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Is A Elisa HIV Fourth Generation Test At 52 Days Conclusive?
Question: Hello. I have a question about HIV tests. I got tested 52 days (7 weeks) after unprotected sex. The test was Elisa, fourth-generation, both HIV antibodies and p24 antigen. The result was negative. I didn't take antibiotics and I didn't have any health condition that can prolongue the window period. I would like to ask if the test is conclusive. In my country (the Czech republic), the test is considered conclusive after 2 months, but I heard that for example in France it's just 6 weeks. What causes the difference?
I would also like to ask whether the occurrence of HIV primary infection makes the test conclusive earlier. I had a fever and a headache for 2 days 6-7 days after the exposure and I got the impression from some of the answeres on this website that in this case one can get tested after 3 weeks or so.
Thank you very much for your answer.
I would also like to ask whether the occurrence of HIV primary infection makes the test conclusive earlier. I had a fever and a headache for 2 days 6-7 days after the exposure and I got the impression from some of the answeres on this website that in this case one can get tested after 3 weeks or so.
Thank you very much for your answer.
Brief Answer:
Window period might vary with the laboratory but most are less than a month
Detailed Answer:
Hi XXXX,
Thanks for writing in to us.
I have read through your query in detail.
ELISA fourth generation tests are highly accurate if done after 12 days because they test for HIV 1 and 2 antibodies and p24 antigen. This is state of the art test and if your results are negative after 52 days then you are not infected.
Your concern about the window period for fourth generation ELISA test for HIV is understandable.
We have many countries in the world and each has its own health guidelines and these tests have been imrpoving in accuracy and shortening window period over the last few years.
Some of the window periods followed by different laboratories for fourth generation HIV tests is as follows
(i)Eleven to 16 days
(ii) 14 days
(iii) 16 days
(iv) Approximately two and a half weeks
(v) Three to four weeks after exposure
(vi) Between 24.5 and 26 days after exposure
(vi) One month
As you have said, 2 months in Czech republic and 6 weeks in France. This is due to the test accuracy in laboratories doing the tests at the time these rules were framed by the governments in consultation with their respective laboratories and health departments.
If you got it done then at 52 days then there is no need to worry.
Early HIV infection appearing as acute HIV syndrome will show up on tests very early and with the start of symptoms. This can be seen on the first test when done after the symptoms happen.
Hope this answers your question. Please feel free to correct any oversight in my interpretation of your problems and discuss them in detail as per your requirements.
Hope your query is answered.
Do write back if you have any doubts.
Regards,
Dr.Vivek
Window period might vary with the laboratory but most are less than a month
Detailed Answer:
Hi XXXX,
Thanks for writing in to us.
I have read through your query in detail.
ELISA fourth generation tests are highly accurate if done after 12 days because they test for HIV 1 and 2 antibodies and p24 antigen. This is state of the art test and if your results are negative after 52 days then you are not infected.
Your concern about the window period for fourth generation ELISA test for HIV is understandable.
We have many countries in the world and each has its own health guidelines and these tests have been imrpoving in accuracy and shortening window period over the last few years.
Some of the window periods followed by different laboratories for fourth generation HIV tests is as follows
(i)Eleven to 16 days
(ii) 14 days
(iii) 16 days
(iv) Approximately two and a half weeks
(v) Three to four weeks after exposure
(vi) Between 24.5 and 26 days after exposure
(vi) One month
As you have said, 2 months in Czech republic and 6 weeks in France. This is due to the test accuracy in laboratories doing the tests at the time these rules were framed by the governments in consultation with their respective laboratories and health departments.
If you got it done then at 52 days then there is no need to worry.
Early HIV infection appearing as acute HIV syndrome will show up on tests very early and with the start of symptoms. This can be seen on the first test when done after the symptoms happen.
Hope this answers your question. Please feel free to correct any oversight in my interpretation of your problems and discuss them in detail as per your requirements.
Hope your query is answered.
Do write back if you have any doubts.
Regards,
Dr.Vivek
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Above answer was peer-reviewed by :
Dr. Chakravarthy Mazumdar
Answered by
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