Shigellosis disease. Shigellosis zonene. Life cycle of shigella
The causative agents of shigellosis are bacteria of the genus Shigella, gram-negative rods from the Enterobacteriaceae family, subdivided into 40 serotypes. There are 4 types of microorganisms: S. sonnei, S. flexneri, S. dysenteriae, S. boydii. In all Shigella species, the R-factor has been identified, which determines resistance to many antibiotics.
Epidemiology of shigellosis (dysentery)
The source is the feces of infected people. Animal reservoirs are unknown. Predisposing factors include residential overcrowding, poor hygiene, closed population groups living in poor sanitation (e.g. orphanages for mentally retarded children), travel to countries with low level food sanitation. The usual route of infection is fecal-oral contact from person to person. Other routes of transmission include ingestion of contaminated food or water, contact with contaminated household items. In the tropics, the role of house flies as mechanical carriers of infected feces is recognized in the spread of shigella.
Symptoms of shigellosis (dysentery)
The incubation period for dysentry lasts from 1 to 7 days, but usually 2-4 days.
During dysentery, acute, chronic forms and shigellosis bacteriocarrier are distinguished. The acute form can proceed according to one of three variants of the clinical course: gastroenteritis, gastroenterocolitis or colitis.
Most common in clinical practice colitis variant. With it, the characteristic signs of shigellosis are determined, especially in severe and moderate course. The disease, as a rule, begins acutely, in some patients it is possible to establish a short-term prodromal period, manifested by a short feeling of discomfort in the abdomen, slight chills, headache, and weakness. After the prodromal period (and more often against the background of complete health), characteristic symptoms of the disease appear. First of all, there are cramping pains in the lower abdomen, mainly in the left iliac region; sometimes the pain has a diffuse character, atypical localization (epigastric, umbilical, right iliac region).
A feature of the pain syndrome is its decrease or short-term disappearance after defecation. The urge to defecate appears simultaneously with the pain or somewhat later. The stool is initially fecal, gradually the volume of feces decreases, an admixture of mucus and blood appears, the frequency of bowel movements increases. At the height of the disease, stools may lose their fecal character and look like a so-called rectal spit, i.e. composed of only a meager amount of mucus and blood. Defecation may be accompanied by tenesmus (drawing convulsive pain in the anus), often there are false urges. The admixture of blood is most often insignificant (in the form of blood points or streaks). On palpation of the abdomen, a spasm is noted, less often - soreness of the sigmoid colon, sometimes flatulence. From the first day of the disease, signs of intoxication appear: fever, malaise, headache, dizziness. Possible cardiovascular disorders that are closely associated with intoxication syndrome (extrasystole, systolic murmur at the apex, muffled heart sounds, fluctuations in blood pressure, the presence of changes in the electrocardiogram, indicating diffuse changes in the myocardium of the left ventricle, overload of the right heart).
The duration of clinical symptoms in an uncomplicated course of acute shigellosis is 5–10 days. In most patients, the temperature first normalizes and other signs of intoxication disappear, and then the stool normalizes. Abdominal pain persists for longer. The criterion for the severity of the course in patients with shigellosis is the severity of intoxication, lesions of the gastrointestinal tract, as well as the state of the cardiovascular, central nervous system and the nature of the lesion of the distal colon.
Gastroenterocolitic variant of acute shigellosis. The clinical features of this variant are that the onset of the disease resembles PTI, and at the height of the disease, the symptoms of colitis appear and come to the fore. The gastroenteric variant of acute shigellosis along the course corresponds to the initial period of the gastroenterocolitic variant. The difference lies in the fact that in later periods the symptoms of enterocolitis do not dominate and clinically this variant of the course is more similar to PTI. With sigmoidoscopy, less pronounced changes are usually observed.
Erased course of acute shigellosis. It is characterized by short-term and unexpressed clinical symptoms (1-2-fold disorder of the stool, short-term abdominal pain), the absence of symptoms of intoxication. Similar cases of the disease are diagnosed by determining sigmoidoscopy changes (usually catarrhal) and isolating shigella from feces. A protracted course of acute shigellosis is said to occur when the main clinical symptoms do not disappear or resume after a short-term remission for 3 weeks to 3 months.
Bacteriocarrier. This form of the infectious process includes cases when there are no clinical symptoms at the time of the examination and in the previous 3 months, with sigmoidoscopy and the isolation of shigella from feces, no changes in the mucous membrane of the colon are detected. Bacteriocarrier can be convalescent (immediately after suffering acute shigellosis) and subclinical if shigella is isolated from individuals who do not have clinical manifestations and changes in the mucous membrane of the distal colon.
Chronic shigellosis. A chronic disease is registered in cases where the pathological process continues for more than 3 months. Chronic shigellosis according to the clinical course is divided into two forms - recurrent and continuous. With a relapsing form, periods of exacerbations are replaced by remission. Exacerbations are characterized by clinical symptoms characteristic of the colitis or gastroenterocolitic variant of acute shigellosis, but mild intoxication. With a continuous course, the colitis syndrome does not subside, hepatomegaly is noted. In chronic shigellosis, sigmoidoscopy also reveals moderate inflammatory and atrophic changes.
The risk of infection exists as long as the pathogen is present in the faeces. Even without antimicrobial therapy, convalescent carriers usually cease after 4 weeks of onset. Chronic carriage (more than 1 year) is observed quite rarely.
Features of shigellosis Grigoriev-Shigi. It proceeds mostly hard, characterized by an acute onset, intense cramping pain in the abdomen, chills, fever up to 40 ° C. Chair on the first day appearance resembles meat slop, then the volume of feces decreases, an admixture of blood and pus appears. Note tenesmus.
Complications
Perhaps the development of infectious-toxic shock, acute pancreatitis, peritonitis, intestinal bleeding, myocarditis, nephritis, polyarthritis, polyneuritis, toxic hepatitis. Rare complications of the disease include Reiter's syndrome or hemolytic uremic syndrome.
Diagnosis of shigellosis (dysentery)
The most reliable method of laboratory diagnosis of shigellosis is the isolation of coproculture of shigella. For the study, stool particles containing mucus and pus (but not blood) are taken, it is possible to take material from the rectum with a rectal tube. For inoculation, 20% bile broth, Kaufman's combined medium, and selenite broth are used. The results of bacteriological examination can be obtained no earlier than 3-4 days from the onset of the disease. Isolation of blood culture is important in Grigoriev-Shiga shigellosis.
The diagnosis can also be confirmed by serological methods. Of these, the most common method is with standard erythrocyte diagnosticums. An increase in antibodies in paired sera taken at the end of the first week of illness and after 7–10 days, and a fourfold increase in titer are considered diagnostic.
ELISA, RKA are also used, it is possible to use aggregation hemagglutination and RSK reactions.
Treatment of shigellosis (dysentery)
Bed rest is prescribed for severe and moderate to severe course. Plentiful drink, diet - table number 4 according to Pevzner, then - table number 13.
Antibacterial therapy helps to reduce the duration of diarrhea and the disappearance of the pathogen from the feces, so it is recommended for most patients. Since the disease resolves on its own and is often mild, the main indication for prescribing antibacterial agents in some patients is to prevent further spread of the pathogen. Often there are strains that are resistant to antibacterial drugs, so it is necessary to determine the sensitivity to these drugs of all isolated strains. If susceptibility is unknown or an ampicillin-resistant strain is isolated, trimethoprim-sulfamethoxazole is the drug of choice. For susceptible strains, ampicillin is effective. Amoxicillin is ineffective and should not be used to treat shigellosis. Patients aged 9 years and older are prescribed tetracycline if the strain is sensitive to it. Acceptable oral route of administration, except for seriously ill patients.
Antidiarrheals that inhibit intestinal motility are contraindicated, as they can prolong the clinical and bacteriological course of the disease.
Isolation of the hospitalized patient. Intestinal precautions are indicated until three consecutive stool cultures are negative 24 hours apart after antimicrobial therapy has been discontinued.
Prevention of shigellosis (dysentery)
Important control measures are handwashing and personal hygiene, sanitary water supply, food processing, sewerage for waste disposal, removal of infected persons from food preparation.
Stool cultures of household contacts with diarrhea should be done. All persons who have had shigella in their stool should receive antimicrobial treatment. Infected individuals are isolated from non-infected individuals until three consecutive stool cultures are negative, taken 24 hours after antimicrobial treatment has been discontinued.
Called Shigella sp. Symptoms include fever, nausea, vomiting, and diarrhea, which is usually bloody in nature. Diagnosis is clinical and confirmed by culture. Treatment is supportive and mainly focuses on rehydration and antibiotics (eg, ampicillin or trimethoprim-sulfamethoxazole). These drugs are the drugs of choice.
Causes of shigellosis
The Shigella species is ubiquitous and is a typical cause of inflammatory dysentery. Shigella is the cause of 5-10% of diarrheal diseases in many regions. Shigella are divided into 4 main subgroups: A, B, C and D, which in turn are divided into specific serotypes.
Flexneri and. sonnei are found more frequently than S. boydii and are especially virulent. dysenteriae. . Sonnei is the most common isolate in the US.
The source of infection is the faeces of sick people and recovering carriers. Direct spread is via the fecal-oral route. Indirect spread occurs through contaminated food and objects. Fleas can serve as carriers of MO. Most often, epidemics occur in densely populated populations with inadequate sanitation measures. Shigellosis is especially common in young children living in endemic regions. In adults, the resulting disease is usually not so acute.
Convalescent and subclinical carriers can be a serious source of infection, but long-term carriage of this MO is rare. This infection leaves almost no immunity.
The causative agent penetrates the mucosa of the lower intestine, which causes mucus secretion, hyperemia, leukocyte infiltration, edema, and often superficial ulceration of the mucosa. S. dysenteriae type 1 (not found in the US) produces Shiga toxin, which causes severe watery diarrhea and sometimes hemolytic uremic syndrome.
Symptoms and signs of shigellosis
The incubation period is 1-4 days. The most common manifestation is watery diarrhea, which is indistinguishable from diarrhea that occurs with other bacterial, viral, and protozoal infections, in which there is an increased secretory activity of intestinal epithelial cells.
In adults, initial symptoms may include episodes of cramping abdominal pain, urge to defecate, and defecation of shaped feces, followed by temporary relief of pain. These episodes are repeated with increasing severity and frequency. Diarrhea becomes pronounced, while the stool can be soft, liquid, contain an admixture of mucus, pus and often blood. Rectal prolapse and subsequent stool incontinence may be the cause of acute tenesmus. In adults, the infection may present without fever, with diarrhea without mucus or blood in the stool, and with little or no tenesmus. The disease usually resolves spontaneously. In the case of a moderate infection, this occurs after 4-8 days, in the case of an acute infection, after 3-6 weeks. Severe dehydration with electrolyte loss and circulatory collapse and death usually occurs in debilitated adults and children under 2 years of age.
Rarely, shigellosis begins suddenly with rice water diarrhea and serous (in some cases bloody) stools. The patient may vomit and quickly become dehydrated. This infection can manifest with delirium, convulsions, and coma. In this case, diarrhea is mild or absent. Death can occur within 12-24 hours.
In young children, the onset of the disease is sudden. This causes fever, irritability or tearfulness, loss of appetite, nausea or vomiting, diarrhea, abdominal pain and bloating, and tenesmus. Within 3 days, blood, pus and mucus appear in the stool. The number of bowel movements can reach more than 20 per day, while weight loss and dehydration become acute. If left untreated, the child may die within the first 12 days of illness. In cases where the child survives, the severity of the symptoms gradually decreases towards the end of the second week.
Secondary bacterial infections may occur, especially in debilitated and dehydrated patients. Acute mucosal ulceration can lead to acute blood loss.
Other complications are rare. These may include toxic neuritis, arthritis, myocarditis, and rarely intestinal perforation. Hemolytic uremic syndrome may complicate shigellosis in children. This infection cannot be chronic course. Also, it is not an etiological factor in ulcerative colitis. Patients with the HLA-B27 genotype after shigellosis and other enteritis are more likely to develop reactive arthritis.
Diagnosis of shigellosis
Diagnosis is made easier by a high index of suspicion for the disease during outbreaks, the presence of the disease in endemic regions, and the detection of stool leukocytes on smears stained with methylene blue or Wright's stain. Stool culture is diagnostic and should therefore be performed. In patients with symptoms of dysentery (presence of mucus or blood in the feces), it is necessary to carry out a differential diagnosis with invasive E. coli, salmonella, yersiniosis, campylobacteriosis, as well as amoebiasis and viral diarrhea.
The surface of the mucous membrane, when examined with a rectoscope, is diffusely erythematous with a large number of small ulcers. Despite the fact that the number of leukocytes is reduced at the beginning of the disease, it averages 13 × 109. Hemoconcentration is common, as is diarrhea-related metabolic acidosis.
Treatment and prevention of shigellosis
Fluid loss is treated symptomatically with oral or intravenous fluids. Antibiotics may improve symptoms associated with dysentery and mucosal injury, but are not required in generally healthy adults with mild infection. Children, the elderly, the debilitated, and those with acute infections should be treated with antibiotics. In adults, the drugs of choice for treating this infection are a fluoroquinolone such as ciprofloxacin 500 mg orally for 3 to 5 days or trimethoprimsul fametoxazole two tablets at a time every 12 hours. In children, treatment is with trimethoprim-sulfamethoxazole at a dose of 4 mg/kg orally every 12 hours. The dosage is calculated according to the trimethoprim component. Many Shigella isolates are likely to be resistant to ampicillin and tetracycline.
Epidemiology. The source of infection is a person. Patients with chronic and obliterated forms of dysentery pose a great epidemic danger. The most common is the contact-household route of transmission. Microbial contamination of food and water is also important. Flies play a role. Dysentery is common in all countries in the form of sporadic cases or isolated outbreaks. Under adverse conditions (for example, during wars), epidemics can occur.
Etiology, pathogenesis. The causative agents of dysentery are a group of microbes (shigella). In Russia, in recent years, microbes of the Sonne subspecies have become predominant (up to 70% of all bacteriologically confirmed cases of acute dysentery), followed by microbes of the Flexner species. Other species are less common. Microbes grow on various nutrient media; they remain in the external environment for up to 10-30 days and more. more. In relation to sulfanilamide drugs, most strains of dysentery pathogens are resistant.
The introduction of even large doses of dysenteric endotoxin into the intestinal lumen of animals does not lead to dysentery intoxication and intestinal damage, while parenteral administration (into the blood, intraperitoneally, subcutaneously) does not a large number toxin causes typical changes resembling human dysentery. Microbes of dysentery penetrate the tissues (including intracellularly) of the intestinal mucosa and submucosa, and regional lymph nodes. After penetration into tissues, microbes multiply, partially die, while releasing endotoxin.
Symptoms, course of bacterial dysentery
In recent years, most patients with dysentery have a mild course with mild clinical manifestations, which makes it difficult to diagnose. In mild cases, the effects of toxicosis are very weak, the temperature rises only to subfebrile figures. The stools remain fecal throughout the illness. Usually the stool is liquid 2-5 times a day with an admixture of a small amount of mucus, but without blood. Even without treatment, after 3-5 days, all manifestations of the disease usually disappear. Such patients often continue to work, do not seek medical help and can serve as a source of infection (diseases of workers in food enterprises are especially dangerous in this regard). Diseases caused by the Sonne pathogen can begin with manifestations of food poisoning. In the future, symptoms of colitis join these manifestations. Severe forms with high fever sharp drop blood pressure(collapse), extensive fibrinous lesions of the intestinal mucosa, are now very rare.
In some patients (5-20% or more), after some time, a relapse of the disease occurs (more often in the first 2-3 months after discharge). The appearance of relapses is facilitated by premature discharge (earlier than 10-12 days from the onset of the disease), the presence of concomitant diseases (chronic cholecystocholangitis, helminthic and protozoal invasions), etc. admission. In some cases, such relapses are repeated several times, i.e., a recurrent form of chronic dysentery occurs. In the future, exacerbations become more and more prolonged, and remissions are shorter and the disease turns into a protracted (continuous) form of chronic dysentery. In chronic forms of the disease, deep dysfunctions of all parts of the gastrointestinal tract become dominant: the stomach is affected (achilia usually develops), pancreas, liver, the motor and enzymatic activity of the intestine is disturbed, disorders of the vegetative section develop nervous system. Re-admission of a patient who has had acute dysentery may also occur as a result of reinfection. You need to think about it if more than a year has passed between the first and second diseases, when there is a change in the type of pathogen, or in the second disease, the symptoms of intoxication and intestinal damage are more pronounced than in the first.
Recognition in typical cases is easy. Consideration should be given to epidemiological data, clinical symptoms, and laboratory and additional methods research. In acute dysentery, in most cases, signs of inflammation of the distal large intestine are revealed. They can be of different severity: a) catarrhal, b) catarrhal-hemorrhagic, c) erosive-ulcerative, d) fibrinous (croupous and diphtheric); the latter are rare. The chronic process is indicated by the presence of atrophic changes in the intestinal mucosa, which are manifested by pallor and thinness, atrophy of natural folds, gaping of the intestinal lumen; often large vessels are visible through the thinned mucosa.
Of great importance is a bacteriological study, but in recent years it has been possible to isolate dysentery microbes only in 30-45% of patients. To increase the seeding rate, it is necessary to conduct studies as early as possible (required before prescribing antibiotics) and do three crops in a row. skin test with dysentery often gives non-specific reactions (up to 40%), therefore it is not very suitable for diagnosing dysentery. Serological reactions are of little importance and only when set in paired sera, since they are often positive in healthy individuals.
Treatment of bacterial dysentery
(module direct4)
The most effective are tetracycline antibiotics (chlortetracycline, oxytetracycline, tetracycline). They are prescribed for 5 days (4-6 g per course). A good effect is the use of chloramphenicol in combination with tetracyclines. Appointment together with antibiotics of sulfanilamide preparations does not improve the results of treatment. The appointment of repeated (so-called anti-relapse) courses of antibiotic therapy is not recommended, since they do not reduce the number of relapses of the disease. In the absence of antibiotics, sulfanilamide preparations (sulfazol, sulfatiazole, sulfadimezin) can be prescribed at a dose of 0.5-1 g 4 times a day for 4-6 days. Ftalazol (and drugs similar to it) is not advisable to use, since it is poorly absorbed from the intestine and does not penetrate into the thickness of the intestinal wall. In chronic dysentery, antibiotics are prescribed in the presence of bacterial excretion, as well as an acute course of relapse (high fever, mucus-bloody stools). In complex treatment, therapy of concomitant chronic diseases (cholecystocholangitis, gastritis) and helminthic-protozoal invasions is important.
Prevention. General sanitary measures are being taken: removal and disinfection of sewage, fight against flies, sanitary supervision of food establishments, trade networks, markets and places of food production, protection of water supply sources and facilities, sanitary and educational work. Timely detection, diagnosis, hospitalization and treatment of patients and suspected dysentery are important.
Isolation of a patient with dysentery is terminated after a course of treatment, normalization of the stool and a single negative study of feces for dysentery, carried out immediately before discharge. Employees of food enterprises and persons equated to them who have had dysentery are discharged after a three-time negative study for bacteriocarrier and a negative result of control sigmoidoscopy. Children attending preschool children's institutions are transferred to convalescent wards after a course of treatment, stool normalization for 10 days and 3 negative results for bacteriocarrier.
In order to identify bacterial carriers of dysentery, the following persons are subject to examination for bacteriocarrier:
- seeking medical help for disorders of the gastrointestinal tract of unknown etiology;
- applicants for work at food enterprises, children's and equivalent institutions;
- children re-entering nurseries, orphanages, kindergartens, boarding schools, children's sanatoriums and hospitals, regardless of their profile;
- patients admitted to psychiatric hospitals and hospitals for the chronically ill;
- persons entering nursing homes;
- persons in contact with patients and carriers of dysentery.
Activities in the hearth. The case of the disease is reported to the sanitary-epidemiological station.
In relation to persons in contact with the patient, the following measures are taken:
- medical observation for 7 days (once every 2-3 days) with the identification of persons with a history of last year diseases of dysentery, bacteriocarrier, intestinal diseases of unknown etiology;
- examination for bacteriocarrier;
- employees of food enterprises are subject to suspension from work until the final disinfection and a single examination of feces for disinteria with a negative result;
- phage with a dysenteric bacteriophage (when a patient is hospitalized - twice, when left at home - three times);
- carrying out sanitary and educational work on the prevention of dysentery.
Convalescents who have had acute dysentery are subject to dispensary observation for 3 months, those who have had chronic dysentery and bacterial excretors - 6 months.
- Feeling of discomfort in the abdomen.
- Light chills.
- Headache.
- Weakness.
- Cramping pains in the lower abdomen (sometimes the pain is diffuse in nature, localization in the navel or stomach is possible). The pain symptom is characterized by a decrease or disappearance of pain during defecation (emptying the colon from feces).
- Loose stools, in the stool there are impurities of mucus and blood (in the form of streaks).
- Defecation may be accompanied by pulling convulsive pain in the anus.
- Fluctuations in blood pressure are possible.
Incubation period
From several hours to several days (usually 2-5 days).
Forms
- Acute typical course.
- Lmild form- observed in 60-70% of cases. Characterized by:
- mild intoxication and disorder of the gastrointestinal tract;
- stool no more than 7 times a day, semi-liquid, not containing pathological impurities (rarely - mucous inclusions);
- pain in the abdomen, unsharp, inconsistent.
- For moderate form characteristic:
- moderate general intoxication;
- rise in body temperature to 39 degrees;
- weakness, weakness;
- cramping pain in the abdomen;
- loose stools up to 20 times a day with an admixture of blood and mucus.
- Severe form flows in the background:
- intense cramping pain in the abdomen;
- chills
- temperature increase up to 40 degrees;
- impurities of pus and blood in the stool, which appear on the second day;
- the presence of pain throughout the body, nausea, vomiting;
- stool up to 60 times a day;
- frequent urge to urinate;
- frequent pulse;
- reduced pressure.
- Lmild form- observed in 60-70% of cases. Characterized by:
- atypical flow.
- At gastroenterocolitic form The causative agent is Shigella Sonne. The disease is characterized by:
- short incubation period, up to 6-8 hours;
- the onset of the disease is accompanied by chills, nausea, a rise in body temperature up to 39 degrees;
- the stool in this form is often watery.
- Hypertoxic form:
- proceeds with severe intoxication (pronounced general weakness, malaise, heat) and damage to the cardiovascular and nervous systems;
- with this form, the development of infectious-toxic shock is possible ( emergency caused by shigatoxins - toxins secreted by shigella), renal failure (syndrome of violation of all kidney functions);
- the skin becomes cyanotic, covered with sticky sweat;
- blood pressure ceases to be determined;
- cramps appear in the limbs, loss of consciousness is possible;
- along with signs of intoxication, frequent loose stools mixed with blood and mucus, abdominal pain are characteristic;
- this form is extremely rare and develops when a large amount of the pathogen enters the human body at the same time.
- For erased form short-term unexpressed clinical symptoms are characteristic:
- 1-2 fold disorder of the stool;
- short-term pain in the abdomen.
- Transient bacteriocarrier more often detected by chance during routine control in persons who do not present any complaints.
- At gastroenterocolitic form The causative agent is Shigella Sonne. The disease is characterized by:
- chronic course(the transition of the disease into a chronic form occurs against the background of late or inadequate treatment, in the presence of concomitant diseases of the gastrointestinal tract).
- Recurrent form:
- the development of relapses of the disease every 1-2-3-5 months, during the period of relapses as in the acute form;
- during the period of remission (the period of attenuation of the symptoms of the disease), there are attacks of dull pain, a feeling of fullness in the abdomen, loosening of the stool, heaviness in the epigastrium (in the stomach area) after eating;
- patients complain of intolerance to milk, spices, coarse fiber;
- with this form of the disease, damage to the pancreas and liver is possible.
- continuous form occurs infrequently.
- There are no remissions in this form.
- The disease is accompanied by constant chills, bloating, rumbling in the abdomen.
- Diarrhea up to 5-6 times a day, the stool can be both formalized and unformed, in some cases there is an alternation of diarrhea and constipation.
- Anemia (anemia), dysbacteriosis (a condition in which the healthy balance of microflora in the intestine is disturbed, which negatively affects immunity, digestion. Accompanied by rumbling in the abdomen, bloating, loose stools, abdominal pain) are added.
- Patients complain of excessive sweating, mental depression, poor sleep.
- Post-dysenteric disorders are enteritis (inflammation of the small intestine) and colitis (inflammation of the large intestine), which developed against the background of the disease.
- Recurrent form:
Causes
- The source of infection is a sick person or a bacteriocarrier.
- The disease is characterized by the oral-fecal route of transmission. Pathogens are excreted with human feces, enter the water, soil.
- The disease spreads through dirty hands, dirty water (for example, for Shigella flexneri, the main route of transmission is water), poorly washed or thermally processed food (Shigella sonnei, under favorable conditions, can even multiply in milk and dairy products, which increases their danger).
- A certain role in the spread of shigella belongs to flies (flies carry the pathogen on their paws from landfills, open latrines to objects and food).
Diagnostics
- To make a diagnosis, the doctor collects an epidemiological analysis (where the patient has been recently, what food and water he has consumed).
- General symptoms (complaints) are taken into account.
- Microbiological diagnostics is carried out: feces serve as the material for the study. For sowing, purulent-mucous-blood formations are taken from the middle portion of feces.
- Examination of gastric lavage.
- ELISA (enzymatic immunoassay) to detect antibodies to the pathogen in the patient's blood.
- Sigmoidoscopy and colonofibroscopy (instrumental methods for diagnosing the condition of the colon, allowing you to fix changes in the intestinal mucosa).
- Consultation is also possible.
Treatment of shigellosis
- The appointment of bacteriophages (viruses that selectively infect bacterial cells) and antibiotics after determining the antibiogram (a method for determining the sensitivity of the pathogen to certain antibiotics).
- In the event of dysbacteriosis (a change in the normal species composition of intestinal bacteria), probiotics are used (drugs containing live microorganisms typical of normal human microflora).
- Dieting: the use of fatty meats and fish, raw vegetables and fruits, spices, fried, smoked and canned foods, etc. is contraindicated.
- Rehydration therapy - the introduction of solutions that compensate for the loss of fluid.
- Detoxification therapy - taking sorbents to bind and remove toxins from the intestines (for example, activated charcoal).
- Various enzymes to aid digestion.
Complications and consequences
With early diagnosis and timely treatment, complications and consequences are rare. A complicated course is possible with the development of:
- erosion (a superficial mucosal defect that heals, unlike ulcers, without scarring) and ulcers on the intestinal mucosa, which can provoke perforation of the intestinal wall (violation of its integrity) and, as a result, the entry of intestinal contents into the abdominal cavity, and the development of peritonitis (inflammation of the abdominal cavity);
- pancreatitis (inflammation of the pancreas);
- intestinal obstruction;
- extremely rarely, erosion of the vessel wall is possible. Against the background of a violation of the integrity of the vessels, intestinal and gastric bleeding are possible;
- myocarditis (inflammatory damage to the heart muscle);
- toxic hepatitis ( inflammatory processes in the liver on the background of intoxication).
- wet gangrene of the colon (necrosis of the tissues of the colon and loss of its function by the organ);
- paresis (decrease in muscle strength) of the intestinal musculature; this phenomenon is observed in complicated cases in young children. The external sphincter of the anus ceases to close, from the rectum there is a continuous release of loose stools with impurities of mucus, pus and blood;
- kidney failure;
- development of infectious-toxic shock (an emergency condition caused by exotoxins of bacteria or viruses). It is characterized by fever, confusion, impaired coordination, and coma may develop.
Prevention of shigellosis
The main principles of prevention are:
- compliance with sanitary and hygienic rules for the preparation, storage and sale of food products;
- compliance with sanitary and hygienic rules at water supply enterprises;
- compliance with sanitary and hygienic rules of personal hygiene;
- regular examination of employees of food enterprises for bacteriocarrier.
is an acute intestinal infection caused by bacteria of the genus Shigella, characterized by the predominant localization of the pathological process in the mucous membrane of the large intestine. Dysentery is transmitted by the fecal-oral route (food or water). Clinically, a patient with dysentery has diarrhea, abdominal pain, tenesmus, intoxication syndrome (weakness, fatigue, nausea). The diagnosis of dysentery is established by isolating the pathogen from the patient's feces, with Grigoriev-Shiga dysentery - from the blood. Treatment is carried out mainly on an outpatient basis and consists of rehydration, antibacterial and detoxification therapy.
General information
is an acute intestinal infection caused by bacteria of the genus Shigella, characterized by the predominant localization of the pathological process in the mucous membrane of the large intestine.
Exciter characteristic
The causative agents of dysentery are shigella, currently represented by four species (S. dysenteriae, S.flexneri, S. boydii, S. Sonnei), each of which (with the exception of Sonne's shigella) is in turn divided into serovars, which currently number over fifty. The population of S. Sonnei is homogeneous in antigenic composition, but differs in the ability to produce various enzymes. Shigella are immobile gram-negative rods, do not form spores, multiply well on nutrient media, and are usually unstable in the external environment.
The optimal temperature environment for shigella is 37 °C, Sonne rods are capable of reproduction at a temperature of 10-15 °C, can form colonies in milk and dairy products, can remain viable in water for a long time (like Flexner's shigella), resistant to antibacterial agents . Shigella quickly die when heated: instantly - when boiled, after 10 minutes - at a temperature of more than 60 degrees.
The reservoir and source of dysentery is a person - a sick or asymptomatic carrier. Patients with mild or obliterated form of dysentery are of the greatest epidemiological significance, especially those related to Food Industry and catering establishments. Shigella are isolated from the body of an infected person, starting from the first days of clinical symptoms, infectiousness persists for 7-10 days, followed by a period of convalescence, in which, however, the isolation of bacteria is also possible (sometimes it can last several weeks and months).
Flexner's dysentery is most prone to becoming chronic, the least tendency to become chronic is observed with infection caused by Sonne bacteria. Dysentery is transmitted by the fecal-oral mechanism mainly by food (Sonne's dysentery) or water (Flexner's dysentery) route. When transmitting Grigoriev-Shiga dysentery, the contact-household transmission route is predominantly implemented.
People have a high natural susceptibility to infection; after suffering from dysentery, unstable type-specific immunity is formed. Those who have recovered from Flexner's dysentery can maintain post-infection immunity, which protects against re-infection for several years.
The pathogenesis of dysentery
Shigella is ingested through food or water digestive system(partially dying under the influence of the acidic contents of the stomach and normal intestinal biocenosis) and reach the large intestine, partially penetrating into its mucous membrane and causing an inflammatory reaction. The mucosa affected by shigella is prone to the formation of areas of erosion, ulcers, and hemorrhages. Toxins released by bacteria disrupt digestion, and the presence of Shigella destroys the natural biobalance of the intestinal flora.
Classification
The clinical classification of dysentery is currently in use. Its acute form is distinguished (it differs in its predominant symptoms into typical colitis and atypical gastroenteritis), chronic dysentery (recurrent and continuous) and bacterial excretion (convalescent or subclinical).
Symptoms of dysentery
The incubation period of acute dysentery can last from one day to a week, most often it is 2-3 days. The colitis variant of dysentery usually begins acutely, the body temperature rises to febrile values, symptoms of intoxication appear. Appetite is markedly reduced, may be completely absent. Sometimes there is nausea, vomiting. Patients complain of intense cutting pain in the abdomen, initially diffuse, later concentrated in the right iliac region and lower abdomen. The pain is accompanied by frequent (up to 10 times a day) diarrhea, bowel movements quickly lose their fecal consistency, become scarce, and pathological impurities are noted in them - blood, mucus, sometimes pus ("rectal spit"). The urge to defecate is excruciatingly painful (tenesmus), sometimes false. The total number of daily bowel movements, as a rule, is not large.
On examination, the tongue is dry, coated with plaque, tachycardia, and sometimes arterial hypotension. Acute clinical symptoms usually begin to subside and finally fade away by the end of the first week, the beginning of the second, but ulcerative mucosal defects usually heal completely within a month. The severity of the course of the colitis variant is determined by the intensity of the intoxication and pain syndrome and the duration of the acute period. In severe cases, disorders of consciousness caused by severe intoxication are noted, the frequency of stools (like “rectal spitting” or “meat slops”) reaches dozens of times a day, pain in the abdomen is excruciating, significant hemodynamic disturbances are noted.
Acute dysentery in the gastroenteric variant is characterized by a short incubation period (6-8 hours) and predominantly enteral symptoms against the background of general intoxication syndrome: nausea, repeated vomiting. The course resembles that of salmonellosis or toxic infection. The pain in this form of dysentery is localized in the epigastric region and around the navel, has a cramping character, the stool is liquid and plentiful, there are no pathological impurities, with intense loss of fluid, dehydration syndrome may occur. Symptoms of the gastroenteric form are violent, but short-lived.
Initially, gastroenterocolitic dysentery also resembles food poisoning in its course, later colitis symptoms begin to join: mucus and bloody streaks in the feces. The severity of the course of the gastroenterocolitis form is determined by the severity of dehydration.
Dysentery of the erased course today occurs quite often. Discomfort, moderate pain in the abdomen, mushy stools 1-2 times a day, mostly without impurities, hyperthermia and intoxication are absent (or extremely insignificant). Dysentery lasting more than three months is considered chronic. At present, cases of chronic dysentery in developed countries are rare. The recurrent variant is recurrent episodes clinical picture acute dysentery, interspersed with periods of remission, when patients feel relatively well.
Continuous chronic dysentery leads to the development of severe digestive disorders, organic changes in the mucous membrane of the intestinal wall. Intoxication symptoms with continuous chronic dysentery are usually absent, there is constant daily diarrhea, stools are mushy, may have a greenish tint. Chronic malabsorption leads to weight loss, hypovitaminosis, and the development of malabsorption syndrome. Convalescent bacterial excretion is usually observed after an acute infection, subclinical - occurs when dysentery is transferred in an erased form.
Complications
Complications at the current level of medical care are extremely rare, mainly in the case of severe Grigoriev-Shiga dysentery. This form of infection can be complicated by toxic shock, intestinal perforation, peritonitis. In addition, the development of intestinal paresis is likely.
Dysentery with intense prolonged diarrhea can be complicated by hemorrhoids, anal fissure, prolapse of the rectum. In many cases, dysentery contributes to the development of dysbacteriosis.
Diagnostics
The most specific bacteriological diagnosis. The isolation of the pathogen is usually made from feces, and in the case of Grigoriev-Shiga dysentery, from the blood. Since the increase in the titer of specific antibodies is rather slow, serological diagnostic methods (RNGA) have a retrospective value. Increasingly, the laboratory practice of diagnosing dysentery includes the detection of Shigella antigens in feces (usually performed using RCA, RLA, ELISA and RNGA with antibody diagnosticum), the complement binding reaction and aggregate hemagglutination.
As a general diagnostic measures, various laboratory methods are used to determine the severity and prevalence of the process, to identify metabolic disorders. Stool is analyzed for dysbacteriosis and coprogram. Endoscopic examination (sigmoidoscopy) can often provide the necessary information for a differential diagnosis in doubtful cases. For the same purpose, patients with dysentery, depending on its clinical form, may need to consult a gastroenterologist or proctologist.
Treatment of dysentery
Mild forms of dysentery are treated on an outpatient basis, inpatient treatment is indicated for people with a severe infection, complicated forms. Patients are also hospitalized according to epidemiological indications, in old age, with concomitant chronic diseases, and children of the first year of life. Patients are prescribed bed rest for fever and intoxication, dietary nutrition (in the acute period - diet No. 4, with diarrhea subsiding - table No. 13).
Etiotropic therapy of acute dysentery consists in prescribing a 5-7-day course of antibacterial agents (antibiotics of the fluoroquinolone, tetracycline series, ampicillin, cotrimoxazole, cephalosporins). Antibiotics are prescribed for severe and moderate forms. Taking into account the ability of antibacterial drugs to aggravate dysbacteriosis, eubiotics are used in combination in a course of 3-4 weeks.
If necessary, detoxification therapy is performed (depending on the severity of detoxification, drugs are prescribed orally or parenterally). Absorption disorders are corrected with the help of enzyme preparations (pancreatin, lipase, amylase, protease). According to indications, immunomodulators, antispasmodics, astringents, enterosorbents are prescribed.
To accelerate regenerative processes and improve the condition of the mucosa during the period of convalescence, microclysters with infusion of eucalyptus and chamomile, rosehip and sea buckthorn oil, and vinyline are recommended. Chronic dysentery is treated in the same way as acute dysentery, but antibiotic therapy is usually less effective. The appointment of therapeutic enemas, physiotherapy, bacterial agents to restore normal intestinal microflora is recommended.
Forecast and prevention
The prognosis is predominantly favorable, with timely complex treatment of acute forms of dysentery, the chronization of the process is extremely rare. In some cases, after the transfer of infection, residual functional disorders of the large intestine (postdysenteric colitis) may persist.
General measures for the prevention of dysentery include the observance of sanitary and hygienic standards in everyday life, in food production and at public catering establishments, monitoring the state of water sources, cleaning sewage waste (especially disinfection Wastewater medical institutions).
Patients with dysentery are discharged from the hospital no earlier than three days after clinical recovery with a negative single bacteriological test (material for bacteriological examination is taken no earlier than 2 days after the end of treatment). Food industry workers and other persons equated to them are subject to discharge after a double negative result of bacteriological analysis.