Nagana, also known as
nagana pest or
animal African trypanosomiasis, is a disease of vertebrate animals. The disease is caused by
trypanosomes of several species in the genus
Trypanosoma such as
Trypanosoma brucei.
Trypanosoma vivax causes nagana mainly in West Africa, although it has spread to South America. The trypanosomes infect the blood of the vertebrate host, causing fever, weakness, and lethargy, which lead to weight loss and anemia; in some animals the disease is fatal unless treated. The trypanosomes are transmitted by
tsetse flies.