Causes and agents of food poisoning

The main causes of food poisoning are the unreasonable use of products contaminated with bacteria or containing toxins, as well as non-compliance with food handling standards and personal hygiene rules. If we summarize the great number of factors that provoke food intoxication or toxic infection, we will get just a few words: 

• Mud.
• Poisons.
• Incorrect storage.

Most often in the infestation one way or another the person is guilty: either he is unreasonable about his nutrition and absorbs the questionable origin of food, or is a hidden carrier of foodborne infection and infects a lot of people around. Much less often the causative agent of the toxic infection are animals and insects that are able to tolerate the infection. For example, if a cow is sick with purulent mastitis, its milk will be infected.

If the milk is not subjected to boiling or other treatment (pasteurization), the probability of food poisoning by dairy products increases by half.

Let's list the typical causes of food poisoning: 

1. Homo sapiens, who does not follow the rules of personal hygiene and starts cooking. Sadly, this banal reason is a factor that provokes more than 60% of all food problems.
2. Meat, fish, milk, not thermally processed. A crude product is considered potentially dangerous in the sense of foodborne disease. 
3. Bacteria contaminated water, as well as crustaceans, seafood, which, like a sponge, absorb all the harmful elements of the water element. 
4. Pets, insects that have contact with food or cutlery. 
5. Untreated, unwashed vegetables, fruits, greens. They are often inseminated by bacteria in the soil.

Also, the following factors contribute to the infection:

• Favorable for germs temperature. Perfect for reproduction of bacteria is the temperature corresponding to the normal temperature of the human body, that is 36.5-37 degrees. However, microorganisms are able to divide and under more severe conditions, the temperature boundaries from +10 to 65 degrees are quite satisfactory. 
• Humidity is what helps to multiply bacteria. 
• The time factor is one of the most important. For any division, reproduction takes time, not one bacterium in the world is able to double instantly. If between the preparation of food and its absorption takes one or two hours, this is quite enough for the reproduction of microorganisms. Food should be stored in the refrigerator or immediately served on the table.

[1], [2], [3], [4], [5], [6]

The causative agents of food poisoning

Most often the disease is provoked by a bacterial cause. The most "famous" of all the huge amount of harmful microorganisms are staphylococcus, E. Coli and Salmonella. The second step in the ranking is taken by the simplest, amoeba, parasites and viruses, toxins (poisons) of plant origin, except for the autumn "mushroom" period, are much less likely to cause food poisoning. It is necessary to distinguish pathogenic microorganisms provoking food infections and the concept - causative agents of food poisoning. Bacteria that are the culprits of toxic infections can not divide and multiply in the digestive tract. The process of reproduction (insemination) occurs directly on the food product.

We list the main, often detected pathogens: 

1. Proteus vulgaris is a proteus, a stick belonging to a large family of Enterobacteriaceae. The bacterium is extremely mobile, multiplies on the product at room temperature in the open air, in the human body secretes intestinal poisons (enterotoxins). 
2. Staphylococcus aureus - Staphylococcus aureus, which in the body (in the intestine) secretes a strong toxin. Staphylococcus aureus is very common, and it can be found everywhere. Especially favorable as conditions for its reproduction are food products - milk, meat. 
3. Clostridia of various species. Especially dangerous is the appearance of Clostridium perfringens, which occurs in soil (earth), feces of animals and humans. The toxin secreted by clostridia is aggressive and rapidly penetrates into the bloodstream, affecting the kidneys, liver, and vessel walls. The disease is characterized by frequent lethal outcomes as a result of anaerobic sepsis. 
4. Clostridium botulinum - botulinum toxin, provoking acute symptoms, severe course of the disease with a rather large percentage of deaths. The causative agent is an anaerobic rod, that is, one that multiplies only without access to air (preservation, hermetic packages). 
5. Bacillus cereus - tsereus, Gram-positive microorganism of the genus Bacillus. Symptoms of infection with cereus resemble the acute symptoms of the disease caused by clostridia. The bacterium produces two dangerous toxins that produce strong vomiting and indomitable diarrhea. 
6. Klebsiella is a klebsiella, a bacterium that can survive for many months in the soil, household dust. In the human body, the microorganism gets through dirty hands, unwashed vegetables, berries, fruits, through water. Klebsiella belongs to the category of conditionally pathogenic microorganisms, as it is normally present in certain quantities in the human intestinal microflora. 
7. Enterococcus - enterococci is a subspecies of lactobacilli of streptococcal genus. Enterococci reproduce in virtually any moist, warm environment. This is also a conditionally pathogenic microorganism living in the human body. Mass insemination of food products Enterococcus can cause food poisoning.

Almost all agents of food poisoning are extremely tenacious and resistant to temperature effects. The main factor contributing to the transmission of pathogens is the insufficiently careful processing of food products, their improper preparation or improper storage. Susceptibility to all pathogens of the disease is very high, according to statistics, 85-90% of people who have tasted the contaminated (contaminated) product fall ill.

Staphylococcal food poisoning

There are certain types of pathogenic staphylococci that produce a strong enterotoxin, trapped in the digestive tract through foods. Staphylococcal food poisoning are variants of infection with one of six bacterial serotypes. Serotypes are distributed in letters of the alphabet, respectively, are allocated A, B, C, D, E, F subspecies. These types of staphylococcus belong to Staphylococcus aureus, since they form a characteristic golden pigment.

Staphylococcal bacteria are very resistant to any conditions and are able to survive in frozen even foods for half a year. Staphylococcus is not afraid of acidic environment, high temperature, alkalis. In order to neutralize the infection, you need a long process of boiling or roasting at a temperature of at least 75-80 degrees. The favorite breeding medium for Staphylococcus aureus is milk and all dairy products, it is the milk that most often becomes the source of the toxic infection caused by the staphylococcal bacterium. Microorganisms can multiply at a temperature of 16-18 to 37-40 degrees, insemination of a dairy product is often enough 4-5 hours. The enterotoxin is produced, as a rule, in products made from unboiled or unpasteurized milk. The source of infection is fresh cheese, cheese mass, sour cream, cheeses made with rennet enzyme. Also, all sweet confectionery products with a creamy layer, especially with a custard on milk, are dangerous. Sugar, moist milk environment, starch are favorable conditions for the life of staphylococcus.

Less often staphylococcus inseminates meat and meat products. It infects sick animals with a weakened immune system or multiplies on meat foods stored in inappropriate conditions.

Organoleptic properties of milk, meat or vegetable dishes, inseminated with staphylococcus, do not change, so the taste and smell of food is absolutely not different from healthy, uninfected. The main culprit, due to which staphylococcal food poisoning comes, is the human factor, that is, the person who cooks, stores, or in any way contacts with food. Also, the source of infection can be a sick animal, for example, a cow with mastitis or diseases of internal organs. In such cases, the seeds are inseminated, possibly contaminating the meat of a slaughtered animal.

Food poisoning of unknown etiology

Diseases of unknown, unclear etiology in modern clinical practice - a rare phenomenon. However, food poisonings of unknown etiology are still encountered, which could have been more thoroughly studied if it were not for the constant seasonal mass infection of already known pathogens. To foodborne illnesses with an unclear reason are: 

1. Disease of Kashin-Bek (Level disease). The disease has a clear territorial location - Priamurye and the Transbaikal zone. Single cases were diagnosed in China, in the central part of Russia. The disease was first described by Kashin at the end of the 19th century, his findings were confirmed decades later, when in the valley of the small river Eve Dr. Beck treated a whole settlement suffering from degenerative changes in the bone system. Most often, the level of the disease affects children and adolescents aged 5-6 to 14-16 years. Obviously, in the period of rapid formation of the bone system and the restructuring of the body due to a lack of calcium in food in children, the spine and limbs are deformed. Also one of the causes of the disease, according to modern microbiologists, may be an imbalance in the content of trace elements in local water sources (an overabundance of silver, magnesium and a lack of selenium). 
2. Haff disease, Yuksovskaya or Sartlan disease or paroxysmal-toxic myoglobinuria (ATPM). Judging by the variety of name variants, the disease has not yet been fully studied. The disease is also clearly localized in the territorial epidemiological picture and is found most often in the coastal zones of the lakes of Western Siberia, the Urals, in some water areas of St. Petersburg, the Baltic countries and Ukraine. Symptoms of Gaffian disease are characterized by sudden, paroxysmal pains in the muscles. The pain is so intense that it leads to a person being temporarily immobilized. Attacks can last up to 4-5 days and cause asphyxia as a result of paralysis of the diaphragm and intercostal muscles. The source of infection is the fish, which in turn becomes toxic due to pollution of the aquatic environment, due to the growth of a poisonous plant - ergot in the area of water bodies, and also because of water contamination with toxins of blue-green and brown algae. 
3. Sigwatera is a toxicoinfection that occurs in peoples living on the coasts of the Indian, Pacific, Central American countries. Toxin produces about 300 varieties of marine and oceanic inhabitants consumed as food. People can poison themselves with octopus, marlin, tuna, mackerel. According to one version, fish accumulate toxin (ichthyosarcotoxin) because they feed on poisonous small organisms. Sigwatera flows extremely hard, causing itching, which is similar to allergic, then the persistent numbness of the tongue and lips is formed. Vomiting and diarrhea, photosensitivity, rash are possible, but the danger is paralysis of the respiratory system. Mortality is 7-10% of the total number of diseases, recovering the victims is difficult and long.

[7], [8], [9], [10], [11]

Types of food poisoning

Food poisoning in clinical practice is divided into the following types: 

1. microbial diseases.
2. food poisoning of non-microbial etiology.
3. food poisoning of unclear etiology.

The table below shows clearly the specific distribution of food poisoning and the main causes that provoke them.

View, group	Subgroup	The main factor, the reason
Microbial food poisoning	Toxicinfections	1. Saprophytes, Tsitrobakter, Seriation, Klebsiella - E. Coli. 2. Cereus, Proteus, Enterococcus, Klebsiella Perfringence, Paragemolytic Vibrio
	Types of toxicosis:
	1.Bacteriotoxicosis	Staphylococcus aureus, botulinum bacillus, emetic form of the ceresius
	2. Mycotoxicosis	Fusariums, ergot, microfungi
Food poisoning of non-microbial etiology	Plants that are poisonous in nature	Wild flowers, berries, herbs, mushrooms
	Components of the product, parts of the product that are toxic	Milk, caviar of some fish species
	Products that have become toxic due to storage conditions	Bones of cherries, apricots, almonds, potatoes lying in the sun, sprouted potato tubers, raw fresh beans (white), beech nuts. Fish eggs stored in inadequate conditions

Types of toxic infections are important not only for accurate diagnosis and study of the disease, but also for the choice of effective therapy, which often affects the life of the victim (poisoning with mushrooms, caviar).

Microbial food poisoning

Food poisoning of microbial etiology is almost 95% of the total number of toxic infections, these diseases can occur in different forms and are divided into: 

1. Food poisoning.
2. Food intoxication (toxicosis).
3. Products contaminated with bacteria are the main source of infection, but a person is considered the main person responsible for the disease.

Microbial food poisoning is a toxicoinfection. These are the most common diseases that begin at one time and are associated with the use of the same dish, the product by many people. Food poisoning begins and flows very sharply, but also passes quickly. Such pathogens provoke the following: 

• Proteus.
• Cereus.
• Sticks of clostridium perfringens.
• Paragemolytic vibrio.
• Tsitrobakter.
• Enterobacter.

Toxic infections most often appear in the warm season and are associated with food that has not been properly heat treated. The main sources of the disease are dairy products, second dishes (salads, mashed potatoes), minced meat (meat, fish). These diseases rarely last more than 5 days and have a favorable prognosis. An exception is a toxicoinfection triggered by a rod of clostridium, which can cause necrotic enteritis. 

Microbial food poisoning - toxicosis. These are diseases that arise from eating food that contains toxins from bacteria. The causative agents of food toxicosis can be: 

1. Staphylococcus aureus.
2. A rod of botulinum toxin.
3. Fungi are fusarium, Penicillium, Aspergillus (mycotoxicosis).

Bacterial food poisoning

Poisoning by food, inseminated by bacteria is a food poisoning (PTI). Most often, the disease is caused by toxins, which produce such pathogens:

1. Staphylococcus aureus - Staphylococcus aureus, which produces a toxin that affects the human digestive tract. Staphylococcus is very resistant to environmental changes and is able to survive even at low temperatures. Food is the ideal environment for Staphylococcus aureus, especially if there is a proper level of humidity and heat. Any cooked dish that is not consumed immediately, but left on the table, is a potentially dangerous source of infection with staphylococcus. Especially it concerns dairy products, confectionery products with a custard, dishes, dressed with mayonnaise (salads). 
2. Cereus - Bacillus cereus "loves" all dishes from rice, and can also be in dry rice. If pilaf or rice porridge is on the table for 2-3 hours, the bacterium may well start to produce toxin. Cereus is very resistant to high temperatures, even prolonged boiling, including repeated, does not always kill Bacillus cereus. 
3. The most dangerous clostridia are Clostridium perfringens, which according to statistics in 2% of cases end with necrosis of intestinal walls. The source of infection can be meat dishes that have not been properly heat treated, dishes from beans, poultry. In an easy form, infection with clostridia is quite rapid.

Bacterial food poisoning is the most frequently diagnosed disease, it is fairly well studied by the medical world, but a large number of people continue to be affected. Most likely, this is due to the lack of awareness of the population about the dangers of toxic infections and the failure to comply with basic sanitary standards and personal hygiene rules.

[12], [13], [14]

Non-microbial food poisoning

Food poisoning of non-microbial etiology does not occupy more than 10% of the total number of food-related toxic infections.

Classify non-microbial food poisoning in this way: 

1. Poisoning by plants, parts of plants (bones), fungi, that is, food substances that can be poisonous in nature.
2. Poisoning associated with the use of raw fresh beans and certain types of toxic fish.
3. Poisoning by products that are in principle not poisonous, but can become so because of changes in storage conditions and under the influence of physiological factors. This applies to potatoes (solanine), fish that go to spawn.
4. Poisoning by poisonous substances that are part of the kitchen utensils (copper, zinc, lead). This applies to pots, frying pans, plastic dishes.

Non-microbial food poisoning by fungi is associated with the season, in winter they practically do not occur. There is a well-known list of poisonous mushrooms, which includes fly agarics, morels, pale toadstool, false honey agarics and other species. The most dangerous toadstool, it provokes acute poisoning, which ends in 90% with a lethal outcome. Bone fruit can also be poisoned if consumed in food in unlimited quantities. The poison - amygdalin in the human body is transformed into hydrocyanic acid. Raw beans are dangerous with a toxin that can be neutralized by conventional heat treatment. Certain types of fish - pufferfish, marinka, barbel with spawning produce a dangerous for human toxin, contained in caviar and milk. The poisoning with zinc or copper can occur due to violation of the rules for using kitchen utensils.