Sleeping sickness and nagana disease caused by Trypanosoma Brucei

Abstract

The hemoflagellate Trypanosoma brucei is the causative agent of human and animal African trypanosomiasis, also known as sleeping sickness and nagana disease, respectively. The infectious disease is transmitted by the bite of infected tsetse flies and afflicts mainly rural populations in sub-Saharan Africa. The subspecies T. b. gambiense and T. b. rhodesiense are responsible for the two forms of human African trypanosomiasis, the West and East African sleeping sickness, respectively. A third subspecies, T. b. brucei, is only infective for animals. The disease progresses in two stages. In the first stage, the parasites are restricted to the blood and lymphatic system, while in the second stage they invade the central nervous system. The presence of the parasites in the brain of humans is associated with disturbance of the sleep-wake cycle which is the main characteristic symptom of second-stage sleeping sickness and in many languages gives the disease its name. Without treatment, infected humans and animals will die within months or years. Only few drugs are available for treatment of sleeping sickness and nagana disease, but most of them are difficult to administer and show serious side effects. Although T. brucei has been extensively studied and many unique molecular and cellular features have been discovered for this organism, no new drugs have been developed for treatment of sleeping sickness and nagana disease since the 1970s. New methods for diagnosis, therapy, and vector control are needed if eradication of the devastating disease is to be achieved.