30 y/o son for 2 months keeps testing pos.for strep, line super light pink,been on 3 antibiotics,no symptoms, just a throat tickle remains,any advice?

May be a carrier: A subset of the population will carry strep in their throat continuously , often without strep disease/symptoms but are treated as strep when they come in on a positive test but have a viral throat problem. They can also have recurrent strep if there is a carrier in their close circle. If he is being retested/treated when there is no symptoms I would stop.