Botulism 

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. They 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 the injection of contaminated heroin or the snorting of 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 old. After a year, children develop a defence against the spores.

How common is botulism?

Botulism is relatively rare in the UK. There have only been 33 recorded cases of food-borne botulism in England and Wales since 1989. Twenty-seven of these were linked to a single outbreak that was caused by contaminated hazelnut yoghurt. Since 1978, there have been eight cases of infant botulism. None of these cases resulted in death.

In contrast to food-borne botulism and infant botulism, the number of wound botulism cases has risen sharply since 2002. 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 1 or 2 cases out of 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.