The parasite of the Chagas disease is a microscopic protozoan (animal of just 1 cell, looking very simple in a common optic microscope). Its scientific name is Trypanosoma cruzi, and it is related to another microorganism that in Africa provokes the "sleeping sickness" transmitted by a fly called "Tse-Tse".

The T. cruzi is very small (around 20 thousandths of an millimeter) and has a very long body with a flagellum and a wavy membrane. When these structures are vibrating and shaking allow the movement in the blood.

The populations of T. cruzi move in nature, human beings, vector and innkeepers. During their evolutionary cycle, they suffer deep form alterations that, in general, represent their adaptation to the environment. Those forms are called differently depending on their general look, the way the flagellum emerges from the cell body and the position of 2 very important intracellular structures: nucleus and the motion organ.

Under experimental conditions different isolations of T. cruzi have different tropism to many tissues, but the majority live in the reticulum-endotelial system, cardiac muscles and bones. There has been many studies about the chemical composition and metabolism of the parasite. What it's known is that the content of proteins in epimastigotes is around 50% and the lipids up to 20%. The T. cruzi metabolizes the glucose and other sugars, making an aerobic fermentation with excretion of organic acids, according to some researches of J.J. Cazzulo and J.B. Cannata.

The antigenic composition of T. cruzi is complex but it does not present any variation mechanism like the African trypanosomes. Getting monoclonal antibodies (from the genetic information of an immune cell)and cloning D.N.A have helped to the identification, characterization and purification of very important biological antigenics.

Fuentes de Información

• Tripanosoma cruzi, el invasor
  Ciencia Hoy - Volumen 1 N° 2 Febrero/Marzo 1989
  http://www.ciencia-hoy.retina.ar/hoy02/trypanosoma.htm

• Yves Carlier, MD, MSc.
  Chagas Disease (American Trypanosomiasis)
  eMedicine.com, Inc.
  http://www.emedicine.com/med/topic327.htm

Used with permission from eMedicine.com, Inc., 2004. Carlier Y, Luquetti AO, Dias JCP, Truyens C, et al. Chagas Disease (American Trypanosomiasis). eMedicine Journal [serial online]. 2004. Available at: http://www.emedicine.com/med/topic327.htm. Accessed Date (i.e., January 19, 2004).

More Information

• Trypanosoma cruzi
• Life cycle
• Frequently Asked Questions