>How do you convince a doctor to actually check for parasites?
Scopolamine and a cattle prod? Actually, if you travelled internationally, it shouldn't take more than a polite request.
I sincerely hope your fears are in vain. I know very little of chagas disease, but it seems early treatment is the most effective treatment. If you have it, you've wasted precious time.
Hindsight would have you plowing through such resistance and demanding the desired tests as you deserve. Perhaps you were too timid. This is slightly odd, with international travel being about the only thing that would have most American doctors considering parasites.
But it's two years after the fact. If I were in such a position, I would resolve to allay my fears and wrest a sure conclusion from the medical bureaucracy. I would take notes of all my symptoms, a chronology of progression, and also adequately inform and prepare myself to hold a compelling dialog with the doctor. Screw their interest. You are the patient and they have responsibilities beyond hurling pills at rote and familiar illnesses. If you test positive, then you may have lawsuit material. If you don't, it may be time to explore other causes or solutions to what ails you, and crucially, you'll have peace of mind about that specific fear. So if you are truly concerned, go demand a test.