Trypanosoma cruzi is a species of
parasitic euglenoid protozoan. Amongst the protozoa, the
trypanosomes characteristically bore tissue in another organism and feed on blood, and lymph. This behaviour causes disease or the likelihood of disease that varies with the organism: for example,
trypanosomiasis in humans (
Chagas disease in
South America and
sleeping sickness in Africa),
dourine and surra in horses, and a brucellosis-like disease in cattle. Parasites need a host body and the haematophagous insect
triatomine (descriptions "assassin bug", "cone-nose bug", and "kissing bug") is the major vector in accord with a mechanism of infection. The triatomine likes the nests of vertebrate animals for shelter, where it bites and sucks blood for food. Individual triatomines infected with protozoa from other contact with animals transmit trypanosomes when the triatomine deposits its faeces on the host's skin surface and then bites. Penetration of the infected
faeces is further facilitated by the scratching of the bite area by the human or animal host.