Complications of typhoid fever

Specific intestinal complications

The most dangerous consequences of the disease are lesions of the digestive tract. They develop during the ulcer formation stage — usually between the end of the 2nd and the 5th week from the onset of the disease.

Intestinal hemorrhage Recorded in approximately 8–9% of patients. With massive blood loss, a characteristic phenomenon occurs — the «scissors» sign. It manifests as a critical drop in body temperature (to normal or subnormal values) against the background of a sharp increase in heart rate, up to embryocardia.

The patient complains of increasing weakness, dizziness, «floaters» before the eyes; blood pressure (BP) drops. Important to remember: melena is not an early sign of hemorrhage. Laboratory parameters react to blood loss earliest — hemoglobin (Hb), hematocrit (Ht), and red blood cell counts decrease.

Perforation of typhoid ulcers Occurs in 1% of patients. Its main feature is the absence of typical «dagger-like» pain characteristic of hollow organ perforation. This is explained by the fact that the destructive process in the distal small intestine develops gradually, and the defect is often covered by the greater omentum.

Early signs are localized progressive pain and muscle guarding (défense musculaire) in the right iliac region. Later, symptoms of peritoneal irritation in this zone join in. If the diagnosis is delayed, the classic picture of generalized peritonitis unfolds with intoxication, tachycardia, leukocytosis, and an accelerated ESR.

Toxic and secondary complications

In addition to local intestinal damage, massive release of endotoxins and depletion of the body's defenses lead to systemic failures.

• Infectious-toxic shock (ITS): Characterized by the absence of a pronounced erectile phase (no motor restlessness and agitation). The patient develops increasing lethargy, the skin becomes pale with acrocyanosis. Shortness of breath, tachycardia, progressive drop in BP, and oliguria appear.
• Infectious psychosis: Occurs at the height of the disease. Patients who already have a prior encephalopathy are most vulnerable.
• Secondary bacterial infections: Due to decreased immunity, intrinsic or hospital flora is activated. This can lead to pneumonia, otitis media, parotitis, pyelonephritis, myocarditis, or osteomyelitis.

Note: Late relapses of the disease can rarely occur — up to the 90th day from the onset of theapyrexia period (sustained normalization of temperature).

Clinical manifestations and outcomes

With a sporadic incidence rate, the prognosis is generally favorable: recovery occurs in 98–99% of patients. However, 3–7% of convalescents develop chronic bacterial carriage.

To timely notice the risk of complications, it is necessary to carefully evaluate the clinical picture. The classic diagnosis is made based on the triad: symptoms, epidemiological history, and laboratory data.

Key clinical landmarks:

• Prolonged fever, adynamia, and lethargy.
• Pallor of the skin and characteristic exanthema.
• Hepatosplenomegaly syndrome and intestinal dysfunction.
• Specific coated «typhoid» tongue.
• Padalka's sign.
• Relative bradycardia and hypotension.

In the epidemiological history, social status, compliance with hygiene, consumption of dubious water, seasonality, contacts with patients, and the presence of background gastrointestinal diseases are important.

Principles of laboratory diagnostics

Any clinical diagnosis requires mandatory bacteriological or immunological confirmation.

1. Hemogram (height of the disease): Leukopenia, neutropenia with a «left» shift, aneosinophilia, and relative lymphomonocytosis are characteristic. ESR values remain normal.
2. Bacteriological method: Blood, stool, urine, and duodenal contents are cultured on bile-containing media. Absolute confirmation is the isolation of hemoculture (maximum probability in weeks 1–3).
3. Serology (Widal reaction, indirect hemagglutination assay): Informative from days 5–6. O-, H-, and Vi-antigens are studied. The minimum diagnostic titer is 1:200, and a 4-fold increase in paired sera is considered significant.
4. Immunology (ELISA, co-agglutination reaction): Allows detection of antigens from the first days of the disease.

Serological screening (Vi antibodies) followed by a search for the pathogen in feces, urine, or duodenal contents is used to identify bacterial carriers.

Class and exam questions

What else to study on this topic

• The mechanism of formation of Padalka's sign and its topographical anatomy
• Differential diagnosis of typhoid fever with other febrile conditions
• Features of O-, H-, and Vi-antigens in evaluating the results of the indirect hemagglutination assay
• Principles of selecting bile-containing media for Salmonella cultivation
• Management tactics for patients with developing chronic bacterial carriage

Other topics in the "Acute Intestinal Infections" section

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