Prevention of acute intestinal infections

Organizational, epidemiological measures and statistics

The basis for preventing the spread of acute intestinal infections (AII) is the strict observance of organizational measures and early isolation of patients. In the Russian Federation, the problem is extremely acute: more than 600,000–700,000 people fall ill with AII every year. Special attention in epidemiological control is paid to particularly dangerous infections. According to WHO, about 300,000 cases of cholera are registered in the world annually. In the territory of the Russian Federation, manifest cases are recorded as sporadic and are predominantly imported in nature.

However, the global medical community is concerned about a new etiological threat. Recently, cases of the disease caused by an atypical factor — Vibrio cholerae serogroup O139, known as the «Bengal» strain — have become more frequent. The emergence and spread of this strain do not exclude the possibility of a new large-scale epidemic surge in morbidity, which could develop into the 8th pandemic. Upon initial detection of a patient with suspected cholera, the most crucial prevention step is the immediate procedure for submitting an emergency notification to health authorities. It is also necessary to strictly follow the indications and rules for hospitalization, and subsequently, the rules for discharging cholera patients and filling out medical documentation.

Clinical and laboratory examination

High-quality information gathering and a comprehensive examination of the patient allow not only for a timely diagnosis but also for preventing outbreaks in organized groups. The primary stage includes targeted collection of complaints, clarification of the history of the disease, and mandatory collection of the epidemiological history (epidemiological anamnesis). The doctor performs a thorough examination and physical assessment, paying special attention to the nature of the patient's secretions.

The key tasks are identifying leading symptoms, such as diarrheal syndrome, and assessing signs of dehydration. The further management tactics depend on the accuracy of assessing the severity of the patient's condition. Laboratory diagnostics require a well-founded examination plan, which necessarily includes the analysis and interpretation of the results of bacteriological and immunological methods. All management tactics, diagnostic and treatment principles must be considered in inextricable connection with etiology, pathogenesis, and immunogenesis. Emergency care implies diagnosis and provision of emergency medical care for various degrees of dehydration, up to the relief of dehydrational shock.

Dynamics of intestinal lesion development

From a clinical standpoint, the course of many specific AII has a gradual development. In the vast majority of cases (90%), the initial stage is asymptomatic, which significantly complicates early prevention. Minimal clinical manifestations amount to abdominal discomfort and mild diarrhea. The stool becomes mushy or liquid, often with mucus admixture, with a frequency of 2–3 times a day. Such episodes are short-lived. Pain syndrome may be completely absent or manifest as moderate, intermittent cramping pain. The patient's general condition remains satisfactory, and body temperature remains normal. Without treatment, this condition lasts from several days to several weeks, while episodes of diarrhea alternate with normal stool or constipation accompanied by signs of flatulence.

In the acute phase, the disease manifests with profuse, liquid, fecal stool with a frequency of 3–5 times a day. Moderate pain appears, localized in the cecum and ascending colon. General symptoms increase: progressive weakness and loss of appetite. Fever is atypical (subfebrile temperature is recorded in only 10–30% of patients).

After 7–10 days, the clinical picture undergoes pronounced dynamics:

• Pain becomes diffuse and intense.
• Stool frequency increases, however, the volume of excrement decreases.
• Nature of the stool: glassy, mucous, sometimes mixed with blood.
• Episodes of formed stool or constipation become rarer and shorter.

Severe forms, complications and chronization

Palpation of the abdomen reveals tenderness in the ileocecal region, as well as along the ascending and other parts of the colon. The cecum is thickened, and the sigmoid colon is often palpable as a painful inflammatory cord. An important sign is that the liver and spleen are most often not enlarged.

With simultaneous involvement of the initial and distal parts of the colon, high fever and excruciating tenesmus develop. A specific symptom is rarely encountered — stool-free feces consisting of mucus evenly mixed with blood (the "raspberry jelly" symptom). The patient loses body weight. If pancolitis develops, it often takes a severe course. The mortality rate in pancolitis without adequate treatment reaches 9–12%.

Among complications, involvement of the appendix is possible (the clinical picture of appendicular colic). Extremely severe conditions include necrotizing colitis, toxic megacolon, ameboma, and the fulminant form of the infection.

The chronic form develops much more frequently than in shigellosis. Two forms are distinguished:

1. Recurrent: relatively long remissions, general well-being is satisfactory.
2. Continuous: progressive weakness, anemia, trophic disorders, protein-free edema, and weight loss (due to protein and vitamin deficiency).

Briefly: answers to topical questions

Class and exam questions

What else to study on this topic

• Pathogenesis of clinical symptoms and dehydrational shock.
• Algorithm for making the clinical diagnosis of "Cholera".
• Principles of providing emergency care for various degrees of dehydration.
• Justification of the laboratory examination plan and interpretation of immunological methods.

Other topics in the "Acute Intestinal Infections" section

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.