 Chagas disease , also known as American <unk> , is a tropical parasitic disease caused by the <unk> Trypanosoma cruzi . It is spread mostly by insects known as Triatominae or kissing bugs . The symptoms change over the course of the infection . In the early stage , symptoms are typically either not present or mild , and may include fever , swollen <unk> nodes , <unk> , or local swelling at the site of the bite . After 8 – 12 weeks , individuals enter the chronic phase of disease and in 60 – 70 % it never produces further symptoms . The other 30 to 40 % of people develop further symptoms 10 to 30 years after the initial infection , including enlargement of the <unk> of the heart in 20 to 30 % , leading to heart failure . An enlarged <unk> or an enlarged <unk> may also occur in 10 % of people . 
