
What Is The Window Period For A HIV Test?

Question: Does taking five days worth of PEP medication affects my HIV results. I took the medication 2 months after exposure and upon finding it was too late, stopped 5 days later.
It has been 3 months post exposure, and with 4th gen testing, I tested negative
It has been 3 months post exposure, and with 4th gen testing, I tested negative
Brief Answer:
Extension of window period is likely
Detailed Answer:
Hi,
Welcome to HCM.
Thanks for posting your query.
PEP two months after the exposure is useless.
In normal immunocomperent individuals window period of HIV tests will not exceed 3 months. But we cannot rule out the possibility of a delay in the window period over 3 months with the intake of ART drugs.
Dr S Murugan
Extension of window period is likely
Detailed Answer:
Hi,
Welcome to HCM.
Thanks for posting your query.
PEP two months after the exposure is useless.
In normal immunocomperent individuals window period of HIV tests will not exceed 3 months. But we cannot rule out the possibility of a delay in the window period over 3 months with the intake of ART drugs.
Dr S Murugan
Above answer was peer-reviewed by :
Dr. Chakravarthy Mazumdar


I understand. However, I only took the medication for 5 days.
Brief Answer:
You are unlikely to have HIV infection
Detailed Answer:
Hi,
Welcome back.
Nothing to worry. 5 days ART would not have much effect. Your result is reliable to a maximum extent.
Dr S Murugan
You are unlikely to have HIV infection
Detailed Answer:
Hi,
Welcome back.
Nothing to worry. 5 days ART would not have much effect. Your result is reliable to a maximum extent.
Dr S Murugan
Above answer was peer-reviewed by :
Dr. Chakravarthy Mazumdar


Thank you. Do I need follow up testing at all?
Brief Answer:
Repeat the test 6 months after the exposure.
Detailed Answer:
Hi,
Welcome back.
Even though it is more unlikely, better to have one more HIV test 6 months after the exposure as there is a remote possibility to have late seroconversion in the presence of an ART intake.
Dr S Murugan
Repeat the test 6 months after the exposure.
Detailed Answer:
Hi,
Welcome back.
Even though it is more unlikely, better to have one more HIV test 6 months after the exposure as there is a remote possibility to have late seroconversion in the presence of an ART intake.
Dr S Murugan
Above answer was peer-reviewed by :
Dr. Chakravarthy Mazumdar


Doctor I'm in an extreme state of fear. Can I be reasssured that the 5 days of medication would not affect my test?
It was a 4th generation test, the test would have picked up infection by 3 months, is that correct?
How did the 5 days of ART medication affect me? Was it too short of a time frame to cause a difference?
I am very scared.
It was a 4th generation test, the test would have picked up infection by 3 months, is that correct?
How did the 5 days of ART medication affect me? Was it too short of a time frame to cause a difference?
I am very scared.
Brief Answer:
You are free from HIV 1 infection
Detailed Answer:
Hi,
Welcome back.
You had taken up 4th generation test. It consists of two parts.
Antigen detection part: P24 Antigen for HIV 1 infection
Antibody detection part: Both HIV 1 and 2 infection
If at all, 5 Days of ART as PEP would have influence, it would be on the Antibody formation and not on antigen detection. So your fourth generation nonreactive report ruled out the possibility of HIV 1 infection beyond any doubt. HIV 1 infection is the most commonest infection throughout the world except few parts of XXXXXXX up to the extent of 99.5%. The prevalence of HIV 2 infection is less than 0.5%. So you are unlikely to have HIV infection.
Dr S.Murugan
You are free from HIV 1 infection
Detailed Answer:
Hi,
Welcome back.
You had taken up 4th generation test. It consists of two parts.
Antigen detection part: P24 Antigen for HIV 1 infection
Antibody detection part: Both HIV 1 and 2 infection
If at all, 5 Days of ART as PEP would have influence, it would be on the Antibody formation and not on antigen detection. So your fourth generation nonreactive report ruled out the possibility of HIV 1 infection beyond any doubt. HIV 1 infection is the most commonest infection throughout the world except few parts of XXXXXXX up to the extent of 99.5%. The prevalence of HIV 2 infection is less than 0.5%. So you are unlikely to have HIV infection.
Dr S.Murugan
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Above answer was peer-reviewed by :
Dr. Chakravarthy Mazumdar

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