What is botulism, and how does it kill?

A common culprit in food-borne botulism is improperly canned or fermented food.

Story highlights

  • Botulism is one of deadliest toxins on the planet
  • Botulism spores are everywhere in soil and sediment
  • Improperly home-canned foods are the most common source

(CNN)Botulism is a paralyzing nerve toxin, considered to be one of the most potent and lethal substances in the world.

It's produced by the bacterium Clostridium botulinum and sometimes by strains of Clostridium butyricum and Clostridium baratii. The rod-shaped bacteria are commonly found in soil and sediments from lakes, rivers and oceans.
    The bacteria thrive in low-oxygen conditions, such as canned foods, deep wounds and the intestinal tract, but when threatened form protective spores with a hard coating that allows the bacteria to survive for years.
      The danger is not from the spores themselves but what they produce while germinating. As the C. botulinum bacteria grow, they create eight types of neurotoxins that are so deadly, even microscopic amounts can kill.
      This deadly nerve toxin is also the source of Botox, a leading cosmetic solution for wrinkles as well as medical conditions such as migraines and excessive sweating, known as hyperhidrosis. Injecting minute, highly diluted amounts of the toxin into a muscle blocks the nerve signals that tell that muscle to contract. That temporarily weakens the muscle, thus smoothing the wrinkle or the pain the contraction causes.

      What are the symptoms of botulism?

        Because botulism toxin paralyzes muscles, early and classic signs of the illness are drooping eyelids and blurred or double vision, dry mouth, slurred speech and difficulty swallowing. If left untreated, greater paralysis of muscles of the arms, legs and trunk of the body will occur, affecting the ability to breathe.