Bioterrorism

Botulism

What is botulism?

Botulism, a paralytic illness, is rare, but can cause serious, paralyzing symptoms and may be fatal. The disease is caused by a nerve toxin formed from a group of bacteria, called Clostridium botulinum, which are found in soil. There are seven known botulism toxins, but only toxins type A, B, E, and F are seen as being harmful to humans. From the four toxins that are known to be harmful to humans, there are three kinds of botulism, characterized differently due to their means of exposure:

foodborne botulism
This type of botulism is caused by eating food contaminated with a botulism toxin. Foodborne botulism can affect a great number of people poisoned by eating contaminated food.

The World Health Organization (WHO) considers botulism one of the four most likely pathogens to be used in biological warfare (a state in which infectious agents or toxic chemicals are being used as a weapon of mass destruction).
wound botulism
This type of botulism is caused by a botulism toxin that is produced from a wound that was contaminated with Clostridium botulinum.
infant botulism
This type of botulism occurs when infants consume spores of Clostridium botulinum, which then release toxins in the intestines.

How prevalent is botulism?

On average, 110 cases of botulism are reported in the United States each year. Of these:

25 percent are foodborne botulism.
72 percent are infant botulism.
3 percent are wound botulism.

What are the symptoms of botulism?

The symptoms of foodborne botulism usually occur 18 to 36 hours after eating the contaminated food. However, symptoms may occur as early as six hours or as late as 10 days following exposure. The following are the most common symptoms of botulism, in general. However, each individual may experience symptoms differently. Symptoms may include:

double vision or blurred vision
drooping eyelids
slurred speech
difficultyswallowing
dry mouth
muscle weakness

Infants with botulism may seem lethargic, feed poorly, experience constipation, and have a weak cry and poor muscle tone. If left untreated, symptoms may progress to paralysis of the arms, legs, trunk, and respiratory muscles.The symptoms of botulism may resemble other medical conditions or problems. Always consult your physician for a diagnosis.

How is botulism diagnosed?

The patient's history and physical examination may lead to a diagnosis of botulism. However, since botulism resembles other diseases such as a stroke, myasthenia gravis, and Guillain-Barré syndrome, other diagnostic testing may be necessary, including the following:

computed tomography scan (Also called a CT or CAT scan.) - a diagnostic imaging procedure that uses a combination of x-rays and computer technology to produce cross-sectional images (often called slices), both horizontally and vertically, of the body. A CT scan shows detailed images of any part of the body, including the brain, bones, muscles, fat, and organs. CT scans are more detailed than general x-rays.
spinal tap (Also called a lumbar puncture.) - a special needle is placed into the lower back, into the spinal canal. This is the area around the spinal cord. The pressure in the spinal canal and brain can then be measured. A small amount of cerebral spinal fluid (CSF) can be removed and sent for testing to determine if there is an infection or other problems.
electromyogram (EMG) - a test that measures the electrical activity of a muscle or a group of muscles. An EMG can detect abnormal electrical muscle activity due to diseases and neuromuscular conditions.
tensilon test (for myasthenia gravis) - a test that helps to determine the cause of muscle weakness. The test is named after the drug Tensilon (also called edrophonium chloride), a rapid-acting drug that improves muscle strength. After Tensilon is administered intravenously (IV), the individual is asked to perform repetitive muscle movements, such as crossing and uncrossing your legs and opening and closing your eyes. Muscle strength is then evaluated to help diagnose myasthenia gravis.
test for botulism toxin in the patient's serum or stool

Treatment for botulism:

Specific treatment for botulism will be determined by your physician based on:

your age, overall health, and medical history
extent of the condition
your tolerance for specific medications, procedures, or therapies
expectations for the course of the condition
your opinion or preference

Treatment may include:

antitoxin treatment for foodborne and wound botulism (when diagnosed early)
removal of contaminated food in the gut through induced vomiting or enemas
surgical treatment for infected wounds (to remove the source of the toxin)
respiratory assistance (ventilator) for patients who experience respiratory failure and paralysis
intensive medical and supportive care

Recovery from botulism may take many weeks. Treatment for severe botulism may take several months. Fatigue and shortness of breath may persist for years.

Preventing botulism:

Most foodborne botulism cases are caused by home-canned foods with low acid content, such as asparagus, beets, corn, and green beans. More unusual sources of foodborne botulism have included the following:

chopped garlic in oil
chile peppers
tomatoes
improperly handled baked potatoes in aluminum foil
home-canned or fermented fish

To reduce contamination, home-canning should be done following strict hygienic procedures set by county extension services or by the US Department of Agriculture. Botulism spores are killed by high temperatures. It is advisable to boil home-canned foods for 10 minutes before consumption. Other preventive measures should include the following:

Garlic and other herbs in oils should be refrigerated.
Potatoes baked in aluminum foil should be kept hot until served or refrigerated.
Children under the age of 12 months should not be fed honey, because it can contain botulism spores.
Seek prompt medical care for infected wounds.
Do not use injectable street drugs.

Always consult your physician for more information.

This page was last updated on: March 11, 2008.

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