Botulism - Symptoms 

Botulism is a serious medical condition that requires immediate medical attention. Dial 999 to request an ambulance if you suspect that you, or someone you know, is having symptoms of botulism.

Food-borne botulism

The symptoms of food-borne botulism usually begin with:

• nausea (feeling sick)
• vomiting
• diarrhoea, followed by constipation (being unable to empty your bowels)

It usually takes 12 to 36 hours after eating the contaminated food for the more serious neurological symptoms (symptoms that affect the nervous system) to begin (see below). However, it can sometimes take as little as six hours, or as long as eight days.

If you have eaten (or drunk) a large amount of the toxin that is produced by the clostridium botulinum bacteria, you may not have these early symptoms. Instead, you may develop the neurological symptoms straight away.

Wound botulism

Following the initial infection, the symptoms of wound botulism take between 4 to 14 days to develop. The symptoms start in the cranial nerves (nerves that connect your brain to your spine) before spreading through your body as the toxins take effect.

Neurological symptoms

The neurological symptoms (symptoms that affect the nervous system) of food-borne botulism and wound botulism are the same. However, in cases of wound botulism, the symptoms can take longer to develop. The neurological symptoms include:

• double vision
• droopy eyelids
• facial weakness
• dry mouth
• difficulties swallowing (dysphagia)
• slurred speech

As the toxin spreads, you will have weakness and paralysis in your upper limbs. If the toxin is allowed to keep spreading, your breathing will be affected and you will eventually have respiratory failure, resulting in death.

Your sensory awareness (your awareness of the world around you) will be unaffected. There are also no symptoms of fever, such as a high temperature, during a botulism infection.

Infant botulism

The symptoms of infant botulism usually begin with constipation (difficulty passing faeces). This may last for several days before the infant begins to have neurological symptoms, such as:

• an inability to suck
• a floppy head
• floppy muscles
• weak crying
• tiredness
• irritability
• poor reflexes
• heavy eyelids and flat, unfocused eyes