Chagas' disease is a parasitic disease caused by a protozoan:Trypanosoma cruzi. It is transmitted to people by bites from infected triatomine bugs or coming into contact with the bug's infected urine or feces.
It causes a 2 phase infection.
First an acute infection within the first few months characterized by fever, headache, enlarged lymph glands, pallor, muscle pain, difficulty in breathing, swelling, and abdominal or chest pain. A tell-tale sign is swelling of the eyelid, but this does not always happen. This is when lots of the parasite are circulating within the body.
In the chronic phase the parasite embeds into muscular tissue of organs, nervous tissue and skeletal muscle. The infection lays low until patients die from complications like heart failure or cardiac arrest.
Treatment is with benznidazole and also nifurtimox. But, there are incidences of the infection coming back and survival rate decreases with severity of the infection.
I hope that helps!