The tsetse fly is a vector for Trypanosoma brucei, a protozoan parasite that causes African trypanosomiasis, also known as sleeping sickness. This disease affects both humans and animals, and can be fatal if left untreated.

Here's why the tsetse fly is a good example:

* It's a widespread parasite: Tsetse flies are found throughout sub-Saharan Africa, impacting a large population.

* It causes a significant health problem: Sleeping sickness can be debilitating and deadly, particularly in areas with limited access to healthcare.

* It has a major impact on livestock: The parasite also infects cattle, causing a disease known as nagana, which significantly reduces productivity and income for farmers.

While there are many other parasites in Africa, the tsetse fly is a particularly impactful example due to its widespread presence and the serious health consequences it causes.