Shigellosis: causative agent, etiology, epidemiology, pathogenesis, symptoms, treatment in children, prevention

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Shigellosis is also called bacterial dysentery. This is an acute intestinal infection affecting the shell of the large intestine. The disease has been known since the time of Hippocrates. The disease is called a group of diseases, which is accompanied by diarrhea with an admixture of blood. The severity of the disease was noted in Japan and China in the 18th century.

Prevalence and code for ICD-10

WHO estimated that in the 1980s there were at least 744 million cases of such diseases only in children under the age of 5 years. The main "blow" falls on the countries of Asia, Africa and Latin America.

According to some data, the death rate of children from dysentery reaches 40%.

A widespread spread of the disease is noted in developing countries, where the poverty level of life prevails. People live in unsanitary dwellings, their homes are not equipped with benign water supply. Medicine in such countries is also poorly developed, so full-fledged assistance in manifesting the disease does not appear.

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Code for ICD-10 disease-A03. Further gradation depends on the pathogen:

  • 03.0 shigella dysenteriae,
  • A03.1 shigella flexneri,
  • A03.2 shigella boydii,
  • A03.3 shigella sonnei,
  • A03.8 other shigellosis,
  • A03.9 shigellosis, unspecified.

The structure and life cycle of the bacterium

Shigella is a fixed bacterium, which in shape resembles a 2-3 μm stick. It is not a source of controversy. Due to this, it is less resistant to the environment. But some subspecies ways for a long time to remain viable in water and dairy products.

Species differ in their habitat, specificity of secreted toxins. In wastewater sewers shigella can live a month or more, but quickly die by boiling, under the influence of direct sunlight.

The life cycle does not have unique features. They multiply exclusively in the human body. If a parasitic object is not found in the process of life outside a person, then death occurs after 2 weeks.

The main gateway to infection is the oral cavity. In it, lysozyme acts on the bacteria, which can destroy their structure. If, against the background of a weakening of immunity or for other reasons, they pass further, under the influence of hydrochloric acid and bile their life cycle ends.

More resistant bacteria enter the large intestine, where I start to multiply and produce toxins. Absorbed through the blood, they cause toxicosis, which affects the central nervous system and other body systems.

Forms of

Disease is different in form. The flow can be typical and atypical. In the latter case, there is an asymptomatic or erased current, mainly in this case they speak of bacteriocarrier.

Separate the disease into both chronic and acute. The latter can flow easily, be of medium severity, or lead to a severe course of the disease. Depending on the severity of the dehydration of the body. The acute form can be caused by any kind of shigella: Sonne, Flexner, Boyd, Sachs and some others. In chronic form, the course of the disease is recurrent and continuous.

Etiology of

The causative agents are shigella of four kinds:

  • A - shigella dysentery( Shigella dysenteriae);
  • B - Shigella Flexneri( S. flexneri);
  • C - Shigella Boudy( S. boydii);
  • D - Shigella Sonne( S. Sonnei).

All of them are stationary sticks with a rounded end. They are capable of producing toxins. Bacteria Grigoriev-Shiga have a strong negative effect on the nervous system.

Epidemiology

The source of the disease is a sick person or bacterium carrier. The disease is transmitted through the fecal-oral route. The bacterium sometimes enters the body together with food that has undergone insufficient thermal treatment. In rare cases, it is possible to get infected by contact-household way.

The most serious risks are patients with a sick or mild infection and convalescent carriers.

The latter include people who are at the stage of infection. Everyone is susceptible to shigellosis, but the overwhelming number of cases are children aged 2-4 years.

Pathogenesis of

There are two stages in pathogenesis. On the first lesion affects the small intestine, and on the second - thick. Severity depends on the variant of the course of the disease.

When infected, the bacteria overcome nonspecific factors of the oral cavity and the acid barrier of the stomach. Then there is an attachment to the enterocytes in the small intestine. Formation of enterotoxins and cytotoxins occurs.

When the shingella dies, a lipolysaccharide complex is produced. It is absorbed into the bloodstream, which causes the development of intoxication syndrome.

In the large intestine, when interacting with the mucosa, the ailment develops in several stages. Specific proteins interact with the plasma membrane receptors. There is an active multiplication of the bacterium, which causes the formation of a serious inflammatory disease. Symptoms of

Symptoms of the disease may be different. It depends on the patient's initial condition, the timing of the onset and the nature of the course. The role and type of the pathogen that caused the disease also plays a role.

Incubation period

It takes 1-7 days. Usually lasts a couple of days. If you start treatment at this stage, you can avoid the development of complications. At this time, there may be diarrhea( 1-2 times a day), a slight increase in body temperature. Pain in the abdomen is weakly expressed, they can be localized in the lower abdomen.

Clinic for acute

In most cases, the course of the disease is acute. There is an increase in all symptoms in 1-2 days. In some patients, there are also manifestations of weakness, a decrease in appetite.

Colitis variant

It is characterized by an acute onset of symptoms. The temperature rises to a high level, there is pain in the abdomen. There may be headache, weakness and lethargy. The child begins to sleep badly, he complains of nausea, vomiting and paroxysmal pains.

In particularly severe cases, intoxication is particularly pronounced. There are signs of twilight consciousness, meningism, tonic-clonic convulsions, as well as lowering blood pressure.

Gastroenterocolitis

It is characterized by a short incubation period that lasts for several hours. Almost immediately there are nausea and vomiting, pain of diffuse cramping. The disease is joined by a loose stool with no pathological impurities.

In the initial period, there may be an impression that a person has a normal poisoning. But after a couple of days, the symptoms of enterocolitis appear in the disease.

The amount of feces becomes small, blood veins may appear in them. Soreness is localized in the left ileal region. There are signs of excision. The facial features become pointed, the skin turgor decreases, the heart sounds are muffled.

of the Erased

In such a flow, it is very difficult to determine the presence of the shigel. There is a feeling of heaviness and discomfort, diarrhea is observed 1-2 times a day, the stool has a mushy consistency.

The soreness and spasm of the bowel is determined by palpation. Body temperature may rise slightly, but more often it is at normal levels. Usually a bacteriological examination is required to confirm the diagnosis.

Bacteriosis

This species includes the case where the clinical symptoms are completely absent, but the bacterium on the mucosa of the colon is.

It can be at the stage of recovery. Then we are talking about a recovless form.

When a subclinical person is sick, but without manifestations. Such a variety is revealed by chance during routine monitoring.

Symptoms of chronic period

In this case shingellosis takes more than 3 months. At present, manifestations of this form are rare. It can proceed through a recurrent and continuous variant.

In the first case, the symptomatology is the same as in the acute phase. In the abdomen, there are pains, there is severe dysfunction of the intestine. There are significant changes in the intestinal mucosa. In this case, deformed areas are combined with inflamed areas. Relapses occur not so often, and the light intervals between them allow the body to recover.

The continuous version is less common. Alterations affect almost the entire gastrointestinal tract. Symptoms, characteristic of intoxication, are practically absent. The chair is cachiform in appearance and has a greenish color. There is no remission. Gradually, the body weight decreases, irritability appears, hypovitaminosis.

Features of the rod of Grigoriev-Shigi

This kind of condition is peculiar to a particularly difficult condition.cramping pains are strong, there is a chill, an increase in body temperature to a mark of 40 degrees. The chair reminds of slops, but gradually the volume decreases, blood and pus appear.

Sometimes there is toxic shock and sepsis with the sowing of the pathogen in the blood. When attaching liquid stool and vomiting, hypovolemic shock is noted.

Complications of

In the absence of treatment, there may be:

  • Mucosal prolapse.
  • Intestinal bleeding.
  • Perforation of intestinal ulcers.
  • Peritonitis.
  • Cracked anus.
  • Infectious-toxic shock.
  • Acute renal failure.

After the transferred illness for several months there is a weakness of the body, exhaustion and fast fatigue.

Laboratory diagnostics

Laboratory diagnostics is performed to identify the pathogen. Vomitive masses are sent for bacteriological examination. Important is the general blood test, which shows a large number of leukocytes, a high level of ESR.

Serological method is also popular. In the process, paired sera in RPGA with erythrocyte diagnosticum are investigated. This allows you to detect antibodies and build up the titer.

From the very first days a coprotic study can be carried out. It allows to identify cysts of protozoa, eggs of worms, the presence of starch, erythrocytes and other elements.

Differential diagnostics

Diagnostic measures are taken to differentiate the disease caused by salmonella, proteus, ascarids, amoebas.

Sometimes, at first, there is a suspicion of acute appendicitis. Sometimes differentiate with ulcerative colitis, poisonings and salts of heavy metals.

Treatment in adults and children

In severe stages of the disease, regardless of etiology and age, antibiotic therapy is prescribed. It is necessary both for hemocoelitis and for treatment of children under one year old, as well as in older children with immunodeficiency diseases.

In adults, antibiotics are needed for bacterial carriage and with an erased form.

Usually preparations of 1 series are prescribed for patients with mild and moderate disease course. Basically it is trimethoprim. In severe conditions, it is advisable to take cephalosporins, aminopenicillins.

Rehydration therapy is mandatory, regardless of the patient's age.

Preference is given to oral methods of treatment, for example, using glucose-salt solutions. Detoxification therapy is carried out in the presence of toxicosis. Use methods of oral rehydration, and in severe forms the administration of isotonic glucose solutions.

Prevention and antiepidemic measures

Hospitalization is prescribed according to the indications. Isolation is not carried out. Monitoring of the patient and in enterprises, educational institutions and other facilities is established to prevent the development of the disease.

When detecting bacteriocarriers, a person is hospitalized to clarify the diagnosis. With simultaneous illness of several people, the whole team is being investigated.

Nonspecific prevention includes sanitary supervision of water supply, sanitary control in educational, medical institutions and in the public catering system.

Shigellosis vaccine

There are several types of vaccines from each type of dysentery. For example, the only way to protect yourself from Shigelosis Sonne is the Shigelwak vaccine. It produces immune cells in the body to prevent disease.

The vaccine against Flexner's disease is under development and has not been fully tested for volunteers.

You can put a dysentery polyvalent bacteriophage. These are natural killers of bacteria. When introduced into the body, the bacteriophage finds the causative agent of infection and destroys the pathogen. Because of this, it is used as a temporary prophylaxis and for treatment.

Preventive measures are carried out for people at risk. These include citizens living in countries at high risk of disease, public catering workers, as well as those who are regularly in dangerous epidemiological countries.

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