Thanks for posting your query.
There are instances of acquiring HIV without sexual exposure and via blood transfusion
. These include accidental medical exposure like pin prick injuries
with an infected needle. Maternal to child transmission does not present so late.
Transmission in IV drug users by needle sharing is seen. I am not sure if this is the reason in you.
There are chances where Tridot can be falsely positive. These include acute viral syndromes, hepatic disease, antibodies
to class 2 antigens, auto-antibodies and recent influenza vaccination
Hope this helps.