What is botulism?
Botulism is a life-threatening poisoning caused by toxins produced by the bacterium clostridium botulinum. The toxin attacks the nerves, brain and spinal cord and can affect people of any age. Left untreated, paralysis can spread to the lungs, causing breathing failure and death.
Botulism is rare in the UK.
How do you get botulism?
There are three different ways of contracting botulism. These are classified as:
- Food-borne botulism: when you eat something contaminated with the toxin as a result of it being improperly canned or preserved
- Wound botulism: caused when a wound becomes infected with botulinum spores which then germinate, reproduce and then produce toxins. An increase in reported cases has been linked to injecting drug users
- Infant botulism: a very rare condition where a baby swallows some botulinum bacteria spores, which then produce toxins in their intestines. The spores are sometimes found in honey, which is why honey is not recommended for children under 12 months old, who will not have had a chance to develop a defence against the spores.
The infection cannot be spread from person to person.
What are the symptoms of botulism?
The first signs of food-borne botulism are usually nausea and vomiting. Diarrhoea is followed by constipation.
More serious symptoms usually begin between 12 and 36 hours after contamination, but can start within six hours or take as long as eight days to appear. These symptoms include blurred vision, difficulty swallowing and speaking and droopy eyelids. As the toxin spreads, this is followed by general muscle weakness, paralysis in the arms and difficulty breathing.
The symptoms of wound botulism begin four to 14 days after infection. They begin in the nerves connecting the brain to the spine before spreading through the rest of the body.
The effects on the nervous system of wound botulism are the same as food-borne botulism, although they take longer to develop.
Infant botulism usually begins with constipation. Several days later, neurological symptoms develop which include an inability to suck, a floppy head and muscles, poor reflexes, heavy eyelids and unfocused eyes.
How is botulism treated?
All cases of botulism will need to be treated in hospital.
An antitoxin is available that can block the effects of the clostridium botulinum toxin on the nervous system. The antitoxin, which is supplied by Public Health England, needs to be given as early as possible because it will not cure any paralysis that has already taken effect.
If the toxin has spread to the lungs, the patient may need to be attached to a ventilator to assist breathing.
Other treatments for food-borne botulism may involve medication to induce vomiting and an enema to cleanse the bowels.
Cases of wound botulism will require the infected wound, and possibly the surrounding portion of skin, to be surgically removed.
Infant botulism is usually less serious and treated with a medication called botulinum immunoglobulin. Most babies respond well to treatment and usually make a full recovery.