BOTULISM

Causes and types of botulism

The bacteria Clostridium botulinum are found in soil, dust, and river or sea sediments. The bacteria themselves aren’t harmful, but they can produce highly poisonous toxins when deprived of oxygen – such as in closed cans or bottles, stagnant soil or mud, or occasionally the human body.

There are three main types of botulism:

• food-borne botulism – which develops after ingestion of food containing the toxins, especially when food hasn’t been properly canned, preserved or cooked
• wound botulism – this occus when a wound becomes infected with the bacteria, usually as penetrating injuries such as during injecting illegal drugs contaminated with the bacteria, such as heroin, into muscle rather than a vein
• infant botulism – occurs when infants ingest resistant form of the bacteria, called a spore, in contaminated soil or food, such as honey. These spores are harmless to older children and adults because the body develops defences against them from about one year of age

Symptoms of botulism

The time it takes to develop symptoms can vary from a few hours to several days after exposure to the Clostridium botulinum bacteria or their toxins.

Depending on the exact type of the condition, some people initially have symptoms such as feeling sick, vomiting, stomach cramps, diarrhoea or constipation.

Without treatment, botulism eventually causes paralysis that spreads down the body from the head to the legs. Symptoms can include:

• drooping eyelids
• blurred or double vision
• facial muscle weakness
• difficulty swallowing
• slurred speech
• breathing difficulties

Affected babies may also have a weak cry, find it difficult to feed and appear to be floppy.

Treatment for botulism

Botulism needs to be treated in hospital.

Management will depend on the type of botulism, but treatment will usually involve:

• neutralising the toxins with antitoxins or antibodies
• supportive care, such as supporting breathing, until recovery

Treatment won’t reverse any paralysis that’s already been caused by the toxin, but it will stop it getting any worse.

In most people, paralysis that occurred before treatment will gradually improve over the following weeks or months.

Preventing botulism

Efforts in setting standards to practice food hygiene decrease the incidence of getting food-borne botulism.

There’s a slightly higher risk of acquiring food-borne botulism when consuming home canned goods. However, following food hygiene procedures and canning recommendations will reduce any risk.

Before eating preserved or can preserved goods, it is important to observe the canned preparation. Avoid eating canned goods when it is visibly bulging or damaged, foul-smelling, or when foods are stored in incorrect temperatures and are out of date.

Heroin use is illegal and should be avoided especially intramuscular injection of the drug.

The specific cause is not identified in many cases of infant botulism, so it may not always be possible to prevent it. However, measures may be done to lessen the risk such as aboiding giving honey to babies less than 12 months old because it has been known to contain Clostridium botulinum spores.