African sleeping sickness or trypanosomiasis is a parasitic disease dependent on a transmission vector, in this case a fly.
It is a disease that generated several epidemics during the 19th and 20th centuries in various regions of Africa. However, today its distribution is focal, so it is endemic in 36 African countries. Like most disease-dependent transmission vectors of an invertebrate nature, this pathology develops mainly in hot environments and with poor health conditions.
Despite all that it may seem to us, knowing the details of this disease becomes essential, both for a matter of wisdom and of human empathy. Therefore, here we will see various data on sleep disorders.
Sleep and fly disease, two inseparable concepts
Before fully entering into the clinical picture and the causative agent of this pathology, it is necessary to talk about its effect on vulnerable populations. The World Health Organization (WHO) launches us several statistical data to consider. They are as follows:
- African trypanosomiasis is endemic in 36 countries in sub-Saharan Africa.
- The inhabitants of rural areas are the population most vulnerable to this disease.
- In 1998, around 500,000 cases were estimated, most of them untreated.
- As a result of control efforts promoted by Western countries, that figure fell to a total of 1,446 cases in 2017.
- Over the past 10 years, more than 70% of cases have occurred in the Democratic Republic of the Congo.
- This place is the only region in the world where more than 1,000 cases per year are still diagnosed today.
As can be seen, sustained control initiatives have had a very positive effect on the distribution and spread of sleeping sickness. Despite this, as long as the number of infected is not reduced to 0, it cannot be said that this disease is completely controlled.
Know the parasite: Trypanosoma brucei
Unlike other pathologies of parasitic origin, African trypanosomiasis is not caused by a single microorganism. In that case, we are in front of two hemoflagellated protozoa of the genus Trypanosoma. These are the species Trypanosoma brucei gambiense and Trypanosoma brucei rhodesiense.
The former is of major epidemiological importance, as it is estimated to be responsible for over 98% of reported cases. The second species only occasionally uses humans as hosts, as it has specialized in infecting livestock and other domestic animals.
These small protozoa, cuckoos and semi-transparent, have a life cycle of vertigo. Here is a summary of that process:
- The tsetse fly injects one of the forms of the parasites, tripomastigotes, into the blood of the host (who may be human).
- Through the bloodstream, parasites reach other organs and fluids (such as lymphoids), and multiply there by binary fission.
- These bloody tripomastigotes are ingested by the fly when it bites an infected person.
The trypanosome parasite undergoes several changes within the fly itselfBut knowing that these protozoa multiply in various organs and are carried by the host’s bloodstream, it is worth understanding the situation of sleeping sickness at the clinical level.
We emphasize that we are going to deepen the symptoms and treatments of the pathology generated by the parasite tb parasite, because it is the species that most affects humans.
Symptoms of African trypanosomiasis
According to various bibliographic sources, this pathology takes place in three different phases.
1. Initial phase
At the site of the tsetse fly bite occurs a local inflammatory process, Which results in a structure called a trypanoma or chancre. It is a painful skin ulcer characterized by a white halo on its extra radius. Trypananoma ends with the appearance of a scar after two or three weeks of sting.
2. Hemolytic phase
After an incubation which can last from a few days to several years (with an average of 1 to 3 weeks), they begin to appear in the patient. clinical signs that respond to the spread and reproduction of the parasite through the lymphatic blood system.
This involves the appearance of very high intermittent fevers, arthralgia (joint pain), lymphadenopathy (hard, painless and mobile lymph nodes), tachycardia, anemia, weight loss and itching among others. As we see, it is not at all a pleasant clinical picture, but the worst is yet to come.
3. Neurological phase
this one it starts when the parasite crosses the blood-brain barrierThat is to say a selective layer which isolates the central nervous system of the human being. As you can imagine, the presence of a flagellated protozoan in the nervous system causes striking and at the same time disturbing symptoms.
From there we go further a clinical picture based on changes in behavior. The patient presents sensory problems (hyperesthesia, increased sensitivity to touch), mental abnormalities (mood swings, irritability, emotional fluctuations), sleep disturbances and various motor and endocrine problems.
Is change in the infected person’s circadian clock, Which causes chronic insomnia in the patient, gives the name of sleeping sickness to this pathology.
To make matters worse, in addition to having entered the central nervous system, some of the parasites still remain in the individual’s bloodstream, causing the symptoms of the hemolytic phase to appear in the neurological stage as well. Left untreated, this period results in profound alteration of the body (cachexia), coma and death.
Anyone diagnosed with African trypanosomiasis should be treated according to the parasitic species whose cause and stage of the disease. Of course, a person who has these protozoa only in the blood and one in whom they have invaded the central nervous system, will require different clinical approaches.
For example, according to the Centers for Disease Control and Prevention (CDC), pentamidine is an antiprotozoal that works by inhibiting the synthesis of proteins and nucleic acids in the parasite, Which limits and inhibits their growth. This medicine is given mainly to patients who are still in the hemolytic phase of the T. b. gambiense. Suramin has the same function, but in this case it acts against T. b. rhodesiense.
The neurological phase, by its most delicate nature, requires more aggressive drugs. In these cases, melarsoprol is usually given, an arsenic derivative that can cause side effects that are sometimes almost worse than the disease (such as reactive encephalopathy leading to death of the patient in up to 10% of cases).
There are other possible treatments, but in short, we can say that this pathology requires a very specific clinical approach, to be carried out by specially qualified personnel.
It is not uncommon to end up with a pathology of parasitic origin which affects so many levels of patient health. As we have seen, sleeping sickness causes symptoms ranging from fever to mood swings, lack of sleep and hypersensitivity to touch.
Of course, it is surprising how the presence of a parasite in the bloodstream and the central nervous system (CNS) he is able to modify the patient’s routine and lifestyleSo much so that he can no longer be considered a functional human being.
It is common that, from a Westernized point of view, this type of pathology is foreign to us and lacks interest. Beyond the possible concerns that can generate sporadic travel on the continent of Africa as tourists, diseases like this require understanding and understanding for the sake of empathy.
These pathologies cannot be treated by the poor monetary conditions of the countries of origin, and therefore the action of organizations like the WHO has become more than necessary to reduce their prevalence.
- of Health, AM (1983). Human African trypanosomiasis (No. WHA36.31). World Health Organization.
- Sleep Disease, World Health Organization (WHO). Retrieved August 7 from https://www.who.int/es/news-room/fact-sheets/detail/trypanosomiasis-human-african-(sleeping-sickness)
- Franco, JR, Ruiz, JA and Simarro, P. African trypanosomiasis.
- Gomez, V. Trypanosoma brucei: characteristics, morphology, life cycle.
- Sleeping sickness, CDC. Retrieved August 7, from https://www.cdc.gov/parasites/sleepingsickness/biology.html
- Torres, OM and Cá, G. (2003). African trypanosomiasis. Presentation of a case. MediCiego, 5 (1).