Chagas disease

Abstract

Trypanosoma cruzi, the protozoan parasite that causes Chagas disease, is a zoonotic infection with many mammal host and vector species. It is transmitted to humans by contamination of mucous membranes or abraded skin with infected faeces of bloodsucking triatomine bugs, also by blood transfusion, organ transplantation, transplacentally, and orally by food contaminated with infective forms. It multiplies intracellularly (pseudocysts) as amastigotes in mammalian cells, particularly heart and smooth muscle, from which flagellated trypomastigotes emerge to reinvade cells or circulate in blood. Around 10 million people are infected in Latin America; imported cases and congenital cases may occur elsewhere. Proven methods of controlling domestic triatomine bugs include insecticide spraying (with pyrethroids), health education, community support, and house improvement. Serological surveillance of children detects residual endemic foci or congenital transmission and is vital for monitoring the success of control programmes. There is no vaccine.