Below is an instruction from Human. Write a response.
    ### Instruction:
    How to diagnose Parasites - American Trypanosomiasis (also known as Chagas Disease) ?
    ### Response:
    The diagnosis of Chagas disease can be made by observation of the parasite in a blood smear by microscopic examination. A thick and thin blood smear are made and stained for visualization of parasites. However, a blood smear works well only in the acute phase of infection when parasites are seen circulating in blood.
    