HIV1. Probably it was an older manual which I got. The newer manual may say something else. The reason I’m asking you these questions is because I believe my tests are missing something  and I say that with a lot of confidence because I know my body. I had a condom break with a CSW and all symptoms including fever and rash and now some lingering symptoms like swollen nodes in underarms. I tested as per below- 
1.) PCR for HIV1 - not detected at 10 days
2.) Combo test at 4 weeks - non reactive 
3.)Combo test at 9 weeks - non reactive 
4.) Combo test at 11 weeks - non reactive
5.) PCR for HIV1 at 12 weeks - not detected
6.) Combo test at 20 weeks - non reactive 
Further to the above tests I also had the below tests post exposure at 9 weeks
HEP C, HEP B, Gonorrhoea, chlamydia, syphillis and HSV 1&2. All results came negative. Are these tests conclusive at 9 weeks ? 

I’m seriously confused and hence I’m searching the Internet as to what possibilities of the test missing some infections and types/subtypes? I’m sorry and I apologise but I ask again to reconfirm that all standard tests today cover all type of HIV1 and 2 subtypes? Can I say this with confidence to my doctor who didn’t seem confident answering this to me? There is no type or subtype of HIV which today’s tests don’t cover? 
I am also now planning at the 5 month mark to take the HIV2 detection by real time PCR and HIV1 RNA decetection by Taqman. What is your opinion on these tests and is 5 month a good window for them? 

I’ve tried earlier a few places to ask the same question and I’ve only got replies saying control my anxiety or believe your results. First time I have a confident reply that these tests cover all. Wouldn’t you agree that it was a valid question and a source of worry when the manufacturer manual itself states that it covers only HIV 1 M&O. I also verified this on the FDA site which approved this test and found the same thing, which caused me a lot of worry. Why would they write this earlier, was it earlier that the tests only covered a few strains and now it’s all updated? 
37 months ago
All these tests have been done by one lab. I’m going to do the new tests in a different lab. When I ask a few questions to the testing service I use they just tell me to believe my results. That’s their one reply to all my questions with no logical explanations. I think they are fed up of me and they tell me not to test more, as per them these 6 tests are 99.9% accurate. Do you agree with them and in your opinion are my tests 99.9%  or in your opinion they are 100%. Please can you tell me which is the most reliable test as per you? 
Edward W. Hook M.D.
Edward W. Hook M.D.
37 months ago
Repeating your questions will not change my answer, just as further testing is not going to change the result of your tests.  You need to understand that the symptoms that you describe are quite non-specific and have many potential non-HIV/STI causes.  Einstein said that to keep asking the same questions and expect different answers is one definition of insanity.  Further, please understand that even in the "bad old days" when tests did not perform as well as they do currently, problem stains like Type O or HIV-2 DIN NOT give negative results, they gave equivocal or indeterminate results.   Your results are repeatedly negative.  To persist in thinking that the "must" be due to HIV is faulty thinking.  Your focus on minuta such as company package inserts is misplaced.  The companies and the FDA negotiate and agree on wording in their package inserts at the time tests are licensed and after that they do not change- to make changes would require multi-million dollar studies and repeat complete examination by the FDA, something that would not happen.   

I urge you to see a qualified health care provider and search for other causes of any residual symptoms you might have.  for instance, MOST people have lymph nodes that can be felt and when lymph nodes are found, they are non-specific. 

I urge you to accept that you DO NOT HAVE HIV and move forward.  EWH
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37 months ago
Thank you Dr. Hook, really appreciate the reply and assurance. I feel that you’re absolutely confident regarding my negative tests. 

Can you please comment on my 9 week tests for other STD’s as well. Are those tests conclusive for each STI i tested for. If there is a STI for which I tested too soon then I will retest - specially HSV, Syphillis and Hep c. I believe a co infection of hep c and HIV can delay accurate results for HIV testing?  Hopefully 9 weeks would be sufficient for these STI’s. Request your opinion. 

I also am aware this will be your last response and I want to Thank you for your help and congratulate you for this amazing service. I’ve spent a lot of time on the internet, probably the last 4 months reading about HIV and testing for HIV, you are so right about the out of date information out there. It’s been very SCARY. Once again thanks and have a great day Sir. 
Edward W. Hook M.D.
Edward W. Hook M.D.
37 months ago
Thanks for your thanks.  

I suspect the Internet has, once again, misled you.  There are no sound scientific data to suggest that hepatitis C, or any other co-infection meaningfully delay or compromised the accuracy of test results.  Your 9 week test results are all conclusive and should be believed. ,as an FYI, should a similar situation arise again in the future, we strongly recommend AGAINST HSV blood tests in most situations such as yours.  The tests are troubled by both poor sensitivity mand a high rate of false positives.  You are fortunate M that your tests were negative.

As you point out, this will be my final reply.  I hope the information,I have provided will be helpful in moving forward from the concerns about HIV and other STIs that you have.  Take care.  EWH
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37 months ago
Thank you Doctor. Really appreciate the help !!!