ttps:////»https://www.w3.org/TR/REC-html40/loose.dtd»>
The bite of the tsetse fly (Glossina palpalis) causes sleep because it transmits a parasite called Trypanosoma brucei. It is this protozoan that leads a person to a state of torpor and lethargy. According to data from the World Health Organization (WHO), 500,000 people, mainly in sub-Saharan Africa, are infected annually by the parasite. Four out of five patients end up dying after experiencing symptoms such as fatigue, tremor, high fever, severe pain and convulsions. However, the disease is curable and the high mortality rate is mainly due to the delay in diagnosis and lack of treatment due to the high price of drugs. The disease was practically eradicated in the 1960s, but the interruption of preventive programs, due to the continuous civil wars on the African continent, caused it to get out of control again.
To combat the disease, scientists are trying to create breeds of cattle resistant to the parasite, since cattle are the main host of Trypanosoma brucei. The tsetse fly measures up to 1.3 cm, has transparent wings, white lines on the abdomen and a groove on the front of the head. They are distinguished from common flies by their larger size, by having a kind of proboscis that extends from the head and by the position of the wings at rest – crossed among themselves.
Protozoan that causes the disease is lodged in the bloodstream of cattle
1. A typically African species, the tsetse fly is a hematophagous insect, that is, it feeds on the blood of people, wild and domestic animals, mainly cattle
2. Many cattle have a protozoan called Trypanosoma brucei in their bloodstream. When the fly sucks the animal’s blood, it takes this parasite with it.
3. Inside the tsetse organism, the protozoa multiply and transform into infective parasites, ready to transmit sleeping sickness. When the fly bites a person, he is infected.
4. In the human body, the protozoan enters the bloodstream and reaches the central nervous system, causing an almost continuous state of drowsiness, high fever and convulsions, which can even lead to death.