Clinical presentation and differential diagnosis
Shigellosis begins acutely, more rarely subclinically. Classically, chills, fever, watery diarrhea, and cramping abdominal pain develop. In some patients, a typical dysentery syndrome joins, indicating involvement of the large intestine.
Acute dysentery, especially its colitic variant, must be differentiated from a number of conditions:
- Infectious and parasitic pathologies: campylobacteriosis, yersiniosis, pseudomembranous colitis, helminthiases, and other infectious enterocolitides.
- Amebiasis: characterized by the absence of fever and severe abdominal pain, a gradual onset, and mucus and blood mixed unevenly with stool. Palpation reveals a thickened and tender cecum.
- Balantidiasis: acute onset, prominent intoxication, and liquid stools up to 20 times a day with a putrid odor. Thickened and spastic areas of the large intestine are palpable.
- Non-infectious and surgical diseases: Crohn's disease, ulcerative colitis, irritable bowel syndrome, neoplasms, mesenteric thrombosis, intestinal obstruction, and heavy metal poisoning.
Diagnostic criteria
In addition to the clinical picture, a properly collected epidemiological history is a critical criterion for diagnosis.
Laboratory diagnostics include:
- Complete blood count: reveals neutrophilic leukocytosis with a band neutrophil shift and accelerated ESR.
- Bacteriological method: aimed at isolating the pathogen from feces and vomit.
- Serological method: detection of antibodies to pathogen antigens using indirect hemagglutination assay (IHA) or complement fixation test.
As part of differential diagnosis, sigmoidoscopy is used. In amebiasis, for example, the mucosa is minimally altered, but deep ulcers with purulent exudate and undermined edges are present. In balantidiasis, whitish loose plaques, infiltrates, and deep ulcers are observed.
Indications for hospitalization
Hospitalization of patients with shigellosis is based on two main groups of indications.
Clinical indications:
- Severe and moderate forms of the disease.
- Protracted and chronic course.
- Presence of comorbid pathology that complicates the course of the infection.
Epidemiological indications:
- Patient belonging to regulated occupational groups (food service workers, water utility staff, etc.).
- Living together with individuals of regulated professions or children attending kindergartens.
- Lack of conditions for isolation and compliance with the sanitary and epidemiological regime (living in dormitories, hotels).
Principles of treatment
Treatment of acute shigellosis must be comprehensive. Patients are prescribed bed rest within the ward until acute manifestations of the disease completely resolve (normalization of temperature, disappearance of pain and diarrhea).
Diet therapy (Pevzner's diet):
- In the acute period: Table No. 4–4k.
- In the early convalescence period: Table No. 2.
- Subsequently (after 3–5 days): Table No. 13, recommended to be followed on an outpatient basis for complete restoration of the intestinal mucosa.
Etiotropic therapy: indicated for moderate and severe courses (primarily in the colitic variant). Fluoroquinolones are the drugs of choice. Nitrofurans or third-generation cephalosporins are used as alternatives. Nalidixic acid derivatives may be used in children. The course of treatment lasts 5–7 days.
Pathogenetic therapy:
- Detoxification and rehydration: oral glucose-electrolyte solutions are used for mild dehydration. For pronounced dehydration, intravenous administration of polyionic solutions (up to 2–5 liters depending on the weight deficit) is mandatory prior to administering colloids.
- Enzyme therapy: prescribed to improve digestion.
- Probiotics: indicated after antibiotic therapy if dysbiosis develops, and can be used as the primary treatment method in mild forms of infection.
In severe cases and with the threat of infectious-toxic shock, glucocorticosteroids are used.
Briefly: answers to topical questions
What clinical forms and variants of the course are distinguished in the classification of shigellosis?
The classification of shigellosis distinguishes acute and chronic forms, as well as bacterial carriage.
- Acute form — proceeds in typical and atypical variants (from latent and mild to hypertoxic).
- Clinical variants — colitic, gastroenterocolitic, and gastroenteritic.
According to severity, the disease is divided into mild, moderate, and severe forms. Bacterial carriage is distinguished separately, which can be convalescent (immediately after an acute illness) or subclinical (in individuals without clinical manifestations).
What species of the genus Shigella are causative agents of shigellosis in humans?
The causative agents of shigellosis in humans are bacteria of the genus Shigella, which are subdivided into several species:
- Shiga bacillus (Shigella dysenteriae) — causes the most severe forms with a classic staged course.
- Flexner bacillus (Shigella flexneri) — moderate and severe course with pronounced distal colitis.
- Sonne dysentery (Shigella sonnei) — milder course, often presenting as gastroenterocolitis.
- Boyd bacillus (Shigella boydii) — mild course with mildly expressed intoxication.
- Newcastle bacillus (Shigella newcastle) — clinically similar to the course of Flexner shigellosis.
What specific intestinal and extraintestinal complications are characteristic of shigellosis?
The sources indicate the following complications for shigellosis.
- Specific complications — infectious-toxic shock, acute adrenal insufficiency, intestinal perforation with peritonitis, encephalitic syndrome, rectal prolapse, hemolytic-uremic syndrome.
- Intestinal complications of acute dysentery — ulcer perforation with peritonitis, intestinal hemorrhage, intestinal phlegmon, paraproctitis, cicatricial strictures of the intestine, toxic megacolon.
- Extraintestinal complications of acute dysentery — bronchopneumonia, pyelonephritis and pyelitis, serous toxic arthritis, emaciation in children; infectious-toxic shock in severe cases.
To memorize etiotropic drugs: "F-N-C" — Fluoroquinolones (choice), Nitrofurans, Cephalosporins (alternative).
What else to study on this topic
- Pathogenesis of dysentery syndrome in the colitic variant
- Complications of shigellosis and intensive care for infectious-toxic shock
- Life cycle and pathogenesis of Entamoeba histolytica
- Mechanism of intestinal dysbiosis development during antibiotic therapy
- Peculiarities of nalidixic acid derivatives use in children
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