Prevention of typhoid fever

Primary prevention and epidemiological control

The basis for preventing the spread of typhoid fever is interrupting the transmission mechanism of the infection and identifying potential sources. Upon admission of a patient with prolonged fever and intoxication, clarifying the epidemiological history is of paramount importance.

The physician is obligated to ascertain the following facts:

• The patient's stay in foci of intestinal infections (including endemic regions, such as the North Caucasus).
• Consumption of unboiled water from dubious sources (open reservoirs, shallow wells, industrial water supply systems).
• Presence in the immediate environment of patients who have recently had typhoid-paratyphoid diseases or chronic carriers.

Any suspicion of a typhoid-paratyphoid disease requires immediate organizational measures, the main one being the compilation and submission of an emergency notification to the sanitary-epidemiological service for examination of the focus.

Antiepidemic measures and isolation

A patient with suspected typhoid fever is subject to mandatory hospitalization in a specialized infectious diseases hospital. Leaving the patient at home is strictly unacceptable, as this creates a direct threat of infection to others.

Indications for immediate hospitalization are:

1. Duration of the febrile period.
2. Severity of the intoxication syndrome (weakness, insomnia, anorexia).
3. Appearance of signs of generalization of the infectious process.

Complete isolation of the patient is ensured in the hospital. Strict bed rest and a specialized sparing Diet No. 4 are prescribed. To monitor the dynamics of the condition, regular thermometry is performed at 3-hour intervals. Antibacterial and detoxification therapy is prescribed, although it should be remembered that in the early stages, there may be an apparent lack of clinical effect from antibiotic intake.

Secondary prevention: complication prevention

An extremely important aspect of patient management is the prevention and early detection of specific complications that can lead to a fatal outcome. These include intestinal hemorrhage and intestinal perforation with the development of acute purulent peritonitis.

Intestinal hemorrhage usually manifests with paradoxical signs: increasing tachycardia against the background of a sharp drop in body temperature, hypotension, and dizziness. When hemorrhage is suspected, emergency diagnostics are necessary: urgent determination of hemoglobin, erythrocyte, and hematocrit levels, inspection of feces (in their absence, digital rectal examination). Prevention of deterioration includes complete rest, fasting, cold applied to the abdominal area, and hemostatic therapy.

Intestinal perforation most frequently occurs in the 2nd-3rd week of the disease. Risk factors for an unfavorable outcome include the presence of the perforation itself, late admission to the hospital, and untimely treatment. With the development of peritonitis, urgent transfer of the patient to an infectious surgical hospital is necessary for parenteral administration of combination antibiotics and surgical intervention.

Laboratory screening and diagnosis confirmation

To reliably localize the focus of infection, laboratory confirmation of the diagnosis is necessary. The examination plan includes:

• Bacteriological methods: blood culture in bile broth (Rapoport medium), as well as stool and urine culture on Ploskirev media, Endo agar, and bismuth sulfite agar.
• Serological studies: Widal test, indirect hemagglutination assay (IHA) with O-, Vi-, and H-salmonella diagnostic agents, as well as countercurrent immunoelectrophoresis (detection of typhoid antigens and antibodies).
• Complete blood count: characteristic markers are leukopenia, aneosinophilia (absence of eosinophils), left shift of the leukocyte formula, and normal or slightly reduced ESR.

Correction of therapy is always carried out only after isolation of the pathogen (e.g., S. typhi group D) and receipt of an antibiogram determining sensitivity to chemotherapeutic drugs.

Clinical suspicion and atypical forms

For the timely isolation of the source of infection, the physician must be able to recognize atypical clinical presentations. For example, typhoid fever may masquerade as acute respiratory pathology (tracheobronchitis, pneumonia), when the patient is treated with ampicillin for a long time while maintaining intoxication and experiencing loose stools. In such cases, coproculture helps identify the infection.

It is also important to perform differential diagnostics with dysentery. In typhoid fever, intoxication prevails over gastrointestinal dysfunction, and symptoms of spastic hemicolitis are absent. Attention is drawn to the classic symptom complex: high fever, pallor, isolated elements of roseolous rash on the abdomen, relative bradycardia, hypotension, "typhoid" tongue (coated with white plaque), meteorism, rumbling in the right iliac region, and hepatosplenomegaly. At the same time, in individuals with an antisocial lifestyle, the diagnosis can be suspected even in the absence of a rash and liver enlargement at the time of examination. Cases of exacerbation (relapse) against the background of drug withdrawal require special monitoring, manifesting as low-grade fever, splenomegaly, and reappearance of roseolae.

Briefly: answers to topical questions

Class and exam questions

What else to study on this topic

• Features of the differential diagnosis between typhoid fever and acute dysentery.
• Management tactics for patients with the development of acute purulent peritonitis against the background of intestinal perforation.
• Causes and precursors of exacerbation (relapse) of typhoid fever after antibiotic discontinuation.
• Serological diagnostics: interpretation of the Widal test and indirect hemagglutination assay (IHA) with various antigens.

Other topics in the "Acute Intestinal Infections" section

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