Botulism (or botulism poisoning) is a rare but very serious illness that transmits through food, contact with contaminated soil, or through an open wound. Without early treatment, botulism can lead to paralysis, breathing difficulties, and death.
There are three main types of botulism:
- infant botulism
- foodborne botulism
- wound botulism
Botulism poisoning is due to a toxin produced by a type of bacteria called Clostridium botulinum. Although very common, these bacteria can only thrive in conditions where there’s no oxygen. Certain food sources, such as home-canned foods, provide a potent breeding ground.
According to the Centers for Disease Control and Prevention (CDC), about 145 cases of botulism are reported every year in the United States. About 3 to 5 percent of those with botulism poisoning die.
Symptoms of botulism can appear from six hours to 10 days after the initial infection. On average, symptoms of infant and foodborne botulism appear between 12 and 36 hours after eating contaminated food.
Early signs of infant botulism include:
- difficulty feeding
- drooping eyelids
- weak cry
- loss of head control and floppy movements due to muscle weakness
Signs of foodborne or wound botulism include:
- difficulty swallowing or speaking
- facial weakness on both sides of the face
- blurred vision
- drooping eyelids
- trouble breathing
- nausea, vomiting, and abdominal cramps (only in foodborne botulism)
Causes and Risk Factors
The CDC reports that 65 percent of botulism cases occur in infants or children younger than 1 year of age. Infant botulism is typically the result of exposure to contaminated soil, or by eating foods that contain botulism spores. Honey and corn syrup are two examples of foods that can have contamination. These spores can grow inside the intestinal tract of infants, releasing the botulism toxin. Older children and adults have natural defenses that prevent the bacteria from growing.
According to the CDC, around 15 percent of botulism cases are foodborne. These can be home-canned foods or commercially canned products that didn’t undergo proper processing. The World Health Organization (WHO) reports that botulism toxin has been found in:
- preserved vegetables with low acid content, such as beets, spinach, mushrooms, and green beans
- canned tuna fish
- fermented, smoked, and salted fish
- meat products, such as ham and sausage
Wound botulism makes up 20 percent of all botulism cases, and is due to botulism spores entering an open wound, according to the CDC. The rate of occurrence for this type of botulism has risen in recent years due to drug use, as the spores are commonly present in heroin and cocaine.
Botulism isn’t passed from person to person. A person must consume the spores or toxin through food, or the toxin must enter a wound, to cause the symptoms of botulism poisoning.
If you suspect that you or someone you know has botulism, get medical help immediately. Early diagnosis and treatment is crucial for survival.
To diagnose botulism, a doctor will complete a physical exam, noting any signs or symptoms of botulism poisoning. They’ll ask about foods eaten within the past several days as possible sources of the toxin, and if anyone else ate the same food. They’ll also ask about any wounds.
In infants, a doctor will also check for physical symptoms, and will ask about any foods that the infant ate, such as honey or corn syrup.
Your doctor may also take blood or stool samples to analyze for the presence of toxins. However, results for these tests may take days, so most doctors rely on a clinical observation of symptoms to make a diagnosis.
Some symptoms of botulism can mimic those of other diseases and conditions. Your doctor may order additional tests to rule out other causes. These tests may include:
- electromyography (EMG) to evaluate muscle response
- imaging scans to detect any internal damage to the head or brain
- spinal fluid test to determine if infection or injury to the brain or spinal cord is causing symptoms
For foodborne and wound botulism, a doctor administers an antitoxin as soon as possible after diagnosis. In infants, a treatment known as botulism immune globulin blocks the actions of neurotoxins circulating in the blood.
Severe cases of botulism may require the use of a ventilator to help support breathing. Recovery may take weeks or months. Long-term therapy and rehabilitation may also be necessary in severe cases. There’s a vaccine for botulism, but it’s not common, as its effectiveness hasn’t been fully tested and there are side effects.
In most cases, botulism is easy to prevent. You can reduce your risk with the following preventative measures:
- Follow proper techniques when canning food at home, ensuring you reach adequate heat and acidic levels.
- Be cautious of any fermented fish or other aquatic game foods.
- Throw away any open or bulging cans of commercially prepared food.
- Refrigerate oils infused with garlic or herbs.
- Potatoes cooked and wrapped in aluminum foil can create an oxygen-free environment where botulism can thrive. Keep these hot or refrigerate immediately.
- Boiling foods for 10 minutes will destroy botulism toxin.
As a rule, you should never feed an infant honey or corn syrup, since these foods may contain Clostridium botulinum spores.