Symptoms

Usually a small sore develops at the bite where the parasite enters the body. If this is near the eye, the eyelid becomes swollen (known as the Romana sign). Within a few days, fever and swollen lymph nodes may develop. This initial acute phase may cause illness and death, especially in young children. More commonly, patients enter a symptomless phase lasting several months or years, during which time parasites are invading most organs of the body, often causing heart, intestinal and esophageal damage and progressive weakness. In 32% of those infected, fatal damage to the heart and digestive tract occurs during this chronic phase.

Myocarditis (pictured to the right) is an inflammation of the heart muscle, frequently associated with the acute stage of the disease, which usually returns to normal without treatment. After an asymptomatic period of up to 10-13 years, chronic Chagas heart disease, characterized by fibrosis of myocardial fibres, is seen in a high percentage of the carriers of Trypanosoma cruzi infection.