Pathogenesis and Clinical Course
The development of the pathological process in shigellosis is largely determined by the patient's premorbid background. These factors, along with specific pathogenetic mechanisms, contribute to the development of chronic forms of the disease and various complications.
The course of the infection is strictly cyclical and includes the following stages:
- Incubation period (the time from infection to the first manifestations).
- Prodromal period.
- Peak period.
- Convalescence period.
The clinical classification takes into account the diversity of forms and variants of the course. Special attention is paid to the main syndromes that determine the severity of the condition, as well as the characteristics of typical and atypical courses. In addition to the acute phase, the infection can transition into bacterial carriage or acquire a chronic course with various variants.
Diagnostic approaches
Establishing an accurate diagnosis requires an integrated approach. Of paramount importance is a thorough collection of epidemiological history and the results of an objective clinical examination of the patient.
Laboratory and instrumental diagnostics include:
- Bacteriological and serological methods (the basis for confirming the diagnosis).
- Coprological examination.
- Endoscopic visualization methods for lesions.
- Rapid diagnostics using the immunofluorescence method.
To obtain reliable results, it is extremely critical to follow the correct specimen collection procedure. These data serve as the basis for differential diagnosis with other infectious lesions of the gastrointestinal tract.
Principles of treatment and prevention
Patient management tactics depend on the stage of care delivery (pre-hospital or hospital) and the presence of indications for hospitalization.
Comprehensive therapy is based on the following principles:
- Prescription of etiotropic and pathogenetic therapy adapted to the severity and form of the disease.
- Inclusion of bacterial preparations in the treatment regimen.
- Mandatory dietary therapy, which plays a crucial role in recovery.
- A special approach to treating patients with chronic shigellosis.
Prevention and control of infection spread are based on early detection of patients. Adequate treatment (both in the hospital and at home), increasing the nonspecific resistance of the population, as well as strict adherence to discharge rules and subsequent dispensary follow-up of convalescents in outpatient infectious disease clinics allow minimizing risks.
Briefly: answers to topical questions
Which species of bacteria belong to the genus Shigella and act as causative agents of the disease?
Sources indicate that shigellosis is caused by bacteria of the genus Shigella. Specific species/names of shigellae explicitly mentioned include: Shigella flexneri; S. sonnei; S. newcastle. Grigoriev-Shiga shigellosis is mentioned separately in the diagnostic section: isolation of hemoculture is significant in this case.
Which groups of antibacterial drugs are used for the etiotropic therapy of shigellosis?
Systemic antibacterial drugs are used for the etiotropic therapy of shigellosis. These include:
- Fluoroquinolones (ciprofloxacin, norfloxacin, and analogues) — are the drugs of choice.
- Nitrofuran derivatives (furazolidone) — used as an alternative.
- Third-generation cephalosporins (cefotaxime) — also serve as alternative drugs.
- Nalidixic acid derivatives (negram, etc.) — used only in children; nalidixic acid is also mentioned in general treatment regimens.
- Co-trimoxazole — mentioned in one of the treatment regimens.
What morphological changes of the mucosa are revealed during endoscopic examination of the intestine in shigellosis?
Morphological changes of the mucosa in shigellosis depend on the severity of the course (sigmoidoscopy):
- In mild cases, catarrhal or catarrhal-hemorrhagic proctosigmoiditis and sphinkteritis are revealed.
- In moderate cases, catarrhal-erosive proctosigmoiditis is observed.
- In severe cases (especially in Flexner dysentery), fibrinous-necrotic, fibrinous-ulcerative, and phlegmonous-necrotic lesions of the large intestine mucosa are revealed.
What variants of the clinical course does chronic shigellosis have?
Chronic shigellosis lasts for more than 3 months and has the following clinical variants: continuous; relapsing — with periods of exacerbation; sluggish — without pronounced intoxication.
Class and exam questions
What periods are distinguished in the clinical course of shigellosis?
The disease proceeds cyclically: the incubation period is followed by the prodromal period, then the peak period ensues, and everything concludes with the period of convalescence.
Which method is used for rapid diagnostics?
The immunofluorescence method is used for rapid preliminary diagnosis of shigellosis.
What factors influence the development of chronic forms?
The development of chronic forms and complications directly depends on specific pathogenetic mechanisms and the patient's premorbid background.
What else to study on this topic
- Principles of differential diagnosis of shigellosis with other infections.
- Detailed characteristics of typical and atypical courses of the disease.
- Features of etiotropic therapy in severe forms.
- Rules and methodology for collecting material for bacteriological examination.
- Regimens for dispensary follow-up of convalescents.
Master the complete topic in the «Infectious Diseases» course
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- Complete study guide on "Etiology of Shigellosis" and 3,312 more pages of the subject
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