Botulism is a condition caused by a toxin made by bacteria called Clostridium botulinum. This toxin triggers sudden, progressive weakness and paralysis. Infant botulism is usually seen in babies younger than 6 months old.
In adults, botulism occurs only after eating foods that contain the full-blown toxin. In infants, tiny spores from the bacteria that would not be harmful to an adult can grow in the baby's gut. Once there, they mature and release toxins.
These toxins enter the bloodstream and are carried to the ends of the nerves that control muscles. They block the release of a chemical called acetylcholine that transmits signals from nerves to muscles. If this chemical is not released at the right time, the muscle cannot contract. This causes muscle weakness or paralysis.
The diaphragm is a strong layer of muscle below the lungs. If nerves in the diaphragm are blocked, the baby will not be able to breathe. If untreated, this can cause death.
The Clostridium botulinum bacteria makes one of the most poisonous substances known to man. Just a small amount of the toxin it produces can be fatal. Some sources of the bacteria and its toxins include: