Most people know that botulism is dangerous, but many are confused about whether it's an infection or a case of poisoning. In fact, it can be both. Clostridium botulinum is a worldwide bacterium that inhabits rivers, soil, and the guts of mammals, fish, and shellfish. It's not an organism that normally makes its living by attacking humans. We most often encounter C. botulinum by accident.
C. botulinum secretes a neurotoxin (nerve poison) that can weaken or paralyze muscles and can even cause death. This is botulin toxin, one of the most dangerous substances known. Botulism is the condition of having been poisoned with C. botulinum toxin.
Botulism is rare, but there are still cases every year.
There are three ways to get botulism:
Occasionally, toxins can be inhaled or absorbed through the eyes.
Ironically, some people intentionally get botulism from their doctor these days. The toxin is used to make a medication that is injected into twitching and spasmodic muscles to calm them. It's a treatment used for a variety of nerve disorders and for the cosmetic purpose of removing frown lines, forehead wrinkles, and "crow's feet" around the eyes.
Botulism can cause death due to the lungs not functioning properly (respiratory failure). However, advancements in supportive care have greatly reduced the death rate, and now less than 10% of people who get botulism die from the condition.
C. botulinum toxin attacks nerve endings, permanently damaging them. It can't cross the barrier that protects the brain. The heart has its own wiring system and also isn't affected. However, botulin can affect all the other nerves of the body, including the nerves of the muscles that operate the lungs. Botulin toxin kills by shutting down breathing.
Symptoms usually appear quickly in foodborne botulism, within 18 to 36 hours, but a few people feel no symptoms for as many as 8 days after eating the poison. Vomiting, nausea, diarrhea, and abdominal cramps are the first signals. Then the neurological symptoms begin to appear - the muscles slowly shut down, starting with the temple and forehead and proceeding slowly down both sides of the body. The face goes slack and expressionless, the eyelids droop, and the victim may drool. Vertigo and double vision are common. The arms slowly get weaker, then the legs. Diarrhea is replaced by constipation. By this time there's also difficulty in talking, swallowing, and breathing. Temperature and pulse remain normal.
The first sign of infant botulism is constipation. The neurological symptoms are the same as in foodborne botulism but develop less rapidly. This is because the spores produce toxin slowly and the child absorbs it bit by bit instead of all at once as in foodborne botulism. The baby may also suck milk weakly, have difficulty crying loudly, lose head control, and lack facial expression.