The tsetse fly, despite being known as the "dream fly," does not promote restorative dreams (unless you consider death to be the Eternal Sleep).
Its bite transmits a deadly parasite, the trypanosome, which attacks the nervous system of its victims. The disease that it transmits is known as "sleeping sickness", but in reality trypanosomiasis (as it is really called) not only disturbs sleep cycles, but also causes sensory, motor, psychic and finally neurological disorders that lead to death .
The eternal dream
African human trypanosomiasis, also known as sleeping sickness, is a parasitic disease dependent on a vector for transmission. The parasites involved are protozoa belonging to the genus Trypanosoma , transmitted to humans by bites of the tsetse fly (genus Glossina ) infected while feeding on humans or animals that hosted the parasite.
This fly dedicates no less than 250 genes to ensure that its saliva facilitates the ingestion of human blood without hindrance; But the trypanosome within it has evolved to decrease the sucking efficiency of that saliva .
It is the Machiavellian strategy of the parasite to force its host fly to bite more and more people for its food, and to guarantee itself a more efficient spread.
Poor continent
Trypanosome is also one of the most devastating diseases in sub-Saharan Africa, with 80% of deaths of infected victims. It harms a total of half a million people, kills three million head of livestock annually and reduces the productivity of sick animals. And there is no chance in the medium term that a vaccine will be obtained, and the few treatments available to date are highly toxic .
So important is the sleep fly for Africa that there are even theories that blame it for the fact that the entire continent has always been structurally poor.
The explanation for this theory lies in the fact that peoples need pack animals to obtain surplus production and, by extension, free time, which facilitates progress in other areas, such as culture or innovation. In Africa, however, there have been no pack animals because they died from the bite of the sleep fly . In the rest of the world, however, horses and donkeys were domesticated, which made it possible to multiply production capacity.
The African equivalent of a horse or donkey is a zebra, but while the zebra does survive trypanosomiasis because its striped pattern on its body confuses the tsetse fly, the zebra is not domesticable .
So don’t think you’re going to fall asleep if you get bitten by a tsetse fly. What is going to happen is that you will sleep forever, being euphemistic.