Botulism - Diagnosis 

If you think that you or someone you know have botulism, dial 999 immediately to request an ambulance.

Once you are in hospital, the doctors treating you may suspect botulism if you have the following three symptoms:

• a number of different paralyses, including double vision, difficulty swallowing and slurred speech
• you do not have a fever (high temperature)
• your sensory awareness (your awareness of the world around you) is not affected

Testing

As botulism is such a rare condition, a number of tests are usually carried out to rule out other conditions with similar symptoms, such as:

• a stroke – a serious medical condition that occurs when the blood supply to the brain is interrupted
• Guillain-Barre syndrome – a rare but serious disease that affects the network of nerves that control the body's senses and movements
• being poisoned with something else, such as carbon monoxide poisoning, or food poisoning from shellfish

Tests that you may have include:

• a magnetic resonance imaging (MRI) scan – strong magnetic field and radio waves are used to produce detailed images of the inside of your body
• a computerised tomography (CT) scan – a series of X-rays of your body are taken at slightly different angles, and a computer puts the images together
• a lumbar puncture (spinal tap) – a hollow needle is inserted into your lower back to extract a sample of cerebrospinal fluid (the fluid that surrounds and protects your spine)

Confirmation

In order to confirm the diagnosis, tests will be carried out to detect the clostridium botulinum bacteria or the botulinum toxin produced by the bacteria. Depending on which type of botulism you have, this may be found in a sample of:

• your blood
• your faeces (stools)
• the contents of your stomach (for food-borne botulism)
• pus or tissue from a wound (for wound botulism)
• the contaminated food, if you still have some left (for food-borne botulism)