Salmonellosis– a bacterial infection that affects humans and animals, transmitted by the fecal-oral route (the pathogen is excreted in feces and enters the body through the mouth), usually affecting the stomach and small intestine.
The symptoms of salmonellosis were described by medieval doctors. In 1885, the causative agent of “swine fever” was discovered by scientist D. Salmon. And in 1888, after comparing microbes isolated from the body of a person who died of illness and from the meat of a cow, scientist A. Gertner discovered that they were the same bacterium. By 1934, several types of similar microorganisms were already known. They were combined into one group and called salmonella.
Salmonellosis can develop either in isolated cases or in outbreaks. Cases of the disease are recorded throughout the year, most often in the summer due to faster spoilage of food products.
Salmonella – the causative agent of salmonellosis
Features of the pathogen:- Salmonella are bacteria in the form of rods 2–4 microns long and 0.5 microns in diameter.
- They have flagella and are therefore mobile.
- Anaerobes - oxygen-free conditions are favorable for their life and reproduction.
- They can be easily grown in the laboratory on regular nutrient media.
- The bacteria can live outside the human body for 120 days. They remain viable in excrement for 80 days to 4 years.
- Salmonella can multiply and accumulate in milk and meat.
- They tolerate low temperatures well.
- At high temperatures they die quickly.
Is it necessary to treat salmonellosis in a hospital?
If the disease is mild, treatment can be carried out at home as prescribed and under the supervision of an infectious disease specialist.In severe forms, hospitalization is mandatory.
Treatment of forms of salmonellosis that affect only the stomach and intestines
| Name of drug/method | Description | Mode of application |
| Antibiotics | Antibacterial drugs are ineffective for these forms of the disease. On the contrary, they contribute to prolongation of treatment time and the formation of dysbiosis. | |
| Gastric lavage | Ideally, it should be carried out when the first symptoms appear. Purpose of the procedure:
|  Gastric lavage must be carried out using a rubber catheter and a special container (Esmarch mug). Some patients take large amounts of water on their own and artificially induce vomiting. This is incorrect, since with repeated vomiting there is a risk of rupture of the gastric mucosa at the junction with the esophagus. For rinsing, use 2 - 3 liters of 2% soda solution (temperature - 18 - 20⁰C). If the disease is mild, then other than washing, no other treatment is required. |
Solutions:
| The patient must drink these solutions to replenish lost fluids and salts. Effects:
|  The amount of solution and the frequency of its administration are determined by the doctor depending on the patient’s condition and the severity of the disease. Usual doses:
|
Solutions:
| Solutions are intended for intravenous administration. Effects:
| The volume of the solution and the mode of administration are chosen by the doctor depending on the patient’s condition, the severity of the disease, and the degree of dehydration. Administration is carried out intravenously through a dropper. When the patient's condition returns to normal and he can drink enough fluids, intravenous drugs are discontinued. |
Drugs that normalize digestion:
| These drugs are enzymes. They improve digestion and absorption of food. | Methods of application:
|
Drugs that bind and remove toxins from the intestines:
| These drugs bind toxins that are released by salmonella, neutralize and remove them. | Directions for use (both drugs are available in powder form in sachets): Smecta:
Enterodes: Dilute at a rate of 2.5 g of powder per 50 ml of water. Doses:
|
Treatment of generalized forms of salmonellosis
When salmonellosis occurs in a typhus-like or septic form, the same therapy is carried out as for separate lesions of the stomach and intestines. To it are added funds aimed directly at combating salmonella.Until 5 months of pregnancy, a woman should be treated only in a hospital.
Traditional methods of treating salmonellosis
Chamomile and calendula infusion
Effects of calendula and chamomile:- antiseptic;
- cleansing the body;
- anti-inflammatory.
- take 1 teaspoon of a mixture of dried calendula and chamomile flowers;
- pour 1 cup boiling water;
- leave for 4 hours.
Take half a glass of infusion 2 – 3 times a day.
Plantain infusion
Effects of plantain:- anti-inflammatory;
- promotes accelerated recovery of affected tissues.
- dry plantain leaves;
- grind;
- pour 1 cup boiling water;
- leave for 10 minutes.
Drink a glass in small sips over an hour.
Infusion of wild strawberry leaves
Effects:Wild strawberry leaves have an anti-inflammatory and antiseptic effect.
Cooking method:
- take a teaspoon of crushed dry wild strawberry leaves;
- pour a glass of cold boiled water;
- leave for 6 – 8 hours.
Take the infusion half a glass, no more than 4 times a day.
This information is for informational purposes only. Traditional methods cannot replace full-fledged drug treatment of salmonellosis. Herbal remedies may cause allergic reactions. Before use, be sure to consult with your doctor. Self-medication can lead to negative consequences
.
Galina Kiryakova, head of the intensive care unit of the Tom Chorbe Infectious Diseases Hospital, told how dangerous bacteria get into food, what consequences their consumption can lead to, how to distinguish them from ordinary ones and protect yourself.
The products in which specialists from the National Food Safety Agency (NAFS) found salmonella and coliform bacteria could have gotten there due to a violation of the technological process of their production, Galina Kiryakova, head of the intensive care unit of the Tom Chorbe Infectious Diseases Hospital, told a Sputnik correspondent.
NAPB on Tuesday published the results of laboratory tests of domestically produced food products for August of this year. Thus, experts found salmonella, coliform bacteria and anaerobic organisms in khinkali and dumplings stuffed with beef and pork. Similar bacteria were found in sheep cheese, cottage cheese and pasteurized milk produced in Moldova and Romania. Nitrates were detected in domestic eggplants and dill, and a number of microorganisms were detected in tomatoes.
How did bacteria get into the food?
The specialist claims that this kind of bacteria can appear in products in two cases - either if storage conditions are violated, or if the technological process is violated. “The presence of these bacteria in pasteurized milk is surprising, since the whole idea of such milk is that it is sterile, which means that this flora is completely absent. This means that there was a violation of the very process of its preparation. The factor of storage conditions is excluded here, since pasteurization implies the presence of protected dishes,” the doctor emphasized. According to Kiryakova, the presence of salmonella in dumplings is understandable due to the presence of meat there. The doctor claims that poultry meat is especially dangerous from this point of view, since chickens and ducks are carriers of salmonella.
“This is understandable, the meat in the dumplings is not yet boiled, that is, not thermally processed. If cooked correctly - 15 minutes of boiling - these dumplings do not pose a danger,” Kiryakova said.
Infection with feta cheese bacteria, according to the expert, could have occurred under various circumstances. “This could happen either during the preparation process, or during transportation, during slicing or packaging. In this case, the human factor is very important. Failure to observe personal hygiene rules by those involved in the preparation process, as well as with dumplings, can lead to infection.” “, the doctor emphasized.
What will be the consequences of eating contaminated products?
The specialist warns that the health of a person who eats dumplings with salmonella or dairy products with coliform bacteria will be seriously affected. “Consumption of such foods can lead to intestinal diseases. With salmonella, the course of the disease is quite complex; coliform bacteria are a little easier to tolerate, but they are dangerous for children. The younger the children, the more difficult it is for them to tolerate this disease,” Kiryakova said.
According to her, the human body itself is not able to cope with such food poisoning, so medical intervention is required.
You should contact a specialist after the first symptoms of the disease appear. As with any intestinal infection, the specialist emphasized, this is a general weakness. With salmonellosis there is always fever, vomiting and diarrhea. The latter can manifest themselves together or separately, but an increase in temperature during such poisoning is always recorded.
How to distinguish contaminated products and what to do with them?
Visually, products with such bacteria, as the specialist said, cannot be distinguished from normal ones, since they all look beautiful. But there are still a number of signs by which you can identify products that you should not buy. “You don’t need to be irresponsible. Even if something has already been purchased, but this product does not smell or look very good, it should be thrown away and not used for food. It is better not to skimp on your health. Another thing is that now stores are going to a lot tricks, including well-packaging goods whose freshness cannot be determined visually or by smell,” Kiryakova said.
According to the doctor, the situation with coliform bacteria discovered by NAPB specialists in feta cheese is different, since feta cheese cannot be subjected to heat treatment.
“If it remains in a saline solution for a long time, then such bacteria will die over time. But it must be a highly concentrated solution. As for feta cheese, there is no other way to get rid of coliform bacteria,” Kiryakova emphasized.
The most dangerous are chicken eggs
Bacteria that can cause poisoning and intestinal diseases can appear in various products, but the most unsafe ones are those where it is simply impossible to check for the presence of bacteria. “The most dangerous thing is everything that is cooked with eggs, because it is impossible to check them. There are no visible signs that salmonella may be there. It is in this environment (eggs) that it reproduces very well. Duck eggs are a 100% breeding ground, chicken eggs are not. always," Kiryakova said. Therefore, according to her, you need to carefully approach the issue of preparing certain products and dishes. “It is important to thermally treat any of the products, where possible. Then everything will be fine,” the doctor concluded.
Salmonellosis is an infectious disease that primarily affects the gastrointestinal tract. The causative agent of salmonellosis is bacteria of the genus Salmonella. Salmonellosis is characterized by a severe course, and the risk of contracting the disease is quite high, so anyone should know how this disease manifests itself and how to avoid it.
Salmonellosis - what is it?
Salmonellosis is predominantly a zoonotic disease. This is the name for diseases transmitted to humans from animals or from products obtained from animals. Thus, the source of infection can be both live animals (dogs, cats, cows, pigs, wild and domestic birds, fish) and animal products - meat, milk, eggs.
Bacteria of the genus Salmonella are classified as gram-negative. They are highly resistant to adverse influences. Bacteria can live for weeks or months in water, on the surfaces of objects, and in the meat and milk of animals at room temperature. They can also withstand significant (down to -80ºС) temperature drops. Boiling and heating to +100ºС quickly kills microorganisms, but in water with temperatures up to +70ºС they can live for several tens of minutes.
Photo: LightField Studios/Shutterstock.com
Neither salting nor canning kills these bacteria. Their only Achilles heel is the impact of disinfectants - most of them quickly kill salmonellosis bacilli. Salmonella bacteria are also highly resistant to most antibiotics.
Mechanism of disease development
Infection usually occurs after contact with infected animals or after eating food containing salmonella. Infection by airborne droplets, water, and everyday objects is also possible. The source of infection may also be other people who are carriers of salmonellosis bacilli.
Not every time bacteria enters the body through the mouth, illness occurs. First, the bacteria enter the human stomach, which contains gastric juice. Salmonella is sensitive to acidic conditions, so gastric juice containing hydrochloric acid can kill some of the bacteria. Therefore, people who have problems with the secretion of gastric juice are most sensitive to bacteria.
If the gastric barrier has been successfully passed, then bacteria colonize the intestines and begin their destructive activities. They can attach well to the intestinal mucosa and penetrate into superficial tissues. In this case, bacteria can release various toxins that poison the body and cause malaise, vomiting and diarrhea. Dying salmonella also release dangerous toxins.
Salmonella is also very good at evading the body's defenses. Having detected an invasion, the immune system sends special cells - macrophages - towards the pathogens. However, salmonella have learned to use these cells to their advantage. Being absorbed by macrophages, some Salmonella do not die, but move along with them through the bloodstream and thus move to other tissues of the body. Thus, salmonella can affect not only the intestines, but also the liver, kidneys, heart and even the meninges. This feature of the causative agents of salmonellosis is the reason that the disease can lead to severe complications and extend far beyond the gastrointestinal tract.
Anyone can get salmonellosis, regardless of age and gender. However, young children and the elderly are most susceptible to it due to their weakened immune systems. In addition, their disease is more severe.
The disease has a clear seasonal dependence. During the warm season, there is a peak in diseases. However, you can become infected with salmonellosis in any season.
Symptoms of salmonellosis
There are two main variants of the disease - gastrointestinal and generalized. The second, in turn, is divided into typhoid and septic. The gastrointestinal variant is the mildest, and the septic variant is the most severe, with the highest probability of death.
Gastrointestinal form
Typical symptoms for this form of the disease:
- Heat,
- Loose stools with characteristic discharge,
- Abdominal pain
- Nausea,
- Vomit.
This form generally does not extend beyond the gastrointestinal tract. The incubation period of the disease is short. Usually it lasts from 3 to 72 hours. After this, the patient’s temperature rises, stool disorders, nausea and vomiting begin.
Characterized by acute pain in the abdomen, most often in the upper part, in the navel area. Symptoms of salmonellosis also include a very high temperature, which can rise up to + 40 ºC. Stools are frequent - up to 10 times per day and can lead to dehydration. The stool is usually watery and foamy, contains green mucous clumps, and has an unpleasant odor. Bloody discharge may appear a little later, on the third day.
In addition, the patient may experience a drop in pressure, tachycardia, and changes in heart sounds. This form usually lasts no more than a week.
The gastric form is a type of gastrointestinal form. Usually the disease is milder, no diarrhea is observed, only vomiting, pain is localized in the epigastric region. This form is quite rare.
Typhoid form
With typhoid salmonellosis, the symptoms initially resemble those of the gastrointestinal form - vomiting, diarrhea, high fever. However, then the disease takes on features that make it similar to typhus. A rash appears on the skin, many organs increase in size - the spleen, liver. This form is more severe and lasts longer - in some cases more than a month.
Septic form
In most cases, it is typical for people with weakened immune systems, the elderly, and young children. In the septic form of salmonellosis, symptoms are not limited to fever and signs of general intoxication. It is also characterized by infectious processes in various organs, primarily in the lungs, kidneys, and bladder. Damage to the endocardium and meninges may be observed.
Septic salmonellosis is more characterized by life-threatening complications such as pulmonary and cerebral edema, renal and heart failure. With this form of salmonellosis, treatment is extremely complicated.
Diagnostics
Not all symptoms, including diarrhea and fever, mean salmonellosis. Salmonellosis, especially at an early stage, is not always easy to separate from other infectious diseases of the gastrointestinal tract, for example, rotavirus infection, dysentery. Therefore, to determine the pathogen, an analysis of the patient’s stool is necessary. In generalized forms, pathogens can also be detected in the blood. An analysis of the actions that could lead to infection also plays an important role in diagnosis.
How to treat salmonellosis
Only a doctor can decide how to treat the disease. In most cases of salmonellosis, treatment is carried out in a hospital. In case of mild forms of the disease, treatment can be carried out at home. However, this is rather an exception, since salmonellosis is an insidious disease, and its seemingly mild course can give way to an exacerbation at any time.
For mild salmonellosis, treatment is mainly symptomatic. If a person has gastrointestinal salmonellosis, then the main attention is paid to rehydrating the body, that is, restoring lost fluid. For this purpose, water-salt solutions are used. Also, in the first days of the disease, gastric and intestinal lavages are regularly done, sorbents are used that absorb bacteria and their toxins, and deintoxication therapy is carried out using colloidal solutions. To restore digestive functions, enzyme preparations (pancreatin, dry bile) are used.
In addition, it is necessary to take medications - probiotics, which restore normal intestinal microflora.
The patient should drink as much fluid as possible. A starvation diet is not indicated; instead, a gentle diet should be used - boiled dishes, low-fat soups, cereals. It is not recommended to take antidiarrheal drugs, such as Loperamide, as they slow down the removal of toxins from the body and can lead to severe intoxication.
Antibiotics are rarely used for mild forms of salmonellosis. This is due to the fact that salmonella are highly resistant to most antibacterial drugs and because antibiotics can aggravate intoxication. However, for severe salmonellosis, treatment may include antibiotics. Antibiotics are also used in cases where other forms of therapy show low effectiveness. Fluoroquinolones are most often used in the treatment of salmonellosis, but only a doctor can prescribe a specific type of antibiotic. There are also special preparations containing bacteriophage viruses that are active against salmonella.
There is no vaccination against salmonellosis. This is due to the fact that there are a huge number of varieties of bacteria that can cause salmonellosis—several hundred—and in this case it is impossible to develop a universal vaccine. In addition, immunity to salmonellosis in humans is usually unstable and disappears after about a year.
After recovery, there is a recovery period that may take several months. This will help avoid the negative consequences of salmonellosis.
Recovered patients, however, can carry salmonella in their bodies for a long time and can be dangerous to others due to the possibility of infecting them. Also, the consequences of salmonellosis include dysbiosis, which can be treated with probiotic drugs.
Prevention
Prevention of the disease is, in principle, similar to the prevention of other infections and diseases of the gastrointestinal tract, but it also has some peculiarities. They are due to the fact that the main source of infection is animals and poorly processed products obtained from animals. Thus, in order to protect yourself from salmonellosis, you must follow simple rules - do not eat raw, poorly fried or cooked meat, fish or eggs. It should be remembered that salmonella does not die even after prolonged cooking, for several hours, if the thickness of the meat is more than 15 cm. Thus, before cooking meat, poultry and fish, they should be cut into as small slices as possible.
Particular attention should be paid to eggs. Poultry is the most common carrier of salmonella. Therefore, you should avoid eating raw eggs and cook them for as long as possible - at least 6 minutes. It is also necessary to pay attention to the surface of the eggs themselves, since they may contain particles of bird droppings. Therefore, after handling the eggs, hands must be washed thoroughly with soap.
True, there is an exception - quail eggs are extremely rarely affected by salmonella, so they can even be eaten raw. However, they should also be washed before use.
You should also pay attention to the cutting procedure for raw meat. Some housewives may use the same knife and cutting board to cut raw meat, poultry and fish and cut foods eaten raw. This should not be done - for these purposes you should use various devices. It is best to wash meat boards and knives after use. You should also not consume raw milk - only boiled or pasteurized milk.
However, salmonella can also live in products that seem to have nothing to do with animals, for example, in confectionery products. This is explained by the fact that contaminated eggs could be used to prepare flour in such products. Therefore, in general, you should make it a rule not to buy questionable food products from street vendors.
The rest of the advice for preventing salmonellosis coincides with standard hygiene rules - wash your hands regularly, especially after visiting the street, contacting animals, do not drink unboiled water, etc. And, of course, strengthen the immune system, treat chronic diseases that can make the body vulnerable to infection.
Salmonella coli is an insidious and very viable bacterium. Having settled in any protein product (eggs, meat and dairy foods), it begins not only to live, but also to actively reproduce in the nutrient medium, especially under favorable temperature conditions (from +6 to +45 degrees). When these products are cut into a salad and dressed with mayonnaise, and then it sits on the holiday table for several hours, an explosion of intestinal infection - salmonellosis - will be inevitable.
Salmonellosis - what is it?
This infectious disease is characterized by serious damage to the nervous system, in severe cases leading to cerebral edema, coma and even death. It develops as a result of severe intoxication of the body by the pathogen - salmonellosis bacteria, accompanied by severe dehydration (dehydration) and disturbance of water-electrolyte balance.
The insidiousness of salmonellosis lies in the fact that neither the appearance nor the smell of products contaminated with salmonella bacilli in any way indicates the danger lurking in them. And the clinical picture of the disease is extremely difficult to differentiate from typhoid or septic manifestations.
Pathogens
The causative agents of salmonellosis infection are intestinal gram-negative motile bacilli of the genus Salmonella, which have several varieties and subspecies.
Most of them are pathogenic for both animals and humans, but out of several thousand serotypes (species groups), not all pose an epidemiological danger to humans.
The most common and cause salmonellosis in adults and children in 85-90% of cases worldwide include:
- Salmonella London;
- S/agona;
- S/newport;
- S/infantis;
- S/panama;
- S/enteritidis;
- S/typhimurium.
The incubation period, regardless of the form and variant of the disease, ranges from several hours to 3 days. The incubation period depends on the form and subtype of salmonellosis. Previously, it was customary to designate its varieties into groups in the diagnosis, but due to their insignificant symptomatic differences, today such clarifications as, for example, “salmonellosis group D” or “group C” are not indicated. Only clinical forms of the disease with the serotype of the detected salmonella are indicated to establish the source of infection.
The impact of salmonellosis on the body
The development of intoxication due to poisoning by products affected by the bacterium occurs according to several schemes, depending on the form of the disease.
Gastroenteric form
It is considered the most common. It is characterized by acute, rapid development, literally within a few hours from the moment of infection. The disease first appears:
- body aches;
- chills, elevated body temperature;
- headache.
Then the following symptoms appear:
- spastic pain localized in the navel and epigastrium;
- nausea, and then repeated vomiting;
- frequent stools, turning into diarrhea with watery, foaming, often greenish stools that emit a specific stench;
- against the background of high body temperature, the skin is pale, sometimes cyanosis (blue discoloration) is observed;
- dry and coated tongue;
- bloating, palpation – pain and intestinal rumbling;
- muffled heart sounds, tachycardia, decreased blood pressure, and, over time, weakening of the pulse;
- decreased urinary function;
- the urge to defecate is always productive.
Severe cases of this form of salmonellosis are accompanied by clonic convulsions (involuntary twitching), usually in the lower extremities.
Gastroenterocolitic form
At first, the symptoms are similar to the gastroenteric form, but by 2-3 days there is usually a decrease in the volume of stool and the appearance of mucus or blood in it. On palpation, the abdomen is spasmodic and painful in the area of the colon. There is an unproductive urge to defecate (tenesmus). The clinical signs are thus similar to those of the dysentery variant of the same name.
Gastritis form
This is one of the rare variants, characterized by an acute onset, repeated vomiting and epigastric pain. Intoxication is mild, no diarrhea is observed, the course of salmonellosis is short-lived, with a favorable prognosis.
Typhoid-like form
- severe weakness;
- insomnia;
- headache;
- wave-like or constant increase in temperature;
- pale skin.
On days 3-5, an outbreak of hepatolienal syndrome (a sharp increase in the size of the liver and spleen) may occur, blood pressure may drop, and the heart rate may decrease (signs of bradycardia). The main features of the clinical picture are very similar to the symptoms of typhoid fever, which makes clinical differentiation of the diagnosis difficult.
Septic form
This form may begin with manifestations of gastroenteritis, alternating with feverish states with chills and profuse sweating, myalgia and tachycardia. Hepatosplenomegaly (enlargement of the liver and spleen) may also develop. This form of the disease is characterized by a complicated clinical picture - the appearance of secondary purulent foci:
- in the kidneys (cystitis, pyelitis);
- in muscles and subcutaneous tissue (phlegmon, abscesses);
- in the heart (endocarditis);
- in the lungs (pneumonia, pleurisy), etc.
In addition, the development of iritis and iridocyclitis (inflammatory eye diseases) is often observed. The septic form is characterized by a long course of the disease.
Typhoid-like and septic forms are generalized forms of salmonellosis.
Pathogenesis
The pathogenesis of the development of the disease in any of its forms is due to the extreme toxicity of the pathogens, or rather, the products of their vital activity. Resistant to gastric microflora, Salmonella bacilli quickly penetrate the mucous membrane of the small intestine and attach to the cell membranes of enterocytes (intestinal epithelial cells). As a result of the active life of salmonella, large amounts of cytotoxins, enterotoxins and endotoxins are released. They provoke pain, diarrhea and other intoxication symptoms, leading to dehydration and catastrophic loss of electrolytes.
A previous infection, as a rule, contributes to the development of immunity in a person, but only to a certain form of the disease.
At-risk groups
- First of all, people with weakened or underdeveloped immunity - the elderly population over 60 years of age and children under 1 year of age. Infection in healthy people occurs when 107 bacterial agents enter the body. And for people with weak immunity or its deficiency (for example, those with AIDS or those weakened by chronic pathologies), this amount may be several times smaller.
- Workers of poultry farms and livestock complexes, as well as people raising pigeons and other domestic animals (taking into account the sources and methods of transmission of salmonellosis).
- Those who do not observe basic rules of personal hygiene, and also often eat processed foods or products from street vendors.
- Lovers of homemade food, but prepared with minimal heat treatment (rare meat, homemade raw smoked sausages, eggnog made from raw eggs).
Products hazardous to contamination
As already mentioned, the best nutrient medium for salmonella is protein foods. Therefore, most often carriers of salmonellosis bacilli are products of animal origin:
- milk and dairy products;
- meat and meat products;
- eggs.
The rod can also be found in plant sources - vegetables and berries, especially if manure or chicken droppings are used as fertilizer when growing them.
The longer the product is stored, the more likely it is that salmonella colonies will appear in it. For example, it is known that after 1 month of storing chicken eggs in the refrigerator, bacteria located on the surface of the shell are able to penetrate inside and, having reached the yolk, form a real cluster in it.
In other environments, Salmonella viability may vary:
|
Habitats |
Salmonella viability |
| Up to 5 months | |
| The soil |
Up to 18 months |
|
Up to 2 months |
|
| Surface of eggshell | |
|
Egg powder |
3-9 months |
| Cheese |
Up to 12 months |
|
Butter |
Up to 4 months |
| Kefir |
Up to 1 month |
| Up to 20 days | |
| Meat |
Up to 6 months |
How can you get infected?
You can become infected with salmonellosis in several ways:
- food route;
- waterway;
- contact and household path.
Food route
As can be seen from the list of main sources of infection, the easiest way to get a deadly infection is through food.
The food route is the most common cause of illness and hospitalization of a large number of victims.
Waterway
A certain number of sticks can also end up in water resources, for example, when, due to damage to sewer lines, feces, including infectious ones, end up in water bodies. Untreated effluent from poultry farms can also become a source of contamination if it enters natural waters.
Contact and household path
Much less frequently, salmonellosis is transmitted through contact and household contact from person to person. This is only possible in case of gross violation of personal hygiene rules:
- if patients infected with salmonella do not wash their hands after visiting the toilet (and carriage of the infection persists for several months);
- if you do not wash your hands after contact with animals that may be carriers of the stick;
- if personal items of patients in the infectious diseases department of the hospital - children's potties, dishes, towels - do not undergo sufficient sanitary treatment.
Preventive measures
Knowing how dangerous salmonellosis is and how it is transmitted, you should try to prevent contracting this infection. Preventive measures should cover not only social and domestic spheres, but also the production conditions of enterprises involved in breeding animals and birds.
Thus, it is necessary:
- Comply with the regime and veterinary and sanitary requirements when slaughtering poultry and livestock, processing carcasses, preparing, transporting and storing meat and fish products.
- To prevent contaminated dust from entering the respiratory tract and onto the corneas of the eyes, poultry farm employees should wear safety glasses and respirators when working.
- At home, observe sanitary and hygienic standards when preparing food - ensure separate processing of raw and cooked meat, wash and wipe the shells of eggs before storing them, do not store them in the refrigerator for too long, subject meat, fish, and eggs to thorough heat treatment.
- Be sure to wash your hands before eating and after contact with animals (including pet turtles, iguanas and other exotic animals).
- Carefully handle utensils and cutting boards used for cutting raw meat. It is known that at temperatures above 70 degrees, salmonella dies in 3-4 minutes, and when boiled - almost instantly.
- Inside large pieces of meat, the boiling temperature may not reach 100 degrees, so you need to observe the cooking time for certain types of meat: pork - at least 2 hours, beef - at least 1.5 hours, poultry - 50-60 minutes.
- Do not store meat salads and other dishes with a combination of cooked and raw foods for a long time.
Considering the danger of infection and what complications of salmonellosis can lie in wait for the carrier of the stick (abscesses, endocarditis, purulent arthritis, peritonitis, appendix and even meningitis), you should not neglect simple hygiene rules and safe food preparation technologies. In this way, you can not only protect yourself from this insidious disease, but also not expose others to the risk of infection.
The causes of salmonellosis are a complex of etiological and pathogenetic factors that lead to infection of a specific person or bacteria carriers with a salmonella infection. The disease affects people of all ages, as well as wild and domestic animals, cattle, and poultry. The entry point for infection is predominantly the mucous membrane of the small intestine. As a result of the pathogen entering the body, an acute infectious process develops in it, which is limited to the gastrointestinal tract or spreads to other tissues and organs.
The causative agent of the disease
Salmonella was first discovered in 1880, during a post-mortem autopsy of a corpse who died of typhoid fever. The microorganism was present in the lymph nodes, spleen and Peyer's patches. In 1884 and 1885, several varieties of pure bacterial culture were isolated, and by the beginning of the 20th century they were combined into a separate genus in the family Enterobacteriaceae. Since the 1930s, Salmonella have been divided according to their antigenic structure into various subspecies.
Microorganisms of the genus Salmonella are gram-negative motile rods. The Salmonella bacterium does not form capsules or spores, and is a facultative anaerobic organism of the opportunistic type. In fact, salmonella have no tropism only for some tissues and organs. In total, there are about 2300 serovars in the genus, which are divided into 46 serogroups based on somatic O-antigens, and into 2500 serovars based on the structure of the H-antigen. Human cases of salmonellosis are caused by only 10-12 serovars.
The main two species that most often attack humans are S. enterica and S. bongori. They are divided into 7 subspecies: S. enterica (I), salamae (II), arizonae (III), diarizonae (IIIb), houtenae (IV), indica (V) and bongori (VI). This division is of epidemiological importance for the study and prevention of outbreaks, since the first subspecies of Salmonella lives in warm-blooded animals, and the reservoir for all others is cold-blooded animals and the environment. Microorganisms grow on typical nutrient media.
Salmonella has a complex antigenic structure with two types of antigens: flagellar thermolabile H-antigen, surface Vi-antigen, and thermostable somatic O-antigen. Almost all subspecies of Salmonella are pathogenic for humans, birds and animals, but only some representatives of the genus are considered the most significant in terms of the spread of the epidemic. Almost 92% of all cases of salmonella infection are caused by:
- S. typhimurium;
- S. panama;
- S. enteritidis;
- S. newport;
- S. derby;
- S. infantis;
- S. agona;
- S. london.
At the same time, S. enteritidis and S. typhimurium are the most common types of pathogens obtained in bacterial cultures from sick people.
Contagiousness of salmonellosis
Salmonellosis is an infectious disease of a predominantly acute course, which, even in isolated cases of the disease, can cause an epidemic outbreak. The disease is considered contagious, as it develops after the pathogen enters the human body in several ways, including through household contacts. However, the main source of infection, according to infectious disease doctors, is still insufficiently processed or raw eggs consumed as food.
The minimum concentration of microbial cells required to infect a person ranges from 1.5 million to 1.5 billion.
Contagious period
The salmonella bacterium is considered very tenacious, since it is not at all afraid of low temperatures, hibernating during frosts, and can live at temperatures up to 50-60 degrees for a long time. In addition, microorganisms persist for a long time in the environment and food. For example, salmonella lives in meat for 6 months, in frozen carcasses - up to a year. The bacterium persists in water for 5-6 months, about 20 days, for a month, and for 4 months. Salmonella lives on eggshells from 2 to 3 weeks, and in soil - 18-20 months. In addition, during long-term storage of eggs, salmonella, which was initially on the shell, that is, on the outside of the egg, can penetrate inside.
In a piece of meat, salmonella can withstand boiling for some time, and in other products it usually dies at a temperature of 70 degrees in 10-20 minutes. Microorganisms live in household dust and sea water for up to 500 days.
Being in products, microorganisms are able to live and multiply without changing the taste and appearance of the food. Salting, drying and smoking have no effect on salmonella. The bacterium is highly sensitive to conventional disinfectants, including those based on chlorine.
Both people and animals after suffering from salmonellosis continue to release a viable pathogen into the environment. The period of infectiousness, or bacterial carriage, which lasts less than 3 months, is called acute, and if after 3 months or longer bacterial titers are present in the tests, we are talking about chronic bacterial carriage. Salmonella is excreted in feces and urine and may be present in the blood.
Sources and routes of transmission of bacteria
There are several routes of transmission of Salmonella, but the main mechanism of infection is fecal-oral. You can become infected:
- contact and household method;
- water;
- airborne or airborne dust method;
- through food products.
As with other intestinal infections, transmission of salmonellosis through household contact occurs through contaminated household items, towels, toys, pots, playpens, and mothers’ hands. The main reason contributing to such infection is lack of personal hygiene, that is, transmission through the patient’s dirty hands, with which he touches surrounding objects, leaving the pathogen on them. It should be noted that in this case, mass infection usually does not occur; only people with a susceptible organism, small children, and people with weak immunity can get sick. The most typical example of contact and household infection with salmonellosis are nosocomial outbreaks of salmonellosis, which are periodically observed in maternity wards. The fact is that newborn children are particularly sensitive to any microorganisms due to weak immunity.
Infection through water is most often observed in birds and animals, on farms and livestock farms.
The pathogen enters water from the feces of infected people and secretions of sick animals. It should be noted that the bacterium does not reproduce in an aquatic environment, so its concentration in water is rarely significant. Accordingly, cases of infection through water are rare. In addition, the pathogen can enter the body while swimming in an infected body of water if a person has swallowed a large amount of water with microorganisms while swimming or diving.
Is it possible to become infected by airborne droplets?
Competent experts express different points of view on this matter. It is believed that directly in the air, as well as in microparticles of human saliva, the bacterium is not transferred to other carriers, so it is not possible to get an intestinal infection in this way. The possibility of airborne dust spreading of salmonella in urban conditions with the participation of wild birds polluting their habitats and feeding areas with their droppings has been proven.
Is it possible to become infected through sexual contact?
Salmonellosis is an intestinal infection that is not transmitted through sexual contact through semen or vaginal secretions.
Products that cause infection
The main way salmonella enters the body is through the consumption of contaminated food. It is important to understand that if the primary reservoir and source of infection are raw or improperly processed products of animal origin, then when they enter the refrigerator with vegetables, fruits and other food products that are stored in open containers, the pathogen from infected eggs or meat can migrate to any nearby food item. The most rapid reproduction and accumulation of salmonella occurs in protein foods, including meat products.
The bacterium can be contained in, in, and most often people suffer from salmonellosis. Any food prepared from such meat, subject to insufficient heat treatment, becomes a source of infection.
The occurrence of salmonellosis can be associated with the consumption of dairy products, eggs and dishes made from them; less often, the bacterium enters the body with fish products.
The bacterium hardly multiplies in vegetables and fruits, so they can cause illness only in people with weakened immune systems. Heat treatment significantly reduces the amount of salmonella in food, so it is believed that eating warm and hot foods is safe for humans. The longer contaminated food is stored unprocessed, the greater the concentration of the pathogen in it becomes, and the likelihood of contracting salmonellosis from eating it also increases.
Eggs as a source of salmonella
Eggs are considered the main source of salmonellosis among people, and goose eggs are the most dangerous of all. and do not so often become the cause of infection, but they cannot be completely excluded as a factor in the etiology of the disease.
It should be noted that the eggs themselves indirectly receive their dose of pathogenic microorganisms, and the direct carrier of salmonella is the bird that carries them. Initially, the infection can only be on the outside of the egg, on the shell. If the egg was laid recently, and the shell is intact and without cracks, then contact with the egg itself does not pose a threat to humans, but unwashed hands after handling infected eggs can cause the development of an infectious process. Therefore, before cooking, be sure to wash the product with soap and warm water.
If the infection has penetrated inside, external treatment will not help, especially if there are cracks in the shell. Such eggs must be thermally processed. Eggs boiled in boiling water for 15 minutes can be considered safe. If you are preparing an omelet or scrambled eggs from them, they need to be fried on both sides.
Duck and goose eggs are not popular due to their taste characteristics. In any case, they need to be cooked for 15-20 minutes.
It is better to wash eggs immediately before cooking, and not in advance, before putting them in the refrigerator, otherwise, by destroying their natural protective barrier by washing, you can contribute to the penetration and proliferation of bacteria inside the egg.
Eggs with cracks cannot be laid on scrambled eggs or scrambled eggs, since this heat treatment is not enough for their condition; they can only be boiled.
Causes of salmonellosis in children
The sources of infection for children are similar to the factors of infection for adults - pets, cats and dogs can be dangerous for a child if they are carriers of salmonella. Cattle and pigs act as a source of infection either through direct contact with feces, for example, if a child lives in a household and has access to animals, or as contaminated meat that is fed to the child.
Infection in young patients can occur as a result of contact with a sick person or a recovering carrier of bacteria, since the child’s body is more susceptible to salmonella.
However, the most common route of infection in children is food, after eating meat, dairy products or eggs, as well as dishes made from them that are insufficiently or improperly processed.
In addition, children can become ill after drinking large quantities of water contaminated with the pathogen, if it is drinking water, and after getting water into their mouths and noses while swimming in reservoirs with salmonella.
In infants, the main route of infection is through household contact, after using a pacifier, toys, objects, or through care items. The pathogen typically found in infants belongs to the subspecies S. Typhimurium. This pathogen often causes epidemics in kindergartens, schools, children's hospitals and maternity hospitals.
Older children are more susceptible to S. enteritidis subspecies.
Is it transmitted through breastfeeding?
Infection of a child who is breastfed is most likely from contact with a carrier mother if she does not wash her hands or breasts well before feeding. Breast milk itself is not a source of infection.
Factors promoting infection and development
The likelihood of a person becoming infected with salmonellosis depends, first of all, on how the infection entered the body. So, for example, with everyday contact the probability of becoming infected is significantly less, while if Salmonella is ingested in food, the disease will manifest itself with a probability of 99.5%. In addition, age also plays a role - children are more susceptible to the bacteria, especially infants. Adults mainly become infected after consuming contaminated food.
Medvedeva Larisa Anatolyevna
Speciality: therapist, nephrologist.
Total experience: 18 years .
Place of work: Novorossiysk, medical center "Nefros".
Education:1994-2000 Stavropol State Medical Academy.
Training:
- 2014 – “Therapy”, full-time advanced training courses at the Kuban State Medical University.
- 2014 – “Nephrology” full-time advanced training courses at the State Budgetary Educational Institution of Higher Professional Education “Stavropol State Medical University”.
