I get a negative 4th Gen rapid test over a month later. At 3 months, I decided to get tested again at Labcorp however there was a warning on their HIV test stating that high doses of biotin interfere with it (internet sleuthing tells me it gives a false negative). I panic because I had been taking a multivitamin with 30mcg biotin in it for the past 2 months.

I stop my vitamin and get a 4th Gen lab test 11 days later at a lab that did not explicitly state their HIV test has biotin interference. I also took 2 Oraquicks and another 4th Gen rapid test (this is all 3 months post exposure). All negative results. I'm still scared so I see my doctor for another test at 4 months exposure (at this point I'm 5 weeks off my vitamin). She assuaged my fears and I get another negative result (the test was called CHIV so I believe it's manufactured by Siemens).

Unfortunately, my problem now is that I cant believe my tests. While I didnt take a high dose of biotin, the fact that I took any at all makes me feel like it's in my system forever doing nefarious things to my HIV tests.

Please help me ease my fears. How long is biotin in my system? Am I exposing my boyfriend to HIV when we kiss (I'm terrified to be intimate with him in case I'm positive)? When is a safe time frame from ceasing biotin to take another test so I can be certain there's no interference? Please help. I just don't want to hurt anyone. Thank you kindly.

Starting first with the title you chose of your question:  there are no medications, drugs, illnesses, or other things that interfere with HIV blood tests and their accuracy. I'll come back to biotin below -- but it is not a cause for worry.

How having read your questions....  First, this seems to have been a low risk exposure. Protection against HIV and STDs is considered complete when the condom stays behind in the vagina. The important aspect is that the penis is covered during penetration. If indeed the condom has come off during sex and not withdrawal, there could have been risk. But when a man has HIV, the average risk to his female partner during a single episode of unprotected vaginal sex is around 1 chance in a thousand. So no matter what, this was a pretty low risk exposure -- even with a partenr who has had sex with men and transgender partners.

I had not previously heard of any problem with biotin and certain kinds of antibody tests. However, there are NO reports of cases in which it actually was known to interfere with HIV tests. In addition, this theoretical concern doesn't appy to the 4th generation HIV blood tests. These tests measure not only antibody, but also HIV antigen -- i.e. the virus itself. If biotin interfered with antibody testing -- the only kind of interference reported -- the antigen component of the test would make the test positive. In addition, you have had several HIV tests. There is no chance they are all falsely negative. Further, biotin is definitely not "in your system forever".

Beyond this, I'm not sure how effectively I can ease your fears. That's not what we do:  we are not psychologists or mental health experts. All I can do is assure you that your tests prove you do not have HIV. The only thing else you might consider is to speak with your doctor about doing an HIV RNA test, i.e. a PCR test to look for the virus in your blood. I'm sure it would be negative. Be clear:  from a medical, scientific, or risk perspective, you don't need it:  for sure you do not have HIV. But if this conclusive test -- it's what HIV experts use to judge how well HIV drugs are working in infected patients -- will help you believe you don't have HIV and can move on without worry, it might be worth considering.

Really, do your best to relax and believe the science. There is no possibility you have HIV. You really needn't worry about it!

I hope these comments are helpful. Let me know if anything isn't clear.

HHH, MD

First of all, thank you so much for your swift yet very thorough reply. I greatly appreciate your time!

I just have a couple of follow up questions:

1. I went to my doctor today but she refused to put in an order for a RNA test because it was "beyond the scope of her practice." I was very upset and dont want to wait for a referral to an infectious disease doctor so I would like to purchase an RNA test through stdcheck.com (basically, I order the test online and their staff of doctors write the order to take the test at a reputable lab). Would you recommend this route or would you suggest I get a referral to a doctor who can write the order for the test in person?

2. Unfortunately, I've burdened myself with too much knowledge on biotin interference in immunoassays. I've literally read through numerous scholarly articles and even HIV test packet inserts of major testing manufacturers. Honestly, taking the RNA test is the only thing that would calm me down, just as you recommended. I opened pandora's box when I shouldn't have, unfortunately.

3. I've read that the P24 antigen peaks and then disappears early on during an HIV infection, and then antibodies begin to form in the blood. Is this correct? Since I took my tests months after my exposure, would there still be any measurable antigen left in my blood? 

Yes, I will be talking to a therapist this weekend so no worries on that front. I've been worried sick for months and it's time to address the emotional issues that have been driving my paranoia...and this is coming from an experienced social worker who does this for a living and should know better, haha. Thank you again for your help! I appreciate what you do 

2. Again, the immunoassays are measures of antibody. I certainly agree your anxieties have been magnified and accelerated by internet research. Like many anxious persons, it seems you're being drawn to information that inflames your fears and missing the reassuring items that also are present.

3. You're asking about a secondary window. Antigen is present first, giving a positive result on the 4th generation tests; then antibody becomes positive. The hypothetical secondary window assumes a negartive period after antigen is gone but antibody is present. It probably doesn't occur at all:  it is the antibody that makes antigen negative -- that is, if antigen is gone, antibody must be present. Some experts believe that in rare cases, there may be a true secondary window. But if so, it lasts only 1-3 days around 2-3 weeks after infection. It has no bearing on testing beyond 4 weeks.

For what it's worth, it was obvious -- before you said anything -- that you're an intelligent, insightful person. Probably a good example of the devide between intellect and emotion, which you've undoubtedly dealt with professionally innumerable times in your own clients. I don't have any particular advice -- I'm not a psychologist -- except maybe to encourage you do your best to concentrate on (and believe) your left brain and ignore the right brain! The science is the science and it is conclusive in this case.

I have no idea if I reached my limit of questions, so I understand if you cannot respond, but I have one last concern: should I be worried if Group O of the virus is not able to be captured on the RNA test? Again, I made the mistake of looking up RNA tests on the FDA website and see that some tests (including the manufacturer used at my lab) are only approved for detecting Groups M Subtypes A - G. 

Thank you for all that you do!

Thanks for the thanks. I'm glad to have hellped. We accommodate two follow-up exchanges, so that completes this thread. Best wishes.