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 muscle paralysis is observed, which is associated with the blocking by toxins of the excretion of these pathogens of acetylcholine in the nerve synapses. More symptoms of botulism are presented below.
Causes of the disease
The causative agent of botulism is the active gram-positive anaerobic and spore-forming microorganism Clostridium botulinum. In smears, it is visualized in the form of sticks with curved ends that are arranged in disordered groups, or in the form of small chains. Under adverse conditions, they are able to form subterminal as well as terminal spores, and in the form of these spores these bacteria are stored in the environment. In the dry state, their viability can be maintained for many decades. Science knows only 8 serovars of botulism - A, G, B, E, Ca2beta, D, F, however, serovars A, E, B and F usually prevail in human pathology.
Symptoms of botulism in the incubation period should be known to everyone.
Significant growth of clostridia and toxin release usually occur under anaerobic conditions at a temperature of about 36 ° C. The vegetative forms of these bacteria die at 80 ° C for half an hour, and when boiled, five minutes is enough for this. Spores can survive boiling for more than 30 minutes and die only by autoclaving. Botulinum toxin is a toxic substance of this type of infectious pathogen, is destroyed rapidly by boiling, but it is resistant to pepsin and trypsin, and is able to withstand high salt concentrations. This toxin is not destroyed in products that contain various spices. The presence of botulinum toxin in food does not change their organic properties. Such a substance is one of the strongest natural poisons. Cases of damage to humans and animals by several types of toxins, which are produced by bacteria of similar serovars, are known.
Symptoms of botulism disease will be considered later.
Epidemiology
The repositories and the main sources of this 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. In this case, the presence of pathogens in the body, as a rule, does not do any harm to animals. An infected person does not pose an epidemiological threat to those around him. From bacteria 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 environment can also be caused 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.
Infection pathways
The pathogen transmission mechanism 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, salted fish infected with clostridia. Almost all foods that have been contaminated with soil or animal feces contain spores of botulism-causing bacteria. This disease can develop when eating only food that was stored under anaerobic conditions. Wound botulism, as well as botulism in infants, which occurs in them when these bacteria enter the intestines and release toxin, is much less common. 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 the aerosol of this toxin in the form of biological weapons.
The susceptibility of people to these bacteria is very high due to the fact that it implements its activity in minimal doses, while high antitoxic immunity reactions do not develop.
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 occurrence and development of this disease has a family nature, which occurs by eating home-made products infected with the infection. All such cases account for about 40%. Botulism is not characterized by a seasonal occurrence. Clinical and epidemiological features of the disease caused by bacteria of different species are also observed. 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 to initiate specific treatment. Type E bacteria infect humans rapidly, and in these cases there is a high mortality rate, and severe clinical forms dominate. Most often, this disease occurs among people aged 20-25 years. Symptoms and treatment of botulism are interconnected.
Pathogenesis of the disease
In most cases, a person is infected by the ingestion of a toxin with nutrition in the digestive tract, however, other ways of infection are possible. The high absorption of the toxin explains its highest concentration in the blood of a person already in the first hours of infection, however, those doses of the toxin that did not manage to contact the nervous tissue leave the body with urine for 3-4 days. The pathogenetic mechanism of the development of such intoxication is still unclear. Nevertheless, it is known that the toxic 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 cholinacetyl transferase, which contributes to 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 function, which manifests itself in the form of mydriasis, dry mucous membranes and constipation.
Many researchers believe that botulism is not intoxication, and it can be qualified as toxic infection, giving the main importance to the pathogen. For example, a long incubation period, which is observed quite rarely, is explained by the germination of spores in the digestive tract and the subsequent production of exotoxin in vegetative forms.
Symptoms of botulism in the incubation period
The symptomatology of this infectious disease varies 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 have clinical symptoms. In this case, it is necessary to carefully monitor the condition of people who ate the same product as the diseased. Symptoms of botulism poisoning occur a bit later.
During the initial period, 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 an early diagnosis of botulism. By 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 eaten food are possible, as well as diarrhea. The disease in this case may resemble manifestations of food poisoning. However, with botulism there is never a strong increase in temperature. The disease is characterized by marked drying of the mucous membranes of the mouth, and this symptom cannot be explained by excessive fluid loss and dehydration. The most common symptom at this stage of botulism is the difficulty in passing food through the esophagus and the sensation of a “lump in the throat”. What other symptoms of botulism occur?
- The "eye" version of the pathological process, which manifests itself in the form of visual impairment, is blurred, grid, "flies" in front of the eyes, loss of ability to determine the clarity of the contours of objects. Sometimes it is possible to develop the so-called "acute hyperopia," 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, fulminant respiratory failure develops in the form of shortness of breath, cyanosis, tachycardia, and the patient may die within a few hours.
Symptoms of botulism in the main period
The clinical signs of this pathology are very characteristic and combine a number of specific syndromes. In case of ophthalmoplegic disorders, bilateral blepharoptosis, diplopia, persistent mydriasis, impaired eye movement, vertical nystagmus can be observed. Also, the patient has a violation of swallowing, 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 caused by paresis of the swallowing muscles. During a visual examination of the oral cavity, a violation is observed or, in more serious cases, a complete cessation of the mobility of the tongue and soft palate. Husky voice also appears due to the 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.
At the height of the disease, 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. Symptoms and causes of botulism we examined. But what are the consequences?
The consequences of the disease
With botulism, the rapid development of pneumonia is observed, which is due to a sharp decrease in the patient's respiratory volume. Moreover, 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 respiratory distress, which can occur at any stage of the development of the disease. At the initial stage of breathing, it increases to 40 per minute, the patient's motor anxiety, diaphragm paralysis are observed.
When using heterogeneous anti-botulinum serum, the occurrence of anaphylactic shock is often observed, and at a later date of its use, serum sickness.
Pathology diagnostics
The first symptoms of botulism are important to quickly be able to recognize. Pathology must be distinguished from food poisoning, poisoning by poisonous mushrooms, polio, encephalitis and diphtheria.
Of particular importance in the diagnosis is differential and laboratory diagnostics in the initial period. With botulism, dyspeptic symptoms, dry mouth, difficulty swallowing, visual disturbances, respiratory failure, muscle weakness, and constipation are possible. Patients develop the phenomena of ophthalmoplegic syndrome, impaired phonation, facial nerve pathology.
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 the detection of toxin, which is possible only at the height of the disease. To do this, put biological samples on animals.
Modern methods for diagnosing the disease are based on the indication of antigens in PCR, ELISA, or RIA.
Identification of the causative agent of botulism does not give rise to a diagnosis, since spores of the bacteria located in the intestines of most healthy people can germinate.
So, the symptoms of botulism in humans have 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 mechanical ventilation.
Therapeutic measures begin with gastric lavage, which is best done in the first 2 days of the disease, when contaminated food may still be in the stomach cavity.
The treatment features and symptoms of botulism disease are not known to everyone.
To neutralize toxins, a multivalent anti -botulinum serum is used, which is administered intravenously after desensitization (the so-called "Limitless method"). When using this serum intravenously, it should be pre-mixed with saline solution, heated 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 anti-botulinum plasma gives a good clinical effect, but its use is difficult due to the very short shelf life.
Along with the introduction of serum, detoxification therapy is carried out, including intravenous infusion. Due to the fact that the patient cannot swallow, his nutrition is carried out through a special thin probe.
We examined the symptoms of botulism in humans.