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Escherichia coli bacteraemia: how preventable is it?
Journal of Hospital Infection 79 (2011) 364e365
Available online at www.sciencedirect.com
Journal of Hospital Infection journal homepage: www.elsevierhealth.com/journals/jhin
Short report
Escherichia coli bacteraemia: how preventable is it? J. Underwood*, J.L. Klein, W. Newsholme Guy’s and St Thomas’ NHS Foundation Trust, London, UK
a r t i c l e i n f o
s u m m a r y
Article history: Received 22 June 2011 Accepted 26 July 2011 by J.A. Child Available online 24 August 2011
Mandatory bacteraemia reporting was extended to include Escherichia coli from June 2011. The purpose of this study was to investigate whether the success seen in reducing meticillinresistant Staphylococcus aureus infection rates could be duplicated with E. coli. All cases of E. coli bacteraemia occurring at our Trust in 2010 were reviewed. There were 216 episodes of E. coli bacteraemia, of which 63% were community-acquired. Only 19% had a potentially preventable cause identified, the majority (71%) of whom had urinary catheter-associated bacteraemia. These data must be kept in mind should targets to reduce E. coli bacteraemia be set in the future. Ó 2011 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.
Keywords: Bacteraemia Escherichia coli
Introduction In October 2010, Andrew Lansley, the new Health Secretary for England, announced that from 2011 the Department of Health would extend mandatory reporting to include cases of Escherichia coli bacteraemia (http://www.dh.gov.uk/en/MediaCentre/Pressreleases/DH_ 120208). Ostensibly, the aim of extending the existing mandatory surveillance is primarily information gathering with a view, long term, to reducing infection rates. Mandatory surveillance of meticillinresistant Staphylococcus aureus (MRSA) bacteraemia has led to notable reductions in infection rates.1 However, given that MRSA and E. coli have very different epidemiology (the latter being predominantly community-acquired), it is questionable whether the same reductions in cases of bacteraemia over the last few years may be achievable with E. coli. In order to shed light on how many E. coli bacteraemia cases might be preventable, all episodes documented at Guy’s and St Thomas’ NHS Foundation Trust during 2010 were analysed. Methods All patients with positive blood cultures that are deemed clinically significant at our Trust are clinically assessed by doctors from the Department of Infectious Diseases. Clinical features such as community or hospital acquisition and focus of infection are collected prospectively using a standardized proforma and entered into a database, under the supervision of an infection consultant. * Corresponding author. Address: Department of Infectious Diseases, North Wing, St Thomas’ Hospital, Westminster Bridge Road, London SE1 7EH, UK. Tel.: þ44 (0) 7980 571113; fax: þ44 (0) 20 7261 9816. E-mail address: [email protected] (J. Underwood).
All E. coli bloodstream infections during 2010 were identified from the database and their original data collection forms (with more information) were scrutinized and collated into a spreadsheet for analysis. Multiple bacteraemia cases within a 14-day period with the same organism were defined as one episode. Communityacquired bacteraemia cases were defined as those with positive blood cultures drawn <48 h into admission and hospital-acquired with those drawn after 48 h. Chi-squared test was used to analyse categorical data and Student’s t-test for continuous variables. Data analysis was performed using Microsoft ExcelÔ. Results The total number of bloodstream infection episodes across the Trust during 2010 was 747. E. coli was the most frequent isolate, accounting for 216 episodes (29% of the total). The majority (63%) were from the community and of a urinary source (49%) (Table I). Of the 105 patients with a urinary tract focus, 65% were female with a mean age of 60 years. Of these, only 18% (14 episodes) of the community-acquired bacteraemia cases had urinary catheters in situ at the time of bacteraemia. By contrast, the majority (15, 56%) of hospital-acquired bacteraemia cases occurred while a urinary catheter was in situ. Having a urinary catheter at the time of an E. coli bacteraemia was significantly associated with hospital acquisition (P ¼ 0.0001), male sex (P ¼ 0.008) and older age (P ¼ 0.01). It was also significantly associated with higher rates of resistance to gentamicin (34% vs 8% P < 0.001), amoxicillin (76% vs 54%, P ¼ 0.017) and co-amoxiclav (38% vs 13% P ¼ 0.005). There were non-significant increases in resistance rates to cefuroxime (33% vs 17%, P ¼ 0.07), ciprofloxacin (30% vs 22%, P ¼ 0.39) and trimethoprim (48% vs 40%, P ¼ 0.55). Only six patients (6%) had bacteraemia associated with recent urinary tract manipulation.
0195-6701/$ e see front matter Ó 2011 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.jhin.2011.07.005
J. Underwood et al. / Journal of Hospital Infection 79 (2011) 364e365 Table I Escherichia coli bacteraemia episodes at Guy’s and St Thomas’ NHS Trust by acquisition and focus of infection Focus of infection
Urinary tract No focus Biliary tract Other abdominal/pelvic Vascular access device Other Respiratory tract Skin and soft tissue Bone Central nervous system Totals
Acquisition Community
Hospital
78 (57%) 20 (15%) 18 (13%) 12 (9%) 3 (2%) 0 1 (0.7%) 3 (2%) 1 (0.7%) 0 136 (63%)
27 (34%) 20 (25%) 6 (8%) 12 (15%) 7 (9%) 5 (6%) 2 (3%) 0 0 1 (1%) 80 (37%)
Total (% of total)
105 40 24 24 10 5 3 3 1 1 216
(49%) (19%) (11%) (11%) (5%) (2%) (1%) (1%) (0.5%) (0.5%)
Forty (19%) cases had no clear focus of infection identified. These included those who died shortly after having the blood cultures taken, neonates, those with neutropenic sepsis, and patients who were discharged home before further investigations delineating a source were performed. Of the 24 patients with a biliary source, three (13%) had blocked stents around the time of their bacteraemia and one (4%) was post-endoscopic retrograde cholangiopancreatography. It was unclear whether this patient had received antibiotic prophylaxis before the procedure. The ‘other abdominal/pelvic group’ is heterogeneous, but the most frequent cases in this group were premature neonates with necrotising enterocolitis (four, 17%), those with ‘acute abdomens’ (four, 17%) and in the setting of gastrointestinal/pelvic malignancy (three, 13%). All those with a vascular access device as the source had intravenous long lines in situ, largely in the context of malignancy and chemotherapy administration. Discussion The main limitation of this study is that although data were collected prospectively, some data, for example presence of a urinary
365
catheter, were sought retrospectively. Also, errors in coding on the computer database could have led to inaccuracies in the data, although these were minimised by review of the paper proforma. The data clearly show that achieving a significant reduction in the number of E. coli bacteraemia cases would be extremely challenging. Intuitively, the cases that may be preventable are those involving urinary or biliary tract instrumentation or vascular access devices. This population represents just 19% (41 cases, 24 (59%) hospital-acquired) of the total E. coli bacteraemia cases, of which 71% consisted of those with urinary catheter-associated bacteraemia. Nearly two-thirds of our cases were community-acquired with a majority of these being non-preventable urosepsis or abdominal pathology. In summary, the data from this study suggest that >80% of E. coli bacteraemia cases occurring in our Trust are not amenable to current prevention strategies. Minimizing insertion and early removal of urinary catheters has been shown to reduce catheterassociated urinary tract infections.2 Whereas this may provide a reasonable infection prevention intervention, the largely unavoidable nature of E. coli bacteraemia must be taken into account should targets be introduced by the Department of Health in the future. Conflict of interest statement None declared. Funding sources None. References 1. Health Protection Agency. Healthcare-associated infections and antimicrobial resistance: 2009/10. London: HPA; 2010. 2. Stéphan F, Sax H, Wachsmuth M, Hoffmeyer P, Clergue F, Pittet D. Reduction of urinary tract infection and antibiotic use after surgery: a controlled, prospective, beforeeafter intervention study. Clin Infect Dis 2006;42:1544e1551.
Available online at www.sciencedirect.com
Journal of Hospital Infection journal homepage: www.elsevierhealth.com/journals/jhin
Short report
Escherichia coli bacteraemia: how preventable is it? J. Underwood*, J.L. Klein, W. Newsholme Guy’s and St Thomas’ NHS Foundation Trust, London, UK
a r t i c l e i n f o
s u m m a r y
Article history: Received 22 June 2011 Accepted 26 July 2011 by J.A. Child Available online 24 August 2011
Mandatory bacteraemia reporting was extended to include Escherichia coli from June 2011. The purpose of this study was to investigate whether the success seen in reducing meticillinresistant Staphylococcus aureus infection rates could be duplicated with E. coli. All cases of E. coli bacteraemia occurring at our Trust in 2010 were reviewed. There were 216 episodes of E. coli bacteraemia, of which 63% were community-acquired. Only 19% had a potentially preventable cause identified, the majority (71%) of whom had urinary catheter-associated bacteraemia. These data must be kept in mind should targets to reduce E. coli bacteraemia be set in the future. Ó 2011 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.
Keywords: Bacteraemia Escherichia coli
Introduction In October 2010, Andrew Lansley, the new Health Secretary for England, announced that from 2011 the Department of Health would extend mandatory reporting to include cases of Escherichia coli bacteraemia (http://www.dh.gov.uk/en/MediaCentre/Pressreleases/DH_ 120208). Ostensibly, the aim of extending the existing mandatory surveillance is primarily information gathering with a view, long term, to reducing infection rates. Mandatory surveillance of meticillinresistant Staphylococcus aureus (MRSA) bacteraemia has led to notable reductions in infection rates.1 However, given that MRSA and E. coli have very different epidemiology (the latter being predominantly community-acquired), it is questionable whether the same reductions in cases of bacteraemia over the last few years may be achievable with E. coli. In order to shed light on how many E. coli bacteraemia cases might be preventable, all episodes documented at Guy’s and St Thomas’ NHS Foundation Trust during 2010 were analysed. Methods All patients with positive blood cultures that are deemed clinically significant at our Trust are clinically assessed by doctors from the Department of Infectious Diseases. Clinical features such as community or hospital acquisition and focus of infection are collected prospectively using a standardized proforma and entered into a database, under the supervision of an infection consultant. * Corresponding author. Address: Department of Infectious Diseases, North Wing, St Thomas’ Hospital, Westminster Bridge Road, London SE1 7EH, UK. Tel.: þ44 (0) 7980 571113; fax: þ44 (0) 20 7261 9816. E-mail address: [email protected] (J. Underwood).
All E. coli bloodstream infections during 2010 were identified from the database and their original data collection forms (with more information) were scrutinized and collated into a spreadsheet for analysis. Multiple bacteraemia cases within a 14-day period with the same organism were defined as one episode. Communityacquired bacteraemia cases were defined as those with positive blood cultures drawn <48 h into admission and hospital-acquired with those drawn after 48 h. Chi-squared test was used to analyse categorical data and Student’s t-test for continuous variables. Data analysis was performed using Microsoft ExcelÔ. Results The total number of bloodstream infection episodes across the Trust during 2010 was 747. E. coli was the most frequent isolate, accounting for 216 episodes (29% of the total). The majority (63%) were from the community and of a urinary source (49%) (Table I). Of the 105 patients with a urinary tract focus, 65% were female with a mean age of 60 years. Of these, only 18% (14 episodes) of the community-acquired bacteraemia cases had urinary catheters in situ at the time of bacteraemia. By contrast, the majority (15, 56%) of hospital-acquired bacteraemia cases occurred while a urinary catheter was in situ. Having a urinary catheter at the time of an E. coli bacteraemia was significantly associated with hospital acquisition (P ¼ 0.0001), male sex (P ¼ 0.008) and older age (P ¼ 0.01). It was also significantly associated with higher rates of resistance to gentamicin (34% vs 8% P < 0.001), amoxicillin (76% vs 54%, P ¼ 0.017) and co-amoxiclav (38% vs 13% P ¼ 0.005). There were non-significant increases in resistance rates to cefuroxime (33% vs 17%, P ¼ 0.07), ciprofloxacin (30% vs 22%, P ¼ 0.39) and trimethoprim (48% vs 40%, P ¼ 0.55). Only six patients (6%) had bacteraemia associated with recent urinary tract manipulation.
0195-6701/$ e see front matter Ó 2011 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.jhin.2011.07.005
J. Underwood et al. / Journal of Hospital Infection 79 (2011) 364e365 Table I Escherichia coli bacteraemia episodes at Guy’s and St Thomas’ NHS Trust by acquisition and focus of infection Focus of infection
Urinary tract No focus Biliary tract Other abdominal/pelvic Vascular access device Other Respiratory tract Skin and soft tissue Bone Central nervous system Totals
Acquisition Community
Hospital
78 (57%) 20 (15%) 18 (13%) 12 (9%) 3 (2%) 0 1 (0.7%) 3 (2%) 1 (0.7%) 0 136 (63%)
27 (34%) 20 (25%) 6 (8%) 12 (15%) 7 (9%) 5 (6%) 2 (3%) 0 0 1 (1%) 80 (37%)
Total (% of total)
105 40 24 24 10 5 3 3 1 1 216
(49%) (19%) (11%) (11%) (5%) (2%) (1%) (1%) (0.5%) (0.5%)
Forty (19%) cases had no clear focus of infection identified. These included those who died shortly after having the blood cultures taken, neonates, those with neutropenic sepsis, and patients who were discharged home before further investigations delineating a source were performed. Of the 24 patients with a biliary source, three (13%) had blocked stents around the time of their bacteraemia and one (4%) was post-endoscopic retrograde cholangiopancreatography. It was unclear whether this patient had received antibiotic prophylaxis before the procedure. The ‘other abdominal/pelvic group’ is heterogeneous, but the most frequent cases in this group were premature neonates with necrotising enterocolitis (four, 17%), those with ‘acute abdomens’ (four, 17%) and in the setting of gastrointestinal/pelvic malignancy (three, 13%). All those with a vascular access device as the source had intravenous long lines in situ, largely in the context of malignancy and chemotherapy administration. Discussion The main limitation of this study is that although data were collected prospectively, some data, for example presence of a urinary
365
catheter, were sought retrospectively. Also, errors in coding on the computer database could have led to inaccuracies in the data, although these were minimised by review of the paper proforma. The data clearly show that achieving a significant reduction in the number of E. coli bacteraemia cases would be extremely challenging. Intuitively, the cases that may be preventable are those involving urinary or biliary tract instrumentation or vascular access devices. This population represents just 19% (41 cases, 24 (59%) hospital-acquired) of the total E. coli bacteraemia cases, of which 71% consisted of those with urinary catheter-associated bacteraemia. Nearly two-thirds of our cases were community-acquired with a majority of these being non-preventable urosepsis or abdominal pathology. In summary, the data from this study suggest that >80% of E. coli bacteraemia cases occurring in our Trust are not amenable to current prevention strategies. Minimizing insertion and early removal of urinary catheters has been shown to reduce catheterassociated urinary tract infections.2 Whereas this may provide a reasonable infection prevention intervention, the largely unavoidable nature of E. coli bacteraemia must be taken into account should targets be introduced by the Department of Health in the future. Conflict of interest statement None declared. Funding sources None. References 1. Health Protection Agency. Healthcare-associated infections and antimicrobial resistance: 2009/10. London: HPA; 2010. 2. Stéphan F, Sax H, Wachsmuth M, Hoffmeyer P, Clergue F, Pittet D. Reduction of urinary tract infection and antibiotic use after surgery: a controlled, prospective, beforeeafter intervention study. Clin Infect Dis 2006;42:1544e1551.