Alimentary Toxification

2021-03-23 12:00 AM

Oral poisoning is caused by eating food that has been contaminated by pathogenic bacteria. Typical is food poisoning caused by Salmonella.


Oral poisoning is an acute infectious disease spread through the gastrointestinal tract. The main clinical picture is acute gastroenteritis syndrome. The disease usually develops suddenly after eating food that has been contaminated by pathogenic microorganisms or their toxins.

Research history

Oral intoxication has been known since the Hippocrates era.

1880 Eberth found the bacillus Salmonella.

1895 Van Ermengem (Belgian) isolated C. botulinum from wild ham, causing poisoning to 23 people.

1940-1950 discovered that strains of E. Coli caused acute diarrhoea.

1950-1960 discovered that the exotoxin of the staphylococcus aureus causes infection with food poisoning.

1960 Campylobacter was isolated from the blood of patients with diarrhoea.

In the following years, other bacteria were found to cause food poisoning such as: Yersinia entrocolitica, Aeromonas, Campylobacter, Clostridium difficile, Clostridium perfringens ...


Oral poisoning is caused by eating food that has been contaminated by pathogenic bacteria. Typical is food poisoning caused by Salmonella.

Infection of ingestion due to ingestion of food containing toxins of bacteria already formed in food and this toxin causes diseases e.g. exotoxins of staphylococcus aureus, Clostridium perfringens, of Clostridium botulinum.

Salmonella food poisoning (Nontyphoidal Salmonellosis)

The most common of the causes of food poisoning. The disease is found all over the world. Especially in tropical countries, with low population and underdeveloped economy.


Salmonella are the group of non-human typhoid and paratyphoid that cause food poisoning infection.

There are about 1,700 serotypes.

Human pathogens have only more than 10 strains, the most common being: S. Typhimurium and S. enteritidis. Following are some less common strains such as: S. beidelberg, S. cholerae suis, S. panama, S. newport, S. anatum, S. sendai, S. gallinarum, S. pullorum, S. Virginchow, S. dublin etc ..

Salmonella is a gram (-) bacillus that has no shell, no spores, has hair, can exist and reproduce in cells, including in macrophages, have good resistance, exist in the field in the soil. for several months, in water and feces for several weeks, in frozen foods for 2-3 months. Salmonella can survive even in foods with high concentrations of salt and sugar. At 1000C, it takes more than 5 minutes to kill bacteria.

Salmonella has 2 antigens:

O-antigen is a lipopolysaccharide (LPS) stem antigen in nature. This is the bacterial endotoxin, which is only released when the bacteria is destroyed.

The H antigen is a hair antigen that is a protein in nature.


Mainly animals. Salmonella is found in the faeces and urine of pigs, chickens, ducks, birds, mice, cats, dogs, etc. that are sick or carry healthy carriers. In clams, clams, mussels, crabs, crabs, fish, etc. Salmonella can also cause acute illness in animals, at that time Salmonella can be in animal blood.

Carriers or sick people in recovery can be a secondary source of infection.


 Gastrointestinal transmission:

When eating foods of animal origin contaminated with Salmonella such as: Meat, especially undercooked meat, milk, eggs (chicken, duck), undercooked clams, mussels ...

When using raw vegetables, fruit and drinking water, it is contaminated with Salmonella by human and animal feces.

Sensory body - immune properties

All ages can get sick. Common in young children, the elderly has weak resistance.

People who do not have stomach acid due to gastric bypass or an acidosis are more likely to develop the disease.

People with immunodeficiency (congenital or gastrointestinal diseases such as cancer, hemorrhagic colorectal inflammation, cirrhosis, etc.) are susceptible to severe forms such as: Sepsis, pus in the viscera ...

Translation are often small, sporadic services. Disperse was related to collectives eating the same contaminated food (army units, kindergartens, in a family ...).

 The immune response in dietary intoxication is the cellular immune response and the humoral immune response but has no protective effect on the body.

Mechanism of pathogenesis and pathology

Mechanism of pathogenesis

The disease is caused by 3 determinants:

The number of bacteria contained in food is introduced into the body.

It is the ability to penetrate intestinal epithelial cells, the ability to multiply in mononuclear phagocytes, and resistance to bacterial gut protective peptides.

It is the acidic state of the stomach, the ability of rapidly moving phagocytic cells and the activation of T lymphocytes in the defence mechanism. The correlation between these three factors determines the disease: From asymptomatic form to typical gastroenteritis and to more severe forms such as Sepsis, there may be much pus in the internal organs.

Salmonella follows food into the gastrointestinal tract, penetrates into the cells of the gastrointestinal mucosa and then thrives where (mainly in the small intestine) can penetrate deeper into the lymph plaques in the intestinal wall. (Peyer plaque) and may enter the bloodstream causing bacteraemia. When dissolved, they release enterotoxins (Enterotoxins). Enterotoxin acts on the regulation of thermostats, causing infection and poisoning syndrome, affecting the nervous system of plants, causing increased bowel motility, sweating. Toxins increase the activity of the enzyme Adenyl cyclase, thereby increasing the concentration of cyclic AMP. Increased cyclic AMP stimulates the intestinal mucosa to increase excretion with a large amount of water and electrolytes into the lumen, causing symptoms of loose, watery stools of gastroenteritis syndrome (Gastroenteritis). Sometimes Salmonella can combine to cause inflammation of the colon.

Pathological anatomical injury

When the toxin penetrates the intestinal mucous cells, it causes diarrhoea due to increased secretion of water and electrolytes in the lumen of the intestine. The inflammatory process will cause vasodilation, congestion, possibly haemorrhage, mucous ulcers, infection of polymorphonuclear leukocytes in the membrane (Lamina propria), causing local oedema in the intestinal wall. The above mechanism is related to the prostaglandin mediating effect.


Divide the clinical form

Oral intoxication infections are classified into the following:

Gastritis, acute urinary tract form (typical common form).

The septic form resembles typhoid.

Sepsis form can be resident in internal organs.

The carrier can heal.

Acute gastroenteritis form (typical common form)

Incubation: Average from 12 to 36 hours.

Onset: Usually sudden, sometimes it can be gradual with a variety of medical conditions.

Mild: No fever, diarrhoea several times, stomach pain a little.

Moderate and severe with 3 syndromes:

Toxic septic syndrome: Sudden onset of fever at 38 0 C - 40 0 C, sometimes with chills, headache, muscle and joint pain, the number of white blood cells usually increases neutrophil increases. Salmonella culture of vomit and leftovers was positive.

Gastritis syndrome, acute urinary tract: Abdominal pain in the epigastric region and around the navel. Sometimes the pain spreads all over the abdomen, the bloating. Nausea and vomiting are many times, vomit is undigested food mixed with gastric juice, no blood, usually vomiting first. Going out several times a day, easy to go like draining the drain without pouring, often going outside after vomiting. The stool is watery, can mix with undigested food. Normally, the stool does not have mucus, blood, but when accompanied by colitis, the stool can also contain less mucus and blood like in dysentery.

Electrolyte dehydration syndrome: thirst, dry lips, sunken eyes, thinning, haggard expression if worse, rapid pulse, small, low blood pressure, stuck, oliguria, anuria, bloating, cramps, cold limbs, small children sunken, crying without tears ...


Stool culture: Before using antibiotics can (+): Common strains S. enteritides and S. typhi murium.

Blood cultures are usually negative. But if the blood is taken early, it can be positive.

Progression: With a healthy body usually recovers on its own after 2-3 days, sometimes diarrhoea can last up to 1 week. Death can be seen in subjects such as: malnourished children, frail elderly people due to electrolyte dehydration or sepsis.

Septicemia resembles typhoid

Pathogens: S. cholarae suis and S. dublin, S. typhimurium.

Contagious route: According to the gastrointestinal tract, after gastroenteritis, but also may not have loose stools early.

Clinical: There are many similarities with typhoid (but no specific pathological lesions of typhoid): Prolonged fever, severe neurotoxicity (with typhos), bloating, hepatosplenomegaly, etc. But the onset is more acute than typhoid. Symptoms: Rubella, dissociated thermolysis vessels, leukopenia are very rare.

Normal blood cultures (+): This form has a severe prognosis, especially in AIDS patients with frequent recurrence and may appear before AIDS is diagnosed.

Sepsis form can be resident in internal organs

Male patient: Normal give mice S. typhi, S. enteritidis, S. cholera suis, S. Virchow.

Contagious route: Through the bloodstream and then invading any organ.

This form is usually followed by intestinal infection, although there is no premature loose stools.

Clinical manifestations similar to sepsis: Sudden high fever, fever with chills, high fever fluctuating, sweating, severe neurotoxicity, blood culture (+), number of white blood cells in average blood. often. May be associated with inflammation or abscesses in many organs such as:

Pneumonia, lung abscess, pleurisy.

Endocarditis, pericarditis, myocardial abscess, arteritis (often occurs in people with aneurysms, fibrosis of the arteries).

Encephalitis, meningitis, cerebral abscess: Common in young children.

Cholangitis, splenic abscess usually caused by S. typhi murium, S. enteritidis.

Urinary tract infections, pyelonephritis often occur in people with urinary tract failure, urinary tract malformations, and immunosuppressive drugs.

Purulent arthritis, bone marrow inflammation.

Disease progression: Often severe, treatment is difficult.

The carrier can heal

Only detected in an outbreak.

There are no clinical symptoms, only confirmed by positive stool culture.

Time of carrier: 1-3 weeks, possibly up to 2 months or longer.


Decision diagnosis, based on:

Clinical symptoms and epidemiological factors (oriented values).

Testing: (of decisive value) when:

Faecal culture, food (+) waste culture with gastroenteritis form, can carry healthy germs.

Blood culture (+): With a typhoid-like form, the internal organs can be resident.

Pus transplant (+): In the internal organs.

Differential diagnosis

Bacterial food poisoning caused by exotoxins of staphylococcus enterotoxins.

Viral diarrhoea in young children.


Acute bacillary dysentery.

Chronic exacerbation of colitis

Enteric dysbiosis

Chemical food poisoning


Dehydration, electrolytes, acid-base balance disorder.


Endotoxin shock.


The principles of treatment

Symptomatic treatment: Hydration, electrolytes with oral or intravenous isotonic solutions, antipyretic, anti-allergic sedation, vitamins of all kinds, body support. 

Specific treatment with antibiotics according to the antibiotic chart.

Acute gastroenteritis form

Most authors believe that antibiotic treatment in this form is not necessary because it does not shorten the duration of illness, but also increases the duration of the carrier during recovery, so with a good location, only treatment Symptoms such as Electrolyte water balance (especially in young children, the elderly). Antipyretic, sedative, anti-diarrhoea (sometimes necessary when having too much diarrhoea).

In immunocompromised people, severe forms in the elderly, children can take antibiotics:

Ampicilin: 1g / time 3 - 4 times / day x 5-7 days for adults. (Children take 100mg / kg / day, divided into 3-4 times).

Bactrim: 0.48g x 4 to 6 tablets / day in 2 divided doses; Drink 5-7 days (adults). Children: 30-40 mg / kg / day in 2 divided doses.

Other antibiotics can be used such as Thiamphenicol, Quinolone (be careful with children).

Sepsis and internal organs

Treat like septicaemia.

Antibiotics: Choose an antibiotic according to the antibiotic map, use a combination antibiotic, with a broad spectrum, high dose, and use it in the static route. Cephalosporin 3rd generation, ampicillin in combination with quinolone can be used (Quinolone only for people over 15 years old). Time to use antibiotics 10-14 days.

Incision, drainage of abscesses, curettage of osteomyelitis foci.


Do not let people carry bacteria to work in food processing factories or making children's toys.

Ensuring the industrial hygiene of food and housewives.

With individuals: Mainly by eating and drinking.

Bacterial infection - food poisoning caused by staphylococci

Staphylococcal food poisoning is an acute digestive disorder caused by eating food contaminated with staphylococcal enterotoxins. The main clinical picture is epigastric abdominal pain. vomiting, diarrhoea, almost no fever. Acute developments, fast, neat end.


Staphylococcus aureus belongs to phage group III, IV that produces exotoxins and this toxin is the culprit of the disease. Staph is an antibiotic-resistant bacterium and its exotoxins also have high heat resistance (at 1000C it takes 1-2 hours to cancel). When contaminating food, they do not change the blood, the taste of the food is difficult to detect and cause disease.


People who suffer from Pharyngitis, sinusitis, pus foci on the skin (acne, boils, etc.) due to staph.

Livestock: Cow, goat, etc., have mastitis, which pollutes the milk when milking.


It is the digestive tract through contaminated food. The most susceptible to foods such as Meat, fish, milk, even canned foods, and vegetables with a high concentration of sugar or salt.

Translation properties

Small, sporadic translation. scattered in a group, a family by eating the same contaminated food.


Staphylococcus after being contaminated with food for 4-5 hours has produced exotoxins. This foreign toxin, when entering the stomach, the intestines are not destroyed by digestive enzymes, they quickly penetrate the gastric mucosa, the intestines and blood impact on the nervous and vegetative systems to strengthen the parasympathetic system, causing an increase in stomach contractility. thicken - intestinal leads to abdominal pain, vomiting, diarrhoea and possibly heart failure.

Clinical symptoms

Incubation: Short, from 30 minutes to 6 hours, average 2 - 4 hours.

Onset: Sudden and goes into full-blown immediately

Full-onset: Sudden onset of illness with symptoms:

Severe abdominal pain, more severe pain in the epigastric region than the navel.

Nausea and vomiting are frequent, usually early, before diarrhoea occurs.

Fluid vomiting: Usually occurs after vomiting. But up to 50% of cases do not have diarrhoea.

No fever or mild fever.

Headache, fatigue, sweating.

The risk of severe dehydration can lead to heart failure.

Progression: Progressive disease usually fusses, but recovers quickly. Only death is found in young children, the elderly, weakened due to severe electrolyte dehydration.

Implementing the quadrants

Clinical manifestations: Short illness, severe abdominal pain in the epigastric region, nausea and vomiting a lot, little diarrhoea, sometimes no loose diarrhoea. Green skin and mucous membranes are sticky with cold sweat without fever, progressing quickly, ending neatly.

Epidemiology: Eating food suspected of having been contaminated by staph

Laboratory tests: Found staphylococcal enterotoxins and staphylococci in leftovers, in gastric lavage.

Differential diagnosis

Surgical abdomen (gastric perforation, acute appendicitis, acute cholangitis ...)

Poisoning chemicals sprayed on vegetables.

Contamination of food by Salmonella.



There is no specific treatment.

Adequate water and electrolyte supplementation are important (drinking, infusion).

Cardiovascular support.


Do not let people with sinusitis and rhinitis work in food processing and cooking.

Take good care of processed foods.

Food poisoning caused by Clostridium Perfringens

Clostridium perfringens are Gram (+) bacilli, anaerobic, with spores, divided into 6 types: A, B, C, D, E, F. Causes human disease, most commonly A, F, C. Foreign Alpha toxin of strain A and exotoxin beta of strain F cause damage to the mucosa and disturb the absorption function of the intestine, damage to the vessels of the viscera.

Clostridium perfringens is abundant in soil, human and animal faeces, living symbiosis in the intestine. When food is contaminated: Meat and fish are covered with soil and faeces that are not thoroughly cooked, can not ensure sterility, causing illness for people under 2 main clinical conditions:

Food poisoning is similar to that of staphylococcal poisoning (sometimes stool like rice water, like cholera) is often caused by strains A, F.

Necrotic hemorrhagic rectal inflammation: Severe abdominal pain, bloating, repeated defecation, whole blood stools, severe intoxication, confirmed by isolating the pathogen, detecting toxins from suspected food, samples (vomit, gastric lavage, feces, blood) are usually caused by strains C and F.

Treatment: Symptomatic treatment is mainly used as in the treatment of staphylococcal food poisoning. For sepsis, an antibiotic of Imidazole (flagyl), chloramphenicol (or a Betalactam group) is used in combination with a substance that inhibits the Beta-lactamase enzyme such as augmentin, unasyl.

Canned meat poisoning infection caused by Clostridium botulinum

Canned meat poisoning infection caused by Clostridium botilinum is a disease often manifested by severe fever due to using canned foods (meat, fish ...) and cold foods contaminated with the exotoxin of Clostridium botulinum. The clinical features are: Acute gastrointestinal syndrome, dilated pupils, dry mouth, loss of reflexes and polio.


Cl. botulinum is a Gram (+) bacillus, anaerobic, and spore-forming. The spores are abundant in the soil and are highly resistant. There are 7 strains (A, B, C, D, E, F, G). Strains A, B, D, E often cause disease in humans. Foreign toxin Cl. botulinum has a very strong virulence and is not stable with the temperature at 1000C for 10 minutes, then destroyed


Symptoms of the disease are caused by exotoxins of Cl. Botulinum affects and damages the parasympathetic nervous system and motor neurons in the brain, spinal cord, causing symptoms of paralysis and decreased secretion.


Incubation from 5 hours - 5 days.

The clinical picture varied depending on the virulence of the strain and the amount of toxin ingested.

Onset with gastrointestinal signs such as nausea, abdominal pain, diarrhoea.

Full development: With paralysis symptoms characterized by symmetrical paralysis of both sides in coordination with gland secretion disorders such as:

Reducing secretion of tears, reducing salivation leading to difficulty speaking, difficulty swallowing, dry mouth - loss of oesophagal atony.

Blurred vision, double vision, dilated pupils  

Bloating, constipation.

Tired, weak, dry skin.

Paralysis of peripheral muscles.

When there is a paralysis of the respiratory muscles, the disease is very serious and easy to die. Meanwhile the patient was awake, had no fever, had no meningeal syndrome.


Diagnosis is mainly based on the clinical mode. Tests showed late results.

Differential diagnosis with myasthenia gravis, polio, viral and streptococcal pharyngitis, intestinal obstruction.


Gastric lavage, intestinal enema to eliminate residual toxins.

Use mixed botulin antitoxin serum A, B, D, E intramuscularly or subcutaneously.

Antibiotics to prevent superinfection. Add water, electrolytes.

Open the trachea, control breathing if there is a paralysis of the respiratory muscles.

Eat through the sonde if there is a swallowing disorder.

Vitamins of groups B, C.

The death rate is still high.


Do not eat damaged canned food (punctures, blisters ...), do not use cold food that is suspected of contamination ...

Food poisoning due to other causes

In addition to the above common causes, there are also some food poisoning infections due to: Bacillies cereus, E.coli enterotoxinogen, Vibrio parahaemolyticus, Aeromonas hydrophila.