What is sleeping sickness. What organism causes sleeping sickness in humans

The main danger of African sleeping sickness for human health is the massive damage to vital organs and systems. These include: the speech apparatus, lymph nodes, thyroid gland, central and nervous systems.

The response of the body to changes in blood cells is the active release of antibodies and immunoglobulins by the immune system, which allows for a short time to contain the massive spread of the disease. But, if no measures were taken during this time, the infection destroys weak immunity and actively progresses.

The development of African trypanosomiasis in adults and children

The causative agent of African trypanosomiasis

The disease is transmitted by blood-sucking insects, which in turn become infected by ingesting the blood of livestock. The pathology of the development of the disease is characterized by an increase in the number of microbial cells throughout the body due to their movement along with the blood. Regardless of the form of the disease, these microbes differ in such features: the shape is flat, oblong, dimensions are 35 by 3.5 microns.

Mechanism of infection and pathogenesis of the disease

At risk are people living near water bodies - places where livestock are watered and, as a result, a large accumulation of flies. However, do not forget about their wide distribution throughout the continent.

The mechanism of human infection is transmissible, through an insect bite. The disease originates from the appearance on the skin, at the site of the bite, the so-called chancre. Then the microbe enters the bloodstream, and a week later infects the lymphatic vessels. At advanced stages, it is characterized by brain damage and the development of pathologies of various internal organs. It is worth noting that trypanosomes cause massive death of nerve cells. Due to its variability in genes, the virus often causes relapses.

Main clinical manifestations

It has already been indicated above about the appearance of an inflamed boil on the skin due to an insect bite, which is the first sign of infection. At the next stages of development, such a disease as sleeping sickness proceeds with serious complications. The patient often has:

sudden changes in body temperature and a state of semi-delusion;
rashes on the body;
general weakness;
indifference;
pain in the joints and muscles;
sudden weight loss;
puffiness of the face.

Eye problems are often observed: general swelling of the skin around the eyes, cracking of the capillaries, clouding of the iris.

Complications of African trypanosomiasis

Sleeping sickness is most dangerous at its last stage, due to brain damage, which is manifested by a specific feature of the patient falling asleep in different situations. If the causative agent of sleeping sickness is in the carrier's blood in large quantities, the development of the disease leads to serious aggravating consequences, such as:

paralysis of the limbs;
exhaustion of the body and painful thinness;
epilepsy;
speech problems;
vision problems;
incontinence;
coma.

There is a very high trend of mortality among those infected in the advanced stages of the disease.

Testing for suspected trypanosomiasis

When contacting a hospital, a specialist must conduct a patient survey, a complete examination of the entire skin and lymph nodes. Although the symptoms of sleeping sickness are specific, a definitive diagnosis requires the study of laboratory tests, such as a standard blood test, a deep biological study of the lymph, and a skin biopsy.

With the advanced form of the disease, the appearance of the infected person changes dramatically: puffiness of the face and swelling of the eyes, swelling of the tongue, hanging down the jaw and absolute apathy to what is happening around are observed.

Symptoms of sleeping sickness and the clinical picture of the disease

African sleeping sickness can cause the following symptoms:

inflamed boil with a hard crust - a painful knot at the site of the bite, appearing a week after inoculation;
characteristic fever with constant jumps in temperature from high to low from the norm;
severe headaches;
lack of desire to do anything and complete indifference to what is happening;
cardiopalmus;
painful swelling of body parts;
characteristic rash on the extremities.

In the early stages, the disease may not manifest itself in any way up to one year after infection. In this case, the above described symptoms can be observed, but in a minor form. And so it can continue until the disease develops to a chronic stage.

As the disease progresses, more and more symptoms appear. Infected people have a general swelling of the face, the jaw droops, and problems with concentration appear. It is worth noting that if proper treatment is not provided at this stage, this leads to complications already known to us and a possible fatal outcome.

How to prevent the development of trypanosomiasis?

In order to prevent infection, the following simple measures should be followed:

use special insecticide preparations that repel insects;
systematically destroy tsetse flies;
get vaccinated regularly;
during work, use protective equipment covering exposed areas of the skin;
avoid places of high concentration of insects;
isolate those infected from contact with other people;
regularly increase the body's immunity.

Since trypanosomiasis is transmitted through infected insects, patients should be protected from contact with insects. If this is not done, an uninfected fly can suck his blood and, in the future, transmit the disease to the relatives of the ill person or his neighbors.

With minimal manifestations of symptoms, you should immediately seek the help of specialists who will conduct a timely diagnosis and prescribe treatment. However, due to the low quality of medical care in most African countries, this complicates the fight against the virus.

Conclusion

Sleeping sickness or African trypanosomiasis is a dangerous pathology caused by the protozoan trypanosoma. There are two types of them, both transmitted by the bite of an infected tsetse fly. Cases of the disease are frequent in rural areas where the insect vector lives.

What is known about sleeping sickness

It is common in Africa, where about 70 thousand people receive such a diagnosis every year. However, due to the improvement in the quality of life in developing countries, this number is gradually decreasing every year.

Basically there are two types of this disease:

Gambian sleeping sickness

The main places of distribution are the coasts of rivers and large reservoirs.

Rhodesian sleeping sickness

Places of distribution - the African savannah and treeless spaces.

The causative agent is a flat microorganism, has a membrane along the body and moves easily.

How infection occurs

A fly that becomes infected carries African trypanosomiasis throughout its life. A single bite is enough to infect a person - a peddler fly secretes saliva that contains pathogens in an amount sufficient to infect a thousand people!

After a bite, viable microorganisms remain under the skin, which are trypanosomes in the invasive stage of development.

Some of them immediately enter the bloodstream, but most remain in place and begin to multiply intensively. A painful chancre is formed at the site of the lesion, it has a typical appearance for this disease.

How the disease manifests itself

At the beginning of sleeping sickness, fever and headache appear, then itching, joint pains join them. The onset of the disease - the hemolymphatic stage - is considered a period of one to three weeks.

Symptoms of a lesion in the hemolymphatic stage:

indisputable sign of the disease - chancre or trypanoma

It appears a week after the bite, it can be on any part of the body, but more often on the head or limbs. Very painful, has a characteristic appearance. It heals in one to two weeks.

simultaneously with the appearance of trypanoma, pink-violet spots with a diameter of up to a decimeter appear on the trunk or limbs - trypanids
swelling of the face, arms and legs
fever

swollen lymph nodes, especially posterior cervical

They can reach 2-4 cm in diameter, gradually compacted

enlarged liver and spleen
sleep disorders
headache
gradually increasing tachycardia
skin rashes
permanent swelling of the eyelids

This symptom can result in damage to the eyes.

The rate of development of sleeping sickness depends on the state of the body, but even in a strong and healthy person, after a fairly long time (from several weeks to several months), the symptoms of sleeping sickness will begin to appear.

The hemolymphatic stage can last for many months and even several years, but sooner or later it will begin to move into the terminal stage - late.

At this stage, trypanosomes infect the brain.

A characteristic sign of the onset of the second stage of the disease is constant drowsiness during the day. A person can fall asleep while talking or eating, and this phenomenon gradually increases.
There may be tremors in the limbs
Constant lethargy, which can be replaced by a manic state
Sometimes the pathology develops in a different direction - the sick person shows complete apathy, this is often accompanied by severe headaches. In this case, the patient often feels calm, which gradually turns into apathy and stupor. Indifference to food appears, they do not ask for it, although they do not refuse if it is in front of them. Stop communicating with others.
Gradually, convulsions, seizures, and possibly a coma are added to this.

Gambian sleeping sickness is more often characterized by such a long development and course, the Rhodesian form can be more transient and severe. Fever, exhaustion attack a person with such intensity that he can die long before the onset of the second stage of the disease.

In the absence of urgent medical measures, the disease ends with seizures, paresis of the limbs and body, and coma. All this leads to death.

Diagnostics

Trypanosoma can be found on a blood smear or in lymph fluid. Sometimes a lumbar puncture is performed, which can be a means to clarify the stage of the disease.

Lumbar puncture is performed to analyze the composition of the cerebrospinal fluid - a needle is inserted into the space of the spinal cord at the lumbar level. Establishing a diagnosis in severe infectious lesions of the central nervous system becomes accurate if based on the data of this study.

Other biomaterials are also used for research:

chancre puncture
contents of the lymph node
blood.

Treatment of the disease

The disease is curable, but it is much easier to cope with it if the diagnosis is made before the onset of the second neurological stage.

At the first stage, therapy is carried out using the following drugs:

"Pentamidine"

An antibiotic based on natural ingredients that has an effect on protozoa and gram-negative (especially resistant to drugs) bacteria.

It is not used orally, as it is not absorbed in the intestines. With parenteral administration, it can have undesirable effects, therefore, there are a number of contraindications for its use.

It affects trypanosomes, but only at the beginning of the disease, in the first stage. At the second, neurological stage, it becomes almost useless, since it does not have the ability to penetrate the BBB.

The BBB is the blood-brain barrier, which is the guarded boundary between the circulatory and central nervous systems. Performs a protective function, protects the brain from toxins, microorganisms, and other factors. However, sometimes it is an obstacle to the penetration of therapeutic agents.

At an early stage, the course of treatment is 10 days.

"Suramin"

An effective antiprotozoal agent, used in the treatment of sleeping sickness, affects both types of pathogen. It is administered intravenously, excretion from the body is prolonged.

May have side effects, sometimes severe.

Effective in the first stage of the disease.

At the second stage of the development of the disease, apply:

"Eflornithine"

It can cause side effects of moderate and mild severity, all of them are reversible - they disappear when the intake of the active substance stops. Vomiting, diarrhea may begin, sometimes hearing is temporarily impaired. It is considered a less dangerous drug than Suramidin and Pentamidine.

"Nifurtimox"

An effective drug that destroys both types of trypanosoma. It works especially well in the early stages of the disease. Mild side effects, used in the treatment of children.

"Benznidazole"

It is used in the treatment of an acute form, the therapeutic effect and the degree of toxicity are almost the same as those of Nifurtimox. The mechanism of action of this drug has not been studied.

Prevention

The only way to prevent the disease is through regular blood sampling from people living in areas where the disease is likely to spread. In this way, infections can be detected at an early stage.

Besides:

to reduce the risk of disease, do not visit potentially hazardous areas
wear light-colored clothing, sleeves should be long
always carry a repellant that is active against flies
if there is a need for a long stay in a potentially dangerous area, an injection of Pentamidine should be given every six months.

Tsetse flies are subject to widespread extermination, for this insecticidal preparations are used - this is an important measure in the prevention of the disease. It is also recommended to carry out regular cutting of thickets and bushes around settlements.

annotation

What is sleeping sickness and what causes it? Symptoms of the disease, ways of infection, diagnosis and treatment. What you need to know in order not to get infected.

Sleeping sickness - the main symptoms:

mood swings
Weakness
Joint pain
Skin rashes
Cardiopalmus
Enlargement of the spleen
Liver enlargement
Enlarged lymph nodes in the neck
Muscle pain
Fever
Eye hemorrhages
Pink spots on the skin
Weight loss
Edema of the eyelids
swelling of the face
Clouding of the cornea
Red nodule on the skin
Daytime sleepiness
Swelling of the hands
Foot swelling

The tsetse fly carries agents of trypanosomiasis: the pathogen enters the bloodstream after being bitten by a carrier, which can also lead to the development of malaria. There are no other mechanisms of infection. It is noteworthy that the insect becomes infected from a sick person.

The clinical picture is specific, pronounced, includes the formation of a trypanosomal chancre at the site of the bite, fever with an undulating course, severe edema, and gradually increasing drowsiness.

Only a clinician can establish the correct diagnosis, which will be based on symptoms and laboratory results. Instrumental procedures are secondary.

To date, there is a special treatment for sleeping sickness - all therapy is limited to long-term medication. The course of treatment is compiled on an individual basis.

Causes of sleeping sickness pathogen

Sleeping sickness belongs to the category of transmissible trypanosomiasis, characterized by a significant deterioration in the patient's condition and severe damage to the lymphatic system and central nervous system.

The main reason why pathology develops is the introduction of a pathological agent into the body.

To date, there are 2 forms of leakage, which, accordingly, differ depending on the pathogen. Provocateurs are the protozoa of the genus Trypanosoma brucei and Trypanosoma brucei rhodesiense. None of the two types of microorganisms is transmitted sexually.

The causative agent of sleeping sickness has the following features:

shape - flat, oblong-fusiform;
dimensions - width from 1.5 to 3.5 micrometers, length - 12–35 micrometers;
only the tsetse fly, a blood-sucking arthropod that transmits infection from one person to another, can release the pathogen throughout its life.

On average, 1-3 weeks after the life cycle of the pathogen has begun, the bacteria already completely affect the lymphatic and blood systems, and after some time the CNS is involved in the pathology.

Ways of transmission of sleeping sickness

It is noted that the main risk group is:

inhabitants of the African continent;
persons engaged in agriculture and fishing;
people associated with hunting and animal husbandry;
villager.

In addition to African trypanosomiasis, American trypanosomiasis, which has a name, is dangerous for humans.

Classification

As sleeping sickness progresses, trypanosomiasis goes through several stages:

Humans can become infected with several types of protozoa. Clinicians distinguish several options for the course of the disease:

Rhodesian - causative agent Trypanosoma brucei rhodesiense;
Gambian is the source of Trypanosoma brucei.

None of the diseases are sexually transmitted.

Sleeping sickness symptoms

African trypanosomiasis has an infectious nature, so it is advisable to talk about the incubation period - the time from the moment the pathogen enters the body until the first manifestations appear. In this case, this period of time will be purely individual, it can vary from several days to a month. The duration of the incubation period depends on the site of the bite.

As sleeping sickness progresses, the symptoms will be as follows:

fever of the wrong type (temperature indicators rise to 38–40 degrees) - the condition is so called because there is an alternation of such values with their normalization, which can last from 2 to 7 days;
an increase in the volume of regional lymph nodes (the posterior cervical segments often suffer, which are closest to such a segment as the carotid artery) - they can increase to the size of a pigeon's egg;
weakness and weakness;
minor muscle and joint pain;
and frequent mood swings
increased heart rate;
weight loss;
clouding or scarring of the cornea;
hemorrhages in the iris of the eyes;
urticarial rashes;
increasing daytime sleepiness;
swelling of the eyelids.

In severe cases of African sleeping sickness, the presence of such signs is noted:

atactic gait;
tremor of the limbs and tongue;
slurred speech;
lethargy;
severe headaches;
salivation;
depression or mania;
convulsive seizures;
paralysis;
epileptic seizures;
coma.

These signs are characteristic of the Gambian form of the disease. As for the Rhodesian variant of the course, the disease is accompanied by a more severe manifestation of symptoms and transient development. Fever and are much more pronounced, the human body is sharply depleted and very often there are problems with the heart.

The death of patients can occur already in the first year of infection, even before the disease passes into the meningoencephalitic stage.

Main symptoms of sleeping sickness

Diagnostics

Sleeping sickness (trypanosomiasis) is diagnosed by an infectious disease specialist - a clinician can make a preliminary diagnosis based on symptoms. However, laboratory and instrumental examinations are used for accurate confirmation.

First of all, the doctor must perform the following actions:

study the medical history;
collect and analyze a life history - to confirm the fact of visiting African countries;
assess the condition of the skin;
to palpate the anterior wall of the abdominal cavity - it will make it possible to detect an increase in the liver and spleen;
measure heart rate and temperature;
to interview the sick person or his relatives in detail - to determine the severity of symptoms.

The pathological microorganism that causes sleeping sickness can be detected during the following laboratory tests:

general and biochemical blood tests;
bacterial culture of punctate trypanosomal chancre or altered lymph nodes;
microscopic examination of cerebrospinal fluid;
staining of biological material according to the Romanovsky-Giemsa method;
PCR tests;
serological tests - ELISA and RIF.

In some cases, clinicians perform a biological test with the introduction of blood or cerebrospinal fluid of guinea pig patients to definitively confirm the diagnosis.

With regard to instrumental procedures, studies are of secondary importance and are more focused on finding complications. In such cases, ultrasound, CT, MRI and x-rays are performed.

African sleeping sickness must be differentiated from malaria and such diseases:

Chagas disease.

Sleeping sickness treatment

Treatment of sleeping sickness is carried out only with the use of specially targeted drugs that are most effective in the early stage, before the CNS is affected.

The Rhodesian variant is treated with the following drugs:

Melarsoprol;
Suramin.

African trypanosomiasis has additional therapeutic recommendations:

the use of antipyretics and other means to relieve symptoms;
implementation of detoxification and hyposensitizing therapy;
intake of fortifying substances.

The duration of taking a particular medication is determined only by the attending physician on an individual basis.

Sleeping sickness. mechanism of infection.

African sleeping sickness. Disease symptoms.

Some time after being bitten by an infected tsetse fly, a person develops signs of fever and a reddish skin rash. The fever progresses, but may subside for a while, then the patient becomes a little better. Weakness and anemia increase, lymph nodes and ascites enlarge, the human brain is affected and it becomes apathetic, drowsy and lethargic. Severe headaches with convulsions may appear, a person tends to sleep all the time. After this condition, a coma occurs and the following symptoms are most characteristic of African sleeping sickness:

The presence of an entrance chancre.
Severe headaches.
Insomnia.
Fever.
Violation of concentration.
in the posterior cervical triangle.
developing tachycardia.
Subcutaneous edema.
found mostly in Europeans.

The first symptoms of the disease appear several years before brain damage, and therefore a timely visit to a doctor during this period can save a person's life.

Treatment of African trypanosomiasis

To effectively treat this disease, scientists have developed an effective combination therapy, which is included in the "List of Essential Medicines" and is provided to patients completely free of charge. In general, African sleeping sickness in the early stages of the disease is perfectly cured with eflornithine and suramin. Later processes, when the brain is affected, require the use of mercury-containing drugs. They are used with great care because these drugs are toxic and can cause unwanted reactions in the body.

Prevention of sleeping sickness is simple, it consists in following a series of rules that are aimed at reducing the risk of contracting this disease.

Without urgent need, do not visit the foci of the disease.
Wear light colored clothing with long sleeves.
Use insect repellant when going outside.
To prevent the disease, do an injection of pentamidine once every six months.

Sleeping sickness is a serious disease, so it is easier to prevent than to treat.

The content of the article

SLEEPING SICKNESS, a disease caused by trypanosomes, i.e. protozoa of the genus trypanosoma. Sleeping sickness is sometimes referred to as African trypanosomiasis, in contrast to other trypanosomiasis, in particular South American trypanosomiasis, also known as Chagas disease. Sleeping sickness is transmitted through the bites of infected tsetse flies (genus Glossina); it is endemic in 36 African countries south of the Sahara Desert, i.e. where these insects live. With this prevalence, up to 50 million people are at risk of the disease; about 25,000 new cases of sleeping sickness are recorded annually.

clinical picture.

Sleeping sickness occurs in two forms. Gambian, which calls Trypanosoma gambiense, distributed mainly in West and Central Africa. Rhodesian form called T. rhodesiense, more commonly found in East Africa. The clinical manifestations of both forms of sleeping sickness are similar, but the Rhodesian variant in most cases is more acute and, without treatment, can result in the death of the patient in a few months or even weeks. The Gambian form progresses slowly, and in untreated cases, the disease can last for several years before death occurs.

Both forms of the disease usually have two stages. The first symptoms usually appear 1-3 weeks after being bitten by a tsetse fly. At this stage, while trypanosomes are still in the blood, the main clinical manifestations include fever, headache, joint pain, muscle tremors, increased sweating, itching, and, contrary to the name of the disease, insomnia. In the second stage, when trypanosomes have already penetrated the central nervous system, the main clinical manifestations are severe headache, fever, general weakness and apathy, excessive drowsiness (in accordance with the name of the disease), movement disorders and coma. If the disease is not treated, death is almost inevitable.

Treatment

sleeping sickness consists mainly in the use of suramin and pentamidine at an early stage and melarsoprol at a later stage; in the case of the Gambian form of the disease at any stage, eflornithine (DFMO) is quite effective. If treatment is started at the first stage, the probability of recovery can reach 100%; the effectiveness of therapy in the late stage is significantly lower.