- Email: [email protected]
Prevalence of healthcare-associated infection in Scottish intensive care units
Journal of Hospital Infection 76 (2010) 308e310
Available online at www.sciencedirect.com
Journal of Hospital Infection journal homepage: www.elsevierhealth.com/journals/jhin
Prevalence of healthcare-associated infection in Scottish intensive care units S. Cairns*, J. Reilly, M. Booth Health Protection Scotland, Glasgow, UK
a r t i c l e i n f o
s u m m a r y
Article history: Received 19 May 2009 Accepted 7 May 2010 Available online 23 October 2010
A national point prevalence survey of healthcare-associated infection (HCAI) in all acute hospitals, including intensive care units (ICUs), was carried out in Scotland from October 2005 to October 2006. The survey measured the prevalence of HCAIs to determine the burden on ICU resources. HCAI prevalence in ICUs was compared with HCAI prevalence in patients outside ICU. The prevalence of HCAI in ICU patients was 27.1%, significantly higher than HCAI prevalence in patients outside ICU, which was 9.3%. The prevalence of specific infections, namely pneumonia and lower respiratory tract, bloodstream and surgical site infections, was also significantly higher in ICU patients compared with non-ICU patients. These results highlight the burden on ICU resources from all HCAIs, regardless of site of infection. High HCAI prevalence in Scottish ICUs has major implications for patient safety and ICU resources and emphasises the need for continuing strong collaboration between intensivists and infection control teams. Ó 2010 Published by Elsevier Ltd on behalf of The Hospital Infection Society.
Keywords: Healthcare-associated infection Intensive care unit Point prevalence survey Scotland
Introduction Healthcare-associated infection (HCAI) is an increasing problem worldwide and contributes significantly to morbidity and mortality in the hospital population.1 The additional costs arising from treatment of HCAI place a significant burden on healthcare resources. The Plowman Report published in 1999 estimates that HCAI costs the National Health Service an additional £1 billion per year.2 The Scottish National Healthcare-associated Infection Prevalence Survey in 2005/2006 reported the prevalence of HCAI in acute care hospitals to be 9.5%; inpatient cost was an estimated £183 million per year.3 HCAI places an increased burden on the resources of the specialty responsible for the patients’ care including costs associated with an increased length of stay. This burden may be especially important in intensive care units (ICUs) due to the high cost of care in this setting; £1,853 per bed-day in Scotland in 2007/2008.4 Patients who require admission to ICUs are among the most severely ill and many have underlying chronic illness and some degree of immunosuppression.5 The routine management of severely ill patients involves numerous invasive procedures that may be performed inside the ICU or prior to ICU admission in other hospital areas. Most of the literature focuses on the burden that ICU-acquired infections place on ICU resources but without reference to the * Corresponding author. Address: Health Protection Scotland, Cadogan Square, Glasgow G2 7HF, UK. Tel.: þ44 0141 282 2921; fax: þ44 0141 847 0399. E-mail address: [email protected] (S. Cairns).
burden from all HCAIs, both ICU-acquired and HCAI acquired elsewhere in the hospital.5e7 Patients admitted to ICU may have acquired HCAI in otherparts of the hospital. These infections contribute to the burden on ICU resources including costs associated with extended length of stay and treatment of HCAI.8,9 As in many other countries, Scotland has implemented a programme aimed at reducing HCAI. The remit of the Scottish Patient Safety Programme, which began in 2008, includes measures aimed to reduce HCAI in Scottish ICUs. The HCAI burden and most prevalent infection types contributing to this burden must be known so that measures can be targeted effectively. Monitoring HCAIs is an essential component of infection prevention and control activities.10 Many countries, including Scotland, have implemented prospective incidence surveillance of HCAI in ICU patients.11,12 Prospective surveillance is the reference method for monitoring HCAI but this can be costly and is usually targeted at common infection types such as ventilator-associated pneumonia. Cross-sectional prevalence surveys offer a relatively cost-effective and rapid method of measuring the burden of all HCAI types in the hospital population. Measuring HCAIs can identify priority areas for infection control and targeted surveillance in the ICU setting and hospital as a whole. This study reports the secondary analysis of the Scottish National HAI Prevalence Survey dataset with a particular focus on HCAI prevalence in all ICUs in Scotland. The prevalence of antimicrobial prescribing in ICU patients as opposed to non-ICU patients is also described and compared.
0195-6701/$ e see front matter Ó 2010 Published by Elsevier Ltd on behalf of The Hospital Infection Society. doi:10.1016/j.jhin.2010.05.010
S. Cairns et al. / Journal of Hospital Infection 76 (2010) 308e310
Methods A national rolling point prevalence survey of all acute hospitals in Scotland (N ¼ 45) was carried out from October 2005 to September 2006. The survey included all ICUs (N ¼ 29). All inpatients were surveyed with the exception of day case patients and patients aged <16 years. Data were collected by seven trained data collectors who were independent of the hospitals using a bespoke database held on portable tablet computers. The data collectors sought information on eligible inpatients from all relevant sources including medical and nursing case records, microbiology reports, X-ray reports, temperature charts, prescribing records and where necessary through discussion with clinical staff and by direct clinical observation. Each ward was started and completed within one day. HCAI was defined as an infection arising 48 h after admission to hospital that was neither present nor incubating on admission. HCAI was confirmed if the patient had signs and symptoms which met the Centers for Disease Control and Prevention (CDC, Atlanta, GA, USA) definition at the time of survey, or, who had one or more signs or symptoms included in the CDC definition and was being treated with an antimicrobial at the time of survey.13 Rigorous quality assurance of data was undertaken to ensure that recorded infections met one of the case definitions. Inter-rater reliability was tested on two occasions during the survey. The validation recorded a 100% agreement between data collectors for diagnosis of HCAI type. The data were analysed using Stata Version 9.1 for Windows. The overall HCAI and antimicrobial prevalence proportions were calculated with 95% confidence interval (CIs) for ICU and non-ICU patients. The infection type specific HCAI prevalence and the prevalence of antimicrobial use were described in ICU and non-ICU patients. Pearson’s c2-test was used to compare prevalence in ICU and non-ICU patients.
Results In total, 11 608 patients were surveyed including 129 patients in 29 ICUs. The age and sex distribution of the surveyed patients is shown in Table I. During the survey, 35 patients in ICUs had a total of 46 HCAIs. There were nine patients with more than one infection. The prevalence of HCAIs in ICU patients was 27.1% (95% CI: 19.7e35.7). The prevalence of HCAI in non-ICU patients was 9.3% (95% CI: 8.8e9.9), significantly lower than the ICU patients (P < 0.0001). The prevalence of each infection type in ICU and non-ICU patients and the P-value comparing the infection type specific prevalence are shown in Table II. At the time of survey, 90 ICU patients and 3631 non-ICU patients were receiving antimicrobial agents. The prevalence of
Table I Age and sex distribution of surveyed intensive care unit (ICU) and non-ICU patients Age group (years)
ICU patients
Non-ICU patients
Male N (%)
Female N (%)
Male N (%)
Female N (%)
16e24 25e44 45e59 60e74 75
1 (25.0) 10 (55.6) 21 (75.0) 30 (55.6) 10 (40.0)
3 (75.0) 8 (44.4) 7 (25.0) 24 (44.4) 15 (60.0)
131 (34.4) 499 (36.5) 794 (50.6) 1568 (49.9) 1783 (35.6)
250 (65.6) 868 (63.5) 774 (49.4) 1574 (50.1) 3222 (64.4)
Total
72 (55.8)
57 (44.2)
4775 (41.7)
6688 (58.3)
Date of birth was not recorded for 16 patients.
309
Table II Healthcare-associated infection (HCAI) type specific prevalence in intensive care unit (ICU) and non-ICU patients HCAI type
ICU patients
Non-ICU patients
P-value
No. of Prevalence No. of Prevalence infections % infections % Bone and joint Bloodstream Central nervous system Cardiovascular system Eye, ear, nose, throat and mouth Gastrointestinal Lower respiratory tract Pneumonia Reproductive system Systemic Surgical site Skin and soft tissue Urinary tract
0 4 1 0 1
0 3.10 0.78 0 0.78
6 51 1 11 154
0.05 0.44 0.01 0.10 1.34
0.79 <0.0001 <0.0001 0.72 0.86
4 11 9 1 0 11 3 1
3.10 8.53 6.98 0.78 0 8.53 2.33 0.78
187 128 100 16 2 186 134 221
1.63 1.12 0.87 0.14 0.02 1.62 1.17 1.93
0.19 <0.0001 <0.0001 0.06 0.88 <0.0001 0.23 0.64
antimicrobial use in ICU patients, 69.8% (95% CI: 61.7e77.8), was significantly higher (P < 0.0001) than the prevalence in non-ICU patients, 31.6% (95% CI: 30.8e32.5). The prevalence of antimicrobial use by specific antimicrobial group is shown in Table III. Discussion This paper reports the first HCAI prevalence survey in ICUs in Scotland and demonstrates the burden on ICU resources in Scotland. The prevalence of HCAI was significantly higher in ICU patients compared with patients cared for outside of an ICU, 27.1% versus 9.3% (P < 0.0001). As would be expected, a similar situation was observed during the Four Country HCAI prevalence survey carried out in England, Wales, Northern Ireland and the Republic of Ireland in 2006, although there were differences in the definitions and methods used.14 The prevalence of HCAIs in critical care medicine wards during this survey was 23.3% and the overall prevalence for all wards was 7.6%. A significantly higher prevalence of specific HCAI types is reported in ICU patients compared with patients cared for outside of the ICU, namely pneumonia and lower respiratory tract, bloodstream and surgical site infections. These infection types are often
Table III Antimicrobial group prevalence in intensive care unit (ICU) and non-ICU patients Antimicrobial group
ICU patients
Non-ICU patients
P-value
No. of Prevalence % No. of Prevalence % patients patients Aminoglycosides Antifungals Antivirals Cephalosporins Carbapenems and monobactams Glycopeptides Macrolides, lincosamides, streptogramin Other Penicillins Quinolones Sulphonamides and trimethoprim Tetracyclines Multiple No antimicrobial
1 3 0 8 2
0.8 2.3 0 6.2 1.55
16 194 28 213 12
0.1 1.7 0.2 1.86 0.10
0.06 0.58 0.58 <0.0001 <0.0001
1 2
0.8 1.6
83 136
0.7 1.2
0.94 0.70
2 5 2 0
1.6 3.9 1.6 0
240 802 299 159
2.1 7.0 2.6 1.4
0.67 0.17 0.45 0.18
0 64 39
0 49.6 30.2
16 1433 7848
0.1 12.5 68.4
0.67 <0.0001 <0.0001
310
S. Cairns et al. / Journal of Hospital Infection 76 (2010) 308e310
associated with extrinsic risk factors arising from invasive procedures and devices such as mechanical ventilators and vascular catheters and are considered to have the greatest potential for reduction.15 Knowledge of this risk allows for infection prevention and control planning for ICUs. In this study, it was not possible to determine where the infection was acquired, due to the application of strict point prevalence methodology. Only data sources available on the day of survey were reviewed, so a retrospective review to determine whether the HCAI was ICU-acquired or acquired elsewhere in the hospital was not performed. Such data would be needed to target infection prevention measures. There are several important advantages to a strict point prevalence survey methodology in ICUs. These can be carried out rapidly with little impact on ICUs. This study design enabled every hospital in Scotland to be surveyed by independent data collectors, maximising data collection time. Point prevalence surveys can also be used to identify infection types that are not monitored using targeted incidence surveillance. Almost threequarters of the infections identified in ICU patients in this survey would not have been identified by the surveillance systems commonly used in ICUs, namely, bloodstream infection and ventilator-associated pneumonia surveillance. This demonstrates the applicability of prevalence surveys and their strength when used in collaboration with targeted incidence surveillance programmes. Using the same methodology, it is possible to collect data on antimicrobial prescribing in hospitals. In this survey, almost threequarters of patients were receiving antimicrobials at the time of the survey and almost half were receiving two or more drugs. As was expected, a significantly higher proportion of ICU patients was receiving antimicrobials than was the case for patients cared for outside (P < 0.0001). It is acknowledged that the comparison of HCAI and antimicrobial usage in ICU and in non-ICU patients is likely to have been subject to confounding by the underlying medical condition of the patients. These data measure the burden that HCAI place on ICUs and can be used to focus future targeted incidence surveillance, which would allow for the application of robust risk adjustment methodologies. The largest burden on ICU resources due to HCAI resulted from an increased prevalence of HCAI, typically associated with invasive devices and procedures. This demonstrates the continued need for focused infection control measures tailored to this specific patient group and to the hospital population in general.
Acknowledgements We gratefully acknowledge the co-operation and support of infection control and ward staff in all of the participating hospitals. The authors would like to thank the Scottish National HAI Prevalence Survey team for dedicated data collection. Conflict of interest statement None declared. Funding sources The Scottish Executive Health Department HAI Task Force funded this project.
References 1. European Centre for Disease Prevention and Control. Annual epidemiological report on communicable diseases in Europe 2008. Stockholm: European Centre for Disease Prevention and Control; 2008. 2. Plowman R, Graves N, Griffin M, et al. The socio-economic burden of hospital acquired infection. London: Public Health Laboratory Services; 1999. Part 1. 3. Reilly J, Stewart S, Allardice G, et al. NHS Scotland national HAI prevalence survey: final report. Glasgow: Health Protection Scotland; 2007. 4. Information Services Division. Scottish national tariff. 2007/2008. Edinburgh: ISD Scotland; 2008. 5. Vincent JL. Nosocomial infections in adult intensive-care units. Lancet 2003;361:2068e2077. 6. De Rosa FG, Garazzino S, Audagnotto S, et al. SPIR01 and SPIR02: a two-year 1-day point prevalence multicenter study of infections in intensive care units in Piedmont, Italy. New Microbiol 2008;31:81e87. 7. Richards MJ, Edwards JR, Culver DH, Gaynes RP. Nosocomial infections in combined medicalesurgical intensive care units in the United States. Infect Control Hosp Epidemiol 2000;21:510e515. 8. Warren DK, Shukla SJ, Olsen MA, et al. Outcome and attributable cost of ventilator-associated pneumonia among intensive care unit patients in a suburban medical center. Crit Care Med 2003;31:1312e1317. 9. Warren DK, Quadir WW, Hollenbeak CS, Elward AM, Cox MJ, Fraser VJ. Attributable cost of catheter-associated bloodstream infections among intensive care patients in a nonteaching hospital. Crit Care Med 2006;34:2084e2089. 10. National Audit Office. The management and control of hospital acquired infection in acute NHS trusts in England. London: National Audit Office; 2000. 11. Suetens C, Morales I, Savey A, et al. European surveillance of ICU-acquired infections (HELICS-ICU): methods and main results. J Hosp Infect 2007;65 (Suppl. 2):171e173. 12. Health Protection Scotland. Surveillance of intensive care unit associated infections. Pilot report. Glasgow: Health Protection Scotland; December 2005. 13. Centers for Disease Control and Prevention. National nosocomial infection surveillance system manual. Atlanta: CDC; 1999. 14. Smyth ET, McIlvenny G, Enstone JE, et al. Four country healthcare associated infection prevalence survey 2006: overview of the results. J Hosp Infect 2008;69:230e248. 15. Harbarth S, Sax H, Gastmeier P. The preventable proportion of nosocomial infections: an overview of published reports. J Hosp Infect 2003;54:258e266.
Available online at www.sciencedirect.com
Journal of Hospital Infection journal homepage: www.elsevierhealth.com/journals/jhin
Prevalence of healthcare-associated infection in Scottish intensive care units S. Cairns*, J. Reilly, M. Booth Health Protection Scotland, Glasgow, UK
a r t i c l e i n f o
s u m m a r y
Article history: Received 19 May 2009 Accepted 7 May 2010 Available online 23 October 2010
A national point prevalence survey of healthcare-associated infection (HCAI) in all acute hospitals, including intensive care units (ICUs), was carried out in Scotland from October 2005 to October 2006. The survey measured the prevalence of HCAIs to determine the burden on ICU resources. HCAI prevalence in ICUs was compared with HCAI prevalence in patients outside ICU. The prevalence of HCAI in ICU patients was 27.1%, significantly higher than HCAI prevalence in patients outside ICU, which was 9.3%. The prevalence of specific infections, namely pneumonia and lower respiratory tract, bloodstream and surgical site infections, was also significantly higher in ICU patients compared with non-ICU patients. These results highlight the burden on ICU resources from all HCAIs, regardless of site of infection. High HCAI prevalence in Scottish ICUs has major implications for patient safety and ICU resources and emphasises the need for continuing strong collaboration between intensivists and infection control teams. Ó 2010 Published by Elsevier Ltd on behalf of The Hospital Infection Society.
Keywords: Healthcare-associated infection Intensive care unit Point prevalence survey Scotland
Introduction Healthcare-associated infection (HCAI) is an increasing problem worldwide and contributes significantly to morbidity and mortality in the hospital population.1 The additional costs arising from treatment of HCAI place a significant burden on healthcare resources. The Plowman Report published in 1999 estimates that HCAI costs the National Health Service an additional £1 billion per year.2 The Scottish National Healthcare-associated Infection Prevalence Survey in 2005/2006 reported the prevalence of HCAI in acute care hospitals to be 9.5%; inpatient cost was an estimated £183 million per year.3 HCAI places an increased burden on the resources of the specialty responsible for the patients’ care including costs associated with an increased length of stay. This burden may be especially important in intensive care units (ICUs) due to the high cost of care in this setting; £1,853 per bed-day in Scotland in 2007/2008.4 Patients who require admission to ICUs are among the most severely ill and many have underlying chronic illness and some degree of immunosuppression.5 The routine management of severely ill patients involves numerous invasive procedures that may be performed inside the ICU or prior to ICU admission in other hospital areas. Most of the literature focuses on the burden that ICU-acquired infections place on ICU resources but without reference to the * Corresponding author. Address: Health Protection Scotland, Cadogan Square, Glasgow G2 7HF, UK. Tel.: þ44 0141 282 2921; fax: þ44 0141 847 0399. E-mail address: [email protected] (S. Cairns).
burden from all HCAIs, both ICU-acquired and HCAI acquired elsewhere in the hospital.5e7 Patients admitted to ICU may have acquired HCAI in otherparts of the hospital. These infections contribute to the burden on ICU resources including costs associated with extended length of stay and treatment of HCAI.8,9 As in many other countries, Scotland has implemented a programme aimed at reducing HCAI. The remit of the Scottish Patient Safety Programme, which began in 2008, includes measures aimed to reduce HCAI in Scottish ICUs. The HCAI burden and most prevalent infection types contributing to this burden must be known so that measures can be targeted effectively. Monitoring HCAIs is an essential component of infection prevention and control activities.10 Many countries, including Scotland, have implemented prospective incidence surveillance of HCAI in ICU patients.11,12 Prospective surveillance is the reference method for monitoring HCAI but this can be costly and is usually targeted at common infection types such as ventilator-associated pneumonia. Cross-sectional prevalence surveys offer a relatively cost-effective and rapid method of measuring the burden of all HCAI types in the hospital population. Measuring HCAIs can identify priority areas for infection control and targeted surveillance in the ICU setting and hospital as a whole. This study reports the secondary analysis of the Scottish National HAI Prevalence Survey dataset with a particular focus on HCAI prevalence in all ICUs in Scotland. The prevalence of antimicrobial prescribing in ICU patients as opposed to non-ICU patients is also described and compared.
0195-6701/$ e see front matter Ó 2010 Published by Elsevier Ltd on behalf of The Hospital Infection Society. doi:10.1016/j.jhin.2010.05.010
S. Cairns et al. / Journal of Hospital Infection 76 (2010) 308e310
Methods A national rolling point prevalence survey of all acute hospitals in Scotland (N ¼ 45) was carried out from October 2005 to September 2006. The survey included all ICUs (N ¼ 29). All inpatients were surveyed with the exception of day case patients and patients aged <16 years. Data were collected by seven trained data collectors who were independent of the hospitals using a bespoke database held on portable tablet computers. The data collectors sought information on eligible inpatients from all relevant sources including medical and nursing case records, microbiology reports, X-ray reports, temperature charts, prescribing records and where necessary through discussion with clinical staff and by direct clinical observation. Each ward was started and completed within one day. HCAI was defined as an infection arising 48 h after admission to hospital that was neither present nor incubating on admission. HCAI was confirmed if the patient had signs and symptoms which met the Centers for Disease Control and Prevention (CDC, Atlanta, GA, USA) definition at the time of survey, or, who had one or more signs or symptoms included in the CDC definition and was being treated with an antimicrobial at the time of survey.13 Rigorous quality assurance of data was undertaken to ensure that recorded infections met one of the case definitions. Inter-rater reliability was tested on two occasions during the survey. The validation recorded a 100% agreement between data collectors for diagnosis of HCAI type. The data were analysed using Stata Version 9.1 for Windows. The overall HCAI and antimicrobial prevalence proportions were calculated with 95% confidence interval (CIs) for ICU and non-ICU patients. The infection type specific HCAI prevalence and the prevalence of antimicrobial use were described in ICU and non-ICU patients. Pearson’s c2-test was used to compare prevalence in ICU and non-ICU patients.
Results In total, 11 608 patients were surveyed including 129 patients in 29 ICUs. The age and sex distribution of the surveyed patients is shown in Table I. During the survey, 35 patients in ICUs had a total of 46 HCAIs. There were nine patients with more than one infection. The prevalence of HCAIs in ICU patients was 27.1% (95% CI: 19.7e35.7). The prevalence of HCAI in non-ICU patients was 9.3% (95% CI: 8.8e9.9), significantly lower than the ICU patients (P < 0.0001). The prevalence of each infection type in ICU and non-ICU patients and the P-value comparing the infection type specific prevalence are shown in Table II. At the time of survey, 90 ICU patients and 3631 non-ICU patients were receiving antimicrobial agents. The prevalence of
Table I Age and sex distribution of surveyed intensive care unit (ICU) and non-ICU patients Age group (years)
ICU patients
Non-ICU patients
Male N (%)
Female N (%)
Male N (%)
Female N (%)
16e24 25e44 45e59 60e74 75
1 (25.0) 10 (55.6) 21 (75.0) 30 (55.6) 10 (40.0)
3 (75.0) 8 (44.4) 7 (25.0) 24 (44.4) 15 (60.0)
131 (34.4) 499 (36.5) 794 (50.6) 1568 (49.9) 1783 (35.6)
250 (65.6) 868 (63.5) 774 (49.4) 1574 (50.1) 3222 (64.4)
Total
72 (55.8)
57 (44.2)
4775 (41.7)
6688 (58.3)
Date of birth was not recorded for 16 patients.
309
Table II Healthcare-associated infection (HCAI) type specific prevalence in intensive care unit (ICU) and non-ICU patients HCAI type
ICU patients
Non-ICU patients
P-value
No. of Prevalence No. of Prevalence infections % infections % Bone and joint Bloodstream Central nervous system Cardiovascular system Eye, ear, nose, throat and mouth Gastrointestinal Lower respiratory tract Pneumonia Reproductive system Systemic Surgical site Skin and soft tissue Urinary tract
0 4 1 0 1
0 3.10 0.78 0 0.78
6 51 1 11 154
0.05 0.44 0.01 0.10 1.34
0.79 <0.0001 <0.0001 0.72 0.86
4 11 9 1 0 11 3 1
3.10 8.53 6.98 0.78 0 8.53 2.33 0.78
187 128 100 16 2 186 134 221
1.63 1.12 0.87 0.14 0.02 1.62 1.17 1.93
0.19 <0.0001 <0.0001 0.06 0.88 <0.0001 0.23 0.64
antimicrobial use in ICU patients, 69.8% (95% CI: 61.7e77.8), was significantly higher (P < 0.0001) than the prevalence in non-ICU patients, 31.6% (95% CI: 30.8e32.5). The prevalence of antimicrobial use by specific antimicrobial group is shown in Table III. Discussion This paper reports the first HCAI prevalence survey in ICUs in Scotland and demonstrates the burden on ICU resources in Scotland. The prevalence of HCAI was significantly higher in ICU patients compared with patients cared for outside of an ICU, 27.1% versus 9.3% (P < 0.0001). As would be expected, a similar situation was observed during the Four Country HCAI prevalence survey carried out in England, Wales, Northern Ireland and the Republic of Ireland in 2006, although there were differences in the definitions and methods used.14 The prevalence of HCAIs in critical care medicine wards during this survey was 23.3% and the overall prevalence for all wards was 7.6%. A significantly higher prevalence of specific HCAI types is reported in ICU patients compared with patients cared for outside of the ICU, namely pneumonia and lower respiratory tract, bloodstream and surgical site infections. These infection types are often
Table III Antimicrobial group prevalence in intensive care unit (ICU) and non-ICU patients Antimicrobial group
ICU patients
Non-ICU patients
P-value
No. of Prevalence % No. of Prevalence % patients patients Aminoglycosides Antifungals Antivirals Cephalosporins Carbapenems and monobactams Glycopeptides Macrolides, lincosamides, streptogramin Other Penicillins Quinolones Sulphonamides and trimethoprim Tetracyclines Multiple No antimicrobial
1 3 0 8 2
0.8 2.3 0 6.2 1.55
16 194 28 213 12
0.1 1.7 0.2 1.86 0.10
0.06 0.58 0.58 <0.0001 <0.0001
1 2
0.8 1.6
83 136
0.7 1.2
0.94 0.70
2 5 2 0
1.6 3.9 1.6 0
240 802 299 159
2.1 7.0 2.6 1.4
0.67 0.17 0.45 0.18
0 64 39
0 49.6 30.2
16 1433 7848
0.1 12.5 68.4
0.67 <0.0001 <0.0001
310
S. Cairns et al. / Journal of Hospital Infection 76 (2010) 308e310
associated with extrinsic risk factors arising from invasive procedures and devices such as mechanical ventilators and vascular catheters and are considered to have the greatest potential for reduction.15 Knowledge of this risk allows for infection prevention and control planning for ICUs. In this study, it was not possible to determine where the infection was acquired, due to the application of strict point prevalence methodology. Only data sources available on the day of survey were reviewed, so a retrospective review to determine whether the HCAI was ICU-acquired or acquired elsewhere in the hospital was not performed. Such data would be needed to target infection prevention measures. There are several important advantages to a strict point prevalence survey methodology in ICUs. These can be carried out rapidly with little impact on ICUs. This study design enabled every hospital in Scotland to be surveyed by independent data collectors, maximising data collection time. Point prevalence surveys can also be used to identify infection types that are not monitored using targeted incidence surveillance. Almost threequarters of the infections identified in ICU patients in this survey would not have been identified by the surveillance systems commonly used in ICUs, namely, bloodstream infection and ventilator-associated pneumonia surveillance. This demonstrates the applicability of prevalence surveys and their strength when used in collaboration with targeted incidence surveillance programmes. Using the same methodology, it is possible to collect data on antimicrobial prescribing in hospitals. In this survey, almost threequarters of patients were receiving antimicrobials at the time of the survey and almost half were receiving two or more drugs. As was expected, a significantly higher proportion of ICU patients was receiving antimicrobials than was the case for patients cared for outside (P < 0.0001). It is acknowledged that the comparison of HCAI and antimicrobial usage in ICU and in non-ICU patients is likely to have been subject to confounding by the underlying medical condition of the patients. These data measure the burden that HCAI place on ICUs and can be used to focus future targeted incidence surveillance, which would allow for the application of robust risk adjustment methodologies. The largest burden on ICU resources due to HCAI resulted from an increased prevalence of HCAI, typically associated with invasive devices and procedures. This demonstrates the continued need for focused infection control measures tailored to this specific patient group and to the hospital population in general.
Acknowledgements We gratefully acknowledge the co-operation and support of infection control and ward staff in all of the participating hospitals. The authors would like to thank the Scottish National HAI Prevalence Survey team for dedicated data collection. Conflict of interest statement None declared. Funding sources The Scottish Executive Health Department HAI Task Force funded this project.
References 1. European Centre for Disease Prevention and Control. Annual epidemiological report on communicable diseases in Europe 2008. Stockholm: European Centre for Disease Prevention and Control; 2008. 2. Plowman R, Graves N, Griffin M, et al. The socio-economic burden of hospital acquired infection. London: Public Health Laboratory Services; 1999. Part 1. 3. Reilly J, Stewart S, Allardice G, et al. NHS Scotland national HAI prevalence survey: final report. Glasgow: Health Protection Scotland; 2007. 4. Information Services Division. Scottish national tariff. 2007/2008. Edinburgh: ISD Scotland; 2008. 5. Vincent JL. Nosocomial infections in adult intensive-care units. Lancet 2003;361:2068e2077. 6. De Rosa FG, Garazzino S, Audagnotto S, et al. SPIR01 and SPIR02: a two-year 1-day point prevalence multicenter study of infections in intensive care units in Piedmont, Italy. New Microbiol 2008;31:81e87. 7. Richards MJ, Edwards JR, Culver DH, Gaynes RP. Nosocomial infections in combined medicalesurgical intensive care units in the United States. Infect Control Hosp Epidemiol 2000;21:510e515. 8. Warren DK, Shukla SJ, Olsen MA, et al. Outcome and attributable cost of ventilator-associated pneumonia among intensive care unit patients in a suburban medical center. Crit Care Med 2003;31:1312e1317. 9. Warren DK, Quadir WW, Hollenbeak CS, Elward AM, Cox MJ, Fraser VJ. Attributable cost of catheter-associated bloodstream infections among intensive care patients in a nonteaching hospital. Crit Care Med 2006;34:2084e2089. 10. National Audit Office. The management and control of hospital acquired infection in acute NHS trusts in England. London: National Audit Office; 2000. 11. Suetens C, Morales I, Savey A, et al. European surveillance of ICU-acquired infections (HELICS-ICU): methods and main results. J Hosp Infect 2007;65 (Suppl. 2):171e173. 12. Health Protection Scotland. Surveillance of intensive care unit associated infections. Pilot report. Glasgow: Health Protection Scotland; December 2005. 13. Centers for Disease Control and Prevention. National nosocomial infection surveillance system manual. Atlanta: CDC; 1999. 14. Smyth ET, McIlvenny G, Enstone JE, et al. Four country healthcare associated infection prevalence survey 2006: overview of the results. J Hosp Infect 2008;69:230e248. 15. Harbarth S, Sax H, Gastmeier P. The preventable proportion of nosocomial infections: an overview of published reports. J Hosp Infect 2003;54:258e266.