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Case-Control Investigation of a Drug- Resistant Acinetobacter baumannii Outbreak at a Regional Medical Center in Eastern Kentucky, 2010 Alexander J. Freiman, MPH, CPH CDC/CSTE Applied Epidemiology Fellow Kentucky Department for Public Health June 15, 2011 1

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Background A. baumannii A. baumannii Aerobic, gram negative bacteria Aerobic, gram negative bacteria Persist in environment Persist in environment Person-person or direct contact Person-person or direct contact Drug resistance Drug resistance Outbreaks of multi drug-resistant (MDR) A. baumannii in healthcare setting a growing concern Outbreaks of multi drug-resistant (MDR) A. baumannii in healthcare setting a growing concern Healthcare-associated infection Healthcare-associated infection Especially in intensive care units (ICUs) Especially in intensive care units (ICUs) 2

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Background Kentucky Department for Public Health (KDPH) notified of Acinetobacter outbreak in September, 2010 Kentucky Department for Public Health (KDPH) notified of Acinetobacter outbreak in September, 2010 66 cases initially reported 66 cases initially reported Assistance requested from KDPH Assistance requested from KDPH New Infection Preventionist New Infection Preventionist Reported gaps in infection control process Reported gaps in infection control process Hand hygiene Hand hygiene Lacked comprehensive environmental cleaning protocols Lacked comprehensive environmental cleaning protocols 3

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Background Response team assembled from KDPH and began on-site evaluation Response team assembled from KDPH and began on-site evaluation CDC collaboration CDC collaboration Medical epidemiologist Medical epidemiologist Laboratory experts Laboratory experts 4

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Objectives Two main objectives Two main objectives Identify risk factors associated with recovery of A. baumannii in hospitalized ICU patients Identify risk factors associated with recovery of A. baumannii in hospitalized ICU patients Investigate potential environmental sources of A. baumannii in healthcare facility Investigate potential environmental sources of A. baumannii in healthcare facility 5

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Methods Study Design Study Design Case-control Case-control Case definition: Case definition: Laboratory-confirmed cultures of MDR A. baumannii 72 hours after hospital admission Laboratory-confirmed cultures of MDR A. baumannii 72 hours after hospital admission ICU admission ICU admission January-September 2010 January-September 2010 6

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Methods Control definition Control definition ICU admission ICU admission December 2009-October 2010 December 2009-October 2010 No history of A. baumannii infection in chart No history of A. baumannii infection in chart Controls were matched to cases 1:1 Controls were matched to cases 1:1 ICU admission date ICU admission date ICU length of stay ICU length of stay 7

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Methods Abstracted information from medical records Abstracted information from medical records Demographics Demographics Admission/discharge Admission/discharge Medical history Medical history Laboratory results Laboratory results Consultations Consultations Procedures Procedures Medications Medications 8

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Methods Statistical Analysis Statistical Analysis Frequencies Frequencies T-test, Chi square test, Fishers exact test T-test, Chi square test, Fishers exact test Odds ratios between potential risk factors and MDR A. baumannii recovery using logistic regression Odds ratios between potential risk factors and MDR A. baumannii recovery using logistic regression Univariate Univariate Multivariate Multivariate Conducted using SPSS software Conducted using SPSS software 9

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Methods Collected environmental samples using wide sponge culturettes Collected environmental samples using wide sponge culturettes Site selection Site selection High touch surfaces in areas with infected patients High touch surfaces in areas with infected patients Identified in previous studies Identified in previous studies CDC recommendations CDC recommendations 10

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Methods One sample taken at each of five sites One sample taken at each of five sites ICU glucometer ICU glucometer ICU medication dispensing unit ICU medication dispensing unit ICU nursing station digital camera ICU nursing station digital camera Portable x-ray machine Portable x-ray machine Countertops in radiology unit Countertops in radiology unit 11

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Methods Five environmental and three patient samples sent to state and CDC labs for pulsed field gel electrophoresis (PFGE) typing Five environmental and three patient samples sent to state and CDC labs for pulsed field gel electrophoresis (PFGE) typing Similarity between strains from environmental and patient samples determined using computer software Similarity between strains from environmental and patient samples determined using computer software 12

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Case Selection 13

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Case Selection 14

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Case Selection 15

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Case Selection 16

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Results 17

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Results Selected Characteristics of Cases and Controls Characteristic Case n (%) Control n (%) P value Race/Ethnicity Caucasian 29 (97) 1.00 Non-Hispanic 29 (97) 1.00 Age (in years) Mean 6867 0.72 Median 7069 Range 40-8738-105 Sex Female 12 (40)17 (57) 0.30 Comorbidity Diabetes 18 (60)10 (33) 0.04 18

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Results Source of MDR A. baumannii culture from cases (N=30) Sourcen (%) Respiratory19 (63) Blood5 (17) Wound4 (13) Urine2 (7) 19

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Results 20 Environmental culture results SiteResult Portable x-ray machinePositive ICU nursing station digital cameraPositive ICU medication dispensing unitNegative ICU glucometerNegative Countertops in radiology unitNegative

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Results Patient 4 from another healthcare facility 21 * *

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Results Patient 4 from another healthcare facility 22 * *

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Results Patient 4 from another healthcare facility 23 * *

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Results Patient 4 from another healthcare facility 24 * *

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Results Crude Associations for Risk Factors and Positive MDR A. baumannii Culture Risk FactorsORP value95% Confidence Interval Received subcutaneous or intravenous insulin4.970.014*(1.39, 17.82) Fingersticks performed5.020.025*(1.23, 20.49) Total number of chest x-ray procedures1.100.032*(1.01, 1.21) Diabetic3.000.041*(1.05, 8.60) Central line performed3.140.043*(1.03, 9.55) Decubitis ulcer present2.620.072(0.92, 7.46) Consulted with occupational therapist3.080.094(0.82, 11.50) Did patient have cardiovascular issues3.270.107(0.77, 13.83) Obese2.410.111(0.82, 7.10) *p value 0.05 25

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Results Crude Associations for Risk Factors and Positive MDR A. baumannii Culture Risk FactorsORP value95% Confidence Interval Received subcutaneous or intravenous insulin4.970.014*(1.39, 17.82) Fingersticks performed5.020.025*(1.23, 20.49) Total number of chest x-ray procedures1.100.032*(1.01, 1.21) Diabetic3.000.041*(1.05, 8.60) Central line performed3.140.043*(1.03, 9.55) Decubitis ulcer present2.620.072(0.92, 7.46) Consulted with occupational therapist3.080.094(0.82, 11.50) Did patient have cardiovascular issues3.270.107(0.77, 13.83) Obese2.410.111(0.82, 7.10) *p value 0.05 26

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Results Crude Associations for Risk Factors and Positive MDR A. baumannii Culture Risk FactorsORP value95% Confidence Interval Received subcutaneous or intravenous insulin4.970.014*(1.39, 17.82) Fingersticks performed5.020.025*(1.23, 20.49) Total number of chest x-ray procedures1.100.032*(1.01, 1.21) Diabetic3.000.041*(1.05, 8.60) Central line performed3.140.043*(1.03, 9.55) Decubitis ulcer present2.620.072(0.92, 7.46) Consulted with occupational therapist3.080.094(0.82, 11.50) Did patient have cardiovascular issues3.270.107(0.77, 13.83) Obese2.410.111(0.82, 7.10) *p value 0.05 27

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Results 28 Adjusted Associations for Risk Factors and MDR A. baumannii Culture for Sampled Equipment Risk FactorsORP value95% Confidence Interval Fingersticks performed*4.340.048(1.01, 18.62) Total number of chest x-ray procedures1.100.065(0.99, 1.22) Decubitis ulcer photographed*2.710.083(0.88, 8.37) *Model adjusted for age, type of admission, and mechanical ventilation Model adjusted for age, type of admission, and fingersticks

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Results 29 Adjusted Associations for Risk Factors and MDR A. baumannii Culture for Sampled Equipment Risk FactorsORP value95% Confidence Interval Fingersticks performed*4.340.048(1.01, 18.62) Total number of chest x-ray procedures1.100.065(0.99, 1.22) Decubitis ulcer photographed*2.710.083(0.88, 8.37) *Model adjusted for age, type of admission, and mechanical ventilation Model adjusted for age, type of admission, and fingersticks

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Discussion Lab cultures identified two possible sources for MDR A. baumannii transmission to patients in the facility Lab cultures identified two possible sources for MDR A. baumannii transmission to patients in the facility Portable chest x-ray machine Portable chest x-ray machine Digital camera used for wound photography Digital camera used for wound photography PFGE pattern similarity between environmental and patient samples matched between 92-100% PFGE pattern similarity between environmental and patient samples matched between 92-100% 30

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Discussion Epidemiologic analysis suggests receiving fingersticks is a risk factor for becoming a case Epidemiologic analysis suggests receiving fingersticks is a risk factor for becoming a case Breakdowns in disease prevention activities Breakdowns in disease prevention activities Hand hygiene Hand hygiene Cleaning shared equipment Cleaning shared equipment Lack of clear equipment-cleaning responsibility might have contributed to ongoing transmission Lack of clear equipment-cleaning responsibility might have contributed to ongoing transmission 31

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Discussion Limitations Limitations Generalizability Generalizability Small sample Small sample Reliability Reliability Cases: Controls only 1:1 Cases: Controls only 1:1 Validity Validity Lack of true electronic medical records Lack of true electronic medical records Incomplete line listing from healthcare facility Incomplete line listing from healthcare facility 32

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Discussion Have procedures in place to clean all shared equipment Have procedures in place to clean all shared equipment Recognition of an outbreak and immediate implementation of effective controls is CRITICAL to preventing MDR A. baumannii transmission in the healthcare setting Recognition of an outbreak and immediate implementation of effective controls is CRITICAL to preventing MDR A. baumannii transmission in the healthcare setting 33

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Acknowledgments Kentucky Department for Public Health Margaret A. Riggs, PhD, MPH, MA Fontaine Sands, DrPH, MSN, CIC David R. Reese, MA, MPH, FRSPH Kraig E. Humbaugh, MD, MPH Doug Thoroughman, PhD, MS Robert L. Brawley, MD, MPH, FSHEA Centers for Disease Control and Prevention, Division of Healthcare Quality and Promotion Alexander J. Kallen, MD, MPH Judith Noble-Wang, PhD Heather A. OConnell, PhD 34

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Acknowledgments This study was supported in part by an appointment to the Applied Epidemiology Fellowship Program administered by the Council of State and Territorial Epidemiologists (CSTE) and funded by the Centers for Disease Control and Prevention (CDC) Cooperative Agreement Number 5U38HM000414. This study was supported in part by an appointment to the Applied Epidemiology Fellowship Program administered by the Council of State and Territorial Epidemiologists (CSTE) and funded by the Centers for Disease Control and Prevention (CDC) Cooperative Agreement Number 5U38HM000414. 35

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Contact Information Alex Freiman CDC/CSTE Applied Epidemiology Fellow Kentucky Department for Public Health Phone: (502)564-3261 x3278 Email: Alex.Freiman@ky.gov 36