Shigellosis is an infectious disease caused by Shigella bacteria, which invade and destroy intestinal epithelial cells. This leads to inflammation and damage of the intestines and symptoms like diarrhea, abdominal pain, and bloody stool. The disease ranges from mild to severe and can become chronic with recurring symptoms. Treatment involves rehydration, antibiotics in moderate to severe cases, and prevention through hygiene, sanitation and control of bacterial carriers.

1. Shigellosis

2. Shigellosis
 this is an infectious disease caused by shigella,
occurring with intoxication phenomena and
predominant inflammation of the distal colon.

3. Aetiology
 4 types of shigella:
 1) Sh. dysenteria, these include Grigoriev–Shiga, Stutzer–Schmitz and Large—Sachs bacteria; 2) Sh. flexneri with
the Newcastle subspecies
 3) Sh. boydii
 4) Sh. sonnei.
 Currently, there are over 50 serological varieties of dysentery bacteria.
 Morphologically, all shigella are similar to each other, have the form of sticks measuring (0.3— 0.6) x (1.0—3.0)
microns with rounded ends.
 They are immobile, do not form spores and capsules, are gram-negative, grow well on simple nutrient
media.Shigella contain a thermally stable somatic O-antigen.
 When they are destroyed, endotoxin is released, which is largely associated with the development of intoxication
syndrome. Shigella are capable of producing exotoxins.
 Among them are enterotoxins (thermolabile and thermostable), which enhance the secretion of fluid and salts into
the intestinal lumen, and cytotoxin, which damages the membranes of epithelial cells.
 Grigoriev – Shigi bacteria, in addition. produce a potent neurotoxin.

4. Aetiology
 The virulence of shigella is determined by three main factors – the ability to adhere to the
membranes of epithelial cells, invasion into them and the production of toxins.
 Grigoriev–Shig shigella has high pathogenicity.
 The pathogenicity of other types of dysentery bacteria is significantly lower.
 Depending on the temperature, humidity, pH of the medium, the type and number of
microorganisms, the duration of survival of dysentery bacteria varies from several days to
months.
 Food products are a favorable environment for bacteria. Shigella Sonne in milk and dairy
products are able not only to exist for a long time, but also to multiply.
 The causative agents of dysentery tolerate drying and low temperatures well, but they
quickly die under the influence of direct sunlight and heating (at 60 ° C – after 30 minutes,
100 ° C – almost instantly).
 Disinfectants (hypochlorites, chloramines, lysol, etc.) in normal concentrations kill
dysentery bacteria within a few minutes.

5. Epidemiology
 The source of infection is a person
 The mechanism of transmission is fecal-oral
 Transmission routes are mainly contact and water, sometimes alimentary
 Seasonality – summer-autumn

6. Pathogenesis
 The pathogenesis of shigellosis is associated with the colonization and invasion of Shigella bacteria
more often in the large intestine, sometimes the small intestine, which leads to an inflammatory
process in these areas of the intestine.
 Shigella bacteria secrete virulence factors that allow them to invade and multiply in intestinal
epithelial cells.
 One of these factors is LPS (lipopolysaccharide), which causes an inflammatory reaction in the
intestinal mucosa.
 This leads to changes in the permeability of the mucous membrane and a decrease in the height of
the intestinal villi, which leads to a violation of the absorption of water and electrolytes, and, as a
consequence, to diarrhea.
 Bacteria are also able to invade the intestinal epithelial cells, which leads to their destruction and
the formation of ulcers.
 This leads to bleeding and bloody diarrhea, which are characteristic signs of shigellosis.
 So, the pathogenesis of shigellosis is associated with invasion and destruction of intestinal epithelial
cells, inflammation and changes in the permeability of the mucous membrane, as well as damage to
the lymph nodes around the intestine. These processes lead to the characteristic symptoms and
complications of shigellosis.

7. Classification of shigellosis
1. Acute dysentery
- Gastroenteritic variant
- Gastroenterocolitic variant
- Colitic variant
2. Chronic dysentery
- Recurrent course
- Continuous flow
3. Bacterialcarrier
- Acute
- Chronic
- Transient

8. Acute shigellosis, colitic variant
 The colitic variant with a mild course of the disease is characterized by moderate or mild intoxication.
 It usually begins acutely with a short-term rise in temperature to 37-38 ° C.
 In the first hours of the disease, weakness, decreased appetite are observed, and later moderate
abdominal pain appears. Stool jn 3-5 to 10 times a day.
 The bowel movements are semi-liquid or liquid, often with mucus, and sometimes with streaks of
blood.
 Patients remain able-bodied.
 On examination, the tongue is overlaid.
 The sigmoid colon is painful and spasmodic, with its palpation, rumbling is noted.
 During rectoromanoscopy, catarrhal or catarrhal hemorrhagic proctosigmoiditis and sphincteritis can
be detected.
 The disease lasts 3-5, less often 7-8 days and ends with recovery.

9. Acute shigellosis, colitic variant
 The colitic variant with a moderate form of the course usually begins acutely, with chills, a feeling of
ache throughout the body.
 The temperature rises to 38-39 ° C and stays at this level for 3-5 days, rarely longer.
 Anorexia, headache, nausea, sometimes vomiting, sharp cramping pains in the abdomen, tenesmus
are often observed.
 The frequency of stool is 10-20 times a day.
 Stools quickly lose their fecal character and consist of mucus stained with blood.
 They can be meager, in the form of "rectal spit" or more abundant, mucous.
 Signs of hemohemocolitis are observed in 70-75% of patients.
 Symptoms gradually weaken on the 3rd-5th day of the disease.
 The amount of mucus and blood in the stool decreases, the stool normalizes.
 Rectoromanoscopy reveals catarrhal erosive proctosigmoiditis.
 Clinical recovery occurs by the end of the 2nd week of the disease.

10. Acute shigellosis, colitic variant
 The severe course of the colitic variant of dysentery is characterized by an acute onset with a rise in temperature to 39 ° C
and above, pronounced intoxication.
 There may be fainting, delirium, nausea, vomiting.
 Abdominal pain is pronounced and accompanied by excruciating tenesmus.
 Stool from 20-25 to 50 times a day, scanty, fecal-free, muco-bloody.
 Patients are sluggish, adynamic.
 The skin and mucous membranes are dry, blood pressure is reduced, there is a constant tachycardia.
 By the end of 1-2 days, a collaptoid state may develop.
 Tenesmus and intestinal spasms can be replaced by its paresis, bloating, gaping of the anus and involuntary defecation.
 Palpation of the abdomen reveals spasm, soreness and rumbling of the large intestine (or only the sigmoid colon),
flatulence.
 The serious condition of the patients persists for 7-10 days.
 During rectoromanoscopy, in the case of dysentery, catarrhal hemorrhagic, catarrhal erosive, and less often ulcerative
changes of the mucous membrane are determined in the zone.
 In the severe course of Flexner's dysentery, fibrinous-necrotic, fibrinous-ulcerative and phlegmonous-necrotic lesions of
the colon mucosa are detected. The disease lasts 3-6 weeks or more.

11. Acute shigellosis, gastroenterocolitic variant
 The main syndrome at the beginning of the disease is gastroenteritis, which is accompanied by
pronounced symptoms of intoxication.
 In the future, the symptoms of enterocolitis prevail.
 Vomiting, profuse diarrhea, copious watery bowel movements without admixture of blood and mucus,
diffuse abdominal pain are typical for the initial period.
 Subsequently, the stool becomes less abundant, impurities of mucus and blood are found in it.
 This variant can have a mild, moderate and severe course.
 When assessing the severity of the disease, the degree of dehydration of the body is taken into
account. In the case of mild dysentery, there are no symptoms of dehydration.
 Moderate severity of the disease is accompanied by dehydration of the first degree (fluid loss is 1-3%
of body weight).
 With severe dysentery, dehydration of the II—III degree develops (fluid loss is 4-9% of body
weight).About

12. Acute shigellosis, gastroenteritic variant
 Absence of symptoms of colitis in the later period of the disease (after 2-3
days of illness)
 The leading symptoms are gastroenteritis and signs of dehydration

13. Chronic shigellosis
 The recurrent form is more common than continuous and is characterized by alternating remissions and relapses of
dysentery.
 Intestinal dysfunction is characterized by persistence and duration.To a greater or lesser extent, the central nervous
system suffers.
 Patients are irritable, excitable, their performance is reduced, sleep is disturbed, headaches are frequent.
 Rectoromanoscopy reveals polymorphic changes in the mucous membrane of the rectum and sigmoid colon.
 During an exacerbation, the rectoromanoscopic picture resembles the changes characteristic of acute dysentery.
 In the inter-relapse period, the condition of patients is satisfactory.
 Operability is preserved.
 During rectoromanoscopy, a pale, atrophic mucous membrane with a pronounced vascular network is visible in the
remission period.
 With the continuous form of chronic shigellosis, there are practically no light intervals, the patients' well-being is
constantly poor, their condition worsens.
 Deep digestive disorders develop, exhaustion, signs of hypovitaminosis, anemia appear, pronounced dysbiosis joins.
 Currently, this form is rare, mainly in the elderly and senile, with severe concomitant pathology.

14. Bacteriocarriage (bacterial excretion )
 There are no clinical symptoms with bacterial carrier.
 Acute bacterial excretion , in which the pathogen continues to be released
up to 3 months after clinical recovery, is much more common than chronic.
 In chronic bacterial excretion, the pathogen is detected in the stool for
more than 3 months after clinical recovery.
 Transient bacterial excretion is diagnosed in cases where there is only one
or two salmonella secretions followed by multiple negative results of
bacteriological examination of feces and urine.

15. Complications
 Toxic-infectious and mixed (toxic-infectious + dehydration)
shocks. Relapses (5-15% of cases).
 Exacerbations of hemorrhoids, anal sphincter cracks.
 Weakened patients have pneumonia, ascending urogenital
infection, as well as severe intestinal dysbiosis.
 More rare complications are perforation of intestinal ulcers
with subsequent peritonitis, toxic dilation of the intestine,
thrombosis of mesenteric vessels, rectal prolapse.

16. Diagnostics
 Diagnosis of salmonellosis is carried out on the basis of epidemiological, clinical and laboratory
data
 Changes in the hemogram:
- leukocytosis
- the shift of the leukocyte formula to the left
- neutrophilic granulocytosis
 To confirm the diagnosis:
- bacteriological method (culture) – feces
- serological method - indirect hemagglutination reaction, ELISA
 Additionally
- Rectoromanoscopy

17. Treatment
 Gastric lavage (when vomiting)
 Cleansing enema
 Diet. During the period of the disease, patients should adhere to a diet that
provides for a reduction in the amount of fats and carbohydrates rich in
fiber, and also completely excludes alcohol and spicy foods.
 Etiotropic treatment - Antibiotic therapy (with moderate and severe
course) – ciprofloxacin, azithromycin, ceftriaxone, cefotaxime
 Correction of the water-electrolyte balance. With severe diarrhea and
vomiting, it is necessary to maintain the water-electrolyte balance by
intravenous infusion of electrolyte solutions and vitamins.

18. Prevention
 veterinary-sanitary
 sanitary-hygienic
 anti-epidemic measures
 Current and final disinfection is carried out in the foci of the disease.
 Those who have been ill are discharged after clinical recovery and negative
control bacteriological studies of bowel movements.