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HIV-2 Window Period

Question: 

Hello.

I had one unprotected vaginal sexual exposure with a girl. Next day after exposure, we went to a clinic to test. I knew my results won't be accurate but I just wanted to know her HIV status. Clinicians used Alere Determine HIV1/2 Ag/Ab test and she was negative. I also tested with Alere after 50 days and with 4th generation lab test after 60 days. Both were negative.

What I'm worried is, she said she had relationships with African people nearly 2-3 years ago. I know that some African people has HIV-2 type of virus, different than HIV-1. I wonder if she was HIV-2 positive, does this means a prolonged window period? Basically, does HIV-2 has different window period than HIV-1? I searched some articles but I couldn't find exact reports. Alere Determine doesn't have any HIV-2 spesific antigen detection so there needs to be established HIV-2 infection to detect antibodies. But I do not know what is the maximum window period to establish HIV-2 antibodies. I'd be so glad If you can help me.

Thank you!

Answer: 

Hello,

Thank you for your inquiry. From what we gather from the question, you were asking about the seroconversion timeline for HIV-2 and if the window period differs from HIV-1 when using 4th Generation Ab/Ag tests for diagnosis.

After a high risk exposure, such as unprotected vaginal sex, it is very responsible to seek out HIV testing. Many clinicians and guidelines state that completely conclusive HIV results can be obtained with an antibody test 12 weeks post-exposure. With this in mind, there is no evidence to suggest that the seroconversion of HIV-2 is shorter or longer than that of HIV-1 (1). Thus, the window period for the diagnosis of HIV-2 is the same as HIV-1 when using an antibody test for HIV-1/2.

Since your partner's potential HIV-2 exposure occurred more than 3 months ago, you can rely on the accuracy of the test results.

Recommendation: No need for an HIV test with the scenario provided, refer to a physician for other health related questions.

Regards,

AIDS Vancouver Helpline/Online, Marie