BOTULISM

29 years old female evaluated in the emergency department for two days history of blurred vision,diplopia,slurred speech, followed by bilateral upper extremity weakness.examination of the patient ,the patient was alert,,awake fully oriented,afebrile,blood pressure 90/60,pulse rate 50/min,and respiratory rate 12/min,pupiledilated,with bilateral VI nerve palsy and she cannot abduct her arm against resistance.brain CT and cerebrospinal fluid examination normal

Which of the following is the most likely diagnosis

a-botulism
b-Guillain –Barre syndrome
c- stroke
d-poliomylitis
e- meningitis

Botulism

Clostridium botulinum

Gram positive
Obligate anaerobic bacillus
Spores


Ubiquitous
Resistant to heat, light, drying and radiation
Specific conditions for germination
Anaerobic conditions
Warmth (10-50oC)
Mild alkalinity

Neurotoxins

eight different types: A through G
Different types affect different species
All cause flaccid paralysis
Only a few nanograms can cause illness
Binds neuromuscular junctions
Toxin: Destroyed by boiling
Spores: Higher temperatures to be inactivated

History

1793, Justinius Kerner
“Wurstgift”
“Botulus” = Latin for sausage
1895, Emile von Ermengem
Isolated organism during Belgium outbreak

Transmission

Ingestion
Organism
Spores
Neurotoxin
Wound contamination
Inhalation
Person-to-person not documented

Categories of Human Botulism

• Foodborne botulism
• Infant botulism
• Wound botulism
• Adult infectious botulism

Foodborne Botulism

Preformed toxin ingested from contaminated food
Most common from
home-canned foods
Asparagus, green beans, beets, corn, baked potatoes, garlic, chile peppers, tomatoes;
Improperly fermented fish (Alaska); type E

Infant Botulism

Most common form in U.S.
Spore ingestion
Germinate then toxin released and colonize large intestine
Infants < 1 year old
94% < 6 months old
Spores from varied sources
Honey, corn syrup

Wound Botulism

1951 Wound botulism was described for the first time.
is rare and organism gets into an open wound
Develops under anaerobic conditions
organism typically comes from ground-in dirt or gravel
It does not penetrate intact skin

Adult Clinical Symptomes

Nausea, vomiting, diarrhea
Cranial nerve involvement, which almost always marks the onset of symptoms, usually produces
Double vision
Difficulty speaking or swallowing

Descending Symmetrical flaccid paralysis

Respiratory muscle paralysis


Paralytic ileus, severe constipation
urinary retention are common.

Typically, they have no fever or it is rare

Patients are usually alert and oriented
Ptosis is frequent; the pupillary reflexes may be depressed
fixed or dilated pupils are noted in half of patients.
The gag reflex may be suppressed,
have intact deep tendon reflexes
Sensory findings are usually absent.

Infant Clinical Signs

Constipation
Lethargy
Poor feeding
Weak cry
Bulbar palsies
Failure to thrive

Mechanism of Toxin

Neurotoxin 0 binds to neurons 0

internalized 0

prevents release of acetyl choline (neurotrasmitter)

Diagnosis

A diagnosis of botulism is clinical and must be considered in patients with
symmetric descending paralysis
who are afebrile
and mentally intact
Toxin in serum, stool, gastric aspirate, suspected food
Culture of stool or gastric aspirate
Takes 5-7 days
Electromyography also diagnostic

Differentiate from?

Guillain-Barré syndromea and its variants, especially Miller-Fisher variant paralysis
History of antecedent infection
paresthesias often ascending
early areflexia;
EMG findings
Myasthenia gravis:
Recurrent paralysis
EMG findings

Stroke

Paralysis often asymmetric
abnormal CNS image

Lambert-Eaton syndrome

EMG: Increased strength with sustained contraction
evidence of lung carcinoma

CNS infections, especially of the brainstem

Treatment
Intensive care immediately
Patients should be hospitalized and monitored closely, both clinically and by spirometry, pulse oximetry, and measurement of arterial blood gases for incipient respiratory failure
equine antitoxin should be administered as soon as possible after specimens are obtained for laboratory analysis

Treatment

In food-borne case
purging the gut with cathartics ,enemas, and emetics to remove unabsorbed toxin also may be of value.

Antibiotic therapy does not affect the course of illness