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Botulism - Human Botulism Symptoms

A paralytic illness, botulism results from an exotoxin produced by the gram-positive, anaerobic bacillus Clostridium botulinum. It occurs as botulism food poisoning, wound botulism, and infant botulism. Mortality from botulism is about 25%, with death most often caused by respiratory failure during the first week of illness.

In the United States an average of 110 cases of botulism are reported each year. Of these, approximately 25% are food borne, 72% are infant botulism, and the rest are wound botulism. Outbreaks of food borne botulism involving two or more persons occur most years and usually caused by eating contaminated home-canned foods. The number of cases of foodborne and infant botulism has changed little in recent years, but wound botulism has increased because of the use of black-tar heroin, especially in California.

Causes

Botulism is usually the result of ingesting inadequately cooked contaminated foods, especially those with low acid content, such as home-canned fruits and vegetables, sausages, and smoked or preserved fish or meat. Honey and corn syrup may contain C. botulinum spores and shouldn't be fed to infants. Rarely, botulism results from wound infection with C. botulinum.

Botulism occurs worldwide and affects adults more often than children. Recently, findings have shown that an infant's GI tract can become colonized with C. botulinum from some unknown source, and then the exotoxin is produced within the infant's intestine. Incidence had been declining, but the current trend toward home canning has resulted in an upswing (approximately 250 cases per year in the United States) in recent years.

Signs and symptoms

The disease usually presents within 12 to 36 hours (range is 6 hours to 8 days) after the ingestion of contaminated food.The severity varies with the amount of toxin ingested and the patient's degree of immunocompetence. Generally, early onset (within 24 hours) signals critical and potentially fatal illness. Initial symptoms include dry mouth, sore throat, weakness, vomiting, and diarrhea.

The cardinal sign of botulism, though, is acute symmetrical cranial nerve impairment (ptosis, diplopia, dysarthria), followed by descending weakness or paralysis of muscles in the extremities or trunk and dyspnea from respiratory muscle paralysis. Such impairment doesn't affect mental or sensory processes and isn't associated with fever.

Infant botulism

Usually afflicting infants ages 3 to 20 weeks, infant botulism can produce hypotonic (floppy) infant syndrome. Symptoms are constipation, feeble cry, depressed gag reflex, and inability to suck. Cranial nerve deficits also occur in infants and are manifested by a flaccid facial expression, ptosis, and ophthalmoplegia. Infants also develop generalized muscle weakness, hypotonia, and areflexia. Loss of head control may be striking. Respiratory arrest is likely.

Diagnosis

Identification of the offending toxin in the patient's serum, stool, or gastric content or in the suspected food confirms the diagnosis. An electromyogram showing diminished muscle action potential after a single supramaximal nerve stimulus is also diagnostic.

Treatment

I.V. or LM. administration of botulinum antitoxin (available through the Centers for Disease Control and Prevention) is the treatment of choice.

If you're having trouble breathing, you will probably need to use a ventilator. The ventilator pumps air to your lungs through a tube inserted in your airway through your nose or mouth. You may remain on the ventilator for some time - perhaps several weeks - as the effects of the toxin gradually lessen.

If you have botulism in a wound, a doctor may need to remove infected tissue surgically. You may also require therapy to improve your speech, swallowing and other functions affected by the disease.

Prevention

Kids aren't the ones canning food, but if their parents do, they can talk to them about the safety rules.

• Do NOT give honey or corn syrup to infants younger than 1 year old -- not even just a little taste on a pacifier!
• Always discard bulging cans or off-smelling preserved foods. Sterilize home-canned foods by pressure cooking at 250 degrees Fahrenheit for 30 minutes.
• To prevent wound botulism and other serious blood-borne diseases, never inject street drugs.
• Keep foil-wrapped baked potatoes hot or in the refrigerator, not out in room temperature.
• Prevent infant botulism by breast-feeding, if possible.