Clostridium difficile

Dealing with Outbreaks

• What is the definition of an outbreak of Clostridium difficile (C. difficile) in Ontario?
• What is the process of declaring a C. difficile outbreak?
• What happens when an outbreak is declared? How is it managed?
• What has Ontario done to prevent C. difficile outbreaks?

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What is the definition of an outbreak of Clostridium difficile (C. difficile) in Ontario?

In Ontario, defining a C. difficile outbreak involves the concept of notification thresholds, which are more sensitive than outbreak definitions. These thresholds are set low to encourage vigilance, promote transparency in our health care facilities and protect Ontarians.

The thresholds involve determining the number of nosocomial (meaning, related to health care) infections. The levels that trigger notification are defined as :

• For wards/units with ≥ 20 beds: Three cases of nosocomial C. difficile infection (CDI) identified on one ward/unit within a seven day period, or five cases within a four week period
• For wards/units with < 20 beds: Two cases of nosocomial CDI identified on one ward/unit within a seven day period, or four cases within a four week period
• Hospitals that have a facility nosocomial CDI rate that exceeds their annual nosocomial baseline rate for a period of two consecutive months. Note: This is not valid for a small community hospital where a single case of nosocomial CDI can artificially elevate the facility rate.

Once a threshold is reached, the health care facility is required to discuss with the local medical officer of health about initiating an investigation to determine if there is an outbreak, and the possible actions to control infection.
Exceeding a threshold does not necessarily imply that an outbreak will be declared. Declaration of an outbreak can be made by either the institution or the local medical officer of health.

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What is the process of declaring a C. difficile outbreak?

As soon as a health care facility thinks that it may have an outbreak, it is required to report the situation to its local public health unit and take all the necessary actions to manage the outbreak. The decision to declare an outbreak is made in conjunction with the local medical officer of health.

Declaration of an outbreak is based on two criteria:

• Significant (as determined by the facility and health unit) increase in C. difficile numbers or rate compared to the hospital's own baseline and/or that of comparator institutions
• Epidemiologic evidence of ongoing hospital-based transmission within a ward/unit or facility

Ontario publicly reports hospitals that experienced a C. difficile outbreak that was declared and confirmed in the previous month. These reports and other patient safety indicator results, are available on Health Quality Ontario's (HQO) website (http://www.hqontario.ca/public-reporting/patient-safety). Hospitals are encouraged to report the outbreaks on their websites.

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What happens when an outbreak is declared? How is it managed?

Once an outbreak is declared, an Outbreak Management Team is formed. The team consists of members of the hospital's infection prevention and control program, affected departments, senior management and representatives of the local public health unit. Other key members may include representatives from environmental services and patient flow coordination.

The Outbreak Management Team provides direction on the day-to-day management of the outbreak. At the end of the outbreak, this group reviews all aspects of the outbreak and provides a summary that may include recommendations to the hospital, to help prevent and manage future outbreaks.

In situations where local capacity to deal with the outbreak has been exhausted (i.e. resources from the hospital, local public health unit and Regional Infection Control Network) and additional outbreak management assistance is needed, a request for an Infection Control Resource Team can be made. This team will be established by Public Health Ontario.

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What has Ontario done to prevent C. difficile outbreaks?

Ontario has taken major steps to strengthen infection prevention and control among its health care institutions. When it comes to guarding patient safety, Ontario has established itself as a leader. Ontario has instituted full public reporting on nine patient safety indicators, beginning with reporting of C. difficile-associated infection rates in all its hospitals since September 2008.

In addition, Ontario has also :

• Implemented a hand hygiene program, widely praised by the World Health Organization
• Required hospitals to report outbreaks to their local medical officers of health
• Established regional infection control networks
• Funded infection prevention and control practitioners in hospitals
• Educated frontline health care providers
• Created infection control resource teams
• Improved effective use of antibiotics