[Question #13433] Think I've finally understood It (test)

1 months ago

Hello doctors,
After the last response from Dr. Hook, I feel much calmer. I just want to check if what I've understood and am now calm about is correct.

Dr Hook responded me "With a negative test on August 25, there is no way that you could have transmitted HIV on August 1."

I understand if I could have been contagious on August 1st, I should already have RNA in my blood, meaning 7-11 days of infection, and from there, the p24 antigen should appear in a few days, right? And it shouldn't take, for example, more than 3 weeks?

I would like you to explain it to me a bit because I'm about to finally understand it and move on.

I also understand that for me to have been contagious on August 1st, I would have needed to have been infected around July 23rd/24th, which would be about 32/33 days since my test. At that point, a result in a healthy person is practically conclusive, right?

Thanks so much again

Edward W. Hook M.D.

1 months ago

I’m sorry you continue to worry. For HIV to be transmitted, it must be detectable. A negative test, even immediately after contact, provides proof that infection cannot have been transmitted. Your summary is correct. There should be no need for further repetition. EWH---

1 months ago

Thanks again, doctor, for your explanation, you mentioned that the test is always positive once a person is able to transmit. My test was an antigen/antibody test, not an RNA test. Is it because once RNA becomes detectable (and therefore transmission is possible), the p24 antigen also appears very soon afterward—so that the antigen/antibody test will already pick it up?

I just want to clearly understand your ‘no way’ that it’s practically impossible to transmit (on 1 August) if I had a negative test on August 25. but he part about RNA and antigen confuses me a bit

I’ve read that in some people the antigens take longer to appear, or that the test might not always detect well the transition from antigens to antibodies

I would really appreciate an explanation with your knowledge and experience so I can understand it clearly and put the matter to rest

Thanks a lot

Edward W. Hook M.D.

1 months ago

You’re getting into “the weeds” here. Because of test methods RNA tests become positive shortly before antigen tests. As I said, antigen/antibody tests are always positive when symptoms are present and nearly always at the time transmission occurs. HIV viral levels are too low for transmission risk to be appreciable when RNA tests are positive but antigen levels are undetectable.

One follow up remaining. EWH

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1 months ago

tou are right, Dr. Hook, and I appreciate your response, I was only trying to understand or have you explain the scientific or studied reason why there was no way I could have been infectious on August 1st with a negative 4th-generation test on August 25th.

The part about RNA and that some people’s antigens take longer to appear confused me, but now I understand that if RNA is already detectable, then antigens should also appear within a few days on a test, right?

So I should trust my negative result at 32 days after an exposure that apparently was not very risky.

Best regards

Edward W. Hook M.D.

1 months ago

As you know, this will be my final response. There should be no need to return.

You are correct that, because the RNA tests are so very sensitive these tests will detect the virus a few days before antigen test became positive. At those very low levels, when RNA is present but antigens are not quite detectable, the risk of infection is virtually zero. This is analogous to breathing the air in a room where someone has influenza or COVID and breathing in minimally contaminated air but not becoming infected.

This thread is now complete and will be closed. As I said there should be no need to return. EWH

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