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Utility of a focused vancomycin-resistant enterococci screening protocol to identify colonization in hospitalized children
American Journal of Infection Control 40 (2012) 891-2
Contents lists available at ScienceDirect
American Journal of Infection Control
American Journal of Infection Control
journal homepage: www.ajicjournal.org
Brief report
Utility of a focused vancomycin-resistant enterococci screening protocol to identify colonization in hospitalized children Gina Weddle DNP, RN, CPNP *, Mary Anne Jackson MD, Rangaraj Selvarangan PhD Children’s Mercy Hospitals and Clinics, Kansas City, MO
Key Words: VRE Pediatric Surveillance
Screening for vancomycin-resistant enterococci (VRE) is controversial, and disagreement exists on policy implementation. This study investigated the likelihood of a positive test using 1, 2, or 3 rectal screenings for VRE colonization. In this descriptive study of positive VRE screening cultures, a total of 1211 VRE screens identified 41 positive results. The mean age of these positive patients was 5.7 years. Thirty-nine of the 41 had a chronic illness, and only 2 were healthy. Diagnoses included pulmonary disease in 11 patients and chronic gastrointestinal abnormality in 7. Six patients had been born preterm, and 12 had been treated in a neonatal intensive care unit within the previous 6 months. Thirty-six of the 41 positive results were identified on the first screen. The likelihood of subsequently having a positive screen after a negative screen was 0.43% (95% confidence interval, 0.15%-1.02%). The cost of cultures plus isolation was $50,000 for the study period. Our data show that the likelihood of detecting a positive VRE culture after an initial negative was low, particularly in otherwise healthy children. Copyright Ó 2012 by the Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.
The genus Enterococcus contains multiple species of grampositive organisms, with strains of E faecalis and E faecium the most common strains colonizing the gastrointestinal system. An increasing percentage of strains has developed resistance to the commonly used antibiotic vancomycin.1 Vancomycin-resistant enterococcci (VRE) was first reported in Europe in 1988 and in the United States in 1989.2 VRE has shown a much steeper increase in resistance rate than methicillin-resistant Staphylococcus aureus and is currently the third-leading cause of health careeassociated infections, making it a significant infection control problem.2,3 The Centers for Disease Control and Prevention (CDC) has reported VRE infection rates of 29% in the intensive care unit (ICU) setting and 25% in the non-ICU setting.3 In 1994, the CDC published guidelines for preventing the spread of VRE, which focused mainly on the judicious use of vancomycin.2 Screening cultures have established high prevalence rates for asymptomatic carriage.3 Universal screening has been controversial, and disagreement exists among experts on whether and how to implement universal screening. Two states, Illinois and Maryland,
* Address correspondence to Gina Weddle, DNP, RN, CPNP, 2401 Gillham Rd, Kansas City, MO 64108. E-mail address: [email protected] (G. Weddle). First presented as a poster presentation at the 48th Annual Meeting of the Infectious Diseases Society of America, October 21-24, 2010. Conflict of interest: None to report.
have mandates for active surveillance.3 The Society for Health Care Epidemiology of America consensus statement follow that legislation, which does not support mandating active surveillance, but advocates additional research to determine appropriateness of surveillance programs for resistant organisms.4 Our pediatric institution detected the first case of VRE from a patient transferred from an outside facility in 1998, prompting implementation of a screening policy. In 2005, active surveillance in our institution, which included VRE screening of patients who had been admitted to an outside facility for 5 or more days within the previous 6 months, was instituted. Screening included 3 rectal cultures performed on 3 consecutive days. During the screening procedure, the patients are placed in contact isolation pending the results. The purpose of this study was to determine the likelihood of a positive test using 1, 2, or 3 rectal screenings to identify VRE colonization. Our facility’s Institutional Review Board approved the study as an exempted protocol. This was a descriptive study that performed secondary data analysis of microbiological results for all VRE screening cultures obtained from children admitted between 2005 and 2009. Descriptive statistics were used to explore patterns within the data and risk ratio analysis was performed to assess the probability of the event occurring in the exposed group versus a nonexposed group. The study site was a Midwestern US tertiary freestanding 263bed children’s hospital with an average yearly admission rate of
0196-6553/$36.00 - Copyright Ó 2012 by the Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved. doi:10.1016/j.ajic.2011.12.005
892
G. Weddle et al. / American Journal of Infection Control 40 (2012) 891-2
Table 1 Incidence Data
Table 2 Demographics
Year
Admissions
VRE Screens
Positive Screens
2005 2006 2007 2008 2009 Total
12,831 12,427 14,716 15,236 13,536 68,746
114 162 318 312 305 1,211
7 3 11 9 11 41
approximately 15,000 patients. Inclusion criteria included all children who had been admitted to an outside facility for 5 days within the previous 6 months. Children known to be colonized with VRE at the time of transfer were excluded. A total of 68,746 patients were admitted during the 5-year study period, of which 1,211 met the policy criteria for VRE screening (Table 1). A total of 41 patients had a positive screening test (3% of screenings performed). The mean age of the patients with a positive culture was 5.7 years (range, 5 days to 23 years), and 68% were under 7 years of age (Table 2). The group of patients with a positive test was predominately female (25 of 41; 61%) and Caucasian (24 of 41; 58%). Thirty nine of the 41 positive patients (95%) had an underlying chronic illness. The most common admitting diagnosis was respiratory in nature (27%), and underlying diagnoses included cystic fibrosis and chronic lung disease. The second most common underlying diseases were gastrointestinal in origin, including inflammatory bowel disease and short bowel syndrome (17%). Six of the patients were born preterm (15%). Neither the referral hospital size (P ¼ .714) nor length of stay there (P ¼ .643) were statistically significant predictors of a positive VRE screen. Not all patients underwent all 3 screening tests, either because of a previous positive test or early discharge from the hospital. Twenty-five of the 41 positive patients underwent all 3 screenings, 9 had 2 screenings, and 7 had only 1 screening (Fig 1). Thirty-six patients (88%) had a positive test on first screening, 3 (7%) were negative on the first screen and positive on the second screen, and only 2 (5%) were negative on the first 2 screens and positive on the third screen. The likelihood of a later positive VRE screen after an initial negative screen was 0.43% (95% confidence interval, 0.15%1.02%). There is no universally accepted approach to active surveillance for VRE, and currently such surveillance is not reimbursed by thirdparty payers. Yearly laboratory costs are projected as $26,661 and estimated isolation costs as $38,752 per positive patient, for a total of $327,065 for the study period. Although this cost may be lower than that for an outbreak investigation, stricter screening protocols can reduce unnecessary testing and isolation of patients. The vast majority of patients who tested positive on the first screening had an underlying chronic illness. Performing an initial screening test in otherwise healthy children would be reasonable, with a second screening test reserved for high-risk groups, including those with an underlying respiratory or gastrointestinal diagnosis or a history of preterm birth.
Age <1 month 1-6 months 6-12 months 1-3 years 4-6 years >7 years Sex Male Female
Race Caucasian African American Asian/Pacific Islander Hispanic Other
2 10 3 9 4 13 16 25
Ref Hospital Size <100 beds 100-249 beds 250-499 beds >500 beds Not documented
5 10 10 12 4
Ref Hospital LOS 1-7 days 7-14 days 2-3 weeks >4 weeks
8 7 5 21
25 4 2 5 5
Positive Screens 40 35 30 25 20 15 10 5 0
First Screen
Second Sceen
Third Screen
Fig 1. Positive VRE screens.
A limitation of this study was the small sample size of positive screens. Achieving adequate power in a study such as this is difficult because of the low prevalence rate of VRE in the pediatric population. Hospitals with higher prevalence rates would require more aggressive screening. Ongoing surveillance could provide early detection of trends that might warrant further research to evaluate changes in surveillance protocols. References 1. Long S, Pickering L, Prober C. Principles and practices of pediatric infectious diseases. 3rd ed. Philadelphia [PA]: Elsevier Churchill Livingstone; 2008. 2. Reik R, Tenover F, Klein E, McDonald C. The burden of vancomycin-resistant enterococcal infections in US hospitals, 2003-2004. Diagn Microbiol Infect Dis 2008;64:81-5. 3. Huang S, Shiman R, Pottinger J, Herwaldt L, Zembower T, Noskin G, et al. Improving the assessment of vancomycin-resistant enterococci by routine screening. J Infect Dis 2007;195:339-46. 4. Weber S, Huang S, Oriola S, Huskins C, Noskin G, Harriman K, et al. (2007). Legislative mandates for use of active surveillance cultures to screen for methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci: position statement from the joint SHAE and APIC Task Force. Available from: www.shae-online.org. Accessed September 22, 2009.
Contents lists available at ScienceDirect
American Journal of Infection Control
American Journal of Infection Control
journal homepage: www.ajicjournal.org
Brief report
Utility of a focused vancomycin-resistant enterococci screening protocol to identify colonization in hospitalized children Gina Weddle DNP, RN, CPNP *, Mary Anne Jackson MD, Rangaraj Selvarangan PhD Children’s Mercy Hospitals and Clinics, Kansas City, MO
Key Words: VRE Pediatric Surveillance
Screening for vancomycin-resistant enterococci (VRE) is controversial, and disagreement exists on policy implementation. This study investigated the likelihood of a positive test using 1, 2, or 3 rectal screenings for VRE colonization. In this descriptive study of positive VRE screening cultures, a total of 1211 VRE screens identified 41 positive results. The mean age of these positive patients was 5.7 years. Thirty-nine of the 41 had a chronic illness, and only 2 were healthy. Diagnoses included pulmonary disease in 11 patients and chronic gastrointestinal abnormality in 7. Six patients had been born preterm, and 12 had been treated in a neonatal intensive care unit within the previous 6 months. Thirty-six of the 41 positive results were identified on the first screen. The likelihood of subsequently having a positive screen after a negative screen was 0.43% (95% confidence interval, 0.15%-1.02%). The cost of cultures plus isolation was $50,000 for the study period. Our data show that the likelihood of detecting a positive VRE culture after an initial negative was low, particularly in otherwise healthy children. Copyright Ó 2012 by the Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.
The genus Enterococcus contains multiple species of grampositive organisms, with strains of E faecalis and E faecium the most common strains colonizing the gastrointestinal system. An increasing percentage of strains has developed resistance to the commonly used antibiotic vancomycin.1 Vancomycin-resistant enterococcci (VRE) was first reported in Europe in 1988 and in the United States in 1989.2 VRE has shown a much steeper increase in resistance rate than methicillin-resistant Staphylococcus aureus and is currently the third-leading cause of health careeassociated infections, making it a significant infection control problem.2,3 The Centers for Disease Control and Prevention (CDC) has reported VRE infection rates of 29% in the intensive care unit (ICU) setting and 25% in the non-ICU setting.3 In 1994, the CDC published guidelines for preventing the spread of VRE, which focused mainly on the judicious use of vancomycin.2 Screening cultures have established high prevalence rates for asymptomatic carriage.3 Universal screening has been controversial, and disagreement exists among experts on whether and how to implement universal screening. Two states, Illinois and Maryland,
* Address correspondence to Gina Weddle, DNP, RN, CPNP, 2401 Gillham Rd, Kansas City, MO 64108. E-mail address: [email protected] (G. Weddle). First presented as a poster presentation at the 48th Annual Meeting of the Infectious Diseases Society of America, October 21-24, 2010. Conflict of interest: None to report.
have mandates for active surveillance.3 The Society for Health Care Epidemiology of America consensus statement follow that legislation, which does not support mandating active surveillance, but advocates additional research to determine appropriateness of surveillance programs for resistant organisms.4 Our pediatric institution detected the first case of VRE from a patient transferred from an outside facility in 1998, prompting implementation of a screening policy. In 2005, active surveillance in our institution, which included VRE screening of patients who had been admitted to an outside facility for 5 or more days within the previous 6 months, was instituted. Screening included 3 rectal cultures performed on 3 consecutive days. During the screening procedure, the patients are placed in contact isolation pending the results. The purpose of this study was to determine the likelihood of a positive test using 1, 2, or 3 rectal screenings to identify VRE colonization. Our facility’s Institutional Review Board approved the study as an exempted protocol. This was a descriptive study that performed secondary data analysis of microbiological results for all VRE screening cultures obtained from children admitted between 2005 and 2009. Descriptive statistics were used to explore patterns within the data and risk ratio analysis was performed to assess the probability of the event occurring in the exposed group versus a nonexposed group. The study site was a Midwestern US tertiary freestanding 263bed children’s hospital with an average yearly admission rate of
0196-6553/$36.00 - Copyright Ó 2012 by the Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved. doi:10.1016/j.ajic.2011.12.005
892
G. Weddle et al. / American Journal of Infection Control 40 (2012) 891-2
Table 1 Incidence Data
Table 2 Demographics
Year
Admissions
VRE Screens
Positive Screens
2005 2006 2007 2008 2009 Total
12,831 12,427 14,716 15,236 13,536 68,746
114 162 318 312 305 1,211
7 3 11 9 11 41
approximately 15,000 patients. Inclusion criteria included all children who had been admitted to an outside facility for 5 days within the previous 6 months. Children known to be colonized with VRE at the time of transfer were excluded. A total of 68,746 patients were admitted during the 5-year study period, of which 1,211 met the policy criteria for VRE screening (Table 1). A total of 41 patients had a positive screening test (3% of screenings performed). The mean age of the patients with a positive culture was 5.7 years (range, 5 days to 23 years), and 68% were under 7 years of age (Table 2). The group of patients with a positive test was predominately female (25 of 41; 61%) and Caucasian (24 of 41; 58%). Thirty nine of the 41 positive patients (95%) had an underlying chronic illness. The most common admitting diagnosis was respiratory in nature (27%), and underlying diagnoses included cystic fibrosis and chronic lung disease. The second most common underlying diseases were gastrointestinal in origin, including inflammatory bowel disease and short bowel syndrome (17%). Six of the patients were born preterm (15%). Neither the referral hospital size (P ¼ .714) nor length of stay there (P ¼ .643) were statistically significant predictors of a positive VRE screen. Not all patients underwent all 3 screening tests, either because of a previous positive test or early discharge from the hospital. Twenty-five of the 41 positive patients underwent all 3 screenings, 9 had 2 screenings, and 7 had only 1 screening (Fig 1). Thirty-six patients (88%) had a positive test on first screening, 3 (7%) were negative on the first screen and positive on the second screen, and only 2 (5%) were negative on the first 2 screens and positive on the third screen. The likelihood of a later positive VRE screen after an initial negative screen was 0.43% (95% confidence interval, 0.15%1.02%). There is no universally accepted approach to active surveillance for VRE, and currently such surveillance is not reimbursed by thirdparty payers. Yearly laboratory costs are projected as $26,661 and estimated isolation costs as $38,752 per positive patient, for a total of $327,065 for the study period. Although this cost may be lower than that for an outbreak investigation, stricter screening protocols can reduce unnecessary testing and isolation of patients. The vast majority of patients who tested positive on the first screening had an underlying chronic illness. Performing an initial screening test in otherwise healthy children would be reasonable, with a second screening test reserved for high-risk groups, including those with an underlying respiratory or gastrointestinal diagnosis or a history of preterm birth.
Age <1 month 1-6 months 6-12 months 1-3 years 4-6 years >7 years Sex Male Female
Race Caucasian African American Asian/Pacific Islander Hispanic Other
2 10 3 9 4 13 16 25
Ref Hospital Size <100 beds 100-249 beds 250-499 beds >500 beds Not documented
5 10 10 12 4
Ref Hospital LOS 1-7 days 7-14 days 2-3 weeks >4 weeks
8 7 5 21
25 4 2 5 5
Positive Screens 40 35 30 25 20 15 10 5 0
First Screen
Second Sceen
Third Screen
Fig 1. Positive VRE screens.
A limitation of this study was the small sample size of positive screens. Achieving adequate power in a study such as this is difficult because of the low prevalence rate of VRE in the pediatric population. Hospitals with higher prevalence rates would require more aggressive screening. Ongoing surveillance could provide early detection of trends that might warrant further research to evaluate changes in surveillance protocols. References 1. Long S, Pickering L, Prober C. Principles and practices of pediatric infectious diseases. 3rd ed. Philadelphia [PA]: Elsevier Churchill Livingstone; 2008. 2. Reik R, Tenover F, Klein E, McDonald C. The burden of vancomycin-resistant enterococcal infections in US hospitals, 2003-2004. Diagn Microbiol Infect Dis 2008;64:81-5. 3. Huang S, Shiman R, Pottinger J, Herwaldt L, Zembower T, Noskin G, et al. Improving the assessment of vancomycin-resistant enterococci by routine screening. J Infect Dis 2007;195:339-46. 4. Weber S, Huang S, Oriola S, Huskins C, Noskin G, Harriman K, et al. (2007). Legislative mandates for use of active surveillance cultures to screen for methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci: position statement from the joint SHAE and APIC Task Force. Available from: www.shae-online.org. Accessed September 22, 2009.