Health conditions


What is botulism?

Botulism is a rare but serious condition caused by toxins (poisons) produced by the bacterium Clostridium botulinum.

How do you get botulism?

Clostridium botulinum bacteria are found worldwide in soil and sediments. They can enter your body through cuts and they can also find their way into animals, fish and agricultural products which may then become food for human consumption.

Clostridium botulinum produces one of the most potent (strongest) toxins known and tiny amounts can cause paralysis.

There are 3 types of botulism.


Food-borne botulism occurs when the bacteria grow in the food and produce toxins that are not destroyed by the cooking process. Eating these contaminated foods can cause botulism.

The bacterial growth happens most often in foods with low acidity such as:

  • home-preserved fruits and vegetables
  • potato salad
  • minced garlic in oil.

It is also associated with:

  • canned foods
  • meat
  • fish
  • soft cheeses.

The symptoms are severe and usually develop 12 to 36 hours after eating contaminated food. This form of botulism can be fatal, and about 5 to 10 per cent of adults who acquire food-borne botulism will die.


Intestinal botulism occurs when spores from the bacteria are ingested and then multiply in your intestinal tract and produce toxins.

The spores are spherical structures produced by bacteria. These spores can survive boiling and extremes of cold and drying, and can develop into bacteria if in suitable growing conditions.

Children under 12 months are most susceptible to infection, but adults with gastrointestinal problems can also be at risk.

However, in most adults, even if the spores are ingested they do not make you ill because your body’s natural defences stop the bacteria from multiplying and producing toxins. Intestinal botulism is most commonly associated with eating raw honey.


This form of botulism is rare and occurs when bacterial spores in soil or gravel get into an open wound and reproduce, then release toxins. Symptoms typically develop between 4 days and 2 weeks after the bacterial spores enter the wound.

Signs and symptoms

Symptoms in adults may include:

  • an initial short period of diarrhoea and vomiting, followed by constipation
  • blurred vision
  • difficulty in speaking, swallowing and breathing
  • dry mouth
  • weakness, fatigue and ultimately paralysis of the muscles.

Signs and symptoms in infants may include:

  • constipation
  • weak cry
  • loss of head control
  • loss of appetite
  • breathing difficulties
  • reduced movement of limbs and weakness.

Death may result from paralysis of the breathing muscles.

How do I know I have botulism?

To begin with, the diagnosis of botulism is based on the presence of typical signs and symptoms in the affected person.

Faecal (poo) specimens, blood samples, wound swabs or food samples can then be tested to show the presence of Clostridium botulinum bacteria and/or toxin.

Treatment of botulism

Patients with signs and symptoms of botulism should be considered as severely ill and require urgent hospitalisation.

Clostridium botulinum anti-toxin should be given as early as possible to lessen the severity of symptoms.

How can botulism be prevented?

  • Cook and reheat foods evenly and thoroughly to an internal temperature of 75 °C.
  • Keep cold food below 5 °C and hot food above 60 °C.
  • Throw away canned foods that are damaged, out of date or show signs of spoilage.
  • When canning or preserving foods use the correct equipment and follow the instructions carefully. Pay attention to hygiene, pressure, temperature, cooking time, refrigeration and storage.
  • Wash any wounds with antibacterial soap.
  • Do not feed honey to babies less than 12 months.

Where to get help

  • If you have symptoms of botulism go directly to a hospital emergency department.
  • See your doctor
  • Visit a GP after hours.
  • Ring healthdirect Australia on 1800 022 222.


  • Although rare, botulism is potentially life threatening.
  • Safe food preparation and thorough cooking can help prevent botulism.
  • Honey should not be fed to babies less than 12 months.


Public Health

This publication is provided for education and information purposes only. It is not a substitute for professional medical care. Information about a therapy, service, product or treatment does not imply endorsement and is not intended to replace advice from your healthcare professional. Readers should note that over time currency and completeness of the information may change. All users should seek advice from a qualified healthcare professional for a diagnosis and answers to their medical questions.

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