Root Causes of Clostridium perfringens Outbreaks

Findings from CDC’s National Environmental Assessment Reporting System

Retail food establishments, such as restaurants, can work to avoid the root causes of Clostridium perfringens outbreaks.

Outbreak investigators reported three underlying root causes that precede C. perfringens outbreaks. These causes are linked with people, processes, and equipment.

We Recommend

To avoid outbreaks linked to C. perfringens and their root causes, restaurants can

  • Provide food safety training and certification programs
  • Conduct routine maintenance on equipment
  • Use only properly working equipment
  • Train workers on how to properly use equipment

C. perfringens outbreaks occur when food reaches unsafe temperatures.

C. perfringens bacteria are one of the most common causes of foodborne illness (food poisoning). CDC estimates these bacteria cause nearly one million illnesses in the United States every year. Properly preparing and storing food can keep foods within safe temperatures. This study identified situations in the restaurant environment that caused food to reach unsafe temperatures and result in an outbreak of C. perfringens. This study describes common factors that came before C. perfringens outbreaks, as reported by the investigators of those outbreaks.

We found three types of root causes of C. perfringens outbreaks. Each type included three categories.


  • Lack of adherence to food safety procedures
  • Poor food safety culture
  • Lack of managerial control over food safety


  • Process changed during preparation
  • New operations
  • Increased customer volume

Equipment (for storing and holding food)

  • Lack of equipment
  • Malfunctioning equipment
  • Equipment not used properly

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