Variable Correlation Between Hand Hygiene Compliance and MRSA, VRE, and C. difficile incidence
Background: Hand hygiene (HH) programs have been shown to reduce nosocomial infections but their relative impact on specific bacterial pathogens remains unclear. Understanding the effect of HH compliance on these pathogens may be important in prevention efforts. We sought to quantify the correlation between HH compliance and the incidence of MRSA, VRE and C. difficile at our institution.
Methods: A retrospective study was conducted using HH and MDRO data collected from Jan 2011 - Mar 2014. HH compliance was measured via product usage. Empty soap and alcohol hand rub containers are collected and counted weekly. HH events are calculated as the volume of product used divided by the standard aliquot per HH event. HH product usage rate (PUR) is calculated as the number of events per patient-days for each inpatient unit. All incident clinical and surveillance cultures positive for MRSA or VRE and nucleic acid amplification assays positive for C. difficile, obtained ≥2 calendar days after admission, were considered nosocomial cases. Only first cases per patient per organism were included. Number of cases and PUR were obtained for each unit and quarter, and then correlated using Pearson's correlation coefficient and generalized linear models controlling for unit type (intensive care unit [ICU] vs non-ICU), quarter.
Results: Eighty-three periods were included: 63 (75.9%) ICU periods and 20 (24.1%) non-ICU periods. PUR ranged from 31.8 to 437.0 HH/patient/day. The median was significantly higher in ICUs than in non-ICUs (231.8 vs 59.8, p<0.001). There were significant negative correlations between MRSA and PUR (r=0.43, p<0.001) and VRE and PUR (r=0.25; p= 0.022), but correlation was poor for C. difficile (see Figures). Adjusting for quarter and stratified by unit type, correlations for ICUs remained strong for MRSA (r=0.52, p=0.002) but weakened for VRE (r=0.37, p=0.081). Correlations for non-ICU units became non-significant.
Conclusion: HH compliance measured by product usage correlated well with MRSA cases overall and in ICU settings. VRE correlated more weakly and C. difficile correlated poorly. This ecological study suggests that the impact of HH over specific organisms is variable and may be related to the modes of transmission of each pathogen.
R. V. Araujo-Castillo,
L. M. Baldini, None
G. M. Snyder, None