Clostridium difficile–Associated Diarrhea (CDAD) : surveillance results 2014–2015

In 2014–2015, the provincial incidence rate for HA CDAD was 6.8 cases per 10,000 patient days (Table 2). According to number of beds and teaching vocation, incidence rates for CDAD remained significantly higher in facilities with 100 beds or more, whatever the proportion of admitted patient aged 65 years or older and the teaching vocation (Figure 1 and Table 2).

Figure 1 – Healthcare-associated CDAD Incidence Rate, by Healthcare Facility Category, Québec, 2014–2015 (Incidence Rate per 10,000 Patient Days [95% CI])

p65 : Proportion of admitted patients aged 65 years or older
95% CI: 95% confidence interval.

In 2014–2015, the types of healthcare facility (Table 2) that reported a CDAD incidence rate higher than that of the reference facilities (facilities ˂ 100 beds and p65 < 35%) were:

• Facilities ˂ 100 beds and p65 ≥ 35% (univariate rate ratio = 1.6);
• Non-teaching facilities ≥ 100 beds and p65 < 35% (univariate rate ratio = 2.5);
• Non-teaching facilities ≥ 100 beds and p65 ≥ 35% (univariate rate ratio = 2.3);
• Teaching facilities ≥ 100 beds and p65 ˂ 35% (univariate rate ratio = 2.7);
• Teaching facilities ≥ 100 beds and p65 ≥ 35% (univariate rate ratio = 2.5).

Table 2 – Percentile, Incidence Rate and Univariate Rate Ratio of Healthcare-Associated CDAD by Healthcare Facility Category, Québec, 2014–2015 (Incidence Rate per 10,000 Patient Days [95% CI])

There are two teaching facilities included in the healthcare facilities with the fewer than 100 beds category.
^*Significant statistical difference (p < 0.05) between univariate rate ratio of the heatlcare facility category and reference (ref).
p65 : Proportion of admitted patients aged 65 years or older.

The univariate analysis presented on Table 3 reveals that:

• Facilities with 100 to 249 beds have a higher annual incidence rate of CDAD than facilities with fewer than 100 beds (univariate rate ratio of 1.3);
• Facilities with 250 beds or more have a higher annual incidence rate of CDAD than facilities with fewer than 100 beds (univariate rate ratio of 1.8);
• Facilities with a proportion of admitted patients aged 65 years or older equal of greater to 35% have a similar incidence rate than facilities  with a proportion of admitted patients aged 65 years or older lower than 35% (univariate rate ratio of 0.9);
• Teaching facilities have a higher incidence rate than non-teaching facilities (univariate rate ratio of 1.2);
• Rehabilitation facilities have a lower incidence rate than non-teaching facilities (univariate rate ratio of 0.5);
• Pediatric facilities have a lower incidence rate than non-teaching facilities (univariate rate ratio of 0.5).

Table 3 – Healthcare-associated CDAD Incidence Rate and Univariate Rate Ratio Stratified by Number of Beds, Proportion of Admitted Patients Aged 65 Years or Older and Type of Healthcare Facility, Québec, 2014–2015 (Incidence Rate per 10,000 Patient Days [95% CI])

^* The six rehabilitation facilities are excluded from the analysis.
^**The six rehabilitation facilities and two pediatric facilities are excluded from the analysis.
^*** Significant statistical difference (p < 0.05) between univariate rate ratio of the heatlcare facility category and reference (ref).
p65 : Proportion of admitted patients aged 65 years or older.

HA CDAD incidence rates in 2014–2015 were lower compared to 2013–2014 (Table 4, Figures 2 and 3).

Figure 2 – Healthcare-associated CDAD Incidence Rate for Participating Healthcare Facilities, Québec, 2004–2005 to 2014–2015 (Incidence Rate per 10,000 Patient Days [95% CI]) (N = 95)¹

¹ Data are those from facilities that participated in surveillance in 2014-2015 as well as at least height periods in 2004.2005 and at least 11 periods between 2005-2006 and 2013-2014.

Figure 3 – Healthcare-associated CDAD Incidence Rate and 75th percentile Threshold Value (for Participating Facilities, Québec, 2010–2011 to 2014–2015 (Incidence Rate per 10,000 Patient Days [95% CI]) (N = 95) 

Compared to 2013-2014, non-teaching healthcare facilities with 100 or more beds and less than 35% of admitted patients aged 65 years or older (p65 < 35%) demonstrated a significant increase in their CDAD incidence rate from 3.8 to 7.6 healthcare-associated CDAD / 10 000 patient days. In contrast, teaching facilities with 100 or more beds and 35% or more admitted patients aged 65 years or older (p65 ≥ 35%) demonstrated a significant drop for a second consecutive year in their CDAD incidence rate from 8.8 to 7.5 healthcare-associated CDAD / 10 000 patient days (Table 4).

Table 4 – Healthcare-associated CDAD Incidence Rate by Healthcare Facility Category (N = 95)¹, Québec, 2014–2015 (Incidence Rate per 10,000 Patient Days [95% CI])

* Significant statistical difference (p < 0.05) between healthcare-associated CDAD of 2013-2014 and 2014-2015.
p65: Proportion of admitted patients aged 65 years or older.
¹  Data are those from facilities that participated in surveillance in 2014-2015 as well as at least 11 periods between 2010-2011 and 2013-2014.

In total, 5,004 cases of CDAD were reported of which 3,453 were healthcare-associated (current or previous hospitalisation) (cat. 1a, 1b), and 304 cases which were associated with ambulatory care in the reporting facility (cat. 1c) (Table 5).

Table 5 – Distribution of CDAD Cases by Presumed Origin of Acquisition, Québec, 2014–2015 (N, %)

Data related to complications were available in 2,922 of the 3,453 cases of HA CDAD (84.6%). The 10-day case fatality rate (n = 285) was 9.8% whereas the 11- to 30-day case fatality rate (n = 258) was 8.8%. In addition to the 543 deaths that occurred within 30 days (18.6%), 36 colectomies (1.2%), 202 readmissions (6.9%) and 98 transfers to an intensive care unit (ICU) (3.4%) were reported (Table 6). As of 2010-2011, the percentage of deaths within 30 days has remained stable, ranging from 15.1% to 18.6%.

Table 6 – Number of Deaths, Case Fatality Rate and Complications Related to Healthcare-associated CDAD, Québec, 2010–2011 to 2014–2015 [N (%)]

^*The number of deaths within 30 days includes the number of deaths within 10 days

A laboratory surveillance of C. difficile strains is performed by the Laboratoire de santé publique du Québec every year. This surveillance took place in 2014-2015 and results will be incorporated into this report shortly. 

The HA CDAD incidence rates by healthcare facility and healthcare facility category are shown in Figures 4 through 11.

Figure 4 – Healthcare-associated CDAD Incidence Rate, Among Facilities with Fewer than 100 Beds and a Proportion of Admitted Patients Aged 65 Years or Older Below 35% , Québec, 2014–2015 (Incidence Rate per 10,000 Patient Days [95% CI])

Figure 5 – Healthcare-associated CDAD Incidence Rate Among Facilities with Fewer than 100 Beds and a Proportion of Admitted Patients Aged 65 Years or Older of 35% or More, Québec, 2014–2015 (Incidence Rate per 10,000 Patient Days [95% CI])

Figure 6 – Healthcare-associated CDAD Incidence Rate Among Non-Teaching Facilities with 100 Beds or More and a Proportion of Admitted Patients Aged 65 Years or Older Below 35%, Québec, 2014–2015 (Incidence Rate per 10,000 Patient Days [95% CI])

Figure 7 – Healthcare-associated CDAD Incidence Rate Among Non-Teaching Facilities with 100 Beds or More and a Proportion of Admitted Patients Aged 65 Years or Older of 35% or More, Québec, 2014–2015 (Incidence Rate per 10,000 Patient Days [95% CI])

Figure 8 – Healthcare-associated CDAD Incidence Rate Among Teaching Facilities with 100 Beds or More and a Proportion of Admitted Patients Aged 65 Years or Older Below 35%, Québec, 2014–2015 (Incidence Rate per 10,000 Patient Days [95% CI])

Figure 9 – Healthcare-associated CDAD Incidence Rate Among Teaching Facilities with 100 Beds or More and a Proportion of Admitted Patients Aged 65 Years or Older of 35% or More, Québec, 2014–2015 (Incidence Rate per 10,000 Patient Days [95% CI])

Figure 10 – Healthcare-associated CDAD Incidence Rate Among Rehabilitation Facilities, Québec, 2014–2015 (Incidence Rate per 10,000 Patient Days [95% CI])

Figure 11 – Healthcare-associated CDAD Incidence Rate Among Pediatric Facilities, Québec, 2014–2015 (Incidence Rate per 10,000 Patient Days [95% CI])

At the local level, the HA CDAD incidence rate ranged from 0 to 15.7/10,000 patient days in 2014–2015. The incidence rates for the past five years of surveillance are indicated in Table 7. Overall, 17 healthcare facilities (17.9%) saw a significant decrease in their HA CDAD incidence rate compared to 2013–2014, whereas 8 facilities (8.4%) experienced a significant increase. Two regions (Capitale-Nationale and Chaudière-Appalaches) as well as the province have a significant decrease in their HA CDAD as compared to 2013-2014.

Table 7 – Healthcare-associated CDAD Incidence Rate per Healthcare Facility, Québec, 2010–2011 to 2014–2015 (Incidence Rate per 10,000 Patient Days [95% CI])

* Significant statistical difference (p < 0.05) between incidence rates for Periods 1 through 13. 2013–2014 and 2014–2015.
When the incidence rate is 0. the confidence interval [CI] is not calculated.

Comité de surveillance provinciale des infections nosocomiales (SPIN)

Editorial Committee 

Christophe Garenc, Direction des risques biologiques et de la santé au travail, Institut national de santé publique du Québec

Yves Longtin, Hôpital général juif Sir Mortimer B. Davis

Muleka Ngenda-Muadi, Direction des risques biologiques et de la santé au travail, Institut national de santé publique du Québec

Mélissa Trudeau, Direction des risques biologiques et de la santé au travail, Institut national de santé publique du Québec