What is "trypanosoma brucei"

Nagana \Na*ga"na\ (n[.a]*g[aum]"n[.a]), n. [Prob. native name.] (Med.) A disease of horses and other domestic animals, transmitted by the tsetse fly; any trypanosomiasis, especially the variety caused by Trypanosoma brucei. [South Africa]

Trypanosoma brucei is a species of parasitic protozoan belonging to the genus Trypanosoma. It causes African trypanosomiasis, known also as sleeping sickness in humans and nagana in other animals. T. brucei has traditionally been grouped into three subspecies: T. b. brucei, T. b. gambiense and T. b. rhodesiense. The latter two are typically parasites of humans, while the first is that of other animals. Only rarely can the T.b.brucei infect a human.

T. brucei is transmitted between mammal hosts by an insect vector belonging to the species of tsetse fly. Transmission occurs by biting during the insect's blood meal. The parasites undergo complex morphological changes as they move between insect and mammal over the course of their life cycle. The mammalian bloodstream forms are notable for their variant surface glycoprotein (VSG) coats, which undergo remarkable antigenic variation, enabling persistent evasion of host adaptive immunity and chronic infection. T. brucei is one of only a few pathogens that can cross the blood brain barrier. There is an urgent need for the development of new drug therapies, as current treatments can prove fatal to the patient.

Whilst not historically regarded as T. brucei subspecies due to their different means of transmission, clinical presentation, and loss of kinetoplast DNA, genetic analyses reveal that T. equiperdum and T. evansi are evolved from parasites very similar to T. b. brucei, and are thought to be members of the brucei clade.

The parasite was discovered in 1894 by Sir David Bruce, after whom the scientific name was given in 1899.