The Evolution of Trypanosomes Infecting Humans and Primates

Parasitism, the diversity of life, and paleoparasitology

“…The evolutive history of trypanosomes have some recent elucidative studies showing that the Salivaria group (Trypanosoma brucei) diverge in a mid-Cretaceous date, around 100 million years ago, when Africa was totally separated from South America and Euroamerica (Haag et al 1998). The cruzi clade has a southern super-continent (South America-Australia-Antarctica) origin, based on the inclusion of Australian marsupial trypanosomes on the clade (Stevens et al 1998, Stevens & Gibson 1999.…”

“…brucei co-evolved in Africa with the first hominids at 5 million years ago, but T. cruzi contact with human host is considered to have occurred in South America only after permanent settlements were made by previously nomadic cultures (Rothhammer et al 1985, Coimbra Jr 1988, Stevens et al 1998). Chagas disease is believed to have spread through the Americas, originating in the Andean countries as a consequence of the domiciliation of Triatoma infestans.…”

Insect trypanosomatids: the need to know more

“…From published phylogenies (see Hollar & Maslov 1997, Philippe 1998, Stevens et al 1998) it seems that the digenetic insect/plant clade -Phytomonas -also has its roots in insect trypanosomatids. Many Hemiptera, even predatory bugs, use plants sap as a source of fluid and it is possible that this may be a precondition to the nonspecific transfer of flagellates from insect to plant and between plants.…”

“…The trypanosomatid evolutionary tree (Philippe 1998, Stevens et al 1998 has in its base the monophyletic clade of Trypanosoma, while Leishmania is situated in the crown with a range of insect flagellate congeries. Interestingly, although Trypanosoma and Leishmania are superficially close to each other from a medical point of view, they are far from each another on the evolutionary tree, and many isolates from insects and plants are spread between Trypanosoma and the crown of the tree.…”

Characterization of Trypanosoma rangeli Strains Isolated in Central and South America: an Overview

“…Recently, another group used the 18S rRNA as a genetic marker to build an evolutionary tree for human and primate trypanosomes and observed that the single T. rangeli strain isolated from a dog in Venezuela was grouped within the cruzi-clade, together with the bat trypanosomes T. marinkellei, T. dionisii, T. vespertilionis, that are not transmitted by triatomine bugs, and with T. cruzi that is transmitted through feces (Stevens et al 1998).…”