Food poisoning: causes, symptoms, diagnosis and treatment

Foodborne illnesses are acute infectious diseases caused by opportunistic bacteria that produce exotoxins. When microorganisms get into food products, they accumulate toxins that can cause human poisoning.

Brief historical information

For many centuries, humanity has known that eating poor quality foods, primarily meat, can lead to the development of vomiting and diarrhea. After the description of P.N. Lashchenkov (1901) of the clinical picture of staphylococcal food intoxication found that diseases with diarrhea and intoxication syndromes can be caused by opportunistic bacteria. As a result of the work of domestic researchers, these diseases are classified as foodborne toxic infections.

Causes and causative agents of food toxic infections

Foodborne illness (FTI) is a disease caused by infection not with bacteria itself, but with toxins that are formed as a result of the activity of bacteria outside the human body, mainly in food.

The causative agents of foodborne toxic infections are opportunistic microorganisms: various types of Clostridia, Proteus, Klebsiella. Also, foodborne illnesses are caused by Staphylococcus aureus, which multiplies on food products and releases toxins. Infection occurs when food is not cooked properly. The source of infection with diseases such as food poisoning can be a person who does not follow the rules of hygiene, or a person with purulent inflammation on the hands (felon, pyoderma), or with an acute respiratory disease (sore throat, nasopharyngitis), who prepares food and introduces a pathogen into it. Dairy cattle are also dangerous: cows, sheep, goats with mastitis.

The causes of food poisoning are poor quality nutrition. You can become infected by eating low-quality sausage, jelly, eggs, canned meat and fish, soups, dairy products, juices, compotes, and sweet carbonated drinks. Especially dangerous are dishes that are not subjected to heat treatment, but are stored for several hours before consumption - during this time pathogens multiply in them (salads, pastry creams). The insidiousness of the pathogen lies in the fact that for some time the appearance and taste of the products do not change, but they can already cause infection.

Pathogens are destroyed by boiling.

Clostridia is a genus of bacteria that reproduces in an oxygen-free atmosphere, forming spores. It is found in soil, wastewater, and in the digestive tract of healthy people and various wild and domestic animals. Repeatedly isolated from raw meat of domestic animals and poultry. Infects meat products and canned food.

Proteus is a rod-shaped, non-spore-bearing, motile (flagella are located along the periphery of the entire cell) bacterium. The dimensions of a young cell are 0.5x1.3 micrometers; later filaments up to 20 micrometers long appear. Proteus cells change their appearance perfectly. They belong to the normal intestinal flora and are widely distributed in soil and water; affects meat products.

Klebsiella is an anaerobic enterobacterium, one type of which can cause pneumonia, another - foodborne illnesses. The bacterium can exist in soil, water, food, dust, and enters the gastrointestinal tract from poorly washed hands, vegetables and fruits, water, and soil. Capable of forming a capsule, therefore resistant to environmental factors and high temperatures.

Staphylococcus aureus is a spherical bacterium that causes a wide range of diseases, ranging from mild skin infections (acne, impetigo, boil, cellulitis, carbuncle) to pneumonia, meningitis, osteomyelitis, endocarditis, infectious-toxic shock and sepsis. Carriage is widespread (approximately 20% of the population). Lives on the skin and on the surface of mucous membranes (nose, pharynx and vagina). It breeds on dairy products.

Mechanism of development of food toxic infections

When contaminated food enters the body, it contains not only pathogens, but also exotoxins that they managed to produce. Therefore, their incubation period is quite short; a person can feel the symptoms of poisoning after 30 minutes, but most often this happens after 2-6 hours.

How the disease manifests itself depends on what toxins predominate in the body and their “dose” contained in the food consumed.

Enterotoxin

It can be heat-stable and heat-labile, binds to epithelial cells of the gastrointestinal tract, affects the fermentation systems of epithelial cells. Enterotoxin activates the production of the enzymes guanyl cyclase and adenyl cyclase, which change the cells of the mucous membrane. The formation of intestinal hormones, histamine, and prostaglandins is also accelerated. As a result of all this, the secretion of salts and fluid into the lumen of the intestines and stomach increases, diarrhea and vomiting develop.

Cytotoxin

It disrupts the protein synthetic processes of cells and damages their membranes. Thus, the permeability of the intestinal wall and various toxic substances (enzymes, lipopolysaccharides) of bacterial origin increase, and sometimes the bacteria themselves easily pass through it. Intoxication begins, microcirculation of the mucous membrane is disrupted, and inflammation occurs.

We conclude: the manifestations of PTI, provoked by bacteria that produce only enterotoxin, are not so severe. Most often, this disease is not accompanied by serious inflammation of the gastrointestinal mucosa. But if you are unlucky enough to eat foods with enterotoxins and exotoxins, the disease is much more severe. It is accompanied by fever and inflammatory changes in the gastrointestinal mucosa.

Usually, IPT treatment quickly produces positive results. When the bacteria are removed, the effect of their toxins stops literally immediately. Additionally, medications are taken to inactivate unbound toxin molecules.

However, under certain conditions, food poisoning can torment the patient for quite a long time. This happens if, due to some current or experienced disease, the antibacterial protection of the small intestine does not work well in the body. It is also especially difficult:

who have undergone gastrectomy,
patients with malnutrition,
suffering from blind loop syndrome.

Food poisoning: symptoms and treatment of toxic infections

Here you will learn about the symptoms and treatment of foodborne illnesses, as well as disease prevention

Symptoms The incubation period is very short - from 30 minutes to 24 hours, most often 2-6 hours. The disease, as a rule, begins with nausea and repeated vomiting, at the same time or a little later diarrhea develops, the stool is watery, light brown, and foul-smelling. Also symptoms of foodborne toxic infections are mild cramping abdominal pain, fever and other signs of intoxication. Usually the disease lasts 1-3 days.

Treatment. In the first hours, gastric lavage is recommended. It is necessary to drink 4-5 glasses of warm water, after which, irritating the root of the tongue with your finger, induce vomiting. When treating foodborne toxic infections, the child is given water to drink in accordance with the volume of a single feeding according to age, followed by irritation of the root of the tongue by pressing on it. This procedure is repeated until the water flowing from the stomach becomes clear. Vomit removes pathogenic bacteria and toxins from the body.

Symptoms of the disease Food poisoning

Incubation period . As a rule, it lasts several hours, but in some cases it can be shortened to 30 minutes or, conversely, extended to 24 hours or more.

Despite the polyetiology of foodborne toxic infections, the main clinical manifestations of intoxication syndrome and water-electrolyte disorders in these diseases are similar to each other and are little different from those in salmonellosis. The disease is characterized by an acute onset with nausea, repeated vomiting, loose stools of an enteritic nature from several to 10 times a day or more. Abdominal pain and temperature reaction may be minor, but in some cases severe cramping abdominal pain, a short-term (up to 24 hours) increase in body temperature to 38-39 °C, chills, general weakness, malaise, and headache are observed. When examining patients, pale skin, sometimes peripheral cyanosis, coldness of the extremities, pain on palpation in the epigastric and umbilical areas, changes in pulse rate and decreased blood pressure are noted. The severity of clinical manifestations of dehydration and demineralization depends on the volume of fluid lost by patients during vomiting and diarrhea. The course of the disease is short and in most cases lasts 1-3 days.

At the same time, the clinical manifestations of foodborne diseases have some differences depending on the type of pathogen. Staphylococcal infection is characterized by a short incubation period and rapid development of symptoms of the disease. The clinical picture is dominated by signs of gastritis: repeated vomiting, sharp pain in the epigastric region, reminiscent of stomach colic. The character of the stool may not change. Body temperature in most cases remains normal or rises briefly. A pronounced decrease in blood pressure, cyanosis and convulsions can be observed already in the first hours of the disease, but in general the course of the disease is short-term and favorable, since changes in cardiohemodynamics do not correspond to the degree of fluid and electrolyte disorders. In cases of food poisoning caused by Clostridium perfringens, the clinical picture, similar to that of staphylococcal infection, is supplemented by the development of diarrhea with characteristic loose bloody stools, body temperature remains normal. With foodborne infections caused by Proteus vulgaris, the stool becomes foul-smelling.

Complications

Observed extremely rarely; most often - hypovolemic shock, acute cardiovascular failure, sepsis, etc.

Prevention of food poisoning

To prevent foodborne illnesses, you must follow the rules for preparing and selling products:

Do not eat foods that you are not sure of their freshness and quality, or foods that have expired.
Buy products only from certified sellers whose products have passed sanitary inspections. This is especially true for meat, fish, smoked meats and dairy products.
Observe the temperature and time when preparing raw foods. Boiling completely destroys most pathogens.
Wash eggs before breaking them.
Use different boards for preparing food: one for bread, cheese and sausage, one for raw meat, one for raw fish, one for raw vegetables, one for boiled. Place them on the table so that the products do not touch each other. For example, raw and cooked meat should not be in contact.
Wash your hands and kitchen utensils when switching from one type of food to another.
If you are not sure of the quality of drinking water, be sure to boil it, and rinse dishes and raw foods with cold boiled water.
Boil soups and meat dishes at least once a day.
Try to prepare salads immediately before serving, store them in the refrigerator and mercilessly get rid of leftovers.

Foodborne toxic infections are acute diseases that occur as a result of eating food contaminated with microorganisms and are characterized by symptoms of gastroenteritis and impaired water-salt metabolism. In the event that only microbial toxins entering the body with food are sufficient for the development of the disease, they speak of food intoxication.

Etiology. The causative agents of food toxic infections are various opportunistic bacteria - Escherichia coli, Clostridium perfringens, Bacillus cereus, some types of Proteus, Klebsiella, Vibrio, Enterococcus, etc.; pathogens of intoxication include Clostridium botulinum, staphylococci, and some fungi (see Chapter 2). The disease caused by C. botulinum differs in pathogenesis and clinical picture from intoxications caused by other microorganisms and is described separately.

Pathogenicity factors. Pathogens of foodborne diseases produce both endo- and exotoxins. Endotoxins have an enterotropic, neurotropic effect, increase body temperature, cause headache, malaise and other symptoms of general intoxication. Exotoxins have enterotoxic and cytotoxic properties. As a result of the action of enterotoxin, the secretion of fluid and salts into the intestinal lumen increases, diarrhea develops, which is associated with a violation of water-salt metabolism. The cytotoxic effect consists of damage to the epithelial cells of the mucous membrane of the digestive tract, in which inflammatory changes occur. The pathogenicity of foodborne pathogens is also associated with the presence of capsules, pili in some of them, and the production of aggression enzymes.

Resistance. The causative agents of foodborne toxic infections have a fairly high resistance to various environmental factors and can persist for quite a long time in various food products. Long-term heat treatment is required to destroy them. Spore-forming bacteria – representatives of the genera Bacillus and Clostridium – are characterized by very high resistance.

Epidemiology. Acute foodborne illnesses are diseases that are widespread everywhere. People of different ages suffer from them. Susceptibility varies and depends on the dose of the pathogen and the immune status of the person who consumed the infected products. The incidence rate increases in the warm season, which is associated with favorable conditions for the proliferation of microbes in products. The source of infection can be animals and people, who excrete most of the pathogens of foodborne diseases in their feces. Due to the wide distribution of pathogens in soil, water, and on various objects, the source of infection is often difficult to determine. The mechanism of transmission of infection is fecal-oral. The route of transmission is food. Eating a variety of foods can lead to the development of foodborne illnesses or intoxication. Meat and fish may contain, for example, Proteus; dairy products (sour cream, ice cream, cream) are the most favorable nutrient medium for staphylococci, but these same products, as well as many others, may contain other microorganisms. Often, products infected with microorganisms may not be externally changed.

Pathogenesis. A feature of foodborne toxic infections is the ability of pathogens to produce exo- and endotoxins not only in the human body, but also in food products, which explains the short incubation period. The development of staphylococcal food intoxication is caused only by the ingestion of exotoxin into the body. As a result of the action of endotoxin released when bacteria die, body temperature rises, health deteriorates, and disorders of the cardiovascular, nervous systems, etc. may occur. Exotoxins cause damage to the digestive tract and disruption of water-salt metabolism.

Clinical picture. The incubation period ranges from 2 to 24 hours. The disease begins acutely with a short-term increase in body temperature, chills, weakness, nausea, vomiting, abdominal pain, and diarrhea. As a rule, the disease lasts 1-7 days and ends with recovery. But fulminant toxic forms, leading to death, are also possible.

Immunity. After an illness, immunity is fragile and short-lived.

Microbiological diagnostics. The materials for the study are vomit, gastric lavage, feces, and food debris. For diagnosis, the bacteriological method is used.

Treatment. In case of acute food toxic infections, nonspecific treatment is primarily prescribed - gastric lavage. The use of chemotherapy in uncomplicated cases is not advisable.

Prevention. Compliance with sanitary and hygienic standards when preparing and storing food.

Occurrence of disease Food poisoning

Food poisoning is caused by a large group of bacteria ; the main pathogens are Staphylococcus aureus, Proteus vulgaris, Bacillus cereus, Clostridium perfringens, Clostridium difficile, representatives of the genera Klebsiella, Enterobacter, Citrobacter, Serratia, Enterococcus, etc. The pathogens are widespread in nature, have pronounced resistance and are able to reproduce in environmental objects. All of them are permanent representatives of the normal intestinal microflora of humans and animals. Often, it is not possible to isolate the pathogen from sick people, since the clinical picture of foodborne toxic infections is mainly determined by the action of microbial toxic substances. Under the influence of various environmental factors, opportunistic microorganisms change biological properties such as virulence and resistance to antibacterial drugs.

Epidemiology

The source of infection is various animals and people. Most often these are persons suffering from purulent diseases (felons, tonsillitis, furunculosis, etc.); Among the animals there are cows and sheep suffering from mastitis. All of them secrete pathogens (usually staphylococci) that enter food products during processing, where bacteria multiply and accumulate. Both patients and carriers of pathogens pose an epidemiological danger. The infectious period of patients is short; Regarding the timing of bacterial carriage, the data are contradictory.

The causative agents of other toxic infections (C. perfringens, B. cereus, etc.) are released by people and animals into the external environment with feces. The reservoir of a number of pathogens can be soil, water and other environmental objects contaminated with animal and human excrement.

The transmission mechanism is fecal-oral, the main route of transmission is food. For foodborne toxic infections caused by opportunistic bacteria to occur, a massive dose of the pathogen or a certain amount of time is required for its reproduction in food products. Most often, foodborne toxic infections are associated with contamination of milk, dairy products, canned fish in oil, meat, fish and vegetable dishes, as well as confectionery products containing cream (cakes, pastries). The main product involved in the transmission of clostridia is meat (beef, pork, chicken, etc.). The preparation of certain meat dishes and products (slow cooling, repeated heating, etc.), the conditions for their sale, contribute to the germination of spores and the proliferation of vegetative forms. Various environmental objects participate in the relay race of the pathogen: water, soil, plants, household items and patient care items. Products containing staphylococcal and other enterotoxins do not differ from benign ones in appearance, smell and taste. Diseases occur in the form of sporadic cases and outbreaks. They are more often recorded in the warm season, when favorable conditions are created for the proliferation of pathogens and the accumulation of their toxins.

People's natural sensitivity is high. Usually, most people who eat contaminated food get sick. In addition to the properties of the pathogen (sufficient dose, high virulence), the development of the disease requires a number of contributing factors from both the microorganism and the macroorganism (reduced resistance, the presence of concomitant diseases, etc.). Individuals at risk are more susceptible: newborns, weakened individuals, patients after surgery or those who have been receiving antibiotics for a long time, etc.

Basic epidemiological features . Diseases caused by opportunistic microorganisms are widespread. Outbreaks are familial in nature or when food is contaminated in catering establishments, diseases can be dispersed throughout the population. The number of cases determines the number of people who consumed the contaminated food product and can vary significantly. In particular, group diseases are very common among passengers of sea vessels, tourists and members of children's and adult organized groups. Outbreaks are usually explosive in nature. No differences in socio-age or gender composition were identified. Diseases are more often recorded in the summer. Depending on the type of food product, children or adults predominate among the sick. In addition to food outbreaks, household outbreaks are also possible, in most cases occurring in hospital settings. Outbreaks of nosocomial infections caused by C. difficile are associated with long-term use of antibiotics. During water outbreaks as a result of fecal contamination, other pathogens of acute intestinal infections are also released along with opportunistic microorganisms.

Toxic infections

Toxic infections are acute, often widespread diseases that occur when eating food containing a large number of living opportunistic microorganisms (tens and hundreds of millions in one gram of product) and their toxins released during the reproduction and death of microbes.

Toxic infections are characterized by widespread occurrence, a sudden onset, territorial limitation, a strong connection with the consumption of a specific product or dish, and the cessation of the outbreak after the product is removed.

Pathogens of toxic infections

The causative agents of toxic infections can be bacteria of the Escherichia coli group (coliforms), bacteria of the genus Proteus, perfringens and cereus bacilli, parahemolytic vibrio and other bacteria. These microorganisms belong to the group of opportunistic microbes that cause disease only when a very large number (> 10 5 per 1 g of product) of microbes of certain strains (serohypes) enters the body. This accumulation of microbes occurs in food products and food as a result of their reproduction due to gross violations of sanitary rules for processing, storage and timing of sales of products. Most often, diseases are associated with the consumption of food that has been heat-treated and secondarily infected. Outbreaks of toxic infections occur mainly in the warm season.

The group of coliform bacteria includes E. coli, Citrobacter, Enterobacter and other coliform bacteria (coliforms). These bacteria are widespread in nature, found in the intestines of humans, livestock, poultry, etc.

With secretions from the intestines, coliforms enter the soil and various environmental objects. In public catering establishments, the main source of toxic infection may be an employee who carries opportunistic pathogenic strains of E. coli and coliform bacteria and does not observe the rules of personal hygiene.

Such toxic infections are often associated with the consumption of milk and dairy products, mashed potatoes, salads, shellfish and foods that have not been cooked before consumption. Meat and fish dishes, especially minced meat, and other dishes can cause poisoning if, after insufficient heat treatment, they are stored for a long time without refrigeration. The disease may resemble mild forms of dysentery, causing nausea, vomiting, abdominal pain, and diarrhea. Intestinal dysfunction lasts no more than 1-3 days.

Proteus bacilli (Proteus vulgaris and Proteus mirabilis) are widespread in the environment. They belong to putrefactive bacteria and are found in rotting waste. Proteus bacilli can be found in the intestines of humans and animals. A worker carrying bacteria can infect any product or dish. Proteus bacilli are preserved for a long time and multiply in food products. Most often, toxic infections caused by Proteas are associated with the consumption of protein products: meat products and products, meat salads, fish and fish products, pates, etc. There are no changes in the organoleptic properties of food.

The source of infection of dishes is very often dishes, utensils and equipment contaminated with food residues. Contamination can occur when using the same cutting boards, knives, and meat grinders for raw and cooked foods.

Since Proteus bacillus dies during heat treatment, its detection in finished products indicates violations of the heat treatment regime or poor sanitary treatment of inventory, utensils and equipment, as well as non-compliance with storage conditions and sales deadlines. The disease is accompanied by cramping abdominal pain, intestinal dysfunction, and fever. Recovery occurs in 2-5 days.

Fecal streptococci (enterococci) are permanent inhabitants of the intestines of humans, animals and birds; they can be found in the upper respiratory tract of bacteria carriers. Enterococci multiply intensively in minced meat products, puddings, creams, etc. When massively accumulated in food, they cause sliminess of the product and an unpleasant aftertaste. Patients experience diarrhea, fever, and less commonly, nausea and vomiting.

Foodborne illnesses can also be caused by the spore-forming anaerobic bacillus perfringens (Clostridium perfringens). The main role in the occurrence of foodborne toxic infections belongs to Clostridium perfringens type A. In the external environment, in the soil, perfringens is found in the form of spores that are resistant to any external influences. The spores of these sticks can withstand prolonged boiling (up to 6 hours).

The location of perfringens is often the intestines of herbivores. Therefore, the most common cause of the disease is canned meat, as well as meat sausages and culinary products, etc. Vacuum-packed meat products, jellies, dishes with gravies and sauces can pose a danger. Contamination of flour, cereals, spices, and herbs with perfringens sticks is noted. If prepared food is stored in a warm place for a long time, spores can germinate and a significant number of living microorganisms can quickly accumulate in the product.

Toxicinfection caused by perfringens has an incubation period of 6-24 hours and is quite mild. In some cases (with serotype C), necrotic enteritis occurs, which can be fatal.

Spore-forming aerobic bacteria Bacillus cereus can cause foodborne illnesses. They are widespread and are found in soil, water, air, and plant products. Food poisoning occurs after eating low-quality meat, fish, dairy products and dishes where sticks are introduced in the form of spores with flour, starch, and spices. Changes in the organoleptic properties of dishes due to the proliferation of Cereus bacteria are not observed.

Toxic infection of a cereus nature occurs 6-15 hours after eating a dish containing more than 10 4 microbial cells per 1 g. The disease occurs as diarrhea without vomiting and fever and is characterized by a mild course.

The emetic form of poisoning with a cereus toxin is classified as toxicosis, has a short incubation period (0.5-6 hours) and is accompanied by nausea and vomiting. The cause of poisoning is mashed potatoes, boiled pasta, salads, puddings, and dishes with sauce.

Parahaemolytic vibrio (V. parahaemolyticus) lives in sea water and causes food toxic infections when consuming insufficiently thermally processed seafood, most often fish. It is preserved for a long time in these products at low temperatures and can withstand drying and smoking. At 100°C, vibrios quickly die. The disease can be acute with a cholera-like or dysentery-like course.

Toxic infections can be caused by foods and dishes massively contaminated with bacteria Klebsiella, Hafnia, Pseudomonas, etc.

1. General characteristics and pathogens of PTI
2. Botulism

LECTURE No. 16. Foodborne toxic infections. Food toxicoses

1. General characteristics and pathogens of PTI

Foodborne illnesses (FTIs) are a large group of acute intestinal infections that develop after eating foods contaminated with pathogens and their toxins.

Clinically, these diseases are characterized by a sudden onset, a combination of intoxication syndromes, gastroenteritis and frequent development of dehydration.

Foodborne illnesses can be caused by:

1) salmonella;

2) Shigella;

3) opportunistic microorganisms (P. vulgaris, P. mirabilis, enterococci);

4) enterotoxic strains of staphylococcus (St. aureus St. albus);

5) streptococci (beta-hemolytic streptococci of group A);

6) spore anaerobes (Clostridium perfringens);

7) spore aerobes (Bac. cereus);

halophilic vibrios (Vibrio parahaemolyticus), etc.

Most often they are caused by salmonella and opportunistic pathogens that are widespread in the environment. Most of them live in the intestines of healthy people in the form of saprophytes. The development of the disease requires a number of contributing factors:

1) a sufficient dose of the pathogen;

2) appropriate virulence and toxigenicity;

3) reduced resistance of the macroorganism;

4) presence of concomitant diseases, etc.

PTI pathogens are capable of producing toxins both in food products and in the human body. When pathogens are destroyed in the gastrointestinal tract, additional portions of various types of toxic substances are formed. The body responds to a massive influx of pathogens and toxic products into the human gastrointestinal tract with a stereotypical reaction.

The action of the complex of toxins causes local changes in the gastrointestinal tract (inflammatory process, perversion of motility), general toxic syndrome (headache, hyperthermia, disruption of the cardiovascular and nervous systems, etc.).

In general, this group of diseases is characterized by a short incubation period, acute onset and rapid development, a combination of signs of damage to the gastrointestinal tract and severe intoxication.

There are some features of the clinical picture, depending on the type of pathogen:

1) Salmonella PTIs are characterized by a severe course, epidemic outbreaks are possible;

2) with staphylococcal etiology, the disease develops most acutely after a very short incubation period (30–60 minutes); begins with the appearance of nausea, vomiting, severe cutting pain in the abdomen, reminiscent of stomach colic;

3) with clostridial etiology, PTI develops quickly, beginning with the appearance of intense, stabbing abdominal pain, accompanied by nausea, vomiting and loose bloody stools at normal body temperature;

4) PTI of Proteus etiology is characterized by a sharp foul odor of feces.

Diagnostics:

1) bacteriological examination of patient secretions and food products;

2) serodiagnosis.

2. Botulism

The causative agent of botulism belongs to the genus Clistridium, species Cl. botulinum. It is a causative agent of food toxicosis.

Food toxicosis is a disease that occurs when eating food containing exotoxins of a pathogen, while the pathogen itself does not play a decisive role in the development of the disease.

Cl. botulinum are gram-positive large rods. They form subterminal spores. They do not have capsules. Strict anaerobes.

They multiply on glucose-blood agar, forming irregularly shaped colonies with shoots or smooth edges, and a zone of hemolysis around the colonies. When growing in an agar column, they resemble lumps of cotton wool or lentils. In liquid media, a uniform turbidity forms, and then a compact sediment falls to the bottom of the test tube.

The natural habitat of clostridia botulism is the intestines of fish and animals; microorganisms enter the soil with feces. They are able to survive and reproduce in the external environment for a long time in the form of spore forms. Vegetative forms are not very stable in the external environment.

Enzyme activity is variable and is not used for identification.

Based on the antigenic structure of the toxins produced, serovars A, B, C1, D, E, F, Q are distinguished. The antigenic specificity of the bacteria themselves is not determined.

Clostridia botulinum produces the most powerful exotoxin, botulinum. Botulinum toxin accumulates in food products, multiplying in them. Such products are usually home-made canned food, raw smoked sausages, etc.

The toxin has a neurotropic effect. With the development of the disease, toxinemia always occurs, the medulla oblongata and the nuclei of the cranial nerves are affected. The toxin is resistant to the action of digestive enzymes, it is quickly absorbed from the upper parts of the digestive tract into the blood and enters the neuromuscular synapses.

Botulinum toxin binds to the synaptosomal membrane and enters the nerve cell by endocytosis.

The mechanism of action of the toxin is the inhibition of calcium-dependent release of acetylcholine, blockade of the functional activity of the neuron. The bulbar nerve centers are primarily affected. General intoxication and signs of damage to the organ of vision appear - double vision, accommodation disorder, dilated pupils, damage to the extraocular muscles. At the same time, swallowing becomes difficult, aphonia, headache, dizziness, and vomiting appear.

The disease has a high mortality rate.

Diagnostics:

1) infection of laboratory mice; material – vomit, gastric lavage, feces, blood;

2) detection of the toxin in the toxin neutralization reaction;

3) serodiagnosis.

Treatment: antitoxic antibotulinum serum.

Table of contents

Prevention of toxic infections

Prevention of toxic infections is based on a variety of activities that can be grouped into three main groups:

Measures aimed at preventing contamination of food products and food:

identification of carriers of pathogenic forms of E. coli and other opportunistic pathogenic flora and timely treatment of workers suffering from dysbacteriosis;
reduction of contamination of raw materials and sterilization of spices;
strict adherence to the rules of personal hygiene and sanitary regime of the enterprise, disinfection of equipment, equipment and utensils;
exclusion of contact of raw materials, semi-finished products and finished products;
compliance with the rules of mechanical processing of products.

Measures aimed at ensuring conditions that prevent massive proliferation of microorganisms in products:

storing products and prepared food in cold conditions at temperatures below 6 ° C;
sale of prepared food at temperatures above 65 °C, cold snacks - below 14 °C;
strict adherence to product sales deadlines;
storage and sale of canned food in accordance with the rules.

Measures aimed at destroying microorganisms that cause toxic infections through effective heat treatment of food products:

heat treatment of food products and products until complete culinary readiness is achieved (85 ° C - for poultry and natural meat products, 90 ° C - for minced products from cutlet mass);
repeated heat treatment in the preparation of some cold dishes (jelly, aspic), meat or liver filling for pancakes and pies, boiled poultry or meat for first and second courses after portioning, etc., since mechanical operations with boiled products often introduce conditionally pathogenic microorganisms.

Foodborne illness (FTI) is a group of diseases of infectious origin that are caused by toxins of opportunistic microorganisms. Such toxins can accumulate in poor quality food products. The disease has a rapid course and a favorable outcome.

How does food poisoning occur?

Harmful agents must enter a person in very large quantities, more than a hundred microbes in one gram of food, and they form toxins both in the food eaten and inside the person.

The disease is caused by salmonella and E. coli, shigella and staphylococcus, streptococcus and enterococcus, and with them many other bacteria. Not all E. coli and staphylococci are capable of causing infection, only some types. Different pathogens cause diseases with identical manifestations in the same way.

The Medicine 24/7 Clinic has excellent diagnostic equipment installed, eliminating false interpretations and incorrect diagnoses. For help, contact an infectious disease specialist at the Center for Infectious Diseases by calling.

Pathogens of food poisoning

The causative agents of PTI are representatives of opportunistic bacterial flora. Their number is in the dozens. Among the most common are known:

After undergoing IPT, immune reactions are weakly expressed, so it is inappropriate to talk about the formation of immunity. In addition, cross-immunity in the case of foodborne toxic infection is not formed, so cases of recurrent illness are possible due to toxins from another microbial agent entering the human body.

An important difference between PTI is that the clinical picture of the disease develops under the influence of a toxin (exo- or endo), and not the microbial agent itself. The microbial toxin can accumulate in contaminated food. The amount of toxic substance entering the human body determines the severity of the disease.

All pathogens of foodborne toxic infections are resistant to environmental factors (low and high temperatures, ultraviolet radiation, insolation, humidity), so it is inappropriate to talk about the destruction of these microbial agents.

Course of the disease Foodborne toxic infections

A common property for all pathogens of foodborne toxic infections is the ability to produce various types of exotoxins (enterotoxins) and endotoxins (lipopolysaccharide complexes). It is precisely due to the peculiarities of the action of these toxins that a certain originality is noted in the clinical manifestations of foodborne toxic infections caused by various pathogens. The extremely important role of bacterial toxins in the development of foodborne diseases is also indicated by the relatively short incubation period of the disease.

Depending on the types of toxins, they can cause hypersecretion of fluid into the intestinal lumen, clinical manifestations of gastroenteritis and systemic manifestations of the disease in the form of intoxication syndrome.

Bacterial toxins realize their effect through the production of endogenous mediators (cAMP, PG, interleukins, histamine, etc.), which directly regulate the structural and functional changes in organs and systems detected in patients with foodborne toxic infection.

The similarity of the pathogenetic mechanisms of foodborne toxic infections of various etiologies determines the commonality of basic principles in approaches to therapeutic measures for these diseases, as well as for salmonellosis and campylobacteriosis.

Transmission routes

The predominant route of transmission of foodborne pathogens is food (in accordance with the name). The water route of transmission is rarely confirmed, only in the case of mass infection of a large number of people, for example, when mixing tap water and sewage due to an accident.

Contact transmission is less significant than food transmission. However, if an outbreak of food poisoning develops in an organized group, insufficiently thorough cleaning of dishes and kitchen utensils can play a significant role in the spread of the disease.

Among food products that are potential factors for the transmission of foodborne illnesses, the greatest danger is represented by those that are not heat-treated before direct consumption. These include:

confectionery products (pastries, cakes, mousses, creams);
dairy products (whole milk, fermented baked milk, yogurt, kefir, yogurt);
any salads (fruit and vegetable, especially dressed with mayonnaise);
meat jelly, poorly fried meat, pate;
eggs and any dishes made from them with insufficient heat treatment.

Toxins and other waste products of microorganisms can accumulate in food even at low temperatures, that is, storing food in the refrigerator does not prevent the development of the disease. In some cases, the color, smell and appearance of food are not affected by the microbial toxin, which increases the risk of developing the disease.

In the human body, as a result of the ingestion of a microbial toxin and the microorganism itself, inflammatory changes occur in the gastrointestinal tract and the development of general intoxication. Inflammatory changes in the digestive canal lead to impaired absorption and digestion of nutrients, resulting in diarrhea and other dyspeptic symptoms. Changes in other organ systems are functional in nature, that is, there is no disruption of tissue structure.

Clinical manifestations of food poisoning are similar to many other diseases of infectious and non-infectious nature. Therefore, you should not engage in self-medication and self-diagnosis - only a specialist can distinguish PTI from acute appendicitis, which requires immediate surgical intervention.

The following manifestations indicate foodborne toxic infection:

acute onset of the disease, literally half an hour to an hour after eating poor quality food;
increased temperature (sometimes up to 39-40 ° C) combined with chills;
sharp sudden weakness;
repeated episodes of vomiting recently eaten food in combination with painful nausea;
diffuse pain in the abdomen of a spastic nature - a person feels either constant pain or periodic spasms;
loose stools without pathological impurities (mucus, streaks of blood, pus).

With food poisoning, everyone who has eaten poor quality food gets sick at the same time. This disease is characterized by mass distribution - members of the same family, children eating in the school canteen, and people who have visited a certain public catering establishment are affected.

Treatment of food poisoning in adults

First of all, the stomach is washed with clean water to remove microorganisms and endotoxin. A special probe and solutions are used; the “two fingers in the mouth” method threatens elderly patients with cardiac dysfunction.
The intestines are “cleaned” with a siphon enema; if the disease passes without diarrhea, a laxative is given to remove germs and toxins from the feces.
In case of dehydration, copious amounts of special saline solutions are prescribed; in severe cases, intravenous drips are prescribed. The amount of fluid that was lost must be received.

Antibiotic treatment of foodborne toxic infection depends on the severity of symptoms; they are prescribed for severe cases and the threat of septic complications.

It is impossible and not necessary to eat during illness, and during recovery you must adhere to a special gentle diet.

Diagnostics

specialist treats foodborne illnesses If necessary, emergency care is provided by a family doctor or pediatrician. Treatment begins in a hospital and ends at home. In cases of moderate to mild food poisoning (and the possibility of careful patient care), treatment can occur at home.

Diagnosis of PTI is based on clinical and epidemiological data. Due to the transience of the disease and the favorable outcome, microbiological diagnosis is rarely used, since it is not necessary.

Laboratory confirmation of food poisoning is necessary in cases of epidemiological investigation or forensic examination. To do this, a pathogen is searched for in suspicious products and biological fluids of the patient (vomit, feces) using a bacteriological diagnostic method. Confirmation of the diagnosis is the identification of the same microbe in food and in the patient’s body.

Diagnosis of the disease Food poisoning

Differential diagnosis

Foodborne toxic infections should be distinguished from salmonellosis and other acute intestinal infections - viral gastroenteritis, shigellosis, campylobacteriosis, cholera, etc., as well as from chronic gastrointestinal diseases, surgical and gynecological pathologies, myocardial infarction. Since the main pathogenetic mechanisms and clinical manifestations of food toxic infections are little different from those of salmonellosis, in clinical practice a generalized preliminary diagnosis of food toxic infections is often made, and salmonellosis is isolated from this general group if it is bacteriologically or serologically confirmed.

Laboratory diagnostics

The basis is the isolation of the pathogen from vomit, gastric lavage and feces. When sowing a pathogen, it is necessary to study its toxigenic properties. However, in most cases, the excretion is insignificant, and the detection of a specific microorganism in a patient does not yet allow it to be considered the culprit of the disease. In this case, it is necessary to prove its etiological role either using serological reactions with an autostrain, or by establishing the identity of the pathogens isolated from the contaminated product and from the persons who consumed it.

Treatment and clinical recommendations

The prognosis of the disease in the vast majority of patients is favorable. Within 4-7 days the health condition is completely restored. For a doctor, treating food poisoning does not seem to be a difficult task.

An integrated approach to treatment is practiced, which includes medications, diet and protective regimen.

Urgent Care

Before the doctor arrives, the patient (or his relatives) can independently perform some actions that will alleviate the patient’s condition. These include:

bed rest;
refusal to eat;
drink plenty of small portions (boiled water or still mineral water).

You cannot take antipyretics, painkillers, or antispasmodics without a doctor’s prescription. Taking medications complicates the process of making a preliminary diagnosis and, accordingly, adequate treatment of a particular patient.

Regime and diet

In the first 1-2 days from the onset of food poisoning, a complete refusal to eat and bed rest is required. As soon as the condition improves somewhat, expansion of the physical regime and dietary nutrition are allowed. For a damaged digestive canal, the following are useful:

porridge with water (rice, buckwheat, semolina);
pureed vegetable soups (not broth);
fermented milk products with low fat content;
boiled vegetables (potatoes or salad vinaigrette);
crackers;
weak tea with lemon, herbal infusions.

Dietary nutrition is gradually expanding: on days 3-4 you can eat lean meat, fish, etc.; after 7-8 days, the patient with PTI returns to his usual diet.

Drug treatment

Antibiotics are not indicated for IPT, since the main disorders in the body are caused by a microbial toxin. It is advisable to use intestinal antiseptics, which act only in the intestinal lumen and do not have a systemic effect.

To eliminate intoxication and other signs of the disease, the following are prescribed:

The duration of drug therapy is determined by the treating doctor.

Treatment

Patients who experience severe intoxication and dehydration are required to be hospitalized.

Food poisoning involves treatment aimed primarily at regenerating the water balance in the body and preventing dehydration. To do this, the drug Regidron is prescribed in powder form, which you need to start drinking as early as possible.

The drug Regidron

There are 2 degrees of dehydration:

1st degree – the volume of injected fluid should be 30-50 ml/kg of body weight;
Stage 2 – the volume of injected fluid should be 40-80 ml/kg of body weight.

You need to drink approximately 1-1.5 liters per hour in small sips.

If you are constantly vomiting, you need to drink one tablespoon of water every 2-3 minutes, but if vomiting does not allow you to do this, emergency help is needed for a foodborne illness of this kind.

The specialist can also prescribe absorbent medications such as:

Smecta;
Enterosgel;
Polyphepan.

It is necessary to take sorbents three times a day.

If you are bothered by severe cramps and pain in the abdominal area, it is recommended to use no-shpa (1 tablet 3 times a day).

It is difficult to imagine treating food poisoning without following a diet. Preference is given to diet No. 4, which includes foods with a small amount of fat and carbohydrate in their composition, and excludes foods that provoke flatulence.

It is recommended to add the following products to your diet:

crackers made from wheat flour;
low-fat soups with meat or fish broth (you can add rice or semolina, only grated meat, vegetables);
soft lean meat, fish, poultry;
skim cheese;
soft-boiled egg (no more than two per day);
oatmeal, rice, buckwheat porridge (with water).

List of foods that should be excluded from the diet:

flour products, baked goods;
vegetable soups with rich broth;
meat with a layer of fat, sausages, large meat;
canned food, salted fish;
dairy products;
hard-boiled eggs;
millet, barley, pearl barley;
raw vegetables, berries, fruits;
carbonated drinks, cocoa, coffee.

The diet must be followed constantly.

Diet for food poisoning

An important component of treatment is diet. If diarrhea persists, therapeutic diet No. 4 is recommended, which is characterized by a low content of fats and carbohydrates with a normal protein content and a sharp limitation of any irritants of the gastrointestinal tract. Also excluded are foods that can cause flatulence (increased formation of gases in the intestines).

How and from whom can you become infected?

People and animals alike can be spreaders of pathogenic microbes. If we talk about people, then most often they are carriers of purulent diseases. In the animal world, the most common spreaders are cows and sheep that have mastitis. Such animals produce bacteria (staphylococci), which enter products during processing, multiply there and accumulate. You can become infected from sick individuals and carriers in whom food toxic infection has not manifested itself and has not developed into a disease.

Contaminated feces left by humans or animals in soil, water or any other external environment can be potentially dangerous. There they remain until they reach a new carrier. There are two possible scenarios: the carrier gets sick or becomes a spreader of bacteria.

Toxic infections are transmitted by the fecal-oral route. For a person to get sick, they need a very large portion of pathogens or favorable conditions for the active reproduction of bacteria in the food environment. Most of all, bacteria settle in milk and dairy products, canned fish, meat, fish and vegetable dishes, and confectionery cream-containing sweets.

There are both isolated cases of the disease and epidemiological outbreaks. The latter can be of a different nature depending on the number of infected:

small, when one family member infects all or more vulnerable people;
numerous when, for example, in a hospital, patients are weakened by taking antibiotics and suffer en masse from the same form of infection.

A person can become infected with foodborne diseases all year round. The most favorable seasons for a rapid increase in the number of bacteria are summer and autumn. The following factors can increase the likelihood of infection:

Increased dose of microbes in the product;
Increased virulence;
Weak immunity;
The development of other diseases in the human body.

The category of particular risk includes infants, people whose bodies are weakened for some reason, individuals who have undergone surgery, and patients taking medications.

Dehydration due to food poisoning

Perhaps the most dangerous consequence of IPT is dehydration, which occurs as a result of significant fluid loss through diarrhea and vomiting.

There are 4 degrees of dehydration.

Grade 1: fluid loss is 1-3% of body weight.

One feels only a dry mouth, the skin and mucous membranes have normal humidity. Hospitalization is usually not required. However, we must not forget about the need to replenish lost volume by drinking plenty of fluids. If you have severe nausea and vomiting, you should drink a tablespoon of liquid every 2-3 minutes.

Grade 2: fluid loss is 4-6% of body weight.

With degree 2 dehydration, the following symptoms are observed:

Intense thirst;
The mucous membranes of the mouth and nose are dry;
There may be some blueness of the lips and fingertips;
Hoarseness of voice;
Convulsive twitching of hands and feet.

The appearance of cramps is caused by the loss of electrolytes - substances that play an important role in many processes in the body, including the process of muscle contraction and relaxation.

There is also a slight decrease in turgor.

Turgor is the degree of elasticity of the skin; it depends on the amount of fluid in the tissues. Turgor is determined as follows: two fingers form a skin fold - most often on the back of the hand, the front surface of the abdomen or on the back surface of the shoulder; then they release it and watch the time of expansion. Normally and with the first degree of dehydration, the fold straightens instantly. With degree 2 dehydration, the fold can straighten out in 1-2 seconds.