Document Type



Trypanosomes are inoculated into a host (human or animal) in saliva via the biting mouth parts of the tsetse fly. Trypanosomes circulate in the blood of their host, differentiate and spread to other tissues via the lymphatic system during a 30 day period. Humans with African Sleeping Sickness or Human African Trypanosomiasis (HAT) complain of having a fever, headaches and joint pain. If left untreated, a neurological phase develops causing confusion, fatigue, narcolepsy like symptoms, irreversible nerve damage and eventual death. Often associated with malnutrition and poverty, HAT has been reported to have been in existence in Africa since the 14th century. HAT has wreaked havoc and affected millions of lives since that time. Three devastating epidemic waves have occurred since the 1890s in southeast Uganda alone.1 Between 1902 and 1903 the disease agent, a protozoa, was determined to be transmitted by the tsetse fly (Glossinia sp.) and are morphologically the salivarian clade trypanosomes (i.e. their life cycle involves the salivary glands of the tsetse fly).4 Three subspecies of Trypanosoma brucei sensu Jato (s.l.) include Trypanosoma brucei rhodesiense (Southern and Eastern Africa) and Trypanosoma bruceigambiense (Central and Western Africa), which are infective to humans and Trypanosoma brucei brucei, which is not infective to humans, but is to animals. There is uncertainty as to whether Tb. gambiense is zoonotic, if it has a wild animal reservoir that will transmit sleeping sickness to humans or whether it is just transmitted between humans. However, cattle have been implicated as the primary reservoir for Tb. rhodesiense. It is known that clinical manifestation of disease in cattle is caused by T vivax and T congolense. Cattle become anemic, develop a dull attitude, rough hair coat, succumb to severe debilitation due to emaciation and become weak and die if left untreated.

Publication Date


Journal Title

International Journal of Global Health and Health Disparities





First Page


Last Page



©2007 International Journal of Global Health and Health Disparities



File Format


Included in

Public Health Commons



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.