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

Food-borne and wound botulism

In food-borne botulism, it usually takes 12 to 36 hours for symptoms to develop after eating contaminated food, although it can take as little as six hours or as long as eight days. Occasionally, the first signs may be gastrointestinal symptoms such as nausea, vomiting, diarrhoea and stomach cramps.

Wound botulism most often occurs as a result of injecting illegal drugs and, since most of those affected inject drugs several times a day, it's difficult to determine how long it takes for symptoms to develop. In some cases, the area around the infected wound may become inflamed (red and swollen).

In both of these types of botulism, any initial symptoms will eventually be followed a few hours or days later by more serious neurological symptoms (symptoms that affect the nervous system).

Neurological symptoms

Neurological symptoms develop as the toxins released by the Clostridium botulinum bacteria begin to spread throughout the body. The toxins affect the nerves in the skull at first but, without treatment, will spread to the nerves controlling the arms, legs and breathing muscles.

In both food-borne and wound botulism, neurological symptoms can include:

• vision problems, such as blurred vision, double vision and drooping eyelids
• difficulty swallowing (dysphagia) and a dry mouth
• difficulty speaking (dysarthria), such as having slurred speech
• facial weakness initially, followed by paralysis that gradually spreads further down the body to the arms, chest and legs
• breathing difficulties, which may eventually lead to respiratory failure and even death

Unlike many other types of severe infection, your awareness of the world around you will not normally be affected and you won’t usually have a high temperature (fever).

Infant botulism

The symptoms of infant botulism are also caused by the toxins affecting the nervous system, but they can be slightly different to those of food-borne or wound botulism.

The first sign of infant botulism is usually constipation. This may last for several days before the baby starts to have neurological symptoms such as:

• a weak cry
• an inability to suck, making feeding difficult
• tiredness
• irritability
• increased drooling
• droopy eyelids
• a floppy head, neck and limbs (hypotonia)