Botulism is a rare disease, but also very dangerous. It is caused by a nerve toxin, which is produced by the bacterium Clostridium botulinum.
There are three main types of botulism, which are based on the way in which the toxin is taken into the human body. The first type, food-borne botulism, is caused when a human consumes food or drink that contains the toxin. A second type, wound botulism, is caused by contact of an open wound with the toxin. The last type, infant botulism, is caused by consumption of spores of the bacterium. The spores find their way to the intestine, where they become bacteria and produce the toxin.
The bacterium that releases the botulism toxin, Clostridium botulinum, is normally found in soil and grows the fastest in environments containing low amounts of oxygen. The bacterium is rod-shaped and are able to form into spores, which are dormant until they reach an environment that can support their growth.
The actual botulism toxin has seven different types, which have the names A through G. Of this group, only four types, A, B, E, and F, are toxic to humans.
Botulism is a rare disease, which is only reported an average of 110 times annually in the United States. Of these cases, about 25% are of the food-borne type, 72% of infant type, and only 3% of wound type. Outbreaks are rare, but usually occur when a group of individuals eats contaminated home-canned food. Wound botulism cases are usually the result of using contaminated portions of the illegal narcotic heroin.
Symptoms of botulism are all related to the nervous system, since that is the target of the toxin. They typically include double vision, blurred vision, slurred speech, difficulty in swallowing, dry mouth, muscle weakness, and droopy eyelids. Infants infected with botulism will often eat little or nothing, experience constipation, and develop very low muscle tone. If the disease is left untreated, it has the potential of causing complete paralysis or even death.
Diagnosis of botulism can be difficult since other diseases such as Guillain-Barre syndrome and strokes produce similar symptoms. If a physician suspects botulism, they will likely perform brain scans, examine spinal fluid, test the conduction of the nerves, and inject mice with blood or stool samples. If botulism is found, the CDC typically conducts an investigation to determine the source and find any other potential victims.
Once botulism is found, the patient is usually given an antitoxin, which is able to prevent the toxin from causing further damage. If the disease has generated paralysis, the patient may have to endure several weeks of recovery in an iron lung. In most cases, the recovery takes at least several weeks as the body repairs its nervous system.
Recently, a seemingly positive application of botulism was found. A very diluted form of toxin type A was released as Botox, a prescription drug. Botox is used by physicians to paralyze muscles in the forehead, which typically wrinkle during expression. However, many people have criticized the procedure for making people look strange and removing an important element of human emotional expression.