Sleeping Sickness
What is sleeping sickness?
Sleeping sickness is also known as “African trypanosomiasis” and is caused by a tiny parasite, transmitted to humans by the bite of a fly acting as a vector. In this disease seriously affects the brain and the meninges (the membranes that cover the brain and spinal cord). The disease progresses slowly, and if left untreated, is usually fatal.
The parasite is found in the saliva of different species of African flies hematophagous (blood-eating), belonging to the genus Glossina, commonly known as the tsetse fly. Fortunately, not all tsetse flies are infected with the parasite, and often their bite only causes some discomfort.
The parasite exists only where the fly, so-called belt of tsetse fly and comprises an area on both sides of Ecuador which extends to about 15 degrees latitude north and 20 º south.
The bite of the tsetse fly is painful and sometimes difficult to differentiate from the painful sting of the gadfly also.
What is the cause of sleeping sickness?
The disease is caused by a protozoan parasite very small (about 30 microns, or thousandths of a millimeter), Trypanosoma brucei. It is a unicellular organism (composed of a single cell) that belongs to the group of flagellates (as it has a flagellum, a tail that serves to propel).
When the tsetse fly bites a person or an animal with the trypanosome in their blood, she is infected. The parasite develops in your gut after a few weeks and then goes to their salivary glands, where they multiply continuously, so that the fly, once infected, the parasite will for the rest of his life. When the infected fly bites a person or animal can transmit the trypanosome.
The protozoan then multiply in the blood of the person and the symptoms of sleeping sickness will appear gradually as the number of parasites. In addition, the trypanosome passes the central nervous system, where it causes characteristic symptoms.
There are two types (subspecies) of Trypanosoma brucei, which affect humans:
Trypanosoma brucei gambiense
Whose principal vector is Glossina palpalis flies, causes a chronic disease that lasts several years and in which the central nervous system invasion is delayed. But in the end, the infection occurs and the patient goes into a coma from which you can not wake up. This is why it is called “sleeping sickness”. In this variety is usually also a marked swelling of the lymph nodes.
Trypanosoma brucei rhodesiense
Which is the most important vector fly Glossina morsitans, causes an acute illness (ie, changes faster), because the number of parasites in the blood of patients is greater, and the central nervous system invasion earlier ( in a few months usually). There are usually no significant inflammation of the lymph nodes.
The patient who has fallen into a coma may have a nervous system so important that it can not be cured, and eventually may die from infections added.
credit to: Dr. Juan Álvarez Orejón, Dr. Charlie Easmon