African Sleeping Sickness Statistics 60 million people at risk 300,000-500,000 new cases/year >66,000 deaths/year

Impact
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. It threatens more than 60 million people in 36 countries of sub-Saharan Africa, 22 of which are among the least developed countries in the world. 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% 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 a 100% mortality rate.

Symptoms
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.

SBRI's Role
Scientists at SBRI have begun to identify new targets for drugs, vaccines, and diagnostic tools for African sleeping sickness and other related diseases. Scientists at SBRI 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, SBRI researchers sequenced the genomes of the parasites that cause African sleeping sickness, Chagas disease and leishmaniasis, providing the basis for new drugs and treatments.

Kenneth Stuart, Ph.D., investigates the biological mechanics of parasites in order to identify new targets for drugs, vaccines, and diagnostics. His lab recently identified about one third of the proteins that are predicted from the genome sequence of the organism that causes African sleeping sickness and began characterizing more than 100 proteins that are in various multiprotein complexes. This information will provide a foundation for drug and diagnostic development.

Marilyn Parsons, Ph.D., recently identified and characterized proteins that transport molecules into the apicoplast, a unique and essential cellular component of malaria and toxoplasma. The apicoplast is a drug target for malaria and toxoplasma. Her lab has also characterized differences between human and trypanosome proteins that are required for formation of the peroxisome (glycosome), a cellular component that is a drug target in trypanosomatids.

Peter Myler, Ph.D., is determining the function of a regulatory gene that may be a potential drug target.  He also directs the genome sequencing effort to identify new targets for drugs, vaccines, and diagnostics.

Links
WHO African sleeping sickness fact sheet

CDC African sleeping sickness fact sheet

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