What A Negative Duo Test At 26 Days Means In This Case (pep Used) ?

Posted on Fri, 9 Dec 2022

Question: i had a possible hiv exposure through unprotected insertive anal intercourse with a female of unknown status. i began Pep, consisting of Truvada, at 68 hrs post exposure. i tested negative on a 4th gen duo test at Pep initiation and negative again at 26 days post exposure on a 4th gen duo. My doctor says this means it is almost certain that I am negative, he has advised me to retest at 6 weeks at whch point he says a negative result will be conclusive. Given the massive amounts of conflicting/outdated information online could you advise on your view of what a negative duo test at 26 days means in this case (pep used) and if you agree a duo test at 6 weeks is conclusive.

Answered by Dr. Dr. Monika Dede (2 hours later)

Brief Answer:
It is a good news that you are negative after 26 days.

Detailed Answer:
Hello and welcome tohealthcare magic.

I have read carefully your history and I think that it it is a good news that you are negative after 26 days.
But,you should know that according the recommendations for post-PEP HIV testing you should do a 4 th generation HIV test after4-6 weeks and after three months from exposure as a conclusive test
Some guidelines say that even after six months should test as a conclusive test but this depends on the HIV test that is used.

Thanks.

Above answer was peer-reviewed by : Dr. Remy Koshy

Follow up: Dr. Dr. Monika Dede (4 hours later)

Thankyou for your answer Doctor. i would like to ask as follow up, 1. Is it your understanding that the use of Pep will not lengthen the window period for testing? 2. At 26 days (being only 2 days short of 4 weeks), in percentage terms what is your opinion of the likelihood it would pick up an infection? especially given the fact I am negative for antibodies and P24 antigen. 3. in your personal experience have you had patients who have tested neg on a duo at 4 weeks howver subsequently positive? Thanks in advance.

Answered by Dr. Dr. Monika Dede (28 hours later)

Brief Answer:
I think that to get a HIV test 2 days early is not a problem.

Detailed Answer:
Hello,
I am sorry for my late response.

You should know that these guidelines for HIV test are because PEP has been reported as delaying infection if it is not successful at preventing it.

This means that people are recommended to wait 28 days after the end of PEP to test again for HIV and to wait 90 days for a negative result to be confirmed.
I think that to get a HIV test 2 days early is not a problem and the risk to get a false negative result specially with duo test is very low.
In my experience I never have had HIV positive patients with a negative result of duo test after 4 weeks.

I hope I have answered your question.
Feel free to ask me further.

Note: Get personalized answers to your HIV related queries You can choose to talk face to face with your doctor. Book a Video Call now.

Above answer was peer-reviewed by : Dr. Prasad