Vascular Access–Related Bloodstream Infections in Hemodialysis Patients: surveillance 2015-2016

Figure 1 – VARBSI Incidence Rate by Type of Vascular Access, Québec, 2015–2016 (Incidence Rate per 100 Patient-periods [95% CI])

Note: 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, 2015–2016 (%)

In 2015–2016, incidence rates are significantly lower than in 2011-2015. This decrease is mainly attributable to a decrease in VARBSIs on AV fistula with buttonhole and to a decrease of VARBSIs on permanent catheters (Table 2 and Figures 3 and 4).

Figure 3 – VARBSI Incidence Rates by Type of Vascular Access, Québec, 2011–2015* and 2015–2016 (Incidence Rate per 100 Patient-periods [95% CI])

*Incidence rates for AV fistulas, with and without buttonhole, are limited to data from 2013-2014 to 2015-2016, as information on the use of the buttonhole technique was not collected before 2013-2014.
¥ : Significant difference (p ˂ 0.05) between 2011-2015 and 2015-2016.

Table 2 – VARBSI Incidence Rates by Type of Vascular Access, Québec, 2011–2015 and 2015–2016 (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 to 2015-2016, as information on the use of the buttonhole technique was not collected before 2013-2014.
¥   Significant difference (p ˂ 0,05) between 2011-2015 and 2015-2016.

Figure 4 – VARBSI Incidence Rates by Type of Vascular Access, for Units Participating Since 2011–2012 (N = 38)*, Québec, 2011–2012 to 2015–2016 (Incidence Rate per 100 Patient-periods)

^* Data analyzed are data from dialysis units that participated at least 11 periods per year, for every year from 2011-2012 to 2015-2016.

Time trends in patient-periods are presented in Figure 5. As fistula use is decreasing, catheter use has increased through the last five years. Patient-periods with a temporary catheter, the vascular access presenting the highest incidence rate, had decreased in 2013-2014 and 2014-2015, to increase again in 2015-2016.

Figure 5 – Time Trends in Patient-periods by Type of Vascular Access, for Units Participating Since 2011–2012 (N = 38)*, Québec, 2011–2012 to 2015–2016

^* Data analyzed are data from dialysis units that participated at least 11 periods per year, for every year from 2011-2012 to 2015-2016.

Table 3 – Breakdown of Patient-periods by Type of Vascular Access, 2011–2015 and 2015–2016 (%)

The vast majority (86%, or 117 cases) of VARBSIs occurred in patients who receive their hemodialysis treatment via catheter (Figure 6). Only 9% of cases occurred in patients with an AV fistula. The buttonhole technique is used in a third of cases.  

Figure 6 – Breakdown of VARBSIs by Type of Vascular Access, Québec, 2015–2016 (N = 136)

A majority of cases occurred in ambulatory care and two thirds (64.2%) of these cases were subsequently admitted. Overall, 11.8% of VARBSI cases resulted in death within 30 days following the onset of bacteremia. Death occurred in 18.8% of cases of VARBSI among hospitalized patients (Table 4 and Figure 7), compared with 10.8% of cases among patients receiving ambulatory care.

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, 2015–2016 (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, 2015–2016 (%)

Figure 8 shows that Staphylococcus aureus was the most frequently isolated microorganism in all VARBSI cases (n=78; 53%); followed by coagulase-negative Staphylococcus (CoNS; n= 26; 14%) and enterobacteria. S. aureus was the most frequently isolated microorganism in cases resulting in death (62.5%).

Figure 8 – Categories of Isolated Microorganisms in All Reported Cases (N = 147) and Cases Resulting in Death Within 30 Days (N = 16), Québec, 2015–2016 (%)

In 2015–2016, among VARBSI cases, 15.4% of S. aureus strains are oxacillin-resistant and no vancomycin-resistant Enterococcus was identified (Table 5 and Figure 9). An important increase in resistance to quinolones and to third-generation cephalosporins can be observed in enterobacteria, but no resistance to carbapenems is reported.

Tableau 5 – Percentage of Strains Tested and Percentage of Resistance to Antibiotics for Certain Isolated Microorganisms, Québec, 2015–2016 (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, 2011-2012 to 2015–2016 (%)

Note: Resistance proportion computations are based on small numbers, leading to a great volatility in results.

Figures 10 and 11 show the breakdown of patient-periods monitored in 2015–2016, by type of vascular access and by healthcare facility. In 2015–2016, the percentage of fistulas decreased in 13 healthcare facilities and increased in 7 (Table 6). Twelve facilities reported a rate of 0 VARBSI per 100 patient-periods, and five reported a rate higher than the 90th-percentile mark for 2011–2015 (Figure 12 and Table 7). Four of these five facilities have small dialysis units and declared only one or two VARBSIs in 2015-2016. Facilities with an incidence rate of 0 had small dialysis units of 5 to 11 chairs.

Figure 10 – Patient-periods Followed, by Healthcare Facility, Québec, 2015–2016 (%)

Figure 11 – Breakdown of Patient-periods Monitored by Type of Vascular Access and by Healthcare Facility, Québec, 2015–2016 (N)

Figure 12 – VARBSI Incidence Rate per Healthcare Facility (2015–2016) and Incidence Rate Percentile (2011–2012 to 2014–2015), Québec, 2015–2016 (Incidence Rate per 100 Patient-periods)

Table 6 – Number of Patient-periods Monitored and Percentage of Fistulas, by Healthcare Facility, Québec, 2011–2015 and 2015–2016 (N, % [95% CI])

Table 7 – Number of VARBSI Cases and Incidence Rate by Healthcare Facility, and Percentile Ranking, Québec, 2011–2015 and 2015–2016 (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 

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

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

Danielle Moisan, Centre hospitalier régional du Grand-Portage

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

Isabelle Rocher, 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

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