From Invasion to Systemic Dysfunction: Pathophysiology of <em>Trypanosoma brucei</em> in Veterinary Medicine

Trypanosoma brucei is a protist parasite that causes African trypanosomiasis, or sleeping sickness, in humans and animals. The disease consists of two phases, a hemolymphatic phase and a meningoencephalic phase. However, the parasite could colonize other organs, remain as a reservoir, and evade drug treatment, but the mechanisms it uses are unclear. The purpose of this review is to compile information from different sources to provide an in-depth explanation of the pathophysiology of trypanosomiasis, focusing on its virulence factors, host-parasite interaction, and extravascular migration capacity. All information was collected from various articles, research studies, and experiments that were consistent with the objective presented. In conclusion, trypanosomiasis progresses according to the parasite's ability to modulate and evade the immune response, which generates chronic inflammation and contributes to the progression of the disease. Likewise, thanks to growing evidence of the ability of T. brucei to colonize extravascular tissues, it can be said that trypanosomiasis is not exclusively hematological and that several organs can be affected. Finally, the neuropathogenesis of T. brucei is related to the entry of the parasite into brain tissue (the route of which is still unclear) and different immunomodulators that contribute to neuroinflammation and can aggravate the disease.