What Is Botulism (Botulinus Intoxication)? What Causes Botulism?

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Main Category: Infectious Diseases / Bacteria / Viruses
Also Included In: GastroIntestinal / Gastroenterology;  Immune System / Vaccines
Article Date: 14 Dec 2009 - 0:00 PDT

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Botulism, also known as botulinus intoxication is a serious illness that causes paralysis, caused by the botulinum toxin. The toxin is caused by Clostridium botulinum, a type of bacterium. There are four ways the toxin can enter the human body:

• Infant botulism - by colonization of the digestive tract by Clostridium botulinum in babies.
• Adult botulism - by colonization of the digestive tract by Clostridium botulinum in adults.
• Foodborne botulism - as a result of eating foodstuffs with the toxin.
• Wound botulism - when botulinum toxin contaminates a wound.

All types of botulism eventually lead to paralysis, which generally starts with the face muscles and then spreads to the limbs. In severe cases there is respiratory failure when the breathing muscles become paralyzed. Because of this, all botulism cases are treated as medical emergencies. There are good antitoxins available today which have significantly improved the outlook for infected patients. Cooking at 121C (250C) for three minutes destroys the spores, effectively preventing botulism.

According to Medilexicon's medical dictionary:

Botulism is:Food poisoning usually caused by the ingestion of the neurotoxin produced by the bacterium Clostridium botulinum from improperly canned or preserved food; mainly affects humans, chickens, water fowl, cattle, sheep, and horses; characterized by paralysis in all species; can be fatal; pigs, dogs, and cats are somewhat resistant. In some cases (in infants) botulism may be formed in the gastrointestinal tract by ingested organisms.

What are the signs and symptoms of botulism?

A symptom is something the patient feels and reports, while a sign is something other people, such as the doctor detect. For example, pain may be a symptom while a rash may be a sign.

Food-borne botulism signs and symptoms:

• Vomiting
• Diarrhea
• Constipation (usually follows the diarrhea)
• Nausea

More severe (neurological) signs and symptoms usually appear a day or two after infection. In some rare cases, according to the National Health Service (NHS) UK, more serious symptoms can appear within about six hours. Patients who have consumed a large amount of clostridium botulinum toxin may have neurological symptoms immediately.
Wound botulism - the incubation period in this case is from 4 days to a couple of weeks. The nerves that connect the brain to the spine (cranial nerves) experience the first symptoms, and then spread to the rest of the body.

Neurological signs and symptoms of both food-borne and wound botulism are identical, although the wound botulism ones may take longer to appear. The patient may experience double vision, the eyelids may droop, there will be facial weakness, a dry mouth, dysphagia (swallowing difficulties) and speech defects (slurring).

Later the arms will be weak and paralysis will set in. Eventually the patient's breathing muscles will become paralyzed, resulting in respiratory failure and death (without treatment).

During the whole process the patient is fully conscious.

Infant botulism signs and symptoms may include:

• Constipation (first sign)
• Bad temper
• Excessive drooling when feeding
• Eyelids sag
• Facial expression is flat
• Lethargy, listlessness
• Respiratory difficulties
• Slow or improper reflexes
• The baby cries weakly
• The child feels floppy
• The infant does not gag
• Unfocused eyes
• Weak sucking (baby)

What are the causes of botulism?

Botulism is caused by botulinum toxin, a poison produced by the bacterium Clostridium botulinum. The organism is common in the soil and exists in untreated water, and can survive in this environment as a resistant spore.

Clostridium botulinum produces spores that can survive in poorly preserved or canned foods, where they produce a toxin. When consumed even extremely tiny amounts of the toxin can cause severe poisoning.

The most commonly tainted foods are home-canned vegetables, cured pork and ham, raw fish, smoked fish, honey and corn syrup.

The organism can also enter an open wound and produce toxins within the wound.

In cases of infant botulism, the bacteria or their spores are consumed by the baby and grow within his/her gut. According to the National Institutes of Health (NIH) USA, babies most commonly get infant botulism after eating honey or corn syrup. The bacterium may also occur naturally in the stool of an infant.

The CDC (Centers for Disease Control and Prevention) says about 110 cases of botulism are reported in the USA annually. Most of the patients are infants.

How is botulism diagnosed?

Infant botulism diagnosis - diagnosis is confirmed after testing a stool or specimen of enema with the mouse bioassay. If the doctor suspects botulism, treatment with an anti-toxin should begin immediately, and not after test results have come back.

If the patient's history and physical examination suggest botulism, a doctor may consider it. However, as other illnesses/conditions share similar symptoms, such as a stroke, myasthenia gravis or Guillain-Barre syndrome, tests will need to be done to rule them out. Diagnostic tests may include:

• A brain scan
• Cerebrospinal fluid examination
• Electromyography
• Edrophonium chloride test for myasthenia gravis

If the toxin is identified in the food, stomach, vomit, feces or intestinal contents, a definitive diagnosis can be made.

In very acute cases the toxin might be detected in the blood.

What are the complications of botulism?

In the vast majority of cases infant botulism has no long-term side effects. According to the NIH, less than 1% of infant botulism cases in the USA are fatal.

Respiratory failure caused by botulism can result in death. About 50 years ago half of all patients with botulism died, compared to just 8% today. Patients with severe symptoms may need a breathing machine, intensive medical and nursing care for several months. Fatigue and shortness of breath may linger for many years.

What is the treatment for botulism?

Infant botulism - patients need to be hospitalized and will be given BIG-V or BabyBIG (Botulism Immune Globulin Intravenous-Human).

Food borne and wound botulism - the patient needs to be hospitalized. Those with respiratory problems will be on a ventilator. Fluids and nutrients will be given intravenously.

The patient will be given antitoxin injections - these are antibodies that can neutralize the clostridium botulinum toxin. Patients are given antitoxins immediately, even before diagnostic test results have returned.

According to the National Health Service (NHS), UK, antitoxins will stop symptoms from worsening, but will not cure any paralysis that has already occurred.

If the infection occurred as a result of a wound, the wound needs to be treated surgically. The area around the wound is removed (debridement). Antibiotics may also be prescribed to prevent any secondary infections.

Written by Stephanie Brunner B.A.
Copyright: Medical News Today
Not to be reproduced without permission of Medical News Today

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