African Sleeping Sickness

Introduction. 

African sleeping sickness is caused by the flagellated protozoan Trypanosoma brucei. It is transmitted by an insect vector, the tsetse fly. Animal reservoirs exist for at least one strain. Trypanosoma brucei gambiense is marked by chronic disease, while T. brucei rhodesiense has a more acute and virulent presentation (death in <12 months).

Summary

• Cause: Trypanosoma brucei (2 strains)
• Microscopy: Flagellate with undulating membrane
• Transmission: Tsetse fly (vector); zoonotic (T. b. rhodesiense)
• Symptoms: Ulcer at bite site (occasional); fever, myalgia, arthralgia, enlarged lymph nodes (Winterbottom sign)
• Complications: CNS involvement; lethargy, tremors, meningoencephalitis
• Pathogenesis: Invasion of blood, lymph, CSF; tissue destruction
• Treatment: suramin, pentamidine