Clostridium botulinum

This is the medical name for botulism: a rare but serious form of food poisoning which is caused by a toxin released by the clostridium botulinum bacterium.

We can not stress enough the seriousness of this type of food poisoning which can cause muscle paralysis and death if not treated as soon as possible.

These bacteria are found in commercially prepared foods such as those found in cans or vacuum packed foods.

These bacteria form part of the Clostridium genus which includes clostridium perfringens and clostridium difficile.

Clostridium botulinum bacteria

This bacterium is part of a group of rod shaped organisms which are usually found in soils, the sediment at the bottom of rivers and streams and in the gills/intestinal systems of fish and animals.

One example of these is shellfish.

These bacteria exist in a dormant state until they are activated by conditions within their environment which enables them to grow. This growth refers to the growth of spores which are responsible for the production of its deadly toxin.

Botulism occurs if someone consumes food which has been contaminated by this toxin as part of the bacteria’s growth cycle.

Foods which contain the clostridium botulinum bacteria

These include canned foods which have not been properly preserved, packaged or vacuum packed foods, meat and seafood. In most cases it occurs due to foods which have not been adequately preserved or stored in cans.

Examples (canned) include:

• Olives
• Soups
• Cooked meats, e.g. luncheon meat
• Pates
• Tuna
• Ham
• Smoked fish
• Salted fish
• Sweetcorn (and other vegetables)

Causes of botulism

These bacteria secrete a toxin which when ingested, spreads into the bloodstream. Once there it damages the nerves which are responsible for controlling the muscles, causing paralysis and respiratory distress.

Symptoms of botulism

These symptoms first start to appear around 18 to 36 hours after eating contaminated food.

However, in some cases they can appear as little as 4 hours after consumption of this food.

These are caused by the invidious spread of this toxin and include:

• Double/blurred vision
• Slurring of the speech
• Dizziness
• Weakness
• Dry mouth
• Drooping eyelids

These symptoms worsen and lead to difficulties in breathing and swallowing and muscle paralysis. It starts by affecting the muscles around the eyes and face before spreading downwards where it paralyses the muscles of the chest, throat, arms and legs.

The danger here is that of asphyxiation caused by paralysis of the respiratory muscles. This is fatal if left untreated.

This is why it is important to obtain treatment as soon as you suspect botulism.

Diagnosing botulism

This requires further investigation via a series of blood tests and a stool (faeces) sample. Both of these tests will check for the presence of the toxin as well as confirm a diagnosis.

A physical examination will also take place as well as questions being asked about the type of foods eaten recently.

Treatment for botulism

This is a rare condition with only a small percentage of reported cases each year. However it is a serious potentially fatal condition which requires immediate medical treatment.

Treatment involves a botulinum anti-toxin which prevents the spread of the toxin throughout the bloodstream. Intravenous fluids are also given.

If someone has breathing difficulties then they will be placed on a ventilator until this improves. This recovery takes several weeks as the paralysis gradually improves. This condition often requires treatment in Intensive Care due to its life threatening aspects.

Preventing botulism

Following strict guidelines in regarding to canned food will reduce this risk. This also means heating food thoroughly to kill these bacteria before consumption.

Heat canned food at a temperature of at least 80 degrees Celsius (or 176 Fahrenheit) for 10 minutes or so. That should destroy any botulinum bacteria harbouring within the food.