Environmental contaminants in hospital settings and progress in disinfecting techniques

G Messina,E Azzolini,S Burgassi,E Ceriale,D Lenzi,P Manzi

doi:10.1093/eurpub/ckt126.342

Abstract

Medical devices, such as stethoscopes, and other objects found in hospital, such as computer keyboards and telephone handsets, may be reservoirs of bacteria for healthcare-associated infections. In this cross-over study involving an Italian teaching hospital we evaluated microbial contamination (total bacterial count (TBC) at 36°C/22°C, Staphylococcus spp., moulds, Enterococcus spp., Pseudomonas spp., E. coli, total coliform bacteria, Acinetobacter spp., and Clostridium difficile) of these devices before and after cleaning and differences in contamination between hospital units and between stethoscopes and keyboards plus handsets. We analysed 37 telephone handsets, 27 computer keyboards, and 35 stethoscopes, comparing their contamination in four hospital units. Wilcoxon signed-rank and Mann-Whitney tests were used. Before cleaning, many samples were positive for Staphylococcus spp. and coliforms. After cleaning, CFUs decreased to zero in most comparisons. The first aid unit had the highest and intensive care the lowest contamination (P < 0.01). Keyboards and handsets had higher TBC at 22°C (P = 0.046) and mould contamination (P = 0.002) than stethoscopes. Healthcare professionals should disinfect stethoscopes and other possible sources of bacterial healthcare-associated infections. The cleaning technique used was effective in reducing bacterial contamination. Units with high patient turnover, such as first aid, should practise stricter hygiene.

Highlights

The Centre for Disease Control (CDC) defines a healthcare-associate infections (HAIs) as a “localized or systemic condition resulting from an adverse reaction to the presence of an infectious agent(s) or its toxin(s)
The percentage of positive H(0) samples was generally higher on computer keyboards, followed by telephone handsets and stethoscopes
The only exception was MRSA, where the latter had a higher percentage of positive samples: 28.6% compared to 16.2% for telephone handsets and 22.2% for computer keyboards

Summary

Introduction

The Centre for Disease Control (CDC) defines a healthcare-associate infections (HAIs) as a “localized or systemic condition resulting from an adverse reaction to the presence of an infectious agent(s) or its toxin(s). HAIs may be caused by infectious agents from endogenous (body sites) or exogenous sources (patient care personnel, visitors, patient care equipment, medical devices, or the health care environment) [1]. In Europe HAIs cause 16 million extra days of hospital stay and 37000 attributable deaths; they determine approximately costs associated of C 7 billion annually. In the USA around 99000 deaths were attributed to HAIs in 2002 and associated costs were approximately US$ 6.5 billion in 2004 [5, 6]

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