Botulism is a serious illness that causes flaccid paralysis of muscles. It is caused by a neurotoxin, generically called botulinum toxin, produced by the bacterium Clostridium botulinum (and rarely by C. butyricum and C. baratii). There are seven distinct neurotoxins (types A-G) that Clostridium botulinum produces, but types A, B, and E (and rarely F) are the most common that produce the flaccid paralysis in humans. The other types mainly cause disease in animals and birds, which also develop flaccid paralysis. Most Clostridium species produce only one type of neurotoxin; however, the effects of A, B, E, or F on humans are essentially the same. Botulism is not transmitted person to person. Botulism develops if a person ingests the toxin (or rarely, if it is inhaled or injected) or if the Clostridium spp. organisms grow in the intestines or wounds in the body and toxin is released. The recorded history of botulism begins in 1735, when the disease was first associated with German sausage (food-borne disease or food poisoning after eating sausage). In 1870, a German physician by the name of Muller derived the name botulism from the Latin word for sausage. Clostridium botulinum bacteria were first isolated in 1895, and a neurotoxin that it produces was isolated in 1944 by Dr. Edward Schantz. From1949 to the 1950s, the toxin (named BoNT A) was shown to block neuromuscular transmissions by blocking the release of acetylcholine from motor nerve endings. Botulism toxin(s) are some of the most toxic substances known to man; while the toxin has been considered for use as a biological weapon, it has also been used to treat many medical conditions. In 1980, Dr. Scott used the toxin to treat strabismus (deviation of the eye), and in December 1989, BoNT-A (BOTOX) was approved by the U.S. Food and Drug Administration (FDA) for the treatment of strabismus, blepharospasm, and hemifacial spasm in young patients. The use of BOTOX to treat glabellar lines (wrinkles and frown lines) was approved in 2002 by the FDA for cosmetic improvements; the FDA has approved many additional uses (for example, underarm sweating, and muscle pain disorders) since 2002.
Symptoms of botulism
The classic symptoms of botulism include double vision, blurred vision, drooping eyelids, slurred speech, difficulty swallowing, dry mouth, and muscle weakness. Constipation may occur. The doctor's examination may reveal that the gag reflex and the deep tendon reflexes like the knee-jerk reflex are decreased or absent. Infants with botulism appear lethargic, weak, and floppy, feed poorly, become constipated, and have a weak cry and poor muscle tone. In infants, constipation is often the first symptom to occur. These are all symptoms of the muscle paralysis that is caused by the bacterial neurotoxin. If untreated, these symptoms may progress to cause paralysis in various parts of the body, often seen as a descending paralysis of the arms, legs, trunk, and breathing muscles.
How soon do symptoms appear?
In food-borne botulism, symptoms generally begin 18-36 hours after eating a contaminated food, but they can occur as early as six hours or as late as 10 days afterward.
The patient's history and physical examination may suggest botulism, but these clues are usually not enough to allow a diagnosis of botulism. Symptoms of other diseases, such as a stroke, Guillain-Barré syndrome (another disease of muscle paralysis), andmyasthenia gravis (which also causes weakness and eyelid drooping) can appear similar to those of botulism. Special tests may be needed to exclude these other conditions. These tests may include a brain scan, spinal fluid examination, nerve conduction test (electromyography, or EMG), and a tensilon test for myasthenia gravis. However, if botulism is strongly suspected (for example, several patients with botulism symptoms who ate from the same home-preserved food container), samples should be obtained for a mouse...
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