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Botulism:
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Bacterial agent primarily active against humans |
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Synopsis, Diagnosis, Symptoms,
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| See also the entry on Clostridium botulinum toxin. | |
Safety Precautions for Botulism Casualties |
Standard Precautions defined by the 1996 CDC guidelines should be adopted for handling patients.Biosafety level 2 practices should be adopted for handling of samples. |
| Causative organism: (Systematic name in 1997) | Clostridium botulinum |
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| Older names: | Bacillus botulinus |
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| Properties: | Large, Gram-positive, anaerobic bacillus, motile with peritrichous flagella,
spore-forming.
(Cells stain blue in the Gram stain, they do require oxygen for growth, are rod-shaped, move by their own power and are covered with hair-like structures used in movement, and spread by forming spores that are resistant to extremes of the environment. The spores are in a slightly different position in the cell from those seen in Bacillus.) |
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| Vector involvement: | None. The disease is most often contracted from contaminated meat. |
The primary sign is a loss of feeling on both sides of the face with paralysis moving rapidly down the body from the head. The patient remains alert and shows no signs of fever. The key diagnostic test is a positive immunoassay for botulinus toxin in serum or stool.
Symptoms and effects.
The primary symptoms are those of poisoning with botulinus toxin. Strains of C. botulinum that do not produce the toxin do not cause any symptoms.
There is no incubation period as such. Symptoms of poisoning begin to appear within a few hours of ingestion. The sooner they appear, the more serious the effects and the poorer the potential outcome. Initial symptoms include a dry mouth, sore throat, weakness and limp paralysis, dizziness, vomiting and diarrhea. There is no fever and the patient remains alert. The limp paralysis first affects the head and face and then descends through the body. Death comes from an inability to breath as the muscles of the chest and diaphragm that control breathing lose function.
Differential DiagnosisOther disease or conditions that need to be eliminated | |
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| Other infectious diseases | Other problems |
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Vaccination (Immunoprophylaxis).
A toxoid (inactivated toxin) offering immunity to types A-E of the toxin is available as an investigative new drug in the United States.
Polyvalent horse antiserum to the toxin is used treat the disease. Administration must begin at the first indication of possible intoxication.Supplies are extremely limited. At one point in the early 1990's, only one horse was producing horse antiserum.
A vaccine using a genetically engineered form of the toxin is under development in the United Kingdom.
Antibiotics.
Antibiotics are not used as a primary treatment of botulism. C. botulinum may be resistant to some aminoglycoside antibiotics, but is generally susceptible to antibiotics.
Supportive care
Primary treatment is with an antitoxin.
Patients will need to have their breathing supported.
Decontamination.
The bacterium is susceptible to many disinfectants including hypochlorite and ethanol. The toxin is inactivated by 0.1N NaOH and is destroyed by boiling for 10 min. Moist heat at 120°C for at least 15 min destroys spores.
C. botulinum is hardy and forms spore that can survive for decades. These spores could be dispersed as an aerosol, but as the bacterium is very sensitive to oxygen, it will only grow in anaerobic areas of the body, notably the digestive tract and in wounds. It will not grow in the lungs and nasal passages.
The agent achieves its action through its toxin. This is the most poisonous substance known and the quantities involved are too small to allow survivors to develop immunity. Repeated attacks may therefore be used to exhaust supplies of the antitoxin.
Secondary infection through contaminated food can be avoided by thorough cooking and cleaning.
The bacterium can use waterfowl and fish as a reservoir from which it can continue to cause problems.
Terrorist Acquisition and Attempted Use.
Antibiotic Resistance.
There is no information about acquired antibiotic resistance in Clostridium and there is arguably little pressure to develop antibiotic resistant strains because of the extreme toxicity of the bacterial toxin.
| IDC Codes: | ICD-9-CM | ICD-10 |
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| Botulism | 005.1 | A05.1 |
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