Diagnosis of food toxic infections

Diagnosis of food toxic infections is based on the clinical picture of the disease, the group nature of the disease, and the connection with the consumption of a certain product in violation of the rules of its preparation, storage or sale.

Standard of examination of patients with suspected food poisoning

Study	Changes in indicators
Hemogram	Moderate leukocytosis with a left shift of band nuclei. In case of dehydration - an increase in the hemoglobin content and the number of erythrocytes
Urine analysis	Proteinuria
Hematocrit	Increase
Electrolyte composition of blood	Hypokalemia and hyponatremia
Acid-base balance (during dehydration)	Metabolic acidosis, in severe cases - decompensated
Bacteriological examination of blood (if sepsis is suspected), vomit, feces and gastric lavage	Isolation of culture of opportunistic pathogens. Research is conducted in the first hours of illness and before treatment. Study of phage and antigen uniformity of culture of opportunistic flora obtained from patients and during examination of suspicious products. Identification of toxins in staphylococcosis and clostridiosis
Serological testing in paired sera	RA and RPGA from the 7-8th day of illness. Diagnostic titer 1:200 and higher: growth of antibody titer during dynamic study. Setting RA with autostrain of microorganism isolated from a patient with PTI caused by opportunistic flora

The decision to hospitalize a patient is made based on epidemiological and clinical data. In all cases, a bacteriological study should be conducted to exclude shigellosis, salmonellosis, yersiniosis, escherichiosis and other acute intestinal infections. An urgent need for bacteriological and serological studies arises in cases of suspected cholera, in group cases of the disease and in the event of nosocomial outbreaks.

To confirm the diagnosis of food toxicoinfection, it is necessary to isolate the same microorganism from the patient's feces and the remains of the suspicious product. In this case, the massiveness of growth, phage and antigen uniformity, antibodies to the isolated strain of microorganisms detected in convalescents are taken into account. The diagnosis of RA with an autostrain in paired sera and a 4-fold increase in titer (with proteosis, cereosis, enterococcosis) has diagnostic value.

If staphylococcosis and clostridiosis are suspected, toxins are identified in vomit, excrement, and suspicious products. Enterotoxic properties of the isolated staphylococcus culture are determined in animal experiments.

Bacteriological confirmation requires 2-3 days. Serological diagnostics of food toxic infections is carried out in paired sera to determine the etiology of food toxic infection retrospectively (from the 7th-8th day). General blood and urine tests, instrumental diagnostics (rectoscopy and colonoscopy) are of little information.

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Indications for consultation with other specialists

Differential diagnosis of food toxic infections requires consultations:

• surgeon (acute inflammatory diseases of the abdominal organs, mesenteric thrombosis);
• therapist (myocardial infarction, pneumonia);
• gynecologist (impaired tubal pregnancy);
• neurologist (acute cerebrovascular accident);
• toxicologist (acute poisoning with chemicals);
• endocrinologist (diabetes mellitus, ketoacidosis);
• resuscitator (shock, acute renal failure).

Differential diagnostics of food toxic infections

Differential diagnostics of food toxic infections is carried out with acute diarrheal infections, poisoning with chemicals, toxins and mushrooms, acute diseases of the abdominal organs, and medical diseases.

In differential diagnostics of food toxicoinfection with acute appendicitis, difficulties arise from the first hours of the disease, when Kocher's symptom (pain in the epigastric region) is observed for 8-12 hours. Then the pain shifts to the right iliac region; with an atypical location of the appendix, the localization of pain may be uncertain. Dyspeptic phenomena are possible: vomiting, diarrhea of varying severity. In acute appendicitis, pain precedes an increase in body temperature, is constant; patients note an increase in pain when coughing, walking, changing body position. Diarrhea in acute appendicitis is less pronounced: stool is mushy, fecal in nature. Localized pain corresponding to the location of the appendix is possible on palpation of the abdomen. A general blood test shows neutrophilic leukocytosis. Acute appendicitis is characterized by a short period of “calm”, after which, after 2-3 days, destruction of the appendix occurs and peritonitis develops.

Mesenteric thrombosis is a complication of ischemic bowel disease. Its occurrence is preceded by ischemic colitis: colicky abdominal pain, sometimes vomiting, alternating constipation and diarrhea, flatulence. With thrombosis of large branches of the mesenteric arteries, intestinal gangrene occurs: fever, intoxication, intense pain, repeated vomiting, loose stools with blood, bloating, weakening and disappearance of peristaltic noises. Abdominal pain is diffuse, constant. During examination, symptoms of peritoneal irritation are detected; during colonoscopy - erosive and ulcerative defects of the mucous membrane of irregular, sometimes ring-shaped form. The final diagnosis is established by selective angiography.

Strangulation obstruction is characterized by a triad of symptoms: cramping abdominal pain, vomiting, and cessation of stool and gas passage. There is no diarrhea. Abdominal distension and increased peristaltic noise are typical. Fever and intoxication occur later (with the development of intestinal gangrene and peritonitis).

Acute cholecystitis or cholecystopancreatitis begins with an attack of intense colicky pain and vomiting. Unlike food poisoning, the pain is displaced to the right hypochondrium and radiates to the back. Diarrhea is usually absent. The attack is followed by chills, fever, dark urine and discolored feces; icterus of the sclera, jaundice; bloating. Palpation reveals pain in the right hypochondrium, positive Ortner's symptom and phrenicus symptom. The patient complains of pain when breathing, pain to the left of the navel (pancreatitis). Blood tests reveal neutrophilic leukocytosis with a shift to the left, increased ESR; increased amylase and lipase activity.

Differential diagnosis of food toxicoinfection with myocardial infarction in elderly patients suffering from ischemic heart disease is very difficult, since food toxicoinfection may be complicated by myocardial infarction. In case of food toxicoinfection, pain does not radiate beyond the abdominal cavity, it is paroxysmal, colicky in nature, while in case of myocardial infarction, the pain is dull, pressing, constant, with characteristic irradiation. In case of food toxicoinfection, body temperature rises from the first day (in combination with other signs of intoxication syndrome), and in case of myocardial infarction - on the 2nd-3rd day of the disease. In individuals with a complicated cardiological history, ischemia, rhythm disturbances in the form of extrasystole, atrial fibrillation (polytopic extrasystole, paroxysmal tachycardia, ST interval shift on ECG are not typical) may occur in the acute period of the disease. In doubtful cases, the activity of cardiospecific enzymes is examined, ECG is performed in dynamics, echocardiography is performed. In shock in patients with food toxicoinfection, dehydration is always detected, therefore, signs of congestion in the pulmonary circulation (pulmonary edema) characteristic of cardiogenic shock are absent before the start of infusion therapy.

Hypercoagulation, hemodynamic disturbances and microcirculatory disorders due to damage of vascular endothelium by toxins during food toxicoinfection contribute to the development of myocardial infarction in patients with chronic coronary heart disease. It usually occurs during the period of abatement of food toxicoinfection. In this case, relapse of pain in the epigastric region with characteristic irradiation, hemodynamic disturbances (arterial hypotension, tachycardia, arrhythmia) occur. In this situation, it is necessary to conduct a full range of studies to diagnose myocardial infarction.

Atypical pneumonia, pneumonia in children of the first year of life, as well as in persons suffering from disorders of the secretory function of the stomach and intestines, alcoholism, cirrhosis of the liver, can proceed under the guise of food toxicoinfection. The main symptom is watery stool; less often - vomiting, abdominal pain. Characterized by a sharp increase in body temperature, chills, cough, chest pain when breathing, shortness of breath. cyanosis. X-ray examination (in a standing or sitting position, since basal pneumonia is difficult to detect in a lying position) helps to confirm the diagnosis of pneumonia.

Hypertensive crisis is accompanied by repeated vomiting, increased body temperature, high arterial pressure, headache, dizziness, pain in the heart area. Diagnostic errors are usually associated with the doctor's fixation on the dominant symptom, which is vomiting.

Differential diagnostics of food toxicoinfection should be carried out with alcoholic enteropathies; it is necessary to take into account the connection of the disease with alcohol consumption, the presence of a period of abstinence from alcohol, a long duration of the disease, and the ineffectiveness of rehydration therapy.

A clinical picture similar to food poisoning can be observed in people suffering from drug addiction (during withdrawal or overdose of a drug), but in the latter case, the anamnesis is important, the diarrheal syndrome is less severe and neurovegetative disorders predominate over dyspeptic ones.

Food toxic infections and uncompensated diabetes mellitus have a number of common symptoms (nausea, vomiting, diarrhea, chills, fever). As a rule, a similar situation is observed in young people with latent diabetes mellitus type 1. In both conditions, there are disorders of water-electrolyte metabolism and acid-base balance, hemodynamic disorders in severe cases. Due to the refusal to take hypoglycemic drugs and food, observed in food toxic infections, the condition quickly worsens and ketoacidosis develops in patients with diabetes. Diarrhea syndrome in patients with diabetes is less pronounced or absent. Determination of the level of glucose in the blood serum and acetone in the urine plays a decisive role. Anamnesis is important: patient complaints of dry mouth that occurred several weeks or months before the disease; weight loss, weakness. skin itching, increased thirst and diuresis.

In idiopathic (acetonemic) ketosis, the main symptom is severe (10-20 times a day) vomiting. The disease most often affects young women aged 16-24 who have suffered mental trauma, emotional stress. The smell of acetone from the mouth and acetonuria are characteristic. Diarrhea is absent. The positive effect of intravenous administration of 5-10% glucose solution confirms the diagnosis of idiopathic (acetonemic) ketosis.

The main symptoms that help to differentiate a disrupted tubal pregnancy from food poisoning are pale skin, cyanosis of the lips, cold sweat, dizziness, agitation, dilated pupils, tachycardia, hypotension, vomiting, diarrhea, acute pain in the lower abdomen radiating to the rectum, brownish vaginal discharge, Shchetkin's symptom; a history of delayed menstruation. A general blood test shows a decrease in hemoglobin content.

Unlike food poisoning, cholera is accompanied by no fever or abdominal pain; diarrhea precedes vomiting; feces do not have a specific odor and quickly lose their fecal character.

In patients with acute shigellosis, the intoxication syndrome dominates; dehydration is rarely observed. Cramping pain in the lower abdomen, "rectal spitting", tenesmus, spasm and soreness of the sigmoid colon are typical. Rapid cessation of vomiting is characteristic.

With salmonellosis, signs of intoxication and dehydration are more pronounced. The stool is liquid, plentiful, often greenish. The duration of fever and diarrhea syndrome is over 3 days.

Rotavirus gastroenteritis is characterized by an acute onset, pain in the epigastric region, vomiting, diarrhea, loud rumbling in the abdomen, and an increase in body temperature. A combination with catarrhal syndrome is possible.

Escherichiosis occurs in various clinical variants and may resemble cholera, salmonellosis, shigellosis. The most severe course, often complicated by hemolytic-uremic syndrome, is characteristic of the enterohemorrhagic form caused by E. coli 0-157.

A final diagnosis in the above cases is possible only after conducting a bacteriological examination.

In cases of poisoning with chemical compounds (dichloroethane, organophosphorus compounds), loose stools and vomiting also occur, but these symptoms are preceded by dizziness, headache, ataxia, and psychomotor agitation. Clinical signs appear several minutes after taking the toxic substance. Sweating, hypersalivation, bronchorrhea, bradypnea, and abnormal breathing patterns are characteristic. Coma may develop. In cases of poisoning with dichloroethane, toxic hepatitis (up to acute liver dystrophy) and acute renal failure may develop.

In cases of poisoning with alcohol substitutes, methyl alcohol, and poisonous mushrooms, a shorter incubation period than in food poisoning is typical, and gastritis syndrome predominates at the onset of the disease. In all these cases, a toxicologist consultation is necessary.

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