Botulism is an acute toxic infectious disease that is associated with the use of products containing a specific toxin under the Latin name Clostridium botulinum, as well as the pathogens themselves. When this pathology occurs, the development of paresis and paralysis of the muscles is observed, which is associated with the blockade by toxins of the release of these pathogens of acetylcholine in nerve synapses. More symptoms of botulism are presented below.
Causes of disease
Botulism is caused by an active Gram-positive anaerobic and spore-forming microorganism Clostridium botulinum. In smears, it is visualized in the form of sticks with curved ends, which are arranged in random groups, or in the form of small chains. Under unfavorable conditions, they are able to form subterminal as well as terminal spores, and in the form of these spores, these bacteria persist in the environment. In a dry state, their viability can be maintained for many decades. Science knows only 8 serovars of botulism - A, G, B, E, Ca2beta, D, F, sohowever, in human pathology, serovars A, E, B, and F tend to predominate.
Symptoms of botulism in the incubation period should be known to everyone.
Significant Clostridia growth and toxin release usually occur under anaerobic conditions at about 36°C. Vegetative forms of these bacteria die at 80 ° C for half an hour, and when boiled, five minutes is enough for this. Spores are able to survive boiling for more than 30 minutes and are killed only by autoclaving. Botulinum toxin, a toxic substance of this type of infectious pathogens, is intensively destroyed by boiling, but it is resistant to pepsin and trypsin, and can withstand high s alt concentrations. This toxin is not destroyed in foods that contain various spices. The presence of botulinum toxin in food products does not change their organic properties. Such a substance is one of the strongest natural poisons. There are known cases of damage to people and animals by several types of toxins at once, which are produced by bacteria of such serovars.
Botulism symptoms will be discussed later.
Epidemiology
Repositories and the main sources of such infection are soil, humans, wild animals, fish and waterfowl. The causative agent of this infection can live in the intestines of cows, pigs, horses, rats, rabbits, chickens, minks, wild birds and other animals. At the same time, the presence of pathogens in the body, as a rule, does not cause any harm to animals. An infected person does not pose an epidemiological threatfor the people around him. From the body of sick animals or humans, these bacteria are excreted along with feces and enter the environment: soil, livestock feed, water, etc. Pollution of various parts of the external environment can also be triggered by the decomposition of the corpses of rodents, birds and other animals that died from development they have this infection. The first symptoms of botulism are important to identify as early as possible.
Routes of infection
The mechanism of transmission of the causative agent of pathology is fecal-oral. The main cause of the pathology is the consumption of home-made canned foods, most often vegetables and mushrooms, as well as various sausages, ham, s alted fish infected with clostridia. Almost all food products that have been contaminated with soil or animal feces contain spores of the bacteria that cause botulism. This disease can develop when eating only food that has been stored under anaerobic conditions. Much less common is wound botulism, as well as botulism in infants, which occurs when these bacteria enter the intestines and release a toxin. The toxin is well absorbed not only from the mucous membranes of the gastrointestinal tract, but also from the mucous membranes of the eyes and respiratory canals, which is a great threat in cases of using an aerosol of this toxin as a biological weapon.
The susceptibility of people to these bacteria is very high due to the fact that it realizes its activity in minimal doses, and high antitoxic immunity reactions are notevolving.
Epidemiological signs
Symptoms of botulism in adults and children are recorded, as a rule, in the form of single, as well as group diseases. Often the onset and development of this disease is familial, which occurs by eating home-cooked foods that are infected with the infection. The share of all such cases accounts for about 40%. Botulism is not seasonal. There are also clinical and epidemiological features of the disease caused by bacteria of different species. The causative agent of type B causes intoxication with low mortality, and it is distinguished by a longer incubation period and late hospitalization of patients for the start of specific treatment. Type E bacteria infect people rapidly, and in these cases there is a high lethality, as well as severe clinical forms. Most often, this disease occurs among people aged 20-25 years. The symptoms and treatment of botulism are interrelated.
Pathogenesis of disease
In most cases, human infection occurs through the ingestion of toxin with food in the gastrointestinal tract, however, other routes of infection are possible. The high absorbability of the toxin explains its highest concentration in human blood already in the first hours of infection, however, those doses of the toxin that did not have time to contact the nervous tissue leave the body on their own with urine for 3-4 days. The pathogenetic mechanism of development of such intoxication is still unclear. However, it is known thattoxic substance - botulinum toxin can disrupt the carbohydrate metabolism that occurs in nerve cells and provides them with energy. In this case, there is a violation of the synthesis of choline acetyltransferase, which promotes the formation of acetylcholine. As a result, neuromuscular impulses weaken or completely disappear and reversible (in cases of recovery) paresis and paralysis develop.
Botulinum toxin has an active effect on the parasympathetic system, inhibiting its functions, which manifests itself in the form of mydriasis, dry mucous membranes and constipation.
Many researchers believe that botulism is not an intoxication, and it can be qualified as a toxic infection, giving the main importance to the pathogen. For example, a long incubation period, which is quite rare, is explained by the germination of spores in the gastrointestinal tract and the subsequent production of exotoxin in vegetative forms.
Symptoms of botulism in the incubation period
The symptoms of this infectious disease differ depending on what stage of development it is at.
During the incubation period of botulism, which in most cases is very short - 4-6 hours (in rare cases it can be up to 10 days), the patient does not show clinical symptoms. At the same time, it is necessary to carefully monitor the condition of people who ate the same product as the sick person. Symptoms of botulism poisoning occur a little later.
During the initial period, the characteristic manifestations, as a rule,are fuzzy, and therefore the disease can be confused with a number of other diseases, and this greatly complicates the possibility of early diagnosis of botulism. According to the nature of the initial clinical signs of this pathology, at an early stage, the following can be conditionally noted:
- Gastroenteric variant of the disease, when there is pain in the epigastric region, single or double bouts of vomiting of food eaten, as well as diarrhea are possible. The disease in this case may resemble manifestations of food poisoning. However, with botulism, there is never a high fever. The disease is characterized by pronounced drying of the mucous membranes of the mouth, and this symptom cannot be explained by excessive loss of fluid and dehydration. The most common symptom at this stage of botulism is difficulty in passing food through the esophagus and a feeling of "lump in the throat". What other symptoms of botulism occur?
- "Ocular" variant of the pathological process, which manifests itself in the form of visual impairment - clouding, mesh, "flies" before the eyes, loss of the ability to determine the clarity of the contours of objects. Sometimes it is possible to develop the so-called "acute farsightedness", corrected by plus lenses.
- Acute forms of respiratory failure manifest as symptoms of botulism. This type of pathology is the most dangerous, because in such cases, lightning-fast respiratory failure develops in the form of shortness of breath, cyanosis, tachycardia, and the patient can die within a few hours.
Botulism symptoms in the main period
Clinical signs of this pathology are very characteristic and combine a number of specific syndromes. If ophthalmoplegic disorders occur, bilateral blepharoptosis, diplopia, persistent mydriasis, impaired eye movement, and vertical nystagmus can be observed. Also, the patient has a violation of swallowing, which is expressed in the difficulty of swallowing initially solid, and then soft food, and when trying to drink liquid, it begins to pour out through the nose. This symptom of botulism disease is due to paresis of the swallowing muscles. A visual examination of the oral cavity shows a violation or, in more serious cases, a complete cessation of the mobility of the tongue and soft palate. There is also hoarseness of voice, due to dryness of the vocal cords. In the future, the development of dysarthria is possible, the patient does not have a cough reflex, which can lead to an attack of suffocation.
In the midst of illness, patients complain of severe muscle weakness, their gait becomes very unstable, dry mouth and constipation associated with atrophy of the intestinal muscles are very pronounced. Tachycardia and arterial hypertension are also characteristic. We examined the symptoms and causes of botulism. But what are the consequences?
Consequences of illness
In botulism, there is a rapid development of pneumonia, which is due to a sharp decrease in the patient's breathing volume. At the same time, the use of antibacterial drugs for botulism is not able to prevent the onset of this complication.
The most formidable complication, often leading to death, is a respiratory disorder that can occur at any stage of the development of the disease. At the initial stage, breathing quickens to 40 per minute, the patient's motor restlessness, diaphragm paralysis are observed.
When using heterogeneous botulinum serum, anaphylactic shock often develops, and at later stages of its use - serum sickness.
Diagnosis of pathology
The first symptoms of botulism are important to be able to recognize quickly. Pathology must be distinguished from food poisoning, poisonous mushroom poisoning, poliomyelitis, encephalitis and diphtheria.
Of particular importance in the diagnosis is differential and laboratory diagnosis in the initial period. With botulism, dyspepsia, dry mouth, difficulty in swallowing, visual disturbances, respiratory failure, muscle weakness, and constipation may occur. Patients develop phenomena of ophthalmoplegic syndrome, phonation disorders, pathology of the facial nerve.
Currently, there are no special laboratory tests that can identify the presence of botulinum toxin in the human body. The purpose of bacteriological research is to detect the toxin, which is possible only at the height of the disease. To do this, put biological samples on animals.
Modern methods of diagnosing a disease are based onindication of antigens in PCR, ELISA, or RIA.
Identification of the causative agent of botulism does not give grounds for making a diagnosis, since spores of a bacterium found in the intestines of most he althy people can germinate.
So, the symptoms of botulism in a person appeared, what should I do?
Botulism treatment
Due to the high risk to life, hospitalization of patients is necessary even with a simple suspicion of the development of botulism. Patients are sent to a hospital where there is special equipment for ventilation.
Treatment measures begin with gastric lavage, which is best done in the first 2 days of illness, when contaminated food can still be in the stomach cavity.
Features of treatment and symptoms of botulism disease are not known to everyone.
To neutralize toxins, a polyvalent anti-botulinum serum is used, which is administered intravenously after desensitization (the so-called "Bezredka method"). When using this serum intravenously, it should be pre-mixed with saline warmed up to 37°C. Most often, a single injection of a certain dose of serum is enough. If after a day the patient continues to progress neuroparalytic disorders, its administration should be repeated. The use of human antibotulinum plasma gives a good clinical effect, but its use is difficult due to very short shelf life.
Simultaneously with the introduction of serum, detoxification therapy is carried out, which includesintravenous infusion solution. Due to the fact that the patient cannot swallow, he is fed through a special thin tube.
We looked at the symptoms of botulism in humans.
