Botulism

Definition

Definition of Botulism
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.

Symptoms

Symptoms of Botulism
Symptoms usually appear 8 - 36 hours after you eat contaminated food. There is NO fever with this infection.

In adults, symptoms may include:

1. Abdominal cramps
2. Breathing difficulty that may lead to respiratory failure
3. Difficulty swallowing and speaking
4. Double vision
5. Dry mouth
6. Nausea
7. Vomiting
8. Weakness with paralysis (equal on both sides of the body)

Causes

Causes of Botulism
Clostridium botulinum is found in soil and untreated water throughout the world. It produces spores that survive in improperly preserved or canned food, where they produce toxin. When eaten, even tiny amounts of this toxin can lead to severe poisoning.

The foods most commonly contaminated are home-canned vegetables, cured pork and ham, smoked or raw fish, and honey or corn syrup. Botulism may also occur if the bacteria enter open wounds and produce toxins there.

Infant botulism occurs when a baby eats living bacteria or its spores and they grow in the baby's gastrointestinal tract. The most common cause of infant botulism is eating honey or corn syrup.

Diagnosis

Diagnosis of Botulism
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), and myasthenia 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 inoculation test (see below) and then the patients should be treated immediately with botulism antiserum. These tests will help distinguish botulism from infections with Salmonella, E. coli, and other Clostridium species (tetanus).

Treatment

Treatment of Botulism
Most infant botulism patients require supportive care in a hospital setting. The only drug currently available to treat infant botulism is Botulism Immune Globulin Intravenous-Human (BIG-IV or BabyBIG). BabyBIG was developed by the Infant Botulism Treatment and Prevention Program at the California Department of Public Health.

The respiratory failure and paralysis that occur with severe botulism may require a patient to be on a ventilator for weeks, plus intensive medical and nursing care. After several weeks, the paralysis slowly improves. If diagnosed early, foodborne and wound botulism can be treated by inducing passive immunity with a horse-derived antitoxin, which blocks the action of toxin circulating in the blood. This can prevent patients from worsening, but recovery still takes many weeks. Physicians may try to remove contaminated food still in the gut by inducing vomiting or by using enemas. Wounds should be treated, usually surgically, to remove the source of the toxin-producing bacteria. Good supportive care in a hospital is the mainstay of therapy for all forms of botulism.

Prognosis

Prognosis of Botulism
Prompt treatment significantly reduces the risk of death.

Prevention

Prevention of Botulism
Be sure to use proper techniques when canning foods at home to ensure that any botulism germs in the food are destroyed:

• Pressure cook these foods at 250 F (121 C) for at least 30 minutes.
• Consider boiling these foods for 10 minutes before serving them.