Botulism

Medically Reviewed by Kathleen M. Zelman, RD, LD, MPH on August 08, 2022
6 min read

Of the many types of foodborne illnesses, botulism is one of the most dangerous. It can cause paralysis and it can be life-threatening, but it is rather rare.

Botulism is usually linked with canning fruits and vegetables at home. Commercially canned foods can carry the bacteria that cause botulism, but that rarely happens these days. But it’s possible to get botulism in ways besides food poisoning.

Botulism is caused by the bacterium Clostridium botulinum (C. botulinum). It releases a neurotoxin, which is a poison that attacks your nervous system.

One way you can get the toxin in your system is by eating tainted food. But there are other ways for you to get it as well:

  • Infant botulism: If babies up to about 6 months old swallow botulinum spores, the spores can germinate into bacteria. For example, they can swallow it from dust and soil, which is most common, or from honey. The bacteria can then release the toxin. As children get older, they build defenses in their intestines to keep the spores from taking root.
  • Wound botulism: Botulinum spores can get into open wounds and slowly reproduce, eventually releasing the toxin. This type of botulism is associated with drug users who inject black tar heroin into their skin rather than their veins.
  • Inhalation botulism:Breathing in the toxin is rare, though some nations have tried to make biological weapons that would spread a deadly form of the toxin into the air.
  • Adult intestinal toxemia. This very rare kind of botulism is similar to infant botulism. Bacteria spores get into your intestines, where they grow and spread. It’s also called adult intestinal colonization. Adults with serious health conditions of the gut are at most at risk.
  • Iatrogenic botulism. You can get this form of botulism if you have too much of the Botox toxin injected during a cosmetic or medical procedure; for example, when treating migraines or wrinkles. Some people have had this type of botulism after getting counterfeit Botox treatments.

No matter how you get botulism, the symptoms are usually the same. The most defining symptom is weakness that starts on both sides of your face, goes down to your neck, and then to the rest of your body. Other early symptoms include:

  • Double or blurred vision
  • Drooping eyelids
  • Difficulty swallowing
  • Slurred speech
  • Shortness of breath

Other symptoms that can follow include vomiting, belly pain, and diarrhea. Later, you may have a very hard time urinating and have severe constipation. Symptoms do not include a fever.

If you don’t get treatment, your symptoms could progress to paralysis of your arms and legs and the muscles used for breathing.

Infants with botulism have symptoms that include:

  • Lethargy
  • Poor muscle tone starting in the head and neck and moving down
  • Poor feeding
  • Drooling
  • Weak cry

Symptoms of wound botulism are similar to general botulism but may take about 2 weeks to appear. They also can include:

  • Fever
  • Skin redness, swelling, and other signs of infection

Symptoms of inhalation botulism are the same as those for general botulism but usually happen more quickly. Respiratory failure can occur.

Symptoms of adult intestinal toxemia are similar to infant botulism. Symptoms are the same as general botulism but may also include:

  • Constipation
  • Poor feeding
  • Lack of energy (lethargy)

Symptoms of iatrogenic botulism are the same as those seen in general botulism. Along with muscle weakness, you could have:

  • Eye muscle weakness
  • A hard time speaking
  • A paralyzed face
  • A thick, weak tongue
  • Reduced gag reflex

Foodborne botulism symptoms usually appear within 18 to 36 hours of eating food with the bacterium, though they could show up in as little as 6 hours.

In some cases, symptoms of botulism don’t occur for a week to 10 days after exposure.

Infant botulism may not appear for 14 days. A baby with botulism may appear fussy or lethargic, and may be constipated and unwilling to eat.

If you or someone close to you has symptoms that could be signs of botulism, call 911 immediately. Respiratory failure is a concern and close monitoring is important.

Botulism can cause severe symptoms, but it cannot be spread from one person to another. However, if you are sick with botulism, you very likely will have to stay in the hospital for monitoring and treatment.

You may have long-term breathing problems if your case is severe. Problems include shortness of breath and being easily tired out.

With proper treatment, you can fully recover from botulism. How fast you get over it depends on the severity of your case. When your case is mild, you may need weeks or months for a full recovery. It may take months or years to completely get over a very serious case.

If the illness isn’t treated, botulism can be life-threatening. But people recover in about 90% to 95% of cases.

Your doctor will likely start with a physical exam, looking for signs of botulism such as muscle weakness, a weak voice, or drooping eyelids. They might also ask you about foods you (or your baby) have eaten.

They may order a lab test to analyze either your blood or a stool sample to confirm their diagnosis. Other tests may be needed.

If you happened to have saved it, you can also bring in the food you suspect caused the botulism for testing.

Lab tests may take a couple of days. In the meantime, your doctor may try to rule out other possible conditions. Botulism symptoms are similar to those for stroke and Guillain-Barre syndrome, in which your immune system attacks your nerves, causing possible paralysis.

Other tests that may be done to diagnose botulism include:

Brain scan. A magnetic resonance imaging (MRI) or computed tomography (CT) scan of the brain can help rule out other reasons for your symptoms, such as a stroke.

Spinal fluid exam. A cerebrospinal fluid study (CSF), sometimes called a spinal tap, may show a slight increase in the level of protein. But a CSF study is essentially normal in people with botulism.

Nerve and muscle function tests.Electromyography can help confirm a diagnosis of botulism.

Tensilon test. This is done to rule out myasthenia gravis, which can cause similar symptoms.

Tests for these conditions may be done while lab tests are being done.

Your doctor will have you admitted to a hospital, where there are several treatments that may be tried, depending on your case. They include:

Antitoxins: The main treatment for botulism is a medication called an antitoxin. It interferes with the toxin in your bloodstream. This medication can often help stop symptoms from getting worse.

Antibiotics: Sometimes these may work if your case is wound botulism. These bacteria-killing medications aren’t used for other types of botulism.

Breathing aid: If your case of botulism has seriously affected your muscles for breathing, you may need to be hooked up to a machine that helps you breathe. You may be on a mechanical ventilation machine for months if the illness is severe.

Therapy: You may need programs to help with your speech, swallowing, and other body functions as you start to get better.

If you can your own food at home, make sure your hands, containers, and utensils are as clean as possible. Clean and store food carefully to lower the chance of tainting the food you’re canning.

The botulism toxin can be killed at high temperatures, so if you’re eating home-canned food, consider boiling it for 10 minutes to kill the bacteria. Proper refrigeration can help prevent the growth of C. botulinum, too.

Here are a few telltale signs of possible botulism contamination in canned foods:

  • The can has a bulge.
  • The container spurts out foam or liquid when you open it.
  • The contents smell unusual or foul.

If you ever see a bulge pushing out from a can or container, do not open it. Throw it away. If there is something wrong about the way food smells, don’t even taste it.

A couple of other things to remember:

  • Store oils infused with herbs or garlic in a refrigerator.
  • Potatoes cooked and wrapped in aluminum foil create an environment where botulism toxins can thrive. Always keep the potatoes hot or store them in a refrigerator within 2 hours of cooking.
  • Boiling foods for at least 5 minutes can destroy the botulism toxin.
  • Don’t give honey or corn syrup to a baby younger than 1 year old.
  • If you’re addicted to heroin, never share needles and don’t use black tar heroin. Seek out a doctor to help you with your addiction.