Botulism

Botulism is serious, but fortunately rare illness caused by a toxin produced by the bacterium Clostridium botulinum.

• Symptoms of botulism usually start with weakness of the muscles that control the eyes, face, mouth, and throat.
• This weakness may spread to the neck, arms, torso, and legs.
• Botulism also can weaken the muscles involved in breathing, which can lead to difficulty breathing and even death.

Clostridium botulinum

Botulinum toxin

This toxin is made by Clostridium botulinum and sometimes Clostridium butyricum and Clostridium baratii bacteria. These bacteria can be spread by food and sometimes by other means.

Habitat

• The bacteria that make botulinum toxin are found naturally in many places, but it’s rare for them to make people sick.
• These bacteria make spores, which act like protective coatings.
• Spores help the bacteria survive in the environment, even in extreme conditions.
• The spores usually do not cause people to become sick, even when they’re eaten.
• But under certain conditions, these spores can grow and make one of the most lethal toxins known.

The conditions in which the spores can grow and make toxin are:

• Low-oxygen or no oxygen (anaerobic) environment
• Low acid
• Low sugar
• Low salt
• A certain temperature range
• A certain amount of water

Example foods

• Improperly home-canned, preserved, or fermented foods can provide the right conditions for spores to grow and make botulinum toxin.
• When people eat these foods, they can become seriously ill, or even die, if they don’t get proper medical treatment quickly.

Types

The five main kinds of botulism are:

Foodborne botulism can happen by eating foods that have been contaminated with botulinum toxin. Common sources of foodborne botulism are homemade foods that have been improperly canned, preserved, or fermented. Though uncommon, store-bought foods also can be contaminated with botulinum toxin.

Wound botulism can happen if the spores of the bacteria get into a wound and make a toxin. People who inject drugs have a greater chance of getting wound botulism. Wound botulism has also occurred in people after a traumatic injury, such as a motorcycle accident, or surgery.

Infant botulism can happen if the spores of the bacteria get into an infant’s intestines. The spores grow and produce the toxin which causes illness.

Adult intestinal toxemia (also known as adult intestinal colonization) botulism is a very rare kind of botulism that can happen if the spores of the bacteria get into an adult’s intestines, grow, and produce the toxin (similar to infant botulism). Although we don’t know why people get this kind of botulism, people who have serious health conditions that affect the gut may be more likely to get sick.

Iatrogenic botulism can happen if too much botulinum toxin is injected for cosmetic reasons, such as for wrinkles, or medical reasons, such as for migraine headaches.

Medical emergencies

All kinds of botulism can be fatal and are medical emergencies.

Symptoms

The symptoms of botulism may include:

• double vision
• blurred vision
• drooping eyelids
• slurred speech
• difficulty swallowing
• difficulty breathing
• a thick-feeling tongue
• dry mouth
• muscle weakness

Infants with botulism may:

• appear lethargic
• feed poorly
• be constipated
• have a weak cry
• have poor muscle tone (appear “floppy”)

Progression

• These symptoms all result from muscle paralysis caused by the toxin.
• If untreated, the disease may progress and symptoms may worsen to cause paralysis of certain muscles, including those used in breathing and those in the arms, legs, and trunk (part of the body from the neck to the pelvis area, also called the torso).
• People with botulism may not show all of these symptoms at once.
• In foodborne botulism, symptoms generally begin 18 to 36 hours after eating a contaminated food.
• However, symptoms can begin as soon as 6 hours after or up to 10 days later.

Diagnosis

A detailed history to find out the cause of your symptoms.

Tests

• Brain scan
• Spinal fluid examination
• Nerve and muscle function tests (nerve conduction study [NCS] and electromyography [EMG])
• Tensilon test for myasthenia gravis

Treatment

• Doctors treat botulism with a drug called an antitoxin.
• The toxin attacks the body’s nerves, and the antitoxin prevents it from causing any more harm.
• It does not heal the damage the toxin has already done.
• If you have wound botulism, your doctor may need to surgically remove the source of the toxin-producing bacteria and give you antibiotics.

Survival and Complications

• Botulism can result in death due to respiratory failure.
• With antitoxin and proper medical treatment, fewer than 5 of every 100 people with botulism die.
• Even with antitoxin and intensive medical and nursing care, some patients die from infections or other problems that are caused by being paralyzed for weeks or months.
• Patients who survive botulism may have fatigue and shortness of breath for years afterward, and may need long-term therapy to help them recover.

Prevention of Botulism

The preventive measures vary based on the type of botulism.

Prevention of Foodborne botulism

• Many cases of foodborne botulism have happened after people ate home-canned, preserved, or fermented foods that were contaminated with toxin.
• The foods might have become contaminated if they were not canned (processed) correctly.

Foods with low acid content are the most common sources of home-canning related botulism cases. Examples of low-acid foods are:

• Canned veggies carrots corn green beans
• Asparagus
• Green beans
• Beets
• Corn
• Potatoes

Some examples of foods that have been contaminated are:

• Chopped garlic in oil
• Canned cheese sauce
• Canned tomatoes
• Carrot juice
• Baked potatoes wrapped in foil

Wound Botulism Prevent wound botulism by keeping wounds clean. If wounds appear infected, seek medical care quickly. A wound might be infected if it is:

• Red
• Swollen
• Painful
• Warm to the touch
• Full of pus or other drainage
• Accompanied by fever

Infant botulism

• Most infant botulism cases cannot be prevented because the bacteria that causes the disease is in soil and dust.
• The bacteria can be found inside homes on floors, carpet, and countertops—even after cleaning.
• For almost all children and adults who are healthy, ingesting botulism spores is not dangerous and will not cause botulism (it’s the toxin that is dangerous). For reasons we do not understand, some infants get botulism when the spores get into their digestive tracts, grow, and produce the toxin.
• Honey can contain the bacteria that causes infant botulism, so do not feed honey to children younger than 12 months.
• Honey is safe for people 1 year of age and older.

Adult intestinal colonization

• Adult intestinal colonization (also called adult intestinal toxemia) is a very rare type of botulism.
• People who have health conditions that change the structure or proper workings of their intestines (gut) may be at higher risk.
• Only a handful of people have been diagnosed with adult intestinal toxemia, and scientists do not fully understand how a person gets this type of botulism.
• It may be similar to infant botulism, which cannot be prevented.

Iatrogenic botulism You can prevent iatrogenic (an illness caused by medical examination or treatment) botulism by getting injections of botulinum toxin only by licensed practitioners:

• If you need an injection of botulinum toxin for a medical condition, your doctor will choose the safest dose.
• If you get an injection of botulinum toxin for cosmetic reasons, be sure to go to a licensed professional.

Also see

• Botox

Botulism Resources
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