What disease is caused by a paramoecium

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The African sleeping sickness is a tropical disease caused by parasites. These are transmitted through the sting of the tsetse fly. Sleeping sickness is only found in Africa, but related diseases also occur on other continents. Mainly locals get it, tourists, on the other hand, rarely. If left untreated, sleeping sickness is usually fatal. Read more about the African here Sleeping sickness

Sleeping sickness: description

Sleeping sickness (trypanosomiasis) is caused by the unicellular parasite Trypanosoma brucei triggered. There are two forms of the disease - the West African and the East African variants:

  • The East African form only accounts for about two percent of all sleeping sickness cases. It progresses very quickly. This means that there is very little time left for diagnosis and therapy. However, this form of sleeping sickness mainly affects animals and, less often, people.
  • The West African form of sleeping sickness is more common, progresses more slowly, and is sometimes diagnosed years after infection.

The geographical boundaries between the two forms of disease are becoming increasingly blurred. In Uganda, an East African country, both forms are already used in different areas. Even if the data situation is difficult to survey, the Democratic Republic of the Congo and the Central African Republic are particularly affected by the tropical disease. Since the data come from different health systems, it can be assumed that sleeping sickness can also be found in other countries in this region.

The causative agent: trypanosomes

Trypanosomes belong to the group of protozoa just like, for example, the causative agent of malaria. Similar to malaria, sleeping sickness cannot be transmitted from person to person. Rather, the pathogens of the disease are transmitted to humans by the blood-sucking tsetse fly when it stings.

The West and Central African variant of sleeping sickness is from the subspecies Trypanosoma brucei gambiense caused, the East African variant of Trypanosoma brucei rhodesiense.

Sleeping sickness: symptoms

After the bite of a tsetse fly and the transfer of the trypanosomes, it can develop within one to three weeks (subspecies rhodensiense) or weeks to months (subspecies gambiense) develop a sore, inflamed reddening at the puncture site. Doctors speak of a so-called Trypanosome chancre. The puncture site is often in the face or neck area.

In the next stage (hemolymphatic stage) of the disease, the parasites spread throughout the body via the blood and lymphatic pathways. The lymph nodes swell severely and periodic periods of fever occur. Severe headaches and body aches, chills and fatigue are also possible. If the kidneys are also affected, inflammation of the kidneys (nephritis) can result.

Finally, the trypanosomes affect the central nervous system (meningoencephalitic stage). As a result, the eponymous disorders of the sleep-wake cycle occur. In addition, paralysis, cramps or Parkinson's-like symptoms (rigor = muscle stiffness, tremor = tremors, ataxia = impaired movement coordination) can occur. Behavioral disorders and irritability also appear. Eventually the patient falls into a coma and dies.

This general course of the disease can be seen in both forms of sleeping sickness. But there are some differences in detail:

West African sleeping sickness

In West African sleeping sickness (pathogen: Trypanosoma brucei gambiense) the course of the disease is slower than in the East African form. It can take up to three weeks for a change in the skin to show up at the injection site. The feeling of tiredness can last for several months before the actual symptoms of sleeping sickness arise. Personality changes occur after months to years. The patient is easily irritable. He complains of increased tiredness. The distortion of the day-night rhythm often occurs slowly over several months. The feeling of hunger is disturbed and the patients lose weight. After a few years, those affected fall into a coma and ultimately die of multiple organ failure.

East African sleeping sickness

East African sleeping sickness (pathogen: Trypanosoma brucei rhodesiense) is basically a quick and more serious variant of the more common West African form. Fever and chills as well as a painful, inflamed puncture site can show up days to weeks after the bite of the tsetse fly. The parasites quickly infect the lymphatic and blood systems and spread throughout the body. Lymph node, liver and spleen swellings are palpable after just a few weeks. Irritability, sleep disorders and paralysis can appear after weeks to months. After a few months, the patient falls into a coma and dies of multiple organ failure.

Sleeping sickness: causes and risk factors

Sleeping sickness is caused by the parasite (protozoon) Trypanosoma brucei there are two subspecies: T. b. rhodesiense and T. b. gambiense. They are infected by the stings of the blood-sucking tsetse fly either from infected animals (subspecies rhodesiense) or infected humans (subspecies gambiense) transferred to healthy people.

When blood is sucked, the sleeping sickness pathogen gets from the tsetse fly into the human skin. It spreads through the body via the lymphatic system and blood circulation and eventually affects the central nervous system as well.

Since the trypanosomes regularly change their surface, they are not recognized by the immune system quickly enough. This so-called antigen change explains why the human immune system is so helpless in the face of sleeping sickness.

Sleeping sickness: examinations and diagnosis

Sleeping sickness is suspected in patients in Germany when they come to the doctor with symptoms such as fever, headache, limb pain and lymph node swelling and tell of a recent long stay in Africa (short-term vacationers are not the typical patients).

The diagnosis can be confirmed by the detection of trypanosomes in the patient's body. To do this, the doctor can take samples from the puncture site, a blood sample or a sample of the cerebrospinal fluid (liquor) and send it to the laboratory for analysis.

A specialist doctor (tropical medicine) should diagnose and treat sleeping sickness.

Read more about the examinations

Find out here which examinations can be useful for this disease:

Sleeping sickness: treatment

The therapy for sleeping sickness depends, among other things, on the stage of the disease. In the last stage in particular (meningoencephalitic stage), treatment is often very difficult and requires the use of highly effective drugs.

Sleeping sickness: therapy before attacking the brain

If the trypanosomes have not yet attacked the central nervous system, the drugs pentamidine and suramin are used. They fight the protozoa, but have some side effects due to their toxicity. Both drugs were developed before and during World War II.

Sleeping sickness: Therapy when the nervous system is affected

If the brain is already affected by sleeping sickness, further medication is necessary. Because pentamidine and suramin cannot cross the blood-brain barrier and therefore cannot work in the brain. Some of these drugs are chemotherapy drugs that are also used in cancer and HIV therapy. Unfortunately, these drugs can cause severe side effects:

  • Melarsoprol: arsenic compound. Kills the trypanosomes, but has dangerous side effects such as damage to the brain, which is fatal in about three to ten percent of cases.
  • Eflornithine: In this country it is also used against women's beards. Possible side effects are hair loss, gastrointestinal complaints, changes in the blood count and temporary hearing loss.

Read more about the therapies

Read more about therapies that can help here:

Sleeping sickness: disease course and prognosis

If left untreated, sleeping sickness is usually fatal. But if the disease is recognized early and treated consistently, doctors can often cure patients. However, this is a process that often takes months or years. Regular blood draws and spinal cord punctures are part of the monitoring that should guarantee the success of the therapy.

For a long time, many of the drugs for sleeping sickness were not available. Since 2001 there has been a cooperation between the World Health Organization (WHO) and some private pharmaceutical companies, so that the most important drugs against sleeping sickness can be delivered free of charge to affected countries. The "Doctors Without Borders" (MSF) take care of the logistics of this cooperation. In this way, the number of cases of sleeping sickness could be reduced significantly.

Sleeping sickness: prevention

Since there is no vaccination against sleeping sickness, you should protect yourself effectively against insect bites when traveling to risk areas. This includes wearing long trousers and long sleeves and using insect repellants.

It is best to seek advice from a tropical medicine doctor before traveling to a risk area. He can provide you with the most important precautions against that Sleeping sickness and other tropical diseases.

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