Aa
HIV RT-PCR Quantitative, Roche Diagnosis V2 Test
Dear Doctor,
Could you please tell me if the above mentioned test taken after 2 weeks of a sexual exposure that comes with a Negative result (undetectable) + an Antibody Test taken after one month that also comes with a Negative result can be conclusive?
Kind Regards
Cabeca
Could you please tell me if the above mentioned test taken after 2 weeks of a sexual exposure that comes with a Negative result (undetectable) + an Antibody Test taken after one month that also comes with a Negative result can be conclusive?
Kind Regards
Cabeca
Dr, the test i took after 33 days was the 4th Generation Elisa, not sure if that makes any difference...
Dr apologies for returning to the Forum. Last question. If i were to wait for the antibody test due the lower cost in comparison with the PCR, how many weeks i should wait? Thx
MEDICAL PROFESSIONAL
If you are feeling anxious, getting a repeat PCR will get you your answer more quickly. A negative PCR at this time will rule out the possiblity of HIV.
EWH
EWH
Thanks Doctor
Due the high level of anxiety, do you think i should re-test the PCR and rule this out? Or wait 3 months as some people say on the internet?
Does the PCR has false positives?
Due the high level of anxiety, do you think i should re-test the PCR and rule this out? Or wait 3 months as some people say on the internet?
Does the PCR has false positives?
MEDICAL PROFESSIONAL
Welcome to the Forum. the answer to your question is "probably". You say little about the sort of exposure that you are concerned about and the context in which testing is performed is important.
In general we do not recommend HIV PCR testing for diagnosis is HIV infection. While the PCR becomes positive more quickly than other antibody detection tests (i.e. usual blood tests), there are no high quality studies which tell us precisely how soon it is until all infected persons have developed positive PCR tests. We all believe that at two weeks and certainly by 4 weeks everyone with HIV will have a positive PCR test but precisely what proportion of infected people become positive between weeks two and four is not known.
As far as antibody tests are concerned, at the present time the blood tests are becoming more and more sensitive and detecting infection earlier and earlier so that the time difference in detection between PCR test and antibody detection tests is becoming smaller and smaller and at present is, in general only a week or two. At least 90% of persons with HIV and probably more will have positive antibody tests at 4 weeks and probably more.
It is because of the reasoning outlined above, as well as a number of high quality studies that we can say with confidence that at one month a combination of a negative PCR (or HIV p24 antigen such as is used in currently available DUO tests) and a negative HIV antibody test provide definitive evidence that HIV infection has not occurred.
EWH
In general we do not recommend HIV PCR testing for diagnosis is HIV infection. While the PCR becomes positive more quickly than other antibody detection tests (i.e. usual blood tests), there are no high quality studies which tell us precisely how soon it is until all infected persons have developed positive PCR tests. We all believe that at two weeks and certainly by 4 weeks everyone with HIV will have a positive PCR test but precisely what proportion of infected people become positive between weeks two and four is not known.
As far as antibody tests are concerned, at the present time the blood tests are becoming more and more sensitive and detecting infection earlier and earlier so that the time difference in detection between PCR test and antibody detection tests is becoming smaller and smaller and at present is, in general only a week or two. At least 90% of persons with HIV and probably more will have positive antibody tests at 4 weeks and probably more.
It is because of the reasoning outlined above, as well as a number of high quality studies that we can say with confidence that at one month a combination of a negative PCR (or HIV p24 antigen such as is used in currently available DUO tests) and a negative HIV antibody test provide definitive evidence that HIV infection has not occurred.
EWH
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