The 2014-2015 VARBSI incidence rate was 0.28 cases per 100 patient-periods. The incidence rate was 0.09 for patients with an AV fistula, 0.20 for patients with a graft, 0.37 for patients with a permanent catheter and 6.73 for patients with a temporary catheter (Figure 1). In patients with AV fistulas, the VARBSI incidence rate was higher when the buttonhole technique was used (0.20 per 100 patient-periods versus 0.05, p < 0.01). Incidence rates were not statistically different between patients with an AV fistula with buttonhole and those with a graft, nor they were such difference between patients with a graft and those with a permanent catheter; however, the incidence rate for patients with an AV fistula with buttonhole was lower than the incidence rate for those with a permanent catheter (p < 0.03).

Therefore, compared to AV fistulas without buttonhole, the incidence rate with a temporary catheter was 123.6 [54.1 ; 282.3] times greater, with a permanent catheter 6.9 [3.5 ; 13.5] times greater, with a graft 3.6 [1.2 ; 10.8] times greater and with an AV fistula with a buttonhole, the incidence rate was 3.6 [1.5 ; 9.0] times greater (all p values < 0.05). The incidence rate with a temporary catheter was 18.0 [10.5 ; 30.8] times higher than with a permanent catheter (p < 0.05).

Figure 1 – VARBSI Incidence Rate by Type of Vascular Access, Québec, 2014–2015 (Incidence Rate per 100 Patient-periods [95% CI])

95% CI: 95% confidence interval.

Permanent catheters were the most commonly used type of vascular access, followed by AV fistulas without the use of the buttonhole technique (Figure 2).

Figure 2 – Breakdown of Patient-periods by Type of Vascular Access, Québec, 2014–2015 (%)

In 2014–2015, incidence rates per type of vascular access were stable compared to 2010–2014, except for patients with a permanent catheter, which has significantly decreased (p < 0.01) (Table 2 and Figures 3 and 4).

Figure 3 – VARBSI Incidence Rates by Type of Vascular Access, Québec, 2010–2014 and 2014–2015 (Incidence Rate per 100 Patient-periods [95% CI])

Table 2 – VARBSI Incidence Rates by Type of Vascular Access, Québec, 2010–2014 and 2014–2015 (Incidence Rate per 100 Patient-periods and per 1,000 Vascular-Access Days [95% CI]

* Incidence rates for AV fistulas, with and without buttonhole, are limited to data from 2013-2014 and 2014-2015, as information on the use of the buttonhole technique was not collected before 2013-2014.

Figure 4 – VARBSI Incidence Rates by Type of Vascular Access, for Units Participating Since 2010–2011 (N = 28), Québec, 2010–2011 to 2014–2015 (Incidence Rate per 100 Patient-periods)

Despite recommendations to increase the use of fistulas, the proportion of patients who were receiving hemodialysis through a catheter, either temporary or permanent, increased in 2014–2015 compared to 2010–2014. However, the proportion of patients with a temporary catheter, which is the form of vascular access most likely to lead to a VARBSI, decreased significantly (p < 0.01).

Figure 5 – Time Trends in Patient-periods by Type of Vascular Access, for Units Participating Since 2010–2011 (N = 28), Québec, 2010–2011 to 2014–2015

Table 3 – Breakdown of Patient-periods by Type of Vascular Access, 2010–2014 and 2014–2015 (%)

Patients who developed a VARBSI were aged between 0 and 95 years, with a median age of 68 years. The vast majority (85%, or 132 cases) of VARBSIs occurred in patients who received their hemodialysis treatment via catheter, even though they represented only 57% of the patient-periods monitored (Figures 2 and 6). For most of the cases that arose in patients receiving their hemodialysis through an AV fistula, the buttonhole technique was used (53%) even though this technique is used among 23% of patients with AV fistula.

Figure 6 – Breakdown of VARBSIs by Type of Vascular Access, Québec, 2014–2015 (N = 156)

Overall, 12% of VARBSI cases resulted in death within 30 days following the onset of bacteriemia. Death occurred in 16% of cases of VARBSI among hospitalized patients (Table 4 and Figure 7), compared with 12% of cases among patients receiving ambulatory care (p > 0.05). A total of 55% of ambulatory patients who developed a VARBSI required hospitalization.

Table 4 – 30-Day Case Fatality, Percentage of Transfers to ICU and Percentage of Hospitalizations and Rehospitalizations During a VARBSI Episode, by Origin of Acquisition, Québec, 2014–2015 (N, %)

Figure 7 – 30-Day Case Fatality, Percentage of Transfers to ICU and Percentage of Hospitalizations and Rehospitalizations During a VARBSI Episode, by Origin of Acquisition, Québec, 2014–2015 (%)

Figure 8 shows that Staphylococcus aureus was the most frequently isolated microorganism in all VARBSI cases (55%). It was followed by coagulase-negative Staphylococcus (CoNS, 14%) and other enterobacteria (other than Escherichia coli and Klebsiella sp., 9%). Six of the CoNS cases (n = 23) were S. lugdunensis and 8 were S. epidermidis. S. aureus was the most frequently isolated microorganism in cases resulting in death (60%).

Figure 8 – Categories of Isolated Microorganisms in All Reported Cases (N = 163) and Cases Resulting in Death Within 30 Days (N = 20), Québec, 2014–2015 (%)

Isolated Microorganisms—All Cases

Isolated Microorganisms—Death Within 30 Days

In 2014–2015, 15% of S. aureus strains were oxacillin-resistant, which is not significantly different compared with 2010–2014 percentage (Table 5 and Figure 8).

Table 5 – Percentage of Strains Tested and Percentage of Resistance to Antibiotics for Certain Isolated Microorganisms, Québec, 2014–2015 (N, %)

CSE 2: cefepime or ceftazidime.
CSE 4: cefepime, cefotaxime, ceftazidime or ceftriaxone.
Fluoroquinolones 2: ciprofloxacin or levofloxacin.
Fluoroquinolones 3: ciprofloxacin, levofloxacin or moxifloxacin.
Multiresistant 1: intermediate or resistant to an agent in three of the following five categories: cephalosporins 4, fluoroquinolones 3, aminoglycosides, carbapenems, piperacillin or piperacillin/tazobactam.
Multiresistant 2: intermediate or resistant to an agent in three of the following five categories: cephalosporins 2, fluoroquinolones 2, aminoglycosides, carbapenems, piperacillin or piperacillin/tazobactam.
Multiresistant 3: intermediate or resistant to an agent in three of the following six categories: cephalosporins 2, fluoroquinolones 2, aminoglycosides, carbapenems, piperacillin or piperacillin/tazobactam, ampicillin/sulbactam.

Figure 9 – Percentage of Antibiotic Resistance in Certain Gram-Positive Bacteria, Certain Gram-Negative Bacteria and Pseudomonas sp., Québec, 2010–2011 to 2014–2015 (%)

Figures 10 and 11 show the breakdown of patient-periods monitored in 2014–2015, by type of vascular access and by healthcare facility. In 2014–2015, the percentage of fistulas decreased in 14 healthcare facilities and increased in 9 (Table 6). Seventeen facilities reported a rate of 0 VARBSI per 100 patient-periods, and 4 reported a rate higher than the 90th-percentile mark for 2010–2014 (Figure 12 and Table 7). Facilities with an incidence rate of 0 had small dialysis units of 4 to 12 chairs, except for two bigger units.

Figure 10 – Patient-periods Followed, by Healthcare Facility, Québec, 2014–2015 (%)

Figure 11 – Breakdown of Patient-periods Monitored by Type of Vascular Access and by Healthcare Facility, Québec, 2014–2015 (N)

Figure 12 – VARBSI Incidence Rate per Healthcare Facility (2014–2015) and Incidence Rate Percentile (2010–2011 to 2013–2014), Québec, 2014–2015 (Incidence Rate per 100 Patient-periods)

Table 6 – Number of Patient-periods Monitored and Percentage of Fistulas, by Healthcare Facility, Québec, 2010–2014 and 2014–2015 (N, % [95% CI])

Table 7 – Number of VARBSI Cases and Incidence Rate by Healthcare Facility, and Percentile Ranking, Québec, 2010–2014 and 2014–2015 (Incidence Rate per 100 Patient-periods [95% CI])

* Changes in rates within individual facilities were not subjected to statistical analysis, given the small number of cases involved.

1. Fistula First. Graphs of Prevalent AV Fistula Use Rates, By Network [online]. http://www.fistulafirst.org/AboutFistulaFirst/FisultaFirstCatheterLastFFCLData.aspx (last consulted: 2013-08-06).
2. Ayzac, L., Machut, A., Russell, I., et al. Rapport final pour l’année 2011 du réseau de surveillance des infections en hémodialyse – DIALIN. CClin Sud-Est and RAISIN [online]. http://cclin-sudest.chu-lyon.fr/Reseaux/DIALIN/Resultats/rapport_annuel_2011_V2.pdf (last consulted: 2013-08-06).
3. Patel, P. R., Yi, S. H., Booth, S., et al. Bloodstream Infection Rates in Outpatient Hemodialysis Facilities Participating in a Collaborative Prevention Effort: A Quality Improvement Report. American Journal of Kidney Diseases, Vol. 62, No. 2 (August 2013), p. 322–330.

Comité de surveillance provinciale des infections nosocomiales (SPIN) – bactériémies associées aux accès vasculaires en hémodialyse

Editorial Committee 

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

Charles Frenette, Centre universitaire de santé McGill

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