Botulism is a disease that occurs as a result of poisoning by toxins of the bacteria botulism and is characterized by severe damage to the nervous system.
The causative agent – Clostridium botulism – is widely distributed in nature with a permanent habitat in the soil. It forms spores that are extremely resistant to physical and chemical factors. Spores withstand boiling for 5 hours and only at a temperature of 120 degrees.Celsius die in 30 minutes. In an environment with a small amount of oxygen, they multiply and form a toxin. The toxin is partially destroyed when heated to 70-80 degrees. Celsius, when boiling for 5-15 minutes, is completely destroyed. Botulinum toxin is one of the strongest poisons known in nature, its lethal dose for humans is about 0.3 micrograms.
The reservoir of botulism pathogens in nature are warm-blooded, less often cold-blooded, animals with clostridia in their intestines that are excreted with feces into the external environment. The pathogen itself does not cause human disease, only the toxin is dangerous. For the occurrence of poisoning requires reproduction of the pathogen with the accumulation of botulinum toxin in an environment with a small amount of oxygen (ham, sausages, canned food, salted fish), as well as in canned vegetables, fruits, mushrooms.
In recent years, the role of canned mushrooms has increased in the onset of botulism. The accumulation of toxins occur especially intensively at a temperature of 22-37C. A person becomes ill by eating foods containing botulinum toxin. The patient is dangerous to others.
Botulinum toxin enters the human body through the gastrointestinal tract with food. Two exceptions to this rule, which are very rare, are known – botulism in infants, in which the toxin is produced in the intestine, and wound botulism, when clostridia multiplication occurs in dead tissues.
Botulinum toxin is not destroyed by enzymes of the gastrointestinal tract and is absorbed into the blood through the mucous membrane of the stomach and intestines, selectively affecting different parts of the nervous system. There are paralysis of the respiratory muscles, muscles of the larynx, pharynx. This leads to impaired breathing, swallowing, which contributes to the development pneumonia . May develop sepsis (blood poisoning).
The incubation period for botulism is from several hours to 2-5 days; the more severe the disease, the shorter the incubation period. In severe forms of the disease, it is usually about 24 hours. In most cases, the disease begins with the following symptoms:
- symptom development is very rapid
- vomiting, sometimes up to cramping abdominal pain,
- loose stool without impurities
These manifestations last about a day. Then develop a feeling of distention in the stomach, flatulence, constipation.
Early signs of botulism include visual disturbances. Patients complain about the “fog”, “grid” before the eyes, ghosting of objects, difficulty in reading.
At the same time, there is thirst, dry mucous membranes due to impaired salivation, as well as a disorder of swallowing, and the tone of the voice changes. At the same time, patients are worried about the feeling of a “lump” in the throat, pain when swallowing, choking, due to damage to the muscles of the larynx and pharynx.
The defeat of the nervous system is accompanied by a general toxic syndrome – headache, dizziness, insomnia, weakness, fatigue. However, fever, as a rule, is absent, and only some patients have a slight fever.
A terrible sign indicating an unfavorable course of the disease is respiratory failure. Patients feel a lack of air, heaviness in the chest, sometimes chest pain, breathing becomes shallow. The cause of death in botulism is respiratory failure.
The diagnosis is established on the basis of laboratory data. An important role in the diagnosis of botulism is played by the fact of group disease in people who ate the same product (canned food, dried fish, smoked meats, home-made juices, canned vegetables, mushrooms and meat).
Laboratory diagnostics: blood, vomit and gastric lavage, feces, as well as food residues are taken for examination. The presence of botulinum toxin in the test material is determined using a biological method.
All patients with suspected botulism are subject to mandatory hospitalization due to the need for timely specific therapy in order to prevent possible serious complications.
The main objectives of emergency care are the neutralization, binding and elimination of toxins from the body, ensuring the functions of the respiratory and cardiovascular systems of the body.
At the prehospital stage, it is necessary to carry out the following urgent measures: wash the stomach first with boiled water, then with 2% soda solution; plenty of frequent drinking; inject intramuscularly or subcutaneously with 2 ml of a 0.05% prozerin, and in case of acute respiratory failure, conduct artificial respiration.
Used to neutralize botulinum toxin therapeutic anti-tonic sera.
If the type of toxin that caused the disease is unknown, three types of serum are injected – A, B, E. Serotherapy is preceded by an intracutaneous test and desensitization. In severe form of the disease, the first doses of serum are administered intravenously, in other cases – intramuscularly. Initially, 10-15 thousand IU of type A and E serum and 5-7.5 thousand IU of type B serum are administered. Subsequent doses and frequency of administration are determined by the severity of the disease and the dynamics of clinical symptoms.
In severe forms of botulism, the introduction of serum is repeated after 6-8 hours until the effect appears. A full course of treatment consumes up to 50,000-60,000 IU serum types A, E and 25,000-30,000 IU type B, the doses may be increased, however, the course of serotherapy should not exceed three to four days. Given that in the gastrointestinal tract spores can turn into vegetative forms, antibiotic therapy (levomycetin) or tetracycline preparations are prescribed. At the same time carry out detoxification therapy.
For respiratory disorders due to paralysis of the respiratory muscles, artificial lung ventilation is indicated. To combat hypoxia, hyperbaric oxygenation is used.
In convalescent patients, residual effects after paralysis (more than 1-2 months), asthenic syndrome persist for a long time. Botulism may be complicated by pneumonia, sepsis, myocarditis.
Recovering after discharge from the hospital are observed in the absence of complications – 14 days; with complicated course:
- when myocarditis is transferred – the period of disability is not less than 10 days. Treatment by a cardiologist followed by regular follow-up every 6 months for a year with a blood test and ECG;
- with residual effects of neurological symptoms – a period of disability of at least 2 weeks followed by follow-up observation by an infectious disease specialist and a neuropathologist for a year with an examination every 3 months (ECG, CBC).