Symptoms usually start 1-2 weeks after the tsetse fly bite with a swollen, painful ulcer at the site of the bite that can be an inch in diameter, associated with fever and swollen lymph glands and heals over a few weeks.
Weeks to months later there is the onset of high fever alternating with days of normal temperature. This is associated with swollen, painless lymph nodes of the neck, especially the back of the neck (winterbottom sign). Frequently there is also swelling of the face, hands or feet that comes and goes, with a red circular rash that is itchy.
As the protozoa enters the central nervous system, symptoms develop over a period of weeks to months later with changes in personality, difficulty concentrating, irritability, progressive sleepiness during the day and restlessness at night. As symptoms progress one sees tremors, unsteady gait, slurred speech, coma and death.
West African trypanosomiasis is characterized by a prolonged course of illness, while East African trypanosomiasis tends to have a more rapid onset of symptoms and progression occurring over days to weeks, rather than months to years.