Beginning with a subtle fever, sleeping sickness gradually leads to deep exhaustion and is accompanied by drowsiness. If untreated, this disease always ends in death. The disease is caused by trypanosomes - parasitic protozoa that live in the blood of vertebrates. They are transmitted to humans and animals by the blood-sucking tsetse fly.
In severe cases, coma and fatal wasting develops. Experts estimate that at least 60 million people are at constant risk of infection. The danger of this disease is also that the only remedy against it is elofritin, which is a very rare drug. And the main culprit is the tsetse fly, which carries this parasite to humans.
The African tsetse fly belongs to the same family as the European fly fly, which is also capable of carrying various infections.
In total, 5 species are known: four species of tsetse fly live in central and western Africa, and one species is found in Australia. In size, the tsetse is close to the house fly, has a thin proboscis, which is longer than the head and protrudes slightly forward, with the help of which flies feed on the blood of humans and other mammals in the daytime. The fly's chest is reddish-gray with four dark brown longitudinal stripes, and the abdomen is yellow above and gray below.
The International Health Organization estimates that about half a million people living in sub-Saharan Africa are infected with sleeping sickness and 80% of them are likely to die as a result. Many tourists, returning from Africa, bring this deadly disease with them. In 2004, four cases of sleeping sickness were recorded in England. Half of these casualties returned from their travels in Zanzibar. In addition, tsetse bites kill an estimated three million head of livestock every year.
What only mankind has not undertaken to combat this harmful insect. Scientists have been fighting this fly, which is called the "silent killer" in Africa, for over 150 years. However, the results are still few. To rid Africa of the tsetse fly population, which is deadly to humans and animals, scientists even used radiation. But the insect turned out to be extremely adaptable.
Trypanosomes, which infect humans, constantly inhabit the blood of African antelopes, without causing any harm to these animals. The blood-sucking tsetse fly carries the trypanosome from antelope to man. As soon as trypanosomes enter the blood, each changes its protein shell in a thousand different ways, in other words, one drug can kill only a few pieces, it will not work on the rest. The disease first affects the body's immune system and then the central nervous system. Tumors on the human body appear here and there. Soon he becomes so weak that he can no longer stand on his feet, and after many months of illness he dies. Those drugs with which it is theoretically possible to destroy trypanosomes are either too toxic or have too serious side effects.
Scientists from all over the world are struggling to eradicate tsetse flies. The main hope is in the breeding of stronger, but radiation-sterilized males. In the fight for the female, they will defeat the "natural" males. As a result, the tsetse population should decline every year. Scientists promise that in 20 years the world will get rid of this main vector of a deadly disease. However, today there are a lot of these insects in Africa. A very large number of people can become infected and die before scientists can finally defeat the tsetse fly. And even then, for sure, it is not known whether they will succeed.