Botulism is a rare and potentially fatal illness caused by a toxin produced by the bacteria Clostridium botulinum. The disease begins with weakness, trouble seeing, feeling tired, and trouble speaking. This may then be followed by weakness of the arms, chest muscles, and legs. The disease does not usually affect consciousness or cause a fever. Botulism can occur in a few different ways. The bacterial spores that cause it are common in both soil and water. They produce botulinum toxin when exposed to low oxygen levels and certain temperatures. Foodborne botulism happens when food containing the toxin is eaten. Infant botulism happens when the bacteria develops in the intestines and releases toxin. Typically this only happens in children less than six months of age as after that protective mechanisms develop. Wound botulism is found most often among those who inject street drugs. In this situation spores enter a wound and, in the absence of oxygen, release toxin. It is not passed directly between people.