Chagas's disease A disease that can affect humans and other animals. It occurs chiefly in Central and S. America. The causal agent is a protozoon,
Trypanosoma cruzi. The pathogen is transmitted by blood-sucking bugs. Symptoms may include anaemia and various signs of heart, gland, and nervous-system involvement. The disease is named after the Brazilian physician Carlos Chagas. Charles
Darwin may have been infected with this disease in S. America, and some have suggested that his continual ill-health in later years was due to it.