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HIV-2 seroconversion period
Approx. 6 years ago I had a low exposure contact with a sex worker in Mumbai. I have been tested several times for both HIV-1 and HIV-2, with the last test being an HIV ICMA 1/O/2 done 4 years after the exposure.
I am no longer worried about HIV-1, but I am not sure about HIV-2. I know HIV-2 is uncommon in the US, but there is some prevalence in India. I have done extensive research on HIV-2 seroconversion history, and I have found very little data for determining the window period for HIV-2. One study I have found of sex workers in Mumbai shows that seroconversion for HIV-2 may be delayed due to low replication speed: http://www.ncbi.nlm.nih.gov/pubmed/10667898. I have contacted an HIV-2 researcher about this and he believes that it may have been PCR contamination that caused false positives. What is your take on this article?
Have you been able to find any evidence of an established window period for HIV-2? And if there is no established window period, how can I ever know for sure that I am clear of HIV-2? The uncertainty has been a nightmare for me. Please help.
I am no longer worried about HIV-1, but I am not sure about HIV-2. I know HIV-2 is uncommon in the US, but there is some prevalence in India. I have done extensive research on HIV-2 seroconversion history, and I have found very little data for determining the window period for HIV-2. One study I have found of sex workers in Mumbai shows that seroconversion for HIV-2 may be delayed due to low replication speed: http://www.ncbi.nlm.nih.gov/pubmed/10667898. I have contacted an HIV-2 researcher about this and he believes that it may have been PCR contamination that caused false positives. What is your take on this article?
Have you been able to find any evidence of an established window period for HIV-2? And if there is no established window period, how can I ever know for sure that I am clear of HIV-2? The uncertainty has been a nightmare for me. Please help.
MEDICAL PROFESSIONAL
And by the way, even if the seroconversion window indeed is a bit longer for HIV-2 than HIV-1, it's probably a difference only of a few weeks, maybe not even that much. With a negative HIV 1/2 antibody test 4 years after your exposure, I don't know why you are worried about it. I would suggest you just go on with your life, don't worry about infecting current or future sex partners, and stop searching the internet about it.
MEDICAL PROFESSIONAL
Welcome to the forum. Thanks for your question.
It is true that HIV-2 is somewhat more prevalent in India than North America, but still it's rare. According to a recent research report (http://www.ncbi.nlm.nih.gov/pubmed/20404454), among 175,000 blood donors in India 1998-2007, 465 had HIV (0.25%). Of those, 458 (98.5%) had HIV-1 and 13 (2.7%) had HIV-2. (Six persons had dual infections with both HIV-1 and 2.)
So the odds you were exposed to HIV-2 are low, and I'm not sure it is worth the time and energy you apparently have spent researching the issue on line. You probably know more about HIV-2 versus HIV-1 seroconversion times than I do. Given slower viral replication, it makes sense to me that it might take longer for measurable antibody to develop, but I can't say more.
"Seroconversion" refers only to development of antibody. In the past few years, the standard antibody tests have become excellent at detecting antibody to HIV-2 as well as HIV-1, and that includes the tests that (I believe) are more or less routine in your country.
But if despite this you remain concerned your antibody tests may have missed HIV-2, it can also be detected directly (as you apparently know) by PCR to detect HIV RNA. PCR is highly effective in detecting HIV-2 in those rare patients with false negative antibody tests. So if you have been at high risk for HIV, you could ask your doctors about having a PCR test. If that is negative, in addition to your apparently negative HIV antibody tests, you can be confident you do not have HIV-2. It is true, as you imply, that PCR can give false positive results. But that's rare, and negative results are reliable.
Regards-- HHH, MD
It is true that HIV-2 is somewhat more prevalent in India than North America, but still it's rare. According to a recent research report (http://www.ncbi.nlm.nih.gov/pubmed/20404454), among 175,000 blood donors in India 1998-2007, 465 had HIV (0.25%). Of those, 458 (98.5%) had HIV-1 and 13 (2.7%) had HIV-2. (Six persons had dual infections with both HIV-1 and 2.)
So the odds you were exposed to HIV-2 are low, and I'm not sure it is worth the time and energy you apparently have spent researching the issue on line. You probably know more about HIV-2 versus HIV-1 seroconversion times than I do. Given slower viral replication, it makes sense to me that it might take longer for measurable antibody to develop, but I can't say more.
"Seroconversion" refers only to development of antibody. In the past few years, the standard antibody tests have become excellent at detecting antibody to HIV-2 as well as HIV-1, and that includes the tests that (I believe) are more or less routine in your country.
But if despite this you remain concerned your antibody tests may have missed HIV-2, it can also be detected directly (as you apparently know) by PCR to detect HIV RNA. PCR is highly effective in detecting HIV-2 in those rare patients with false negative antibody tests. So if you have been at high risk for HIV, you could ask your doctors about having a PCR test. If that is negative, in addition to your apparently negative HIV antibody tests, you can be confident you do not have HIV-2. It is true, as you imply, that PCR can give false positive results. But that's rare, and negative results are reliable.
Regards-- HHH, MD
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