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Botulism - Diagnosis
Last reviewed: 03.07.2025

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Diagnosis of botulism is based on epidemiological data (consumption of home-made canned food, group diseases) on a comprehensive analysis of the clinical picture of the disease: characteristic localization and symmetry of lesions of the nervous system, the absence of fever-intoxication, general cerebral and meningeal syndromes.
Detection of botulinum toxin in the blood serves as an absolute confirmation of the diagnosis. The pH of botulinum toxins is used with antitoxic serums by means of a bioassay on white mice. For this purpose, it is necessary to take 15-30 ml of venous blood from the patient before the introduction of the therapeutic antitoxic antibotulinum serum. The study allows to determine the presence of botulinum toxin and its type in 8 hours. Similar studies are carried out with gastric lavage or vomit, the patient's feces, and the remains of a suspicious product.
To isolate the botulism pathogen, stomach contents, feces, and suspicious products are cultured on special nutrient media: (Kitt-Tarozzi, casein-mushroom, Hottinger broth, etc.). However, additional time is required to determine the serological type of the toxin produced by the pathogen. Autopsy material is subject to research to determine the toxin and isolate the pathogen, and in cases of wound botulism - discharge from the wound, pieces of rejected dead tissue, tampons from the wound. Infant botulism is confirmed by determining botulinum toxins in their blood and/or pathogens in feces.
Indications for consultation with other specialists
If necessary, consultation with a surgeon (constant pain syndrome at the onset of the disease), neurologist (cranial nerve paresis, peripheral polyneuropathy), cardiologist (myocardial damage syndrome), resuscitator (respiratory disorders, multiple organ failure) is indicated.
Indications for hospitalization
If botulism is suspected, emergency hospitalization in the intensive care unit or resuscitation department is indicated. All patients, regardless of the duration of the disease, already at the prehospital stage require gastric lavage by tube, after which they should be given enterosorbents orally or administered through a tube (activated carbon, dioctahedral smectite, hydrolytic lignin, povidone, microcrystalline cellulose, etc.). Activation of diuresis due to hemodilution is indicated (intravenous infusion of crystalloids and 5% albumin in a ratio of 3:1).
Differential diagnosis of botulism
Differential diagnostics of botulism should take into account signs that exclude botulism. These include meningeal symptoms, pathological changes in the cerebrospinal fluid, central (spastic) paralysis, sensory disturbances (alternating paralysis), convulsions, disturbances of consciousness, mental disorders, as well as general infectious intoxication syndrome with a developed picture of neurological disorders (in the absence of signs of secondary bacterial complications).
Certain difficulties in diagnostics may arise in the initial period of botulism with acute gastroenteritis syndrome. In such cases, there is a need for differential diagnostics with food toxic infections. With botulism, vomitingand diarrhea are short-term, rarely accompanied by feverish intoxication syndrome, and careful examination and subsequent targeted observation allow us to identify muscle weakness, hyposalivation, as well as neurological disorders, primarily visual acuity disorders.
Differential diagnostics of botulism with myasthenic syndrome uses tests with acetylcholinesterase drugs (neostigmine methylsulfate), which do not have a therapeutic effect in botulism. It should be borne in mind that in botulism, paresis or paralysis is always bilateral, although they may differ in severity.
Differential diagnostics of botulism with diphtheritic polyneuritis is necessary. It is necessary to take into account the preceding neurological disorders of angina with high fever, as well as frequent severe myocardial lesions, the timing of the development of polyneuropathy (in toxic forms of diphtheria, damage to the peripheral nervous system, with the exception of the cranial nerves, is observed after the 40th day of illness).
Viral encephalitis differs from botulism by the presence of focal asymmetric symptoms that appear several days after systemic symptoms such as headache, myalgia, general malaise, etc.; worsening of symptoms of general cerebral symptoms (headache, nausea, vomiting, meningeal signs), disorders of consciousness (stupor, sopor, stupor, psychoemotional agitation), fever with neurological deficit; inflammatory changes in the cerebrospinal fluid.
Acute cerebrovascular accident in the vertebral and basilar artery basin also often has to be differentiated from botulism, since diplopia, dysphonia, dysphagia, and dysarthria are usually recorded in the symptom complex. Distinctive symptoms are asymmetry of the lesion, frequent prevalence of pronounced dizziness and/or ataxia, sensory disorders in the trunk and limbs by hemitype (hemiparesis is rare), and in this pathology the respiratory muscles are not affected.
Guillain-Barré syndrome is an acute demyelinating polyneuropathy (most cases are caused by herpes viruses). Particularly difficult is the differential diagnosis of botulism with a variant of Guillain-Barré syndrome, which occurs with ophthalmoplegia, areflexia and ataxia (Fischer syndrome). Distinguishing features are that sensitivity is almost always impaired, and the protein content in the cerebrospinal fluid is often increased.