Foodborne botulism is a rare, life-threatening condition. These are the signs to look for.

USA Today

07-02-2025

Foodborne botulism is a potentially deadly condition that's caused by eating food contaminated with botulinum toxin, a potent toxin that attacks the body's nervous system. The disease is incredibly rare; in 2019, there were 21 reported cases of foodborne botulism across the U.S., according to the U.S. Centers for Disease Control and Prevention.
Botulism is treatable, but it's important to catch it early. As botulinum toxin moves through your body, it can lead to muscle paralysis, difficulty breathing, and in severe cases, death.
Knowing the signs of botulism can be life-saving. Here's everything experts need you to know.
What is Clostridium botulinum?
Clostridium botulinum is a bacterium that produces botulinum toxin, the neurotoxin that causes botulism, says Dr. Daniel Kuritzkes, Chief of the Division of Infectious Diseases at Brigham and Women's Hospital. Clostridium botulinum can be found throughout nature, often on the surfaces of fruits and vegetables, per the U.S. Department of Agriculture's Food Safety and Inspection Service.
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Luckily, exposure to Clostridia rarely makes you sick. It's only under certain conditions that bacteria like Clostridium botulinum, and occasionally Clostridium butyricum and Clostridium baratii, are able to grow spores that make botulism toxin. These bacteria thrive in the absence of air, and tend to germinate in environments that have low acidity, sugar and salt, per the CDC.
Where is Clostridium botulinum most commonly found?
Self-canned and self-preserved foods are particularly susceptible to Clostridia growth, says Shonna McBride, an associate professor of microbiology and immunology, and expert of clostridium, at the Emory University School of Medicine.
If the spores of Clostridium botulinum are living on your fruits, vegetables or whatever else you intend to preserve, and you haven't sufficiently sterilized your canning equipment, you leave the door open for the bacteria to produce the toxin, explains McBride.
These days, incidences of foodborne botulism linked to commercially-canned goods have become extremely rare, Kuritzkes says. This is largely because food processing plants have routine inspections that check cleanliness and sterility standards.
You can't see, smell or taste botulism toxin, so it can be difficult to identify when contamination has occurred, per the CDC. A potential sign, however, is if you see a can that's visibly bulging, notes McBride. As the bacteria multiplies, it produces gas – so much so that it can sometimes stretch a metal can.
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What symptoms does foodborne botulism cause?
'Botulism toxin is quite potent, so even ingesting a small amount of the toxin can have serious effects,' says Kuritzkes. When the toxin enters the body, it gets absorbed through the gastrointestinal tract, and begins targeting the nerves. When your nerves aren't able to communicate with each other, your muscles enter a state of flaccid paralysis, says McBride.
According to Dr. Scott A. Weisenberg, an infectious disease specialist and medical director of the Travel Medicine Program at NYU Langone Health, key signs of foodborne botulism include: Trouble swallowing and speaking, changes in vision, general muscle weakness and difficulty breathing. These symptoms typically appear between 12 to 36 hours after you've ingested the toxin, although they could pop up as early as four hours after exposure, per the World Health Organization.
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Can you fully recover from botulism?
When botulism is left untreated, your body enters a state of complete respiratory paralysis, possibly leading to death, says Kuritzes. Five percent to 10% of botulism cases are fatal, per the WHO. However, you can make a full recovery from the disease if it's caught early, which is why it's important to get to a hospital if you're having botulism-like symptoms.
Botulism antitoxin neutralizes botulinum toxin, preventing it from causing further damage to your nerves. However, it isn't able to repair any existing damage, and in severe cases, people will need to be intubated to help them breathe. Eventually, the toxin will dissipate, but symptoms can persist for months, says McBride.
Again, it's important to underscore that botulism is extremely rare. However, to reduce the likelihood of ever experiencing it, exercise safe food handling and storage practices, recommends Weisenberg. For people preparing canned foods at home, this is especially important, he says.