Trypanosomiasis

Trypanosomiasis or trypanosomosis is the name of several diseases in vertebrates caused by parasitic protozoan trypanosomes of the genus Trypanosoma. In humans this includes African trypanosomiasis and Chagas disease (American trypanosomiasis). A number of other diseases occur in other animals.

African trypanosomiasis in humans, which is caused by either Trypanosoma brucei gambiense or Trypanosoma brucei rhodesiense, is presently estimated to threaten over 40 million people in sub-Saharan Africa, especially in rural areas and populations affected by war or poverty. However, only 1.5 million people are estimated to live in areas at moderate or high risk, and for over 20 years the number of cases has been going down due to systematic surveillance and control efforts: in 1998 almost 40,000 cases were reported but almost 300,000 cases were suspected to have occurred; in 2009, the number dropped below 10,000; and in 2018 it dropped below 1000, and it has remained under that number ever since.

Chagas disease causes 21,000 deaths per year mainly in Latin America.

Signs and symptoms

The tsetse fly bite erupts into a red chancre sore and within a few weeks, the person can experience fever, swollen lymph glands, blood in urine, aching muscles and joints, headaches and irritability. In the first phase, the patient has only intermittent bouts of fever with lymphadenopathy together with other non-specific signs and symptoms. The second stage of the disease is marked by involvement of the central nervous system with extensive neurological effects like changes in personality, alteration of the biological clock (the circadian rhythm), confusion, slurred speech, seizures and difficulty in walking and talking. These problems can develop over many years and if not treated, the person dies.