March 1998

Clostridium Perfringens food poisoning is a reasonably common intestinal intoxication caused by toxins produced by the Clostridium perfringens bacteria.

The Symptoms
Symptoms begin 6 to 24 hours, (but usually 8 to 12 hours) after eating and consist of the sudden onset of acute abdominal pain followed by diarrhoea. Nausea is common, but fever and vomiting are usually absent. The diagnosis is confirmed by a laboratory test on a faecal specimen, with an outbreak being confirmed by tests on suspect foods. The illness occurs when people swallow the bacteria or spores formed by them which then multiply and produce toxin in the intestine, or from eating the toxin already produced in food.

It's Source

• food contaminated by soil or faeces and then kept under conditions that allow the bacteria to multiply.
• inadequately heated or reheated meats, usually stews, meat pies, and gravies made of beef, turkey or chicken.
• the intestinal tract of healthy people and animals (cattle, pigs, poultry and fish).
• soil, water and dust.

Duration
Except in the elderly or debilitated this is generally a mild disease of short duration, usually lasting one day or less.

Treatment
Generally no specific treatment is needed except for fluid replacement if necessary.

Re-infection
No resistance or immunity is gained against reinfection.

Spread to Others
This illness is not spread from person to person.

Work and School
Everyone with this infection should stay off work or school while they have symptoms especially those in High Risk groups, occupations or institutions (infants or children in daycare, school pupils, students, food workers, child-care workers, teachers, and health/care workers).

Reducing the Risk
Clostridium perfringens exists in normal bacterial and spore forms in foods and storing large masses of cooked food between 4°C and 60°C can allow the bacteria to multiply and produce toxins.

Preventive measures that can be taken to help avoid the illness include:-

• Ensuring food handlers have good personal hygiene and adequate food safety training. They must be fully aware of the risks involved in large scale cooking, especially of meat dishes.
• Ensuring adequate temperatures are reached during cooking and that large cuts of meat are cooked thoroughly.
• Encouraging the serving of hot dishes while still hot from initial cooking.
• Keeping cooked hot foods above 60°C (preferably 70°C) if service is not immediate.
• Ensuring the rapid cooling of cooked food by dividing into smaller lots and refrigerating in shallow containers (less than 10cm deep).
• Storing cold foods at or below 4°C to prevent toxin being produced.
• Reheating foods to at least 75°C or until steaming hot, as flash frying or brief rewarming is not adequate to destroy the toxins.
• Preventing cross-contamination from raw to cooked foods (by using separate preparation areas or sanitising between processes).
• Thoroughly washing fruit and vegetables with clean water of drinking standard before use.