Why is it important to notify past partners if you get a positive result from an hiv test?

It´s important because the might have it too and they could unknowingly spread it  

Well, for starters, it is an act of courtesy. I would not want to walk around with an HIV andd not even know it, especially if I have been with multiple partners. plus, if you were to have a HIV, you could be able to figure out who you got it from and how to solve the issue accordingly. Plus, this disease is not curable; they DESERVE the right to know how this will affect their lives, cause this is permanent!!!

{And just to be clear on handling the situation: I f you do find out who you got the disease from DO NOT beat anyone up, key their cars and spread dirty rumors, it is not fair to that person,and it is not fair to yourself as an individual.}
:):):):)