Botulism: What it is, Symptoms and Prevention
Botulism is a very serious, potentially fatal condition that occurs as a result of a toxin that is produced by a bacteria called Clostridium botulinum. Botulism leads to muscle paralysis, which usually begins in the face, causing symptoms like a droopy eyelid and/or slurred speech. The paralysis may then spread downward, affecting the muscles in your neck, chest, arms, and legs.
The diagnosis of botulism requires a careful medical history and physical examination. A laboratory test to identify the botulinum toxin or bacteria is used to confirm the diagnosis. Treatment of botulinum involves taking an antitoxin, along with hospitalization and sometimes, mechanical ventilation.
The Clostridium botulinum and sometimes, Clostridium butyricum and Clostridium baratii bacteria that cause botulism produce a neurotoxin that binds to the tiny space between a nerve and a muscle, preventing the nerve from sending a message to the corresponding muscle. When a nerve cannot send a message to direct a muscle to move, the muscle becomes paralyzed.
The bacteria can produce large amounts of botulinum toxin, which can then spread throughout the body, paralyzing many muscles at a time.
There are five types of syndromes related to botulism.
Keep in Mind
These syndromes all cause similar symptoms related to muscle paralysis, but their origin is different.
Canned foods, such as fruit, vegetables, and fish, can be contaminated with the preformed botulinum toxin.
In general, canned foods that are prepared at home without the use of safe processing methods are at the highest risk. But there are also outbreaks of botulism related to professionally and industrially canned foods, though these outbreaks are few and far between.
Wound botulism is another syndrome. Wounds that become infected with Clostridium botulinum are generally associated with injection drug use; however, surgical incisions, abrasions, lacerations, and open fractures can also be sources.
Infant botulism occurs when the spores of the bacteria get into a baby’s intestines, grow, and eventually produce the neurotoxin.
Adult Intestinal Toxemia Botulism
Adult intestinal toxemia botulism is very rare and occurs when, as with infants, the spores of Clostridium botulinum get into a person’s intestines and then grow and make the toxin.
Sometimes the botulinum toxin (Botox) is deliberately used for cosmetic injections to temporarily prevent the appearance of wrinkles, to prevent migraine headaches and to relieve muscle stiffness. While it is not common, injections of botulinum toxin for medical or cosmetic reasons can cause unwanted paralysis of eye movement or facial muscles, which is usually temporary.
Botulism classically first causes paralysis of the facial muscles, which may cause droopy eyelids, double or blurred vision, difficulty speaking (or slurred speech), trouble swallowing, and/or a dry mouth. The paralysis then may spread to the neck, arms, chest, and legs. Sometimes the respiratory muscles are affected, which can lead to breathing difficulties, and even death.
Anyone can develop botulism, including babies and young children; instead of the above symptoms, though, infants with botulism may appear “floppy” and lethargic, have a weak cry, be constipated, and feed poorly.
If you experience or observe the signs of botulism, you should seek medical attention immediately. The infectious bacteria that causes botulism releases a toxin that can rapidly cause dangerous paralysis, after which it is much more problematic and difficult to recover from.
Botulism is not a common medical condition, but if you experience face, eye, or mouth weakness, your medical team will do a thorough medical history and physical examination to determine the cause of your weakness.
Medical History and Physical Examination
During a person’s evaluation for potential botulism, a doctor will look for the presence of three criteria, based on data from the United States National Botulism Surveillance Database:
- Lack of fever
- A symptom of cranial neuropathy (such as blurred or double vision or difficulty speaking)
- A sign of cranial neuropathy (such as drooping of the upper eyelid or facial paralysis)
In infants, a doctor will look for a sudden onset of weak suck, drooping eyelid, lack of activity, and constipation.
In order to look for potential botulism exposures, various questions may be asked, such as:
- Has your infant been exposed to honey?
- Do you can foods on your own at home?
- Do you have a history of trauma or injection drug use?
- Have you recently undergone Botox injections for cosmetic reasons?
Often times, special tests are required to make a diagnosis of botulism, considering the symptoms can mimic several other neurological conditions, such as:
- Guillain-Barré syndrome
- Myasthenia gravis
- Opioid overdose
- Transverse myelitis
- Tick paralysis
Some of the tests that may be ordered to sort out the correct diagnosis include:
- Computed Tomography (CT) scan of the brain
- Spinal tap with cerebrospinal fluid (CSF) analysis
- Electroencephalogram (EEG)
- Nerve Conduction Velocity Study (NCVS) with an Electromyography (EMG)
Laboratory Tests to Confirm a Diagnosis
Various laboratory tests are used to confirm a diagnosis of botulism. These tests evaluate blood, stool, wound, or food sources to either look for the presence of the toxin or the bacteria. The downside of these tests is that the results may take days to come back. This is why, if botulism is suspected, treatment must be started before the diagnosis is confirmed.
The treatment of botulism starts with immediate hospitalization and antitoxin administration.
Hospitalization and close monitoring, usually in an intensive care unit (ICU), is the mainstay of treatment of people with botulism. Some patients require intubation with mechanical ventilation (a breathing machine) for symptoms or signs of respiratory failure from paralysis of the breathing muscles.
In addition to hospitalization with close monitoring, patients with botulism will be given an antitoxin. The antitoxin works by binding to and preventing the botulinum toxin from paralyzing the muscles.
Surgery to remove the source of the bacteria producing the botulinum toxin, in addition to antibiotics and antitoxin, is reserved for the treatment of wound botulism.
Since the majority of cases of botulism occur as a result of food ingestion, learning proper food handling and preparation is your best bet for prevention.
Proper Food Handling and Preparation
If you have a can of food that has an irregular shape or shows signs or liquid bubbling or a bad smell, it’s safest to discard the can and the food inside it.
In addition, bacteria can grow when canned food is exposed to oxygen through a dent, slit, or a small hole in the can—so be sure to throw away any damaged cans.
If you practice home-canning, be sure to follow pressure cooker/canner instructions precisely to destroy spores produced by Clostridium botulinum. Boiling any home-canned foods for at least 10 minutes is also important, considering the botulin toxin is very heat labile.
Avoiding Honey in Infants
Avoid giving honey to babies less than one year old to help prevent infant botulism.
Avoid Injection Drug Use
To avoid wound botulism, it’s important to avoid injection drug use. Be sure to obtain prompt treatment of all wounds as well.
With the discovery of a botulinum antitoxin and the advances in medical education and monitoring about this condition, less than five out of every 100 people with botulism die. That said, botulism still remains a very serious illness that requires immediate treatment.
Remain diligent in discarding damaged cans of food, using safe methods when home canning food, and avoiding honey in infants—and if you suspect that you or someone else may have signs of botulism, get medical attention right away.
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