Total number of new nosocomial (i.e. hospital acquired) CDI cases

Inclusions: 

1. All publicly funded hospitals
2. Inpatient beds
3. Laboratory-confirmed CDI cases (i.e. confirmation of a positive toxin assay (A/B) for Clostridium difficile together with diarrhea OR visualization of pseudomembranes on sigmoidoscopy or colonoscopy, or histological/pathological diagnosis of pseudomembranous colitis)
4. New nosocomial case associated with the reporting facility defined as - the infection was not present on admission (i.e., onset of symptoms > 72 hours after admission) or the infection was present at the time of admission but was related to a previous admission to the same facility within the last 4 weeks and the case has not had Clostridium difficile-Associated Disease (CDAD) in the past 8 weeks.

Exclusions: 

Patients less than 1 year of age

Outbreak Classification:

CDI outbreak definitions incorporate the concept of notification thresholds that optimally trigger action and dialogue between the local public health unit and the facility to determine if an outbreak is occurring. 

Facilities should use the following CDI notification thresholds to assist them in determining the need for consultation with their local public health unit. Facilities with limited experience in managing CDI should consult with the local public health unit and/or with the local regional infection control network. These thresholds were developed by the Ministry of Health Long-Term Care (the 'Ministry') and can also be found in the Provincial Infectious Diseases Advisory Committee's Annex C: Testing, Surveillance and Management of Clostridium difficile in All Health Care Settings.

Notification thresholds are defined as:

1. For wards/units with >=20 beds, three (3) new cases of nosocomial CDI identified on one ward/unit within a seven day period OR five (5) new cases of nosocomial CDI within a four-week period; OR
2. For wards/units with <20 beds, two (2) new cases of nosocomial CDI identified on one ward/unit within a seven day period or four (4) new  cases of nosocomial CDI within a four-week period; OR
3. Facilities 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 hospitals with a single case of nosocomial CDI which artificially elevates the facility rate. 

It should be noted that exceeding a threshed does not necessarily imply that an outbreak will be declared. Following consultation between the facility and the local public health unit, decisions on the declaration of an outbreak will be made based on the following criteria:

• There has been a significant* (as determined by the facility and the local public health unit) increase in CDI numbers or rate compared to own baseline and/or that of comparator institutions
• Recognized control measures are in place and are being used.
• There is epidemiologic evidence of ongoing nosocomial transmission within the ward/unit or facility

*Significance may be determined by reviewing:

• number of new nosocomial cases associated with the reporting ward/unit or facility;
• historic level of CDI activity of the ward/unit or facility;
• current trend in ward/unit CDI activity or facility rate;
• location of current cases and possible epidemiologic links between cases;

Total number of inpatient days

Inclusions: 

• All publicly funded hospitals
• Inpatient beds

Exclusions: 

Patients less than 1 year of age