How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask TheBugDoctor Your Own Question
TheBugDoctor
TheBugDoctor, Doctor (MD)
Category: HIV and AIDS
Satisfied Customers: 1685
Experience:  I am a Board Certified Infectious Diseases physician with many years experience treating a broad range of infectious diseases.
13956133
Type Your HIV and AIDS Question Here...
TheBugDoctor is online now
A new question is answered every 9 seconds

i did the HIV p24 antigen

Resolved Question:

i did the HIV p24 antigen test after 3 week from the exposure and was negative do i have to do the test again
exposure date: 30/7/2011 

test date 22/8/2011

was  0.361 negative

is it 100% accurate???
Submitted: 5 years ago.
Category: HIV and AIDS
Expert:  TheBugDoctor replied 5 years ago.

Hello-

The answer is yes- You definitely have to repeat blood work again.

At 3 weeks, the p24 Ag is far from 100%. (In fact, in the United States we do not use a P24 ag test for diagnosis because it may miss cases). That early, you could still be in the window period before tests become positive. And some patients have low levels that remain undetectable.

 

I generally advise testing, after a high risk exposure, at 4-6 weeks, 3 months and possibly 6 months.

At 3 months you should have a standard antibody ELISA test- At that time, the test is close to 99% accurate.

 

Good luck.

 

Always ask if you need clarification/more information.


POSITIVE feedback & a BONUS are warmly appreciated.
Please note that answers are for information only, do not take the place of an IN PERSON assessment by your doctor,
and does not establish a patient-physician relationship.

Customer: replied 5 years ago.
greetings-

if your going to antibody test your correct, it need at least 3 month, however, antigen is usually for early detection, and antigen is valid for 1 -3 week from the risk exposure.

what i had understand antigen test detect the infection although your in windows period

Expert:  TheBugDoctor replied 5 years ago.

Yes- but in some the antigen may be low, or undetectable.

That is why we don't use Antigen as a screen / diagnostic test. A negative test does not rule out infection.

 

Yes, it is a little helpful, but not completely reassuring.

I would advise the antibody test as I recommended above.

 

Good luck.

 

Always ask if you need clarification/more information.


POSITIVE feedback & a BONUS are warmly appreciated.
Please note that answers are for information only, do not take the place of an IN PERSON assessment by your doctor,
and does not establish a patient-physician relationship

 

TheBugDoctor and other HIV and AIDS Specialists are ready to help you

Related HIV and AIDS Questions