It's worth mentioning that disease
vector carried by the tsetse fly is the vector for
African sleeping sickness. The disease is caused by
Trypanosoma rhodesiense or
T. gambiense (no doubt named for the location on the
continent of their first discoveries), which acts parasitically in the blood of humans as well as other vertebrates. The disease most commonly caused in other animals is called
nagana.
It's also worth mentioning that the tsetse fly and the common housefly are in the same family.