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Computer keyboards and faucet handles as reservoirs of nosocomial pathogens in the intensive care unit*,**

https://doi.org/10.1067/mic.2000.107267Get rights and content

Abstract

Purpose: We postulate that computer keyboards and faucet handles are significant reservoirs of nosocomial pathogens in the intensive care unit (ICU) setting. Methods: Sterile swab samples were obtained from 10 keyboards and 8 pairs of faucet handles in the medical ICU at Tripler Army Medical Center during a period of 2 months. Methicillin-resistant Staphylococcus aureus (MRSA) obtained from the environmental and patient specimens were sent for DNA identification by using pulsed-field gel electrophoresis. Results: A total of 144 samples were obtained (80 keyboards and 64 faucet handles), yielding 33 isolates. The colonization rate for keyboards was 24% for all rooms and 26% in occupied rooms. Rates for faucet handles in all rooms and occupied rooms were 11% and 15%, respectively. The environmental isolates annd their prevalence were: MRS, 49%; Enterococcus, 18%; Enterobacter, 12%; and all other gram-negative rods, 21%. Fourteen individual patient isolates were recorded: MRSA, 43%; Enterobacter, 21%; other gram-negative rods, 36%; and Enterococcus, 0%. By using pulsed-field gel electrophoresis, an indistinguishable strain of MRSA was identified in two patients, the keyboards and faucet handles in their respective rooms, and on other keyboards throughout the ICU, including the doctors’ station. Conclusions: The colonization rate for keyboards and faucet handles, novel and unrecognized fomites, is greater than that of other well-studied ICU surfaces in rooms with patients positive for MRSA. Our findings suggest an associated pattern of environmental contamination and patient infection, not limited to the patient’s room. Pulsed-field gel electrophoresis results have documented an indistinguishable strain of MRSA present as an environmental contaminant on these two fomites and in two patients with clinical infections patients during the same period. We believe these findings add evidence to support the hypothesis that these particular surfaces may serve as reservoirs of nosocomial pathogens and vectors for cross-transmission in the ICU setting. New infection control policies and engineering plans were initiated on the basis of our results. (AJIC Am J Infect Control 2000;28:465-70)

Section snippets

Methods

Sampling occurred on 2 nonconsecutive days of 2 nonconsecutive weeks for 2 months and resulted in 8 collection periods. Ten computer keyboards (8 in patient rooms, 1 nurses’ station, and 1 doctors’ station) and 8 pairs of faucet handles located at the MICU were the environmental surfaces chosen for testing. A sterile rayon-tipped swab (Baxter Healthcare Corporation, Deerfield, Ill) moistened with sterile saline solution (preservative-free) was moved over the entire surface being tested.

Results

A total of 144 environmental samples were obtained (80 keyboards and 64 faucet handles), collected over 8 sample periods. A total of 33 environmental isolates were obtained as a result of sampling. These 33 isolates were obtained from 26 sample sites, with 6 sample sites yielding multiple organisms. For the purposes of statistical analysis, each site was counted only once whether positive for single or multiple organisms. Fourteen patient isolates were identified for the 2-month period of our

Discussion

The most common pathogens implicated in nosocomial infections are gram-negative rods, mainly Escherichia coli, Pseudomonas, Enterobacter, and gram-positive cocci such as Enterococcus and S aureus.6, 7 Multidrug-resistant organisms such as MRSA and vancomycin-resistant Enterococcus are increasing in frequency and are more difficult to treat.6, 8, 9

Hospital personnel and patients with colonization or infection have been identified as likely reservoirs during institutional outbreaks of MRSA.8, 11,

Acknowledgements

We would like to thank the staff of the Tripler Army Medical Center microbiology laboratory and the Hawaii State Department of Health for their assistance.

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*

The views expressed in this manuscript are those of the authors and do not reflect the official policy or position of the Department of the Army, Department of Defense, or the United States government.

**

Reprint requests: Dr Joel T. Fishbain, MCHK-DMI, Tripler Army Medical Center, Honolulu, HI 96859-5000.

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