Clinical Manifestations and Pathology
Although trypanosomiasis has been studied for over 80 years, much is still unknown about the pathology of the disease. Three phases follow the bite of an infected fly: first the chancre itself; then the hemolymphatic or “primary stage”; and finally the meningocephalitic or “secondary stage.” On average, people infected with T.
b. gambiense live 2 or 3 years before succumbing, although there are recorded cases of infection spanning as much as 2 decades. In contrast, infection with the more virulent T. b. rhodesiense, if untreated, usually leads to death within 6 to 18 weeks.The disease manifests a bewildering, sometimes startling, array of clinical symptoms, which can vary from place to place. Progressing through the two stages, there is increasing parasitemia with eventual involvement of the central nervous system. Clinical symptoms can include fever, headache, and psychiatric disorders such as nervousness, irascibility, emotionalism, melancholia, and insomnia, which reflect neuronal degeneration. Other symptoms include loss of appetite, gross emaciation, sleep abnormalities, stupor, and the characteristic coma from which sleeping sickness derives its name. Some of the initial symptoms of sleeping sickness are also characteristic of early malaria, which can make differentiation between the two diseases difficult in the field. A common, easily recognizable symptom is swelling of lymph nodes, especially those of the cervical, Subclavicular, and inguinal regions. Another common symptom is called “moon face,” an edema caused by leaking of small blood vessels. A most common complication during trypanosomiasis is pneumonia, which is a frequent cause of death. A disturbing aspect of the chronic gambiense form can be its long period of development, sometimes as long as 15 years after the victim has left an endemic area.