Botulism

Botulism (ichthyism, allantism, English botulism, allantiasis, sausage-poisoning, French botulisme allantiasis, German Botulismus Wurst-Vergiftung, Fleischvergtftung) is a neuromuscular poisoning caused by a toxin produced by Clostridium botulinum. Infection is not necessary for the development of this disease; just use the toxin. Symptoms of botulism include muscle weakness and paralysis. The diagnosis of the disease is based on the clinic and laboratory identification of the toxin. The treatment of botulism is the clinical support and use of antitoxin.

ICD-10 code

A05.1. Botulism.

What causes botulism?

Botulism is caused by Clostridium botulinum, which releases 7 types of neurotoxins different in antigenic composition, 4 of which (type A, B and E and, rarely, F) are capable of affecting a person. Types of A and B toxins are strong poisons. In composition, they are proteins that can not be broken down by enzymes of the digestive tract. About 50% of food flashes of botulism in the United States are caused by type A toxins, followed by toxins B and E. Toxin type A is found mainly in the west of the Mississippi, type B toxin in the eastern states, toxin E in Alaska and the Great Lakes region (Upper, Huron, Michigan, Erie, Ontario, Canada and the USA).

Botulism can manifest itself in 3 forms: food botulism, wound botulism and botulism of infants. When the food form of botulism, toxin is absorbed when consuming contaminated food. In wound botulism, as well as infant botulism, a neurotoxin is released in vivo in infected tissue and in the large intestine, respectively. After absorption, the toxin prevents the release of acetylcholine from the peripheral nerve endings.

Spores of Clostridium botulinum are highly resistant to high temperatures. They can remain viable after boiling for several hours. They die when exposed to a humid environment at a temperature of 120 ° C for 30 minutes. On the other hand, toxins quickly break down under the influence of high temperatures, and therefore cooking at a temperature of 80 ° C for 30 minutes is a reliable protection against botulism. The production of toxins (especially toxin type E) can occur at a low temperature, about 3 ° C, that is, in a refrigerator, while the MO does not require strict anaerobic conditions.

The most common source of botulism are domestic canned food, but the cause of about 10% of outbreaks are canned food. The most frequent carriers of the toxin are vegetables, fish, fruits and seasonings, however, toxins contaminated with beef, dairy products, pork, poultry and other types of food. In outbreaks caused by seafood, in 50% of cases there is a toxin type E, the remaining 50% is attributable to A and B toxins. In recent years, restaurant outbreaks of botulism have emerged, which are caused by unconserved food such as potatoes baked in foil, sandwiches with melted cheese and chopped garlic, fried in oil.

Clostridium botulinum spores are often found in the natural environment, and therefore many cases can be caused by inhalation of dust or by absorption from the surface of the eyes or skin lesions. Infant botulism most often occurs in infants younger than 6 months. The smallest known patient was 2 weeks old, and the oldest 12 months old. Botulism of babies is the result of spores entering the body, after which colonization of the colon takes place, where toxin production begins in vivo. Unlike food botulism, infant botulism is not caused by ingestion of an already prepared toxin. In most cases of pediatric botulism, it is not possible to determine the source of infection, but in some cases it is possible to establish honey as a source of controversy. 

What are the symptoms of botulism?

Food botulism begins suddenly, usually 18-36 hours after toxin uptake, but the incubation period can vary from 4 to 8 days. Nausea, vomiting, abdominal cramping and diarrhea often precede neurological symptoms. Neurological symptoms of botulism are usually bilateral and symmetrical, they begin with a lesion of the cranial nerves, followed by a descending muscle weakness and paralysis. Frequent initial symptoms of botulism are dry mouth, double vision, ptosis, disruption of accommodation and weakening, or complete loss of the pupillary reflex. Symptoms of bulbar paresis develop (for example, dysarthria, dysphagia, dysphonia and immobile facial expression). Dysphagia can lead to aspiration pneumonia. The respiratory muscles and muscles of the extremities and trunk progressively weaken in the direction from top to bottom. At the same time, a sensitivity disorder does not develop. There is no fever, the pulse rate is normal or somewhat reduced. These indicators change only in the case of intercurrent infection. After the appearance of neurologic symptoms, constipation often develops. Serious complications of botulism include acute respiratory failure due to diaphragm paralysis and pulmonary infections.

Wound botulism, as well as food, manifests neurological symptoms, but there are no symptoms on the part of the gastrointestinal tract and evidence of eating poisoned food. An anamnesis of getting a traumatic injury or a deep puncture wound two weeks before the onset of symptoms may lead to the thought of botulism. A thorough examination should be carried out in order to detect skin lesions or abscesses caused by the use of illegal drugs.

In infant botulism, constipation as an initial symptom occurs in 90% of cases, followed by neuromuscular paralysis, beginning with the cranial nerves and continuing with respiratory and peripheral musculature. Deficiency of the cranial nerves is usually manifested by ptosis, paresis of the external muscles of the eye, weak crying, poor sucking, reduced sucking reflex, accumulation of oral secrets and an emotionless facial expression. The severity of the disease varies from moderate lethargy and reduced nutrition to acute hypotension and respiratory insufficiency.

How is botulism diagnosed?

Botulism can be mistaken for Guillain-Barre syndrome, poliomyelitis, myasthenia gravis, tick paralysis and poisoning caused by the curare alkaloids and belladonna. In most cases, electromyography reveals a characteristic slow response to rapid re-stimulation.

In food botulism, the sequence of neuromuscular disorders and the presence of suspicious food in the anamnesis are important diagnostic findings. Simultaneous detection of 2 patients who ate the same food, simplifies the diagnosis. The diagnosis is confirmed by the detection of toxin in the serum or stool or by sowing MO from the stool. Detection of toxin in suspected food determines the source of poisoning.

With wound botulism, detection of toxin in the serum or sowing MO from a wound on an anaerobic culture confirms the diagnosis.

Infant botulism can be mistaken for sepsis, congenital muscular dystrophy, spinal muscular atrophy, hypothyroidism, and benign congenital hypotension. Detection of toxin Clostridium botulinum or microorganism in the feces makes the diagnosis obvious.

How is botulism treated?

All persons who have established or suspected use of contaminated food should be carefully screened for botulism. The use of activated carbon may prove useful. Patients with severe symptoms often have impaired respiratory reflexes, so when administering activated charcoal it is necessary to use a gastric tube, the respiratory tract should be protected with an intubation tube with a rubber cuff. For people working with Clostridium botulinum or their toxins, vaccination using toxoids is possible.

The greatest threat to life is represented by respiratory disorders and their complications. Patients should be hospitalized and under constant monitoring of certain indicators characterizing the ability to live. Progressive paralysis does not allow patients to show signs of respiratory distress, while their viability decreases. Respiratory disorders require treatment in an intensive care unit, where intubation and mechanical ventilation are available. The use of such measures can reduce mortality to less than 10%.

Nasogastric intubation is the most preferred method of artificial feeding, since it allows you to simplify the delivery of calories and fluids. This stimulates intestinal peristalsis, in which Clostridium botulinum is eliminated from the intestine. Also, this method of nutrition allows the use of infant feeding mother's milk. In addition, this method makes it possible to avoid the infectious and vascular complications that might occur when using intravenous nutrition.

Trivalent antitoxin (A, B and E) can be obtained from the Centers for Disease Control and Prevention. The antitoxin does not neutralize the toxin, which has already been associated with neuromuscular synapses, so the existing neurological disorders can not be recovered quickly. Complete recovery depends on the rate of regeneration of nerve endings. Restoring the latter can take weeks or even months. Whatever the case, antitoxin may slow or stop further progression of the disease. Antitoxin should be administered as soon as possible after the clinical diagnosis is established. You can not postpone his appointment in anticipation of the results of culture research. If the antitoxin is administered 72 hours after the onset of botulism symptoms, the likelihood that this assignment will be effective is small. In the United States, horse trivalent antitoxin is used. He is appointed once in a dose of 10 ml. One dose contains 7500 IU of antitoxin A, 5500 ME of antitoxin B, and 8500 ME of antitoxin E. All patients who require the administration of an antitoxin should be reported to the leaders of the Center for Disease Surveillance and Prevention. Since the antitoxin is derived from horse serum, there is a possibility of developing anaphylactic shock or serum sickness in the recipient. The use of equine antitoxin is not recommended in infants. The use of antibotulin immunoglobulin (obtained from the plasma of people immunized with the toxoid Clostridium botulinum) for the treatment of infants is under study.

Since even the minimum amounts of Clostridium botulinum toxin can cause a serious illness, all materials suspected of contaminating with toxin require special treatment. Clarifications regarding the collection and processing of samples can be obtained from public health departments or from the Centers for Disease Surveillance and Prevention.

How to prevent botulism?

Botulism can be prevented with the condition of proper canning and adequate preparation of canned food before its consumption. Damaged canned food and canned food with signs of swelling should be destroyed. Infants under 12 months of age should not receive honey as food, since the latter may contain spores of Clostridium botulinum.