Chagas disease (also called "American trypanosomiasis") is caused by a protozoal parasite called Trypanosoma cruzi. It is found mainly in Central and South America, and in some parts of the southern United States.
The parasite infects many wild and domestic animals, including opossums, armadillos, rodents, and wild carnivores. Cats can become infected, but serious illness in cats is rare. Trypanosoma cruzi can also infect people and cause disease.
Chagas disease is usually spread by blood-feeding insects called kissing bugs, reduviids, or assassin bugs. When a kissing bug bites, it often leaves droppings near the bite. A person or animal can become infected if the droppings containing the parasite get into the bite or another skin wound, the eyes, or the mouth.
Animals infected by Trypanosoma cruzi can also serve as sources of infection for the insects, helping the disease continue to spread, or they can bring the parasite into homes, increasing the chance of people becoming exposed to it.
