Shigellosis is a disease caused by microbes of the genus Shigella, which are transmitted by the fecal-oral route, cause intoxication and most often affect the final section of the large intestine.

The cause of shigellosis is microbes of the Enterobacteriaceae family, the genus Shigella. This is typically a bacterial infection. Under a microscope, microbes look like rods with rounded ends. They have neither flagella nor cilia, they do not form capsules or spores. When stained according to Gram, they remain colorless (Gram-negative bacteria). They have different antigenic structure and biochemical properties.

These two principles underlie their classification.

Currently, there are four main types of shigellosis pathogens:

• shigella dysentery;
• Shigella Boyd's;
• Shigella Flexnera;
• Shigella Sonne.

Depending on various combinations of serological and cellular antigens There are more than 70 varieties of these microbes. They have exotoxins, as well as heat-labile and heat-stable endotoxins.

By the way, shigellosis has another common name - dysentery.

Shigella is able to penetrate the epithelium of the colon mucosa and multiply in it (invasiveness). They can also form substances that actively affect living cells (colicinogenicity). They are resistant to various environmental factors. In soil, water, food, as well as on the surface of furniture, fabric and dishes, they remain viable for up to two weeks.

And in wastewater Shigella sewers can even live whole month. But they quickly die under the influence of direct sun rays, phenol, and also during boiling.

The term “dysentery” was first used during the time of Hippocrates. Then it meant any diarrhea with blood. Only in 1891 A.V. Grigoriev discovered shigella in his patients with signs of inflammation of the large intestine. Subsequently, K. Shiga finally proved that the cause of dysentery is precisely this microorganism. Later, various scientists discovered other types of microbes that can cause shigellosis.

Epidemiology

Shigellosis is a typically anthroponotic infection. Infection occurs exclusively from a sick person. The disease can be both acute and chronic, or not manifest itself at all (hidden course), if we are talking about such a phenomenon as carriage of infectious agents. In this situation, the person does not get sick, but can infect others.

This is a dangerous situation, since it is very difficult to identify the carrier.

Dysentery is transmitted by the fecal-oral route. The transmission routes are different - through food, water, and also through general subjects everyday life. The most common route of transmission is water. This is due to the fact that water is easily polluted, and Shigella lives in it for a long time. The most common method for infecting children is through contact and household contact - through contaminated toys, dishes, linen and household items.

Children suffer from shigellosis much more often than adults (60–70%). The most susceptible child is kindergarten age (2–7 years). As for seasonality, this disease most often occurs in the summer-autumn period. Immunity after infection is unstable. Antibody production is specific to only one serotype.

Pathogenesis

Further along the gastrointestinal tract, Shigella is affected in turn hydrochloric acid and bile. Under their influence, most microbes die. Then the pathogen enters the final section of the large intestine, where, along with destruction, its reproduction also occurs. Due to the lysis of microorganisms, toxins are released. Absorbed through the mucous membrane, they penetrate into the blood and cause acute toxicosis in the body. It primarily affects the central nervous system, but the functioning of other systems is also disrupted:

• endocrine;
• cardiovascular;
• blood coagulation systems;
• urinary, etc.

Along with toxic damage to the body, inflammatory processes in the mucous membrane of the large intestine are also observed.

Shigella “sticks” to enterocytes and then penetrates them, actively multiplying there. Because of this, the pathogen affects more and more intestinal tissue, and the inflammation spreads.

But along with this, defensive reactions are also formed.

The concentration of IgM, IgG and IgA increases. Natural killer cells are activated, and the synthesis of y- and a-interferons increases. If the immune system works well, then in most cases of shigellosis there is a rapid recovery.

Clinical picture

Depending on the variations in symptoms there are Various types and forms of shigellosis. All this is reflected in their classification. It is based only on the clinical picture of the disease.

Laboratory indicators are not taken into account, except when they indirectly indicate the degree of severity.

Classification of shigellosis

By form:

• typical;
• atypical (asymptomatic, erased, bacterial carriage).

According to the duration of the disease:

• spicy;
• lingering;
• chronic.

According to the nature of the disease:

• smooth;
• unsmooth.

By severity:

• light;
• average;
• heavy.

Typical symptoms

Infectious diseases are preceded by an incubation period. For a typical form of shigellosis, it is quite variable (from 3–4 hours to seven days). On average, this period lasts 2–3 days. It all depends on the dose of the pathogen, its aggressiveness and transmission routes. The state of the macroorganism into which Shigella falls is also important. In a person with a weakened immune system, the prodromal period will be shorter, and if it is good, then longer.

Dysentery begins acutely. All symptoms inherent in this pathology appear within 1–2 days. Intoxication and colitis syndromes (inflammation of the final section of the large intestine) predominate. Intoxication syndrome is characterized by the following symptoms:

• fever;
• chills;
• malaise ( headache, drowsiness, weakness, lethargy);
• tachycardia;
• urinary disturbance;
• nausea;
• vomiting, etc.

Elevated body temperature usually persists for two to three days and then returns to normal. The severity of intoxication is directly proportional to the severity of the disease and serves as the main criterion for its determination. The second syndrome that accompanies dysentery, colitis, includes the following symptoms:

• constant or cramping pain in the abdomen (left iliac region);
• increased frequency of bowel movements;
• change in stool consistency (closer to watery or watery);
• the presence of impurities in the stool (mucus, greens, blood);
• tenesmus, etc.

Before the urge to defecate, abdominal pain intensifies. Rectal emptying does not stop pain syndrome. Frequent loose stools are always fecal in nature at first, and then mucous-bloody. Tenesmus occurs due to spasms of the smooth muscles of the distal large intestine. This often leads to hemorrhoidal manifestations.

It is noteworthy that intoxication and colitis syndromes are also directly related.

Physical examination reveals the following signs:

• pale and dry skin;
• thickening of the tongue;
• abdominal retraction;
• pain during palpation of the abdomen;
• rumbling of intestinal loops during palpation of the abdomen;
• compaction and poor mobility of the sigmoid colon,
• weakness of the anal sphincter;
• signs of sphincteritis (redness of the skin around the anus with itching and burning).

The acute period of shigellosis can last from five days to two weeks. Then comes a period of convalescence (recovery). Symptoms regress. Your well-being improves and your mood rises. When the body completely gets rid of the pathogen, recovery occurs.

Atypical symptoms

Atypical dysentery can be hidden or asymptomatic. In these cases, clinical manifestations are minimal:

• decreased appetite;
• slight malaise;
• periodic attacks of nausea, etc.

There are no clinical signs characteristic of the acute process. People most often attribute such symptoms to increased fatigue and do not consult a doctor. The infection simply does not have time to capture a large area of ​​the intestinal mucosa due to the fact that the immune system destroys it in a timely manner. After a week or two everything goes away without a trace.

Carriage of Shigella is extremely rare. It is detected accidentally during routine examinations during medical examination. The pathogen is sown once. It is not detected in subsequent samples. The patient feels well. There are no even minimal manifestations. Bacteriological and instrumental studies also remain normal.

Complications

Dysentery is often accompanied by complications. Conventionally, they can be divided into two groups:

• specific;
• nonspecific.

Specific complications are caused directly by the infection itself. These include:

• infectious-toxic shock;
• peritonitis;
• intussusception;
• dysbacteriosis;
• loss of intestines;
• anal fissure, etc.

• pneumonia;
• otitis;
• cystitis;
• pyoderma, etc.

Shigellosis in children occurs with complications much more often than in adults.

Diagnosis of shigellosis

At the prehospital stage, making a preliminary diagnosis of dysentery is not difficult for an experienced doctor. The clinical picture is quite characteristic. The presence of fresh blood in the stool always attracts the attention of both the patient (or the child’s parents) and the doctor. This is only possible with this disease. The pathogen will be identified in the hospital. In addition to pathognomonic symptoms, characteristic epidemiological history and the dependence of the severity of colitis symptoms on the degree of intoxication help to suspect this disease.

Laboratory diagnosis of dysentery includes, first of all, the bacteriological method. Although an infection of the large intestine is also detected in a regular coprogram. There will be pronounced leukocytosis, a large number of red blood cells, mucus and lack of detritus. As for stool cultures, it is better to do them no later than two hours after collection, and preferably directly at the patient’s bedside. The growth of microbes on nutrient media will not only provide material for serological tests, but will also make it possible to determine the sensitivity of bacteria to antibiotics.

Express methods help determine the type of pathogen:

• immunoenzyme reaction;
• coagglutination reaction;
• coal agglomeration reaction;
• latex agglutination reaction;
• complement reaction, etc.

For more accurate diagnosis, serological methods are used (agglutination reaction and indirect hemagglutination).

Treatment of shigellosis

This disease can be treated both in a hospital and at home. It all depends on the severity of the disease.

Children under one year of age are subject to 100% hospitalization.

Like any pathology, dysentery begins to be treated by prescribing a regimen and diet. In the acute period, the regime is always in bed, then in the ward. The diet as a whole does not differ from normal nutrition, with the exception of its focus on easy digestion ( low content fat, boiled and steamed food). This approach is due to the fact that most of the intestinal mucosa retains the ability to absorb nutrients during illness.

Treatment consists of prescribing antibiotics that primarily remove the cause of the disease. This is done taking into account sensitivity. Most often, one drug is prescribed. If there are complications or severe cases, two are administered. The groups of choice of antibacterial agents are:

• aminoglycosides (second and third generation);
• cephalosporins (second and third generation);
• nitrofurans;
• fluoroquinolones.

The course of treatment depends on the specific drug, but on average ranges from five to ten days. In cases of atypical shigellosis and carriage of bacteria, antibiotics are not prescribed.

The following drugs are used for pathogenetic therapy:

• antispasmodics;
• antipyretics;
• disaggregants;
• saline and colloidal intravenous solutions;
• neuroleptics;
• gangloblockers, etc.

The higher the degree of toxicosis in shigellosis, the longer list pathogenetic therapy drugs.

Prevention of shigellosis

Measures to prevent the development of dysentery are as follows:

• sanitary and hygienic;
• health education;
• work in the source of infection.

Prevention of shigellosis is especially important in food processing plants, kindergartens, schools and hospitals. First of all, this is sanitary control throughout the building, regular garbage collection, and insect control.

Considering high probability waterborne transmission route, it is important to ensure that water supplies are not contaminated.

If a patient with shigellosis is identified, it is necessary to carry out ongoing disinfection in the outbreak. If hospitalization occurs, final disinfection is performed. The same is done in case of recovery at home. All people who had contact with the patient are monitored medical supervision. They must undergo bacteriological tests. If there are indications for this, then carry out preventive treatment. All this helps stop the spread of infection.

In the diagnosis of dysentery the following is used:

• general blood analysis ;
• bacteriological examination;
• laboratory research;

General blood test for dysentery

A general blood test for dysentery reveals:

• Increase in ESR. ESR ( erythrocyte sedimentation rate) is a laboratory indicator that allows you to identify systemic inflammatory process in organism. With the development of an inflammatory reaction in the intestine, a number of biologically active substances and proteins of the acute phase of inflammation are released into the systemic circulation ( C-reactive protein, ceruloplasmin, fibrinogen and others). These substances promote the adhesion of red blood cells ( red blood cells), as a result of which the latter more quickly settle to the bottom of the test tube during the study. Normally, ESR in men is 10 mm per hour, and in women – 15 mm per hour. With dysentery, these indicators can increase 2–3 times.
• Neutrophilic leukocytosis. Leukocytosis is an increase in the total number of leukocytes ( immune system cells) more than 9.0 x 10 9 /l. With the development of dysentery, there is an increase in neutrophil production ( types of white blood cells), since these cells are among the first to migrate into the intestinal wall and begin to fight Shigella, preventing their further spread.
• Shift of the leukogram to the left. Under normal conditions, neutrophils are released into the systemic circulation in an immature form ( band forms, which account for 1–5% of all leukocytes), after which they turn into full-fledged protective cells ( segmented forms, which account for 40–68% of all leukocytes). For dysentery ( and any other bacterial infection) mature neutrophils migrate to the site of introduction of the pathogen and begin to actively fight it, dying in the process. At the same time, the process of formation of neutrophils is stimulated, as a result of which more of their immature forms enter the systemic circulation. This leads to the fact that the proportion of band neutrophils in the blood increases, while the proportion of segmented neutrophils decreases ( which is called a shift of the leukogram to the left).
• Monocytosis ( increase in the number of monocytes in the blood). Monocytes are also cells of the immune system, making up about 9% of all white blood cells. After a short circulation in the blood, they migrate into the tissues various organs, turning into macrophages. If you become infected with a bacterial infection ( including dysentery) macrophages absorb foreign bacteria and their particles that have penetrated the intestinal wall. At the same time, the process of formation of monocytes is activated, as a result of which their proportion in the blood increases.

Stool analysis ( coprogram) for dysentery

Feces for analysis are collected after spontaneous bowel movements in a special container. You cannot collect material for analysis immediately after performing an enema, or when taking certain medications ( barium, iron, laxatives, rectal suppositories and others).

Coprogram for dysentery

Bacteriological diagnostics ( sowing) for dysentery

An important stage of the study is to determine the sensitivity of the infectious agent to antibiotics. For this purpose, Shigella is inoculated on a nutrient medium, after which several small tablets with various antibacterial drugs are placed there. These nutrient media are placed in a special thermostat for some time, and then the result is evaluated. If shigella growth is observed around an antibiotic tablet, the pathogen is not sensitive to this drug. If Shigella growth is not observed within a certain radius from the tablet, this antibiotic may be used to treat dysentery in this patient.

Laboratory diagnosis of dysentery

The gold standard, which makes it possible to confirm the diagnosis with almost one hundred percent probability, is serological diagnosis, based on the determination of specific antibodies in the patient’s blood. The principle of the method is based on the ability of the human immune system to react in a certain way to the introduction of foreign microorganisms, that is, to develop special immune complexes against them ( antibodies). These antibodies find and destroy only the bacteria against which they were developed. Therefore, if a person’s blood contains antibodies against any species or subspecies of Shigella, it means that he is infected with this particular pathogen.

Today there are many methods of serological diagnosis, but for dysentery the indirect hemagglutination reaction is most often used ( RNGA). The essence of the method is as follows. Antigens of various types of Shigella are attached to the surface of specially prepared red blood cells. The patient's blood serum is then added to the various samples. If it contains antibodies against Shigella, they will begin to interact with antigens specific to them, resulting in red blood cells sticking together, which will be noticeable macroscopically ( naked eye). If these antibodies are not present in the patient’s blood, no reaction will occur.

With the help of RNGA, antibodies can be detected starting from the 5th day after the appearance of the first clinical signs of the disease ( in more early dates There are no specific antibodies in the patient’s blood). After 2 weeks, the amount of antibodies in the blood reaches a maximum, and after a month begins to decrease.

Sigmoidoscopy for dysentery

Since dysentery most often affects the terminal part of the large intestine, sigmoidoscopy is important ( however not determining) diagnostic method. During the study, the doctor evaluates changes in the intestinal mucosa, which largely depend on the stage of the disease.

Damage to the intestinal mucosa during dysentery is characterized by:

• Acute catarrhal inflammation. Develops in the first days of the disease as a result of the penetration of Shigella and their toxins into the tissue of the mucous membrane. As a result of immune activation, cells of the immune system migrate to the site of bacterial invasion ( neutrophils, macrophages and others), which die in the process of fighting the pathogen, releasing many biologically active substances. These substances promote the expansion of small blood vessels and increasing permeability vascular wall, as a result of which part of the fluid passes from the vascular bed into the intercellular space. The intestinal mucosa becomes hyperemic ( that is, it acquires a bright red hue as a result of the expansion of blood-filled vessels) and edematous. In some places, superficial erosions or minor hemorrhages may be detected.
• Fibrinous-necrotic inflammation. Characterized by the death of cells in the intestinal mucosa as a result of exposure to a cytotoxin. The mucous membrane itself becomes covered with a dense gray coating.
• Stage of ulcer formation. As a result of exposure to cytotoxin, death occurs ( necrosis) cells of the mucous membrane, and after rejection of necrotic ( dead) masses, shallow ulcers form in their place.
• Stage of healing of ulcers. Regeneration process ( recovery) of damaged mucous membranes begins a few days after the first clinical signs of infection appear, but complete recovery may take several weeks or even months ( depending on the severity of the disease and timeliness of treatment).

No special preparation is required to perform sigmoidoscopy. When performed correctly, the procedure is safe and virtually painless. There are no absolute contraindications to sigmoidoscopy, but manipulation should be postponed if there are anal fissures or other infectious and inflammatory diseases in the anal area.

Differential diagnosis of dysentery

Dysentery should be differentiated:

• From salmonellosis. Salmonellosis is also characterized by signs of damage to the gastrointestinal tract ( nausea, vomiting, profuse diarrhea), however, signs of general intoxication of the body are usually more pronounced than with dysentery. To accurately confirm the diagnosis, a bacteriological or serological study is required.
• From escherichiosis. This disease is caused by pathogenic Escherichia coli and is characterized by signs of damage small intestine. Symptoms of general intoxication of the body are usually absent or mild.
• From cholera. Cholera is characterized by damage to the gastrointestinal tract, accompanied by profuse watery diarrhea, which quickly results in dehydration. There is no mucus or blood in the stool, and the symptoms of general intoxication are mild or moderate.
• From yersiniosis. This disease occurs with severe symptoms general intoxication and signs of intestinal damage. A distinctive feature is the rapid defeat internal organs and systems ( liver, kidneys, central nervous system and others), which is manifested by corresponding symptoms ( jaundice, impaired urine formation, and so on).
• From rotavirus infection. This disease is caused by rotaviruses and is characterized by damage to the intestines, as well as the upper respiratory tract (which is manifested by a runny nose or inflammation of the pharyngeal mucosa). Signs of general intoxication of the body are insignificantly expressed.
• From acute appendicitis. Appendicitis ( inflammation of the appendix of the cecum) is characterized by severe pain in the lower abdomen ( mostly on the right) and increased body temperature. One-time vomiting may also occur. An important diagnostic point is to identify signs of peritoneal irritation, which will be positive for appendicitis and negative for dysentery.

Treatment of dysentery

Is hospitalization necessary for dysentery?

• Patients with moderate or severe disease.
• Patients with severe concomitant diseases cardiovascular, respiratory and other systems.
• Patients presenting an increased epidemiological danger ( food industry workers, doctors, kindergarten, school workers and so on).

Caring for a patient with dysentery

With mild forms of the disease, patients begin to feel an improvement in their general condition within a few days after starting treatment, while with severe dysentery, patients may need help from others for several days or even weeks.

• Strict bed rest – from the first day of illness until body temperature normalizes.
• Limiting exposure to stress factors– hypothermia or overheating, psycho-emotional stress, work requiring prolonged mental effort.
• Full sleep- during the height of the disease, the patient should sleep at least 9-10 hours a day, and during the recovery period - at least 8 hours daily.
• Exclusion of any physical activity – for at least 1 week after body temperature normalizes and symptoms of intoxication disappear.

Antibiotics for dysentery

Treatment of dysentery with antibiotics

Bacteriophages in dysentery

Specific dysentery bacteriophage should be taken orally, 3 times a day, 1 hour before meals. You should start taking the drug immediately on the day of diagnosis. The course of treatment is 6–8 days.

A single dose of dysentery bacteriophage ( for oral administration) is:

• Children up to 6 months– 5 ml.
• From 6 to 12 months– 10 – 15 ml.
• From 1 year to 3 years– 15 – 20 ml.
• From 3 to 8 years– 20 – 30 ml.
• Children over 8 years old and adults– 30 – 40 ml.

The dose of bacteriophage for rectal administration is:

• Children up to 6 months– 10 ml.
• From 6 to 12 months– 20 ml.
• From 1 year to 3 years– 30 ml.
• From 3 to 8 years– 40 ml.
• Over 8 years old– 50 – 60 ml.

Symptomatic treatment of dysentery

Diet for dysentery

Food for dysentery should be taken in small portions 5 to 6 times during the day. All food consumed must be well processed ( thermally and mechanically), and their temperature at the time of consumption should not be higher than 60 degrees or lower than 15 degrees. Patients should also drink at least 2 liters of fluid per day, which will prevent dehydration and reduce the severity of intoxication syndrome.

Diet for dysentery

Treatment of dysentery with folk remedies at home

To treat dysentery you can use:

• Oak bark decoction. It has an astringent, anti-inflammatory and antibacterial effect. To prepare a decoction 20 grams ( 2 full tablespoons) crushed oak bark should be poured with 200 ml of boiled water and heated over low heat for half an hour. After this, cool the broth, strain through a double layer of gauze and take 20–30 ml orally 3–4 times a day ( an hour before meals).
• Infusion of bird cherry fruits. Has an astringent and anti-inflammatory effect. To prepare the infusion, pour 20 grams of bird cherry fruit into 400 ml of boiling water. Insist on dark place for 1 – 2 hours, then strain and take 50 ml orally ( 1/4 cup) 3 – 4 times a day half an hour before meals.
• Infusion of plantain leaves. It has anti-inflammatory and antimicrobial effects, suppressing the proliferation of Shigella in the intestines. To prepare the infusion, 5 grams of crushed plantain leaves should be poured into 100 ml of hot boiled water and placed in a water bath for 10 - 15 minutes, and then infused in a dark room for 2 hours. Strain the resulting infusion and take orally half an hour before meals ( children - 1 - 2 dessert spoons 2 - 3 times a day, adults - 2 tablespoons 2 - 4 times a day).
• Infusion of chamomile flowers. Has anti-inflammatory, antibacterial and antispasmodic effects ( eliminates spasm of intestinal smooth muscles). The infusion is prepared as follows. 2 full tablespoons of chamomile flowers are poured into 1 cup of boiling water and placed in a water bath for 15 - 20 minutes. After this, cool at room temperature for 1 hour, filter and take 2–3 tablespoons orally 3–4 times a day ( half an hour before meals).

Prevention of dysentery

Is a person who has had dysentery contagious?

Immunity and vaccine ( graft) for dysentery

Based on the foregoing, it follows that it is almost impossible to develop an effective vaccine that could protect a person from infection with dysentery for a long time. This is why prevention is key of this disease is allocated to sanitary and hygienic measures aimed at preventing contact of a healthy person with an infectious agent.

However, under certain conditions, people can be vaccinated against certain types of dysentery ( in particular against Shigella Sonne, which are considered the most common).

Vaccination against Shigella Sonne is indicated:

• Workers of infectious diseases hospitals.
• Workers of bacteriological laboratories.
• Persons traveling to epidemiologically dangerous regions ( where there is a high incidence of Sonne dysentery).
• Children attending kindergartens ( in case of unfavorable epidemiological situation in the country or region).

Vaccination is contraindicated for children under three years of age, pregnant women, as well as people who have had Sonne dysentery within last year (if the diagnosis was confirmed by laboratory).

Anti-epidemic measures for dysentery

Anti-epidemic measures for dysentery include:

• Carrying out sanitary and educational work among the population. Doctors should tell people about the routes of spread, mechanisms of infection and the first clinical manifestations of dysentery, as well as methods to prevent infection.
• Regular examination of water bodies and food enterprises for the presence of pathogenic types of infectious agents.
• Regular preventive examination of employees of kindergartens, schools and public catering establishments in order to identify latent or chronic forms of dysentery.
• Early detection, registration, full diagnosis and adequate treatment of all patients with signs of acute intestinal infection.
• When a case of dysentery is confirmed, it is mandatory to identify the source of infection. For this purpose, all food products that the patient has consumed over the past few days are examined. If he ate in canteens or other public catering places, a special commission is sent to all these institutions, which collects material ( food products) in order to identify Shigella in them.
• Observation of all people who had contact with a person with dysentery for 7 days. All of them undergo a mandatory one-time bacteriological examination of stool. If necessary, dysentery bacteriophages can be prescribed in prophylactic doses.
• Regular wet cleaning of the room ( during treatment at home) or wards ( while being treated in hospital) in which the patient is located.

Quarantine for dysentery

The reason for declaring quarantine for dysentery may be:

• Simultaneous appearance of clinical signs of dysentery in two or more persons in the same group ( in kindergarten, in school class and so on). In this case, a quarantine is declared in the group. Within 7 days, none of the children can be transferred to another group. All those in contact with the patient must undergo a bacteriological examination and begin taking dysentery bacteriophages in prophylactic doses.
• Detection of a repeat case of dysentery in a group within 7 days. In this case, preventive measures correspond to those described above.
• Identifying signs of dysentery in two or more persons in the same locality who do not work/study in the same institution. In this case, there is a high probability that the infection is present in a local pond or in a public canteen. Suspicious institutions and bodies of water are closed, and samples of water and food are sent to the laboratory for detailed examination. To all residents settlement at the same time, it is recommended to observe the rules of personal hygiene, as well as to consume only well-processed ( thermally) food and boiled water.

Complications and consequences of dysentery

Dysentery can be complicated by:

• Relapse ( re-development) diseases. Most common complication which occurs as a result of improper treatment ( for example, if antibiotic therapy is stopped too early).

• Bacterial infections from other organs and systems. With dysentery, the overall defenses of the body are reduced, which is also facilitated by disruption of the absorption of nutrients when the small intestine is damaged and loss of electrolytes during diarrhea. As a result, favorable conditions are created for the development of bacterial infection in the lungs, urinary tract and other organs.
• Dysbacteriosis. With the development of dysentery, the permanent intestinal microflora is destroyed, which is necessary for the normal process of digestion and absorption of certain vitamins. This may also be facilitated by long-term use of broad-spectrum antibiotics. That is why, during the recovery period, all patients are recommended to take medications that restore normal intestinal microflora.
• Anal fissures. Characterized by damage ( gap) tissues in the anal area as a result of frequent and severe urge to defecate.
• Perforation of an intestinal ulcer. A rare complication of dysentery, the development of which is facilitated by severe ulceration of the intestinal wall. At the very moment of perforation, the patient experiences acute “dagger” pain in the abdomen. After perforation, bacteria and toxic substances located in the intestinal lumen enter the abdominal cavity, leading to the development of peritonitis ( inflammation of the peritoneum) is a life-threatening condition requiring surgical treatment.
• Infectious-toxic shock. Most formidable complication, which can develop at the peak of a severe form of dysentery as a result of severe intoxication of the body and damage to the nervous and cardiovascular systems. Characterized by a pronounced decrease in blood pressure, which can cause disruption of the blood supply to the brain and death of the patient. The patients are pale, their consciousness is often disturbed, the pulse is weak, rapid ( more than 100 beats per minute). During development this complication shown urgent hospitalization patient in the intensive care unit.

Why is dysentery dangerous during pregnancy?

Dysentery during pregnancy can lead to:

• To intrauterine fetal death. The cause of this phenomenon may be severe intoxication of the mother’s body, as well as impaired blood supply to the fetus as a result of various complications ( in particular with the development of infectious-toxic shock). Also, intrauterine fetal death can be facilitated by maternal dehydration, accompanied by the loss of large amounts of electrolytes.
• To premature birth. Frequent tenesmus ( false, painful urges to defecation), accompanied by a pronounced contraction of the smooth muscles of the gastrointestinal tract, can provoke premature onset of labor.
• To infect a child. Infection with dysentery can occur in utero or at the time of birth of a child, which is due to the proximity of the external genitalia and anus in women. Also, in women with large dysentery, intestinal microflora or even the causative agent of dysentery can often be detected ( in particular Shigella Flexner) in the vagina.
• To the death of the mother during childbirth. This can be facilitated by a decrease in the compensatory reserves of the maternal body ( as a result of a progressive infectious-inflammatory process), as well as damage to the central nervous system and cardiovascular system.

Why is dysentery dangerous in children?

Dysentery in children is characterized by:

• More pronounced symptoms of intoxication. The immune system child's body is not fully formed and is not able to adequately respond to the introduction of Shigella. Clinically, this is manifested by a more pronounced increase in temperature ( up to 38 – 40 degrees from the first day of illness), loss of appetite, lethargy, tearfulness.
• Difficulties in diagnosis. Children ( especially newborns and infants) cannot adequately describe their complaints. Instead, they simply cry, scream and refuse to eat. In this case, dysentery can be suspected only on the basis of frequent, large stools, increased body temperature and signs of systemic intoxication. However, a number of childhood diseases also have similar clinical manifestations, which is why a bacteriological examination of stool should be carried out as soon as possible and treatment should begin.
• Rapid development of complications. The compensatory systems of the child’s body have not yet been formed, as a result of which, with profuse diarrhea, dehydration in children occurs much faster than in adults ( signs of mild or moderate dehydration may appear by the end of the first day after the onset of the disease). This is why it is extremely important to start using rehydrating agents in a timely manner ( replenishing fluid loss) funds, and if necessary, resort to intravenous administration liquids and electrolytes.

Test for dysentery is a collective concept that includes general clinical and specific research methods that help establish not only the final diagnosis of shigellosis (a more modern name for dysentery), but also assess the degree of disorders in various systems organs in the body.

Is your husband an alcoholic?

Laboratory diagnosis of dysentery includes:

• general clinical methods (traditional blood and urine tests);
• coprogram;
• biochemical tests;
• bacteriological method;
• serological reactions;
• allergic skin test (rare);
• instrumental studies.

The expediency of a particular diagnostic study is determined by the current medical documentation, namely the protocols for the provision of medical care. Not only the components of the diagnosis of shigellosis are regulated, but also the frequency of their implementation. This detail is important for the so-called decreed group, that is, people working in the food industry and children's groups - a certain number of negative tests is the basis for admission to work.

General clinical methods

Study of the cellular composition of blood

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This routine research method can be quite informative specifically for dysentery, as it reflects the severity of the disease. At mild flow a general blood test may not reveal any changes or they will be insignificant. On the contrary, in severe forms of the disease, the accents typical of a bacterial infection are expressed very violently.

In severe forms of shigellosis, the following can be detected:

• a significant increase in the absolute number of leukocytes (that is, hyperleukocytosis);
• a significant shift of the formula to the left, that is, an increase in the absolute and relative number of band lymphocytes, up to the appearance of young forms;
• toxic granularity of neutrophils;
• increased erythrocyte sedimentation rate;
• decrease in the level of color index and hemoglobin concentration, the number of red blood cells(red blood cells), that is, classic signs of anemia.

Pronounced changes in the general blood test indicate not only a severe course of the disease, but also possible development complications such as intestinal bleeding.

On the other hand, even pronounced changes in the general blood test are nonspecific, that is, they can be observed in many other diseases, and therefore are not the basis for making a final diagnosis.

Urine examination

Only in the case of a very severe course of the disease are changes observed in the general urine analysis, which are a consequence of severe intoxication. Such signs include the appearance of red blood cells, a large number of white blood cells and casts, as well as an increase in protein concentration. For the purpose of exclusion possible pathology urinary tract should be repeated general analysis urine after the clinical symptoms of dysentery have subsided.

Coprogram

Stool analysis reflects all changes typical of dysenteric intestinal damage. In addition, the nature and extent of the identified changes is directly related to the severity of the clinical course of the disease.

When examining stool, the following changes are observed:

• increased number of leukocytes (normally there can be only a few);
• the appearance of red blood cells (normally absent);
• mucus in varying quantities (not normally detected);
• undigested food particles and epithelium as a result of disruption of food digestion processes, as well as damage epithelial tissue intestines.

It is necessary to understand that the obtained results of the coprogram, as well as general clinical tests of urine and blood, cannot be considered as a final diagnosis of shigellosis. To establish the specific type of Shigella that caused the development of clinical symptoms of the disease in a given patient, as well as to assess its sensitivity to certain antibiotics, a full microbiological diagnosis of dysentery is necessary.

Specific diagnostics

If dysentery is suspected, diagnosis involves isolating the pathogen from the patient's biological fluids (primarily from feces, less commonly gastric lavage and vomit) or determining the titer of protective antibodies that are produced in response to the introduction of a microbial agent.

Bacteriological method

It is the most common, informative and accessible in most cases and in the majority of clinics. Stool collection for examination should be carried out in the first days of illness. Feces obtained from in a natural way, as well as taken with a sigmoidoscopy tube or a cotton swab (a kind of smear). Collect biological material in a clean container that has not been treated with disinfectant solutions.

The largest amount of the causative agent of dysentery is detected in those areas of stool where mucus and pus are present. Sowing is done on conventional nutrient media - Levin, Ploskireva, Endo. The result, containing not only comprehensive information about the type of Shigella, but also parameters of sensitivity to antimicrobial drugs, the doctor receives it 3-5 days after collecting the material.

Serological method

Less informative in comparison with the bacteriological method. This is due to the fact that the clinical picture of uncomplicated and mild dysentery does not last more than 5-7 days, and serological method with dysentery it takes much longer. It is rare for a patient to spend 2-2.5 weeks in a hospital bed awaiting serological results. Serological reactions may be useful and informative as a method of retrospective diagnosis or in scientific research.

Most often, an agglutination reaction is performed: the presence of protective antibodies in a certain concentration is detected in the patient’s blood serum using known antigens. It is advisable to evaluate the information content of the agglutination reaction in dynamics.

The reaction of indirect and/or direct agglutination is less specific. Blood serum is taken no earlier than 4-5 days of illness, and again on days 12-14 from the onset of clinical manifestations. Allergy diagnostics

In the middle of the twentieth century, one of the mandatory tests for shigellosis of any severity was a skin allergy test with dysenterin (Tsuverkalov test). In modern medical practice, due to the allergenicity of the population and the non-specificity of this test, most clinics have refused to perform it.

Instrumental diagnostics

The most common method is sigmoidoscopy. To carry it out, you only need a competent trained specialist and a portable device. There is no need to allocate a separate room, its special equipment and other technical details.

The sigmoidoscope tube is inserted into anus to a certain depth. The condition of the mucous membrane of the lower rectum and sphincter is visually assessed. When dysentery is detected:

• ulcerative defects of various sizes;
• diffuse swelling and hyperemia of the mucous membrane;
• areas of hemorrhage.

Sigmoidoscopy is intended to assess the effectiveness of the prescribed therapy (whether there are positive dynamics or not, that is, healing of ulcers), as well as to exclude others similar in clinical symptoms diseases (nonspecific ulcerative colitis, tumor formation). In the initial period of shigellosis, this study is not indicated, since the patient’s discomfort from the procedure exceeds its diagnostic value.

Fibercolonoscopy (penetration into higher parts of the intestine) is indicated only if it is necessary to exclude other intestinal diseases (neoplastic tumors).

Thus, only a comprehensive diagnosis of dysentery allows one to correctly assess the severity of the patient’s condition and the effectiveness of the prescribed therapy.

Laboratory diagnosis of bacterial dysentery

Dysentery is an anthroponotic infectious disease caused by bacteria of the genus Shigella, characterized by ulcerative lesion large intestine and general intoxication of the body. The classification of dysentery pathogens (Shigella) is presented in Table 12, methods microbiological diagnostics in diagram 13.

Table 13. Shigella classification

Scheme 12. Microbiological diagnosis of dysentery

Microscopic method for dysentery it is not used due to the morphological similarity of Shigella with other enterobacteria.

Bacteriological method is the main method of laboratory diagnosis of dysentery . The material under study is inoculated on Ploskirev and Endo media in Petri dishes, as well as on a selenite accumulation medium, from which, after 16-18 hours, reseeding is done on the specified dense nutrient media. Crops are grown in a thermostat at 37 0 C for 18 - 24 hours.

On the second day, the nature of the colonies is studied. Colorless lactose-negative smooth colonies of Shigella are subcultured onto one of the polycarbohydrate media (Olkenitsky, Ressel, Kligler) to accumulate a pure culture. On the 3rd day, the growth pattern on a polycarbohydrate medium is taken into account, and the material is also subcultured onto differential media (Gissa et al.) for biochemical identification of the isolated culture. The antigenic structure of the isolated culture is determined using OPA in order to identify it to the species and serovar levels. On the 4th day, the results of biochemical activity are taken into account (Table 14).

Table 14. Biochemical properties of Shigella

Designations: “k” – fermentation of the substrate with the formation of acid, “+” - presence of the characteristic, “-“ - absence of the characteristic, “±” - unstable characteristic.

Shigella, unlike Escherichia, are immobile microorganisms; they do not ferment lactose, decompose glucose without gas formation, and do not decarboxylate lysine. For serotyping, first RA is placed on glass with a mixture of sera against the species and variants of Shigella that are prevalent in the area, and then RA is placed on glass with monoreceptor species sera. The sensitivity of the isolated culture to polyvalent dysentery bacteriophage and antibiotics is also determined. For epidemiological purposes, phagovar and colicinvar of isolated Shigella are determined. One of the properties of Shigella is their ability to cause keratitis in guinea pigs(keratoconjunctival test)

Serological method. To determine antibodies in the blood of patients with dysentery (usually chronic form) RNGA is used with erythrocyte shigella diagnosticums. Diagnostic titers: for Flexner's Shigella in adults - 1:400, in children under 3 years old - 1:100, in children over 3 years old - 1:200, for other Shigella - 1:200. The reaction is usually repeated with blood serum taken at least 7 days later; An increase in antibody titer by four or more times has diagnostic significance.

Express methods for dysentery - direct and indirect RIF, co-agglutination reaction, ELISA, RNGA with antibody erythrocyte diagnostics for the rapid detection of Shigella in the test material (usually in feces), as well as PCR.

The content of the article

Shigella

Morphology and physiology

Antigens

Pathogenicity and pathogenesis

Immunity

Ecology and epidemiology

Dysentery (shigellosis)

Taking material for research

Bacteriological research

Serological diagnosis

Specific prevention and treatment