Botulism

Botulism is a toxin-based illness that results in flaccid paralysis of a person's muscles. The toxin is a neurotoxin produced by a bacterium known as Clostridium botulinum. In fact, there are seven total neurotoxins that cause the paralysis that are labelled A through F. The most common types to cause paralysis in humans are types A, B, E and rarely F. The toxin cannot be passed on from person to person but is found in unpasteurized food or in wounds.

Botulinum toxin blocks the release of acetylcholine from the nerve endings of the motor nerves. It was first identified in 1895 and was isolated in 1945. It is one of the most dangerous toxins man can encounter. Interestingly, it has been used to treat several medical diseases, such as strabismus, blepharospasm and hemi-facial spasm. It is also used in cosmetic surgery in very small doses. Certain diseases involving muscle pain can be treated with judicious use of botulinum toxin.

There are three major types of botulism. They depend on how the disease is spread. The first is food-borne botulism, which is caused by eating under processed food that contains the botulinum toxin. Infant botulism happens when a baby ingests botulinum spores from honey, which can contain botulism. Other foods can cause the same problem if poorly prepared. Wound botulism is obtained when a person is infected with the toxin through an open wound. In rare cases, older children or adults can get botulism if they have abnormal bowel systems. Some people can get botulism from getting too much Botox injected. Botulism, in any form, is potentially fatal.

Botulism is a severe illness due to its extreme potency. As little as one nanograms per kilogram of body weight can kill a person so that a gram of botulinum toxin can potentially kill a million individuals. This means that botulism would make a good bio-weapon and it has been studied for such purposes. Even small amounts of contaminated food can be deadly if ingested. The neurotoxin paralyzes the nerves to that the muscles, including the muscles for breathing, are paralyzed. Acetylcholine cannot be released from the nerve so that the muscle cannot contract. This is a long lasting phenomenon and it takes many months to recover nerve function again.

Clostridium botulinum is an anaerobic bacterium that grows best in situations of low oxygen. They are gram positive rod-shaped bacteria that can form spores that keep the bacteria dormant until growth can be supported again. The disease is uncommon, affecting around 1000 people worldwide. It is more common in those that can their own food and in those that feed their infants honey. The incidence of wound-caused botulism has increased, due to the increase in use of black-tar heroin.

The main symptoms of botulism include having blurry vision, double vision, drooping eyelids, slurred speech, dry mouth, problems swallowing, constipation and muscle weakness. The gag reflex and other reflexes are diminished. Babies with botulism are weak, lethargic, feed poorly, are floppy and become constipated. The muscle tone is diminished and their cry is weak. Constipation is usually the first symptom to manifest itself. In both adults and babies, the muscles used for breathing are affected and the person needs to be on a ventilator. Symptoms begin within 18 to 36 hours after ingestion of food that is contaminated.

Doctors diagnose botulism by doing a careful history and physical examination. The muscles are weak and the reflexes are diminished. Unfortunately, other diseases can mimic botulism and so doctors need to do a CT scan of the brain, a cerebrospinal fluid evaluation and nerve conduction studies to see if other illnesses are causing the symptoms. If botulism is suspected, antiserum should be given in order to block the effects of the toxin. The best way to diagnose the disease is to identify the neurotoxin in the individual's blood. It is done by injecting patient serum into the peritoneal cavity of mice and injecting another amount of serum or stool treated with antiserum into other mice. If the mice untreated with antiserum die and the treated mice live, the diagnosis is botulism.

The treatment of botulism is medical support and the giving of antitoxin that blocks the neurotoxin in the blood stream. There is a trivalent toxin effective against toxins A, B and E at the CDC, which is given out in cases of suspected botulism. Recovery still takes a great many weeks, even if the antitoxin is given. The US Army or FEMA have antitoxin available against all types of neurotoxins, particularly for cases of bioterrorism.