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BOTULISM
TOXICOLOGY, CLINICAL PRESENTATION AND MANAGEMENT
Agent:
Botulinum toxin derived from Clostridium botulinum
Common
name: "Sausage Poison"
History
Potentials as a biological weapon
Toxicology and Microbiology
Epidemiology
Transmission
Incubation Period
Clinical Features
Morbidity / Mortality
Diagnosis
Features of an outbreak suggesting deliberate release
of botulinum toxin
Therapy
Prevention
Reporting/ Appropriate action
Selected References
View Dr. Janak Koirala's Presentation
on Botulism (Adobe
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History
- Justinus Kerner (1786-1862)
published first complete description as a fatty poison. He also
performed animal and clinical experiments, and even thought about
its therapeutic usage. He is also known as "Sausage Kerner" in Germany
as the toxin was known as "sausage poison" at that time. [1]
- Muller (Germany, 1870)
further characterized and named it "botulus", which means "sausage"
in Latin. Van Ermengem (Belgium, 1895) discovered the bacteria.
Alan B. Scott (USA) used it for chemodenervation in monkey (1973)
and human (1980).
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Potentials
as a biological weapon
- Japanese fed their
prisoners C. botulinum cultures in 1930's with fatal effects.
- Allied troops received
botulinum toxoid vaccine during world war II with the concerns that
Germany had weaponized botulinum toxin. [5]
- Besides USA and former
USSR, four other countries have developed or are believed to be
developing botulinum toxin as biological warfare agent- Iraq, North
Korea, Iran and Syria.
- A Japanese cult Aum
Shinrikyo dispersed aerosols in Tokyo and US military installations
in Japan on 3 occasions between 1990-95. [3]
- United Nations inspecting
team visiting Iraq after Gulf War (1991) reported that Iraq admitted
to having 19000 L of concentrated botulinum toxin, enough to kill
the entire human population 3 times by inhalation. In 1990 Iraq
deployed 600-km range missiles and 100 lb bombs filled with botulinum
toxin, aflatoxin and anthrax spores. [3]
- Botulinum toxin may
be used to immobilize the opponent in military. It has been estimated
that as a point source aerosol, it can be used against a civilian
population in a densely populated area to incapacitate or kill 10%
of population within 0.5 km downwind. In addition, it can be used
to deliberately contaminate food. [3]
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Toxicology and Microbiology
- Botulinum toxin is
an enzyme produced by the Clostridium botulinum, which is a spore
forming, obligate anaerobic bacillus. There are 4 genetically diverse
groups of this organism. They are commonly found in soils and aquatic
habitats throughout the world.
- Besides, Clostridium
baratii and Clostridium butyricum can also produce botulinum toxin.
- C. botulinum is a anaerobic,
motile, gram-positive (in young cultures), straight to slightly
curved rod with oval, subterminal spores. It is about 0.5-2.0 µm
in width, 1.6-22.0 µm in length.
- Botulinum toxin is
the most poisonous substance known to human. One gram of crystalline
toxin is enough to kill one million people. There are 7 subtypes
of this toxin, designated with letters A through G. LD50 (lethal
dose to 50% of exposed population) for botulinum toxin is estimated
to be 1ng/kg parenterally and 3ng/kg by inhalational route. [5]
- It is a zinc protease
that cleaves fusion proteins, which are needed at neuronal vesicles
to release acetylcholine into the neuromuscular junction. This blockade
results in flaccid paralysis of muscles.
- Therapeutic use of
botulinum toxin: US FDA has approved botulinum toxin preparations
(type A= BOTOX, type B= Myobloc) for the treatment of cervical dystonia,
blepharospasm, glabellar lines, spasmodic torticollis, strabismus.
BOTOX has also been approved for the treatment of glabellar frown
lines in both USA and Canada. [2,14]
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Epidemiology
- Worldwide distribution:
sporadic cases, family and general outbreaks occur where food products
are prepared or preserved by proper methods
- USA (source: CDC, year
1999): 174 cases of botulism reported, 26 foodborne, 107 infant
botulism, and 41 wound botulism.
- Recently identified
vehicles for foodborne botulism: homemade salsa, baked potatoes
sealed in aluminium foil, cheese sauce, sauteed onions under a layer
of butter, garlic in oil, salted or fermented fish, Jalapeno peppers,
potato salad, etc. [18]
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Transmission
- 3 natural forms: foodborne,
wound, intestinal- bacteria multiply in food or necrotic tissues
of wound or intestines, resulting in toxin production.
- Inhalational: manmade
aerosolized form can be used as weapon of bioterrorism.
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Incubation Period
- Foodborne: typical:
12-72 hrs (range: 2 hrs to 8 days)
- Inhalational: approximately
72 hrs
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Clinical Features
- Classic triad of botulism:
- acute, symmetric,
descending flaccid paralysis with prominent bulbar palsies
- no fever
- clear sensorium
- Features of bulbar
palsy present in >90% patients: diplopia , dysarthria, dysphonia,
dysphagia (difficulty with seeing, speaking and swallowing)
- Blurry vision with
ptosis, diplopia, enlarged pupils with sluggish reactions
- Flaccid paralysis progresses
in descending manner- loss of head control, generalized weakness
and hypotonia, loss of deep tendon reflexes (in days), airway obstruction
and respiratory muscle paralysis requiring ventilatory support
- Death results from
airway obstruction and respiratory muscle paralysis
- Gastrointestinal symptoms
present in foodborne botulism- abdominal cramps, nausea, vomiting,
diarrhea
- Excerpts from Justinus
Kerner's monograph:
Symptoms of Sausage Poisoning (Botulism):
"The tear fluid disappears, the gullet becomes a dead and motionless
tube; in all mucous cavities of the human machine the secretion
of the normal mucus stands still, from the biggest, the stomach,
towards the tear canal and the excretory ducts of the lingual glands.
No saliva is secreted. No drop of wetness is felt in the mouth,
no tear is secreted anymore. No earwax appears in the auditory canal,
also signs of drying out of the Eustachian tube become apparent.
No mucus is secreted in the nose; no more sperma is secreted, the
testicles decrease. Urination can only be performed by standing
and with difficulty. Extreme drying out of the palms, the soles
and the eyelids occurs."
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Morbidity / Mortality
- Paralysis may persist
for weeks to months
- Mortality: food botulism-
5-10% treated, 60% untreated patients - Early deaths: result from
a failure to recognize the severity of disease or from secondary
pulmonary or systemic infections - Deaths after 2 weeks: usually
from the complications of long-term mechanical respiratory management.
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Diagnosis
- based on clinical features
for initial management
- EMG (electromyography)
may helpful in establishing diagnosis:
- normal NCV (nerve
conduction velocity) and sensory nerve function
- a pattern of brief
small amplitude motor potentials
- a repetitive nerve
stimulation at 20-50 Hz may show a characteristic incremental
response.
- Laboratory diagnosis:
Botulinum toxin is identified by mouse bioassay, which can detect
as little as 0.03ng of the toxin.
- Botulinum toxin
assay is available in CDC and state labs
- samples of serum,
gastrointestinal content and suspected source (e.g. food) should
be collected and tested for botulinum toxin
- Fecal and gastric
samples can also be cultured anaerobically. Takes 7-10 days
(range 5-20 days).
- Acceptable specimens
(for testing at higher-level LRN laboratories) [4]:
- Clinical specimens:
gastric contents, exudates, tissues, serum, etc.
- Postmortem
specimens
- Culture/isolate
- Food samples
(solid or liquid)
- Environmental
samples: soil, water
- Precautions [4]:
- These procedures
should be performed in microbiology laboratories that use
Biological Safety Level-2 practices.
- Level A Laboratories
should not attempt to culture, identify the organism, or
attempt to perform toxin analysis.
- Enzyme linked immunosorbent
assay from nasal mucosa taken within 24 hours of exposure has been
used by military for detection of aerosolized toxin [5]. Alternative
in vitro assays, amplified ELISA and PCR are under development [9,10,16].
- CSF remains normal
but may be useful to differentiate from other CNS causes.
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Features of an outbreak suggesting deliberate release of botulinum
toxin
- Outbreak of a large
number of cases of acute flaccid paralysis with prominent bulbar
palsies
- Outbreak with an unusual
botulinum toxin type (i.e., type C, D, F, or G, or type E toxin
not acquired from an aquatic food)
- Outbreak with a common
geographic factor among cases but without a common dietary exposure,
i.e. suggesting a possible aerosol attack.
- Multiple simultaneous
outbreaks with no common source A careful travel and activity history,
as well as dietary history, should be taken in any suspected botulism
outbreak. Patients should also be asked if they know of other persons
with similar symptoms.
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Therapy
- Passive immunization:
- Botulinum antitoxin
is an equine antitoxin available from CDC via state and local
health departments in USA. It contains neutralizing antibodies
against A, B and E.
- A heptavalent (A-G)
investigational antitoxin is held by US Army.
- A human antitoxin
(Human Botulism Immune Globulin, HBIG) is available as an investigational
agent for infant botulism (California Department of Public Health)
[15]
- Each 10ml vial
of trivalent equine antitoxin (ABE) contains 5500-8500 IU of
antibodies of each type, and is administered IV after diluting
1:10 with 0.9% saline.
- Administer as soon
as possible after clinical diagnosis to minimize neurological
progression. It does not reverse existent paralysis.
- One vial of antitoxin
is generally enough for food borne botulism.
- In case of intentional
exposure, adequacy can be confirmed by retesting serum for toxin
after administering usual dose of antitoxin.
- Children, pregnant
women and immunocompromized group have been treated with equine
antitoxin safely.
- Side effects: serum
sickness (2%), urticaria (9%), mild hypersensitivity (18%),
anaphylaxis (2%). Skin test followed by desensitization in patients
with wheal and flare should be done by administering incremental
doses over 3-4 hours. [3]
- Supportive care
- reverse trendelenberg
positioning (20-250) for airway protection and improved respiration
- assisted ventilation
required in 20% adults and 60% infant botulism
- fluid and nutritional
support
- treatment of complications
including secondary infections
- Role of antibiotics
in treatment of botulism remains unclear, but penicillin G has been
recommended to treat wound botulism. Antibiotics are also useful
in treatment of secondary infections. Aminoglycosides and clindamycin
are contraindicated because of their ability to exacerbate neuromuscular
blockade. [3,7,8]
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Prevention
- Botulinum toxoid
- a pentavalent (ABCDE),
investigational vaccine is available for high risk laboratory
personnel and military. Its efficacy tested during Gulf war
showed good immunogenic response with a second booster (28%
with first, 97% with booster). [12]
- A tetravalent vaccine
(ABEF) tested in Japan seems to need 3 or more doses [13]. A
candidate vaccine against botulinum neurotoxin serotype A (BoNT/A)
developed by using Venezuelan equine encephalitis (VEE) virus
vector is also being tested [17]
- Postexposure prophylaxis
- Early treatment
with antitoxin after exposure to botulinum toxin has been shown
to reduce neurological manifestations.
- To balance between
the need of scarce equine antitoxin with its potential side
effects and the advantages of early treatment after an intentional
or unintentional outbreak, it has been suggested to closely
observe exposed patients and administer antitoxin when early
signs appear.
- CDC maintains US
Botulism Surveillance System and releases antitoxin through
its network within United States. CDC also provides antitoxin
to other countries of Western Hemisphere through its contract
with PAHO (Pan American Health Organization) with exception
of Canada. Canada has its own supply of botulinum antitoxin.
[11]
- Decontamination:
- Botulinum toxin
can be destroyed by heating food and drink to core temperature
of 850 C for 5 minutes, but all suspected food should be removed
and sent to Public Health Department for testing.
- wash exposed clothes
and skin with soap and water
- clean objects and
surfaces with 0.1% hypochlorite bleach solution
- covering mouth
and nose with clothing provides some protection from aerosolized
toxin
- Infection Control:
standard precautions only
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Reporting/ Appropriate action
Clinicians:
Following steps are recommended by the Working Group on Civilian Biodefense
[3]:
Clinicians Caring for
Patients With Suspected Botulism Should Immediately Contact Their:
- Hospital epidemiologist
or infection control practitioner, and
- Local and state health
departments If the local and state health departments are unavailable,
contact the CDC: (404) 639-2206; (404) 639-2888
Labs:
Following Lab Protocol has been recommended by CDC, ASM and APHL [4]:
- Consult with state
public health laboratory director (or designate) if C. botulinum
toxin is suspected.
- General instruction
and information:
- Preserve original
specimens pursuant to a potential criminal investigation and
possible transfer to an appropriate LRN laboratory as instructed.
- Environmental/nonclinical
samples and samples from announced events should not be received
by a Level A laboratory; submitter should contact the state
public health laboratory directly.
- The state public
health laboratory/state public health department will coordinate
notification of local FBI agents as appropriate.
- Assist local law
enforcement efforts in conjunction with guidance received from
the state public health laboratory.
- FBI and state public
health laboratory/state public health department will coordinate
the transfer of isolates/specimens to a higher level LRN laboratory
as appropriate.
- In conjunction with
state public health laboratory, the laboratory may contact CDC as
appropriate.
- Emergency number,
24 h a day, 7 days a week: 770-488-7100
- National Botulism
Surveillance and Reference Laboratory: 404-639-3867
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Selected References
- Ergbuth FJ, Naumann
M. Historical aspects of Botulinum toxin: Justinus Kerner (1786-1862)
and "Sausage Poison". Neurology 1999;53:1850-1853.
- Carruthers A, Carruthers
J. Update on the botulinum neurotoxins. Skin Therapy Lett. 2001
Dec;6(13):1-2.
- Arnon SS, et al. Botulinum
toxin as a biological weapon: Medical and public health management.
JAMA 2001;285:1059-1070.
- CDC, ASM, APHL. Basic
Protocols for Level A Laboratories for Botulinum Toxin. Dec 2001;
1-13.
- Middlebrook JL, Franz
DR. Botulinum Toxins. In Textbook of Military Medicine Medical Aspects
of Chemical and Biological Warfare; By: The Surgeon General, 1997.
- Miller JM. Agents of
Bioterrorism. Infect Dis Clin North Am 2001;15(4):1127-1156.
- Santos JI, Swensen
P, Glasgow LA. Potentiation of Clostridium botulinum toxin by aminoglycoside
antibiotics: clinical and laboratory observations. Pediatrics. 1981;68:50-54.
- Schulze J, Toepfer
M, Schroff KC, et al. Clindamycin and nicotinic neuromuscular transmission.
Lancet 1999;354:1792-1793.
- Centers for Disease
Control and Prevention. Botulism in the United States 1899-1996:
Handbook for Epidemiologists, Clinicians, and Laboratory Workers.
Atlanta, Ga: Centers for Disease Control and Pre-vention; 1998.
Available at: http://www.cdc.gov
- Franciosa G, Ferreira
JL, Hatheway CL. Detection of type A, B, and E botulism neurotoxin
genes in Clostridium botulinum and other Clostridium species by
PCR: evidence of unexpressed type B toxin genes in type A toxigenic
organisms. J Clin Microbiol. 1994;32:1911-1917.
- Shapiro RL, Hatheway
C, Becher J, Swerdlow DL. Botulism surveillance and emergency response:
a public health strategy for a global challenge. JAMA. 1997; 278:433-435.
- Pittman PR, Hack D,
et al. Antibody response to a delayed booster dose of anthrax vaccine
and botulinum toxoid. Vaccine 2002;20(16):2107-15.
- Torii Y, Tokumaru Y,
et al. Production and immunogenic efficacy of botulinum tetravalent
(A,B,E,F) toxoid. Vaccine 2002.20(19-20):2556-61.
- National Drug Data
File (NDDF) from First Data Bank, available on /www.medscape.com/;
accessed on 8/12/2002.
- Shen WP, Felsing N,
Lang D, Goodman G, Cairo MS. Development of infant botulism in a
3-year-old female with neuroblastoma following autologous bone marrow
transplantation: potential use of human botulism immune globulin.
Bone Marrow Transplant 1994 Mar;13(3):345-7
- Ferreira JL, Eliasberg
SJ, et al. Detection of preformed type A botulinum toxin in hash
brown potatoes by using the mouse bioassay and modified ELISA test.
J AOAC Int 2001;84(5)1460-64.
- Lee JS, Pushko P, et
al. Candidate vaccine against botulinum neurotoxin serotype A derived
from a Venezuelan equine encephalitis virus vector system. Infect
Immun 2001;69(9):5709-15.
- Shapiro RL, Hatheway
C, Swerdlow DL. Botulism in the United States: A clinical and epidemiological
review. Ann Intern Med 1998;129:221-228.
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