Botulism is a rare but potentially fatal infection caused by toxins (poisons) that are produced by bacteria called clostridium botulinum.
The toxins produced by clostridium botulinum are the most powerful naturally occurring toxins known to science. They attack the nervous system (the nerves, brain, and spinal cord) and cause paralysis (weakness). Left untreated, the paralysis will spread to the lungs, causing breathing failure followed by death.
There are three different ways of contracting botulism that can be classified as:
- food-borne botulism
- wound botulism
- infant botulism
These are described in more detail below.
Food-borne botulism
Food-borne botulism is caused by eating food that has been contaminated with the botulinum toxin as a result of it being improperly canned or preserved.
Wound botulism
Wound botulism occurs when a wound becomes infected with botulism spores, which then produce toxins. This usually occurs when the tissue is damaged through injecting contaminated heroin or snorting contaminated cocaine.
Infant botulism
Infant botulism can occur if a baby swallows some botulinum bacteria spores, which produce toxins in their intestines (part of the digestive system).
Infant botulism usually only affects babies who are less than 12 months of age. After a year, children develop a defence against the spores.
How common is botulism?
Botulism is relatively rare in the UK. Since 1978, there have been eight cases of infant botulism. All of these cases did not result in death.
In contrast to cases of food-borne botulism and infant botulism, since 2002 the number of wound botulism cases has risen sharply. In 2006, there were 22 recorded cases, which resulted in two deaths. There were a further 11 cases in 2007. The rise in wound botulism is thought to be due to people injecting heroin directly into their muscles - a practice that is often referred to as 'skin-popping'.
Outlook
If treated promptly, the outlook for someone with botulism is usually good. Antitoxins have proven to be very effective in successfully treating the condition, although a full recovery may take several months. In one or two cases in every 20, botulism can be fatal.
Botulism is not contagious and cannot be spread through person-to-person contact. It also cannot enter the body through intact (unbroken) skin.