African Sleeping Sickness


African sleeping sickness (also known as African trypanosomiasis) is a parasitic infection caused by a species of parasite, Trypanosoma brucei, which is transmitted to humans through the bite of the tsetse fly. According to the World Health Organization (WHO), 60 million people who live mainly in rural parts of East, West and Central Africa are at risk of contracting sleeping sickness. Between 300,000 and 500,000 people are estimated to suffer from the disease. With early diagnosis, the chance of recovery from African sleeping sickness is good. However, only 10 percent of patients with African sleeping sickness are accurately diagnosed. There are no effective vaccines, and the drugs used to treat this disease are difficult to administer and often toxic. Untreated cases have 100 percent mortality rate.


A bite by the tsetse fly is often painful and can develop into a red sore, also called a chancre. Initially, parasites multiply in the blood, causing a litany of non-specific symptoms, such as fever, severe headache, extreme fatigue, swollen lymph nodes and aching muscles and joints. In the second phase of disease, the parasites infect the central nervous system resulting in irreversible neurological damage manifested by confusion, personality changes, difficulty walking, sleep disturbance and eventually coma and death.

Seattle BioMed’s Role

Our scientists have begun to identify new targets for drugs and diagnostic tools for African sleeping sickness and other related diseases. Scientists at Seattle BioMed discovered that, contrary to previous expectations, RNA editing — a unique form of control of protein production — is essential for the survival of the bloodstream form of Trypanosoma brucei. Investigators have demonstrated the ability to disrupt this process by blocking production of a selected enzyme. As part of an international consortium, Seattle BioMed researchers sequenced the genomes of the parasites that cause African sleeping sickness, Chagas’ disease and leishmaniasis, providing the basis for new drugs and treatments.