Leishmania is no more than one of the insect trypanosomatid lineages which have successfully colonized two classes of terrestrial vertebrates. Birds serve as a host for various parasites, including many Trypanosoma species. Accordingly, it is important to elucidate the basis of the differences outlined above not only for academic reasons but in order to understand the mechanisms of vertebrate resistance to parasites and, finally, to help find new therapies for leishmaniasis and trypanosomiasis.
Leishmania vectors are free from their own monogenetic parasites.
It can be estimated that from more than 1,000,000 known species of insects no more than 2,000-2,500 species have been studied by parasitologists. So, only a minority of insect taxa originating from a limited number of locations have until now been examined for the presence of trypanosomatids. The vast majority of insect trypanosomatids are still to be described and relationships among them and with Trypanosoma sp. Currently, insect trypanosomatids appear to have the greatest number of formally valid descriptions that cannot be used in research. This report is the only finding of a trypanosomatid in a nematode and it has never been re-isolated.