Botulism

Botulism - the acute infectious disease caused by a lesion by toxins of bacteria of a botulism of the excitatory system, characterised by paresises and paralyses of a cross-section-striatal and smooth musculation, sometimes in a combination to a gastroenteritis syndrome in an initial stage.

Aetiology. Botulism originators - Clostridium botulinum represent themselves anaerobic mobile Gram-negative rods. On antigenic properties of produced toxins they are sectioned into 7 serological types - A, B, C, D, E, F and G. Optimum conditions of growth of vegetative forms - the lowest residual pressure of oxygen (0,40-1,33 kPa) and a temperature regimen in limens 28-35°С. At the same time, the heating at temperature 80°С during 30 mines causes their  destruction.

In unfavorable conditions, in an external environment vegetative forms of originators of a botulism form disputes. They are extremely steady against various physical and chemical factors, in particular, maintain boiling within 4-5 hours, influence of high concentrations of various disinfectants, remain in the products containing to 18 % of table salt. Interest represents a phenomenon of formation from vegetative forms at their insufficient heating so-called "dozing spores", capable to germination only in 6 months of Spore are steady against freezing and drying, to a direct ultra-violet irradiating.

In conditions anaerobic or close to them botulism originators produce the specific lethal neurotoxin which is unique, but exclusive on force the factor of pathogenicity. Specially cleared, finished to the crystalline form, botulotoxin can contain millions lethal doses. Botulinic toxins of the albuminous nature in usual conditions of an external environment remain till 1 year, in tinned products - years. They are steady in acid medium, are not inactivated by digestive tube enzymes, and toxic properties of botulotoxin E under the influence of Trypsinum can strengthen in hundreds times. Botulinic toxins maintain high concentrations (to 18 %) table salt, are not blasted in the products containing various spices. Toxins are rather quickly inactivated under the influence of alkalis, at boiling completely lose the toxic properties during several, and under the influence of small concentrations of a potassium of permanganate, chlorine or iodine - within 15-20 minutes Presence of botulotoxin at foodstuff does not variate their organoleptic properties.

Despite serological specificity, botulinic toxins are identical on the mechanism of pathological influence and its clinical implications. The protective action of antitoxic Serums is specific, ability to heterologous neutralisation is observed only at types With and D, E and F, but it is expressed much more weakly (at 4-10 time).

Epidemiology. Originators of a botulism eurysynusic in the nature. Vegetative forms and disputes are found in an intestine various house and in particular wildings, a waterfowl, fishes. Getting to an external environment (bedrock, silt of lakes and the rivers), they in a sporoid condition it is long remain and collect. Practically all foodstuff polluted by bedrock or contents of an intestine of animals, auks, fishes can contain disputes or vegetative forms of originators of a botulism. However disease can arise only at the use of those from them which were stored under conditions anaerobic or close to them without a preliminary sufficient heat treatment. It can be canned food, especially house preparation, smoked, jerky meat and fish products, and also other products in which there are conditions for development of vegetative forms of microbes and a toxin production. In Russia the diseases bound mainly with the use of mushrooms of house conservation, smoked or jerky fish, in the European countries - meat and sausage products, in the USA - fabaceous canned food are more often registered. These products cause group, "family" flashes of diseases is more often. If the infected product solidphase (sausage, smoked meat, fish) in it are possible a "nested" contamination originators of a botulism and formation of toxins. Therefore there are flashes at which not all persons using the same product, are ill. The diseases caused by venenatings by toxins And now prevail, In or d, the basic by infestation is alimentary, caused the use of the food stuffs preserved in house conditions.

Much less often there are cases of disease as a result of infestation only disputes of originators Cl. Botulinum. The traumatic botulism and a botulism of newborns concern them so-called.

Wound the botulism can arise owing to contamination of wounds in which the conditions close to the anaerobic further are framed. Thus from the spores which have got to a wound sprout vegetative forms which produce botulotoxins. At their resorption neurologic disorders typical for a botulism educe. The original form of a traumatic botulism is the botulism at narcomaniacs. Infestation is carried out as a result of injections or even epicutaneous scarifications of "black heroin" ("black pitch"), the starting material for which preparation is polluted by bedrock and thus is contaminated by disputes. In case of abscessing of places of injections preconditions of development of disease are framed as well as at a traumatic botulism.

The botulism of babies is observed mainly at children of first six months of life. The majority of the diseased were on particulate or full artificial feeding. At investigation of similar cases of disease of spore excreted from the honey used for preparation of nutrient admixtures. As disputes found in medium surrounding the child - bedrock, a household dust of premises and even on a skin of feeding mothers. That fact pays attention, that the botulism of babies is registered exclusively in socially unsuccessful monogynopaediums living in unsatisfactory sanitary-and-hygienic conditions. Owing to features of a microflora of an intestine of babies believe, that got to a gastrointestinal tract of the child of spore find congenial conditions for germination in vegetative forms and a producing of toxins.

Experimental researches and clinical observations testify to possibility of disease as a result of aerogenic infestation by botulotoxins. In such cases their absorption in blood descends through a mucosa of respiratory tracts. In natural conditions similar diseases are impossible.

Thus, a botulism epidemiology rather complex. Disease can educe owing to hit in an organism only botulotoxins, toxins and originators or only dispute. It is necessary to note rough reproduction of originators in corpses of victims from a botulism of humans, carcase gorged animals who become the original reservoir of an infection contamination.

Pathogenesis. In a pathogenesis of a botulism the leading part belongs to toxin. At usual infestation (an alimentary path) it gets to an organism together with the nutrition containing as well vegetative forms of originators - poison producers. The botulotoxin absorption descends through a mucosa of proximal parts of a gastrointestinal tract, since an oral cavity. But toxin entering through a stomach and small bowel mucosa is the most significant, whence it gets to a lymph and in the subsequent in blood to which it is carried on all organism. It is established, that botulinic toxin is strongly bound by the excitatory cells. Are thus amazed both nerve terminations and motoneurons of forward horns of a spinal cord. Botulotoxin selectively influences cholinergic parts of the excitatory system owing to what Acetylcholinum abjection in a synaptic gap and consequently a neuromuscular transmission of exaltations (paresises is broken, paralyses) stops. Cholinesterase activity in synapses practically does not variate. First of all the innervation of the muscles which are in a condition of constant and highly differentiated functional activity (the oculomotor apparatus, pharynx and larynx muscles) is broken. Result of a lesion of motoneurons is as well oppression of function of the basic respiratory muscles up to a paralysis. Influence of botulinic toxins reversible and motorial function is completely recovered in due course. Oppression of cholinergic processes is preceded by rising of the maintenance of catecholamins. Owing to disturbance of a vegetative innervation secretion of alimentiry glands decreases (abjection of a saliva, a gastric juice), educes a nonperishable paresis of a gastrointestinal tract. Pathogenic action of botulinic toxins substantially strengthens at their repeated entering in blood, against a radioactive irradiating or after it.

Paresises or paralyses of intercostal muscles, diaphragms lead to acute ventilating respiratory insufficiency with development of a hypoxia and a respiratory acidosis. Disturbance of ventilation of the lungs is promoted by oppression of function of muscles of a pharynx and a larynx, a clump of dense slime in over - and subligamentous space, an aspiration of vomitive masses, nutrition, water. At a botulism owing to the mediated or direct action of toxin all types of a hypoxia - hypoxic, histotoxic, hemic and circulatory educe. Finally it also defines flow and disease outcomes. The role of such secondary changes, as an aspiration pneumonia, atelectases is thus essential also. Because of a hypoptyalism the stomatopharynx mucosa inflames, the purulent parotitis owing to an ascending infection contamination can educe. The  destruction of patients usually comes from ventilating respiratory insufficiency and is is very rare - from a subitaneous cardiac standstill. The excitatory system is not a unique target for botulotoxins. It is established, that they promote sharp oppression of phagocytal activity of leucocytes, metabolism disturbance in erythrocytes, to trophicity disturbances.

Together with nutrition containing botulinic toxin botulism originators get to an organism of the patient, and also, in case of the conforming contamination of foodstuff, and other anaerobes (С1 also. perfringens, Cl. aedematiens) and their toxic substances. Influence of the last possible short-term fever and a gastroenteritis syndrome in an initial stage of disease at some patients speak. Diseases educing in height conduct a paresis and oppression of secretion of alimentiry glands to stagnation of nutrition and a chyme, the conditions close to the anaerobic. Thus vegetative forms of originators of a botulism can produce the toxin which additional enterings in blood render potentiating toxic effect. Probably cases of subitaneous mors of patients also are bound to it even at easy and moderately severe botulism flow. Hence, at a usual mean of infestation the botulism is as a matter of fact a toxinfection. It is natural, that thus leading value in a course of a disease belongs to the toxin arriving with infected products in a gastrointestinal tract.

The pathogenesis of a traumatic botulism and botulism of babies differs that infestation descends disputes which sprout in anaerobic conditions of a wound or owing to features of flora and enzymatic activity of an intestine of thoracal children in the vegetative forms producing toxins. Botulotoxin entering in blood gives a neurologic picture of disease typical for a botulism. In such cases syndromes of a gastroenteritis, the general infectious intoxication are absent. Meanwhile conditions of germination and a toxin producing in a gastrointestinal tract of babies are not studied. However there is immutable a fact, that the botulism as disease - a consequence of a toxic lesion of the excitatory system, and toxin, possibly, reacts as a fermental poison that demands its insignificant quantities for development of a serious venenating. Botulotoxin circulation can proceed about three weeks. Cases of revealing of toxin in blood are observed at absence or the erased clinical picture of disease.

Pathoanatomical changes at a botulism are not specific. The hyperemia and a plethora of an internals, including a brain and its covers are usually observed. Signs of disturbance of microcirculation in a brain are expressed. Moderate destructive changes of the excitatory cells of all levels become perceptible. However they do not reach such degree to explain arising paralyses. For a botulism dystrophic changes in vascular sides of a microcirculatory bed, plural fine hemorrhages in serous and mucosas, mainly gastrointestinal tract which most likely are caused by a hypoxia are characteristic enough.

Symptoms and flow. The incubation interval at a botulism proceeds about one days, is rarer till 2-3 days and is very rare (in individual descriptions) to 9 and even 12 days. It is not excluded, that longer incubation interval corresponds to a manifestation of the latent implications of disease because of additional entering of botulotoxin from a gastrointestinal tract. At shorter incubation interval it is observed, though and not always, more serious disease. Alcohol reception, as a rule, does not affect disease, and intoxication can shade the first implications of a botulism, interfering with its timely diagnostics.

Key clinical signs of a botulism are the various neurologic symptoms which set can vary in a wide range and a various degree of manifestation. However approximately every second botulism sick of the first implications can have short-term symptoms of an acute gastroenteritis and the general infectious intoxication. In such cases patients usually complain of acute abdominal pains, mainly in epigastric range then come repeated vomiting and liquid, without pathological admixings a chair, it is no more 10 times a day, more often 3-5 times. Sometimes on this background there is a headache, a malaise, the fervescence from subfebrile to 39-40°С becomes perceptible. To the extremity of days the hypermotility of a gastrointestinal tract is replaced by a nonperishable atony, the body temperature becomes normal. The basic neurologic signs of disease start to appear. In rare instances between gastrointestinal and neurologic syndromes the state of health of the patient can is short-term to remain quite satisfactory and only at purposeful survey it is possible to tap signs of a lesion of the excitatory system.

The most typical precursory symptoms of a botulism are visual acuity disturbances, dryness in a mouth and muscular delicacy. Patients complain on "a fog in eyes", "the grid before eyes", badly is distinguished by nearby subjects, cannot read at first a usual font, and then - large. There is a doubling in eyes. The ptosis of a various degree of manifestation educes. The height and a voice timbre variate, the nasonnement sometimes becomes perceptible. At advance of disease the voice becomes hoarse, hoarseness can pass in an aphonia. Typical enough sign of a botulism is swallowing disturbance. Appear sensation of a foreign body in a drink ("not swallowed tablet"), choke, difficulty of swallowing in the beginning firm, and then and liquid nutrition, water. In serious cases there comes a full aphagia. At attempt to swallow water, last pours out through a nose. In this season the aspiration of nutrition, water, a saliva with development of an aspiration pneumonia, a purulent tracheobronchitis is possible. All above-stated neurologic symptoms appear in various combinations, sequence and a degree of manifestation. Some of them can be absent. However an obligatory background for them are sialosis disturbance (dryness in a mouth), progressing muscular delicacy and an obstipation.

The ptosis, muscular delicacy can in easy cases of disease proceed in insufficiently demonstrated form. They can be taped by an exercise stress (some times densely to discover and occlude eyes, repeatedly to measure a muscle strenth by means of a dynamometer). Muscular delicacy accrues according to gravity of disease. In the beginning it is most expressed in occipital muscles owing to what at such patients the head can hang down and they are forced to sustain her hands. In connection with delicacy of intercostal muscles breath becomes superficial, hardly appreciable. At a full paralysis of intercostal muscles patients feel thorax compression "as though as a hoop".

At survey in height of disease patients flaccid, adynamic. The person a mask the figurative. One - more often a bilateral ptosis. Pupils are dilated, torpently or do not react at all to light; the nystagmus, a squint are possible, convergence and accommodation are broken. The tongue protrusion descends hardly, sometimes jerks. The articulation worsens. A stomatopharynx mucosa dry, drinks - bright red. In epiglottidean space the clump of dense viscous slime, in the beginning transparent, and then rather turbid is possible. The paresis of a soft palate, muscles of a pharynx and an epiglottis, vocal chords becomes perceptible, the vocal cleft is dilated. Owing to a paresis or a paralysis of muscles of a diaphragm the expectoration of a sputum which accumulates in subligamentous space is broken. Dense, viscous mucous Membranula in over - and under - guttural space can lead to an asphyxia. Because of delicacy of a sceletal musculation patients are inactive. Mask the figurative fallen asleep person, a shallow breathing, an aphonia can suggest about consciousness loss. At inspection of a respiratory organs the shallow breathing pays attention. Tussis is absent, respiratory hums are relaxed, auscultatory pneumonia phenomena can not be listened. According to severity level of ventilating respiratory insufficiency the hypercapnia, a respiratory acidosis accrues. Changes of cardiovascular system are found mainly at moderately severe disease: a tachycardia, an arterial hypotension, and sometimes a hypertensia, metabolic changes of an electrocardiogram.

For the developed clinical picture of a botulism are characteristic the expressed paresis of the gastrointestinal tract, showing a moderate abdominal distention, sharp weakening of peristaltic hums, persistent and long constipations. From other organs and systems of any changes typical for a botulism it is not defined. There can be an uropoiesis delay.

Researches of peripheric blood do not tap the special deflections from norm, except for a monocytosis which meets too not always. The leukocytosis, a neutrocytosis, accelerated by an ESR should guard concerning possible purulent complication of a botulism.

Easy cases of a botulism are characterised by a blurring of neurologic implications. Disorders of accommodation, a small ptosis, sometimes changes of a timbre of a voice against moderate muscular delicacy, a hypoptyalism are more often observed. Duration from several o'clock about several days. At moderately severe a botulism there are all clinical neurologic symptoms which degree of manifestation is not identical, and the lesion of muscles of a pharynx, a larynx does not reach aphagia and aphonia degree. Respiratory disorders dangerous to life are not present. Duration of disease compounds 2-3 weeks. Serious forms of disease are characterised by prompt increase of lesions of an oculomotor, pharyngeal and guttural musculation, sharp oppression of function of the basic respiratory muscles. In the absence of adequate therapy the mors usually comes from respiratory insufficiency for 2-3rd day of disease

Recover comes slowly. One of enriching precursory symptoms is sialosis restoration. The neurologic semiology gradually regresses. After all there is a full restoration of visual acuity and a muscle strenth. Alternating visual disturbances can be observed within several months. Despite the hardest sometimes incompatible with life neurologic disorders, at had been ill with a botulism does not remain consequences and any nonperishable disturbances of functions of the excitatory system or an internals. Concerning outcomes disease division on severity level is conditional enough, for even at a lung and the more so flow of moderately severe disease cases of a subitaneous apnoea are observed

Some features the traumatic botulism and a botulism of babies differ. In both cases there is no gastrointestinal syndrome and the general infectious intoxication. At a traumatic botulism more long terms of an incubation interval (4-14 days). For a botulism the neurologic semiology is characteristic. It is necessary to notice, that these patients do not have fact of the use of products which could contain botulinic toxin. The botulism at thoracal children (a botulism of babies) is observed more often at artificial feeding. The incubation interval is unknown and to establish it it is not obviously possible. Slackness of children, a weak suction or abandoning of it, a chair delay can be the first implications of disease. Appearance of ophthalmoplegic symptoms, rhonchial crying, choke should suggest about possibility of a botulism with urgent carrying out of the conforming diagnostic and medical actions. At a forwardness of lesions of respiratory muscles this disease can cause so-called subitaneous mors of children of year-ould age.