Development of Therapeutic Agents for Human African Trypanosomiasis

African trypanosomiasis is a parasitic zoonosis that is fatal without treatment and has been recognized as a neglected tropical disease. In humans, this disease is referred to as human African trypanosomiasis (HAT) or sleeping sickness, which is characterized by severe sleep disorders. An overwhelming number of African people have experienced HAT without adequate treatment, as some currently available drugs remain unsuitable to the needs of endemic areas. Since 2001, efforts to eliminate HAT have been reinforced worldwide, thus reducing the number of new HAT cases. In addition, this has led to the discovery of several drugs that are easily applicable for therapy; however, additional chemicals and drug targets need to be explored. In the present review, we summarize the symptoms and epidemiology of HAT, the biology of the causative parasitic protozoa Trypanosoma brucei, and therapeutics used in the present treatments. Lastly, we introduce two representative drug discovery studies that are ongoing.