Clostridium botulinum is a human pathogen that can cause botulism. It is a rod-shaped Gram positive bacteria that produces a number of potent neurotoxins. The most significant are the paralysis inducing toxins that cause botulism and those used in the development of Botox. It is an obligate anaerobe, which means it cannot survive very long in oxygen rich environments. In addition, sporulation, and therefore production of the neurotoxins, can only occur in oxygen-depleted environments. The bacterium was first identified in 1895 by Emile van Ermengem during a botulism outbreak. During the 18th and 19th centuries, meat contamination was a more common problem, most likely caused by Clostridium botulinum.
While somewhat rare nowadays, Clostridium botulinum contamination can occur in improperly preserved canned goods, or goods that are not canned in a timely fashion or under appropriate pressure. Seven chemically different toxins have been identified; generally speaking, most strains produce only one of these, however strains exist that can produce multiple. Not all toxin varieties are disease causing in humans, however; some have been shown to only cause illness in birds, cows and other animals.
The disease botulism, while rare, is a very serious paralytic condition. It is caused by toxins produced as waste by Clostridium botulinum that have colonized the digestive tract or open wound of a host. In all cases paralysis usually begins in the face, and can spread to other parts of the body. Person to person transmission of the disease has not been observed. Initial symptoms can be seen in facial muscles, including those around the eyes and eyelids, then a slow loss of facial expression. Eventually weakness will spread to the limbs, followed by difficulty breathing and finally respiratory failure.
Decontamination of food can be ensured by thorough cooking, and most commercial products undergo a pressure cooking procedure to destroy the toxin. Because of the ease of preventing this form of contamination, most cases of botulism are not caused through food borne contamination. More frequently infection occurs when home canned meat is consumed.
Treatment is available, and is especially important in cases of infant botulism. If treated properly, no long term side effects occur. With the advent of mechanical respirators, the human death rate from botulism has decreased significantly, from close to 70% in the early 1900s down to 2% in the 1990s. Outbreaks in waterfowl are still relatively common, with hundreds of thousands dying at a time due to certain infections.