Hi, my "exposure" was protected vaginal sex, to the best of my knowledge the condom did not break.
I had a 4 Generation HIV Test (Dynacare) at 47 days just to be on the safe side, it was non-reactive. I read that CDC (https://www.cdc.gov/hiv/basics/testing.html) and Catie (https://www.catie.ca/en/fact-sheets/testing/hiv-testing-technologies) regard the 4 Generation HIV Test as conclusive at any time beyond 45 days.
My question is, should I have another test at 3 months? Since my "exposure" was in South America, am I at any risk for HIV-2? Would HIV-2 be picked up conclusively at 47 days as well?
Thank you for your inquiry. From what we gather from the question, you were asking about the conclusiveness of a 4th Generation HIV test taken 47 days after a Low Risk exposure (evidence of transmission occurs through these activities when certain conditions are met).
Protected sex could meet the three components of the Transmission Equation if HIV containing fluids are able to gain access to your bloodstream. Getting an HIV test outside of the window period after such an exposure is a very responsible thing to do. With the 4th Generation test most HIV specialists agree that the results are conclusive after 6 weeks, but some physicians and guidelines still recommend retesting after 3 months for completely conclusive results (1). Since the 4th Generation test can accurately detect 99% of HIV infections after 6 weeks, it is very unlikely that the test result you received is incorrect. HIV-2 is a rare strain of the HIV virus that is prevalent in very few countries and in regards to HIV-2 testing, the antibodies to this strain of HIV would be detectable within the same time frame as HIV-1 antibodies using the 4th Generation test (2). The webpages you cited are great sources of information and I am glad you were able to access them to help with your situation!
Recommendation: Refer to a physician for more personalized answers and for an HIV test 3 months post-exposure (for completely conclusive results).
AIDS Vancouver Helpline/Online, Marie