January 2, 2013 — This article presents a case study, for the purpose of education, that details events at a fictional facility known as “Hospital X.” Breaches in reprocessing protocols are discussed, and considerations and recommendations are provided to minimize the risk of HAIs (or, “healthcare-associated infections”). The sole intent of this article is educational.

Introduction

A case study was performed by Hospital X to investigate a potential clusters of infections in its gastrointestinal (GI) endoscopy department. While preparing a patient for colonoscopy, a nurse noticed patient debris, including feces, on the endoscope.

An investigation was performed and determined that several hundred patients could potentially have been exposed to this contaminated colonoscope. Only those patients undergoing colonoscopy between the fall of 2000 and the spring of 2001 were deemed at risk. No patients displaying clinical infection have been identified.

The identification of feces on a colonoscope may indicate, among other lapses, the failure to have accounted for and to have reprocessed the colonoscope’s auxiliary water channel.

Methods

During its investigation, Hospital  X reviewed its infection control procedures, focusing on potential breaches in its GI endoscopy department’s cleaning and disinfection practices. The hospital sampled several sites on most of its upper and lower GI endoscopes immediately after reprocessing.  For the sake of clinical perspective and comparison, the hospital also sampled several sites on a “dirty” (or  control) colonoscope that had not been reprocessed following patient use.

Results

Several types of bacteria were identified on the “reprocessed” (and “patient-safe,” although contaminated, colonoscope. The cultured bacteria included species of:  Staphylococcus, Streptococcus, Pseudomonas, Klebsiella and Bordetella.

The control endoscope (which had not been cleaned and disinfected after use) was sampled and found to be contaminated with Lactobacillus, Bacteroides, and Enterococcus.

[Note: It is recommended that this be read along with the peer-reviewed article: Muscarella LF. Study of a contaminated colonoscope. Clin Gastroenterol Hepatol 2010 Jul;8(7):577-80.]

Discussion

During its investigation, Hospital X cultured from several sites on its “reprocessed” GI endoscopes bacteria that are often found in the GI tract’s normal flora.

Moreover, several bacteria often isolated in water and on moist surfaces were also cultured from the hospital’s reprocessed endoscopes. Since all of these bacteria are destroyed by proper cleaning, high-level disinfection, and drying, these results indicate that Hospital X’s endoscope  reprocessing practices are inadequate and warrant improvement.

In addition to indicating potential inadequacies in the hospital’s reprocessing protocol, the results of the investigation suggested that the hospital’s quality controls were lacking, too. For example, although Hospital X’s written policy required sampling microbiologically its GI endoscopes once a month, none had been sampled for more than six months prior to this investigation. Periodic sampling of its GI endoscopes had been discontinued, due in part to financial cutbacks that caused the hospital no longer to employ an infection control officer.

Note: The Centers for Disease Control and Prevention (CDC) do not generally recommend routine sampling and culturing of GI endoscopes, except, for example, during an outbreak investigation.

Observations

Several different types of bacteria were cultured from several of Hospital X’s “reprocessed” endoscopes and environmental surfaces during the investigation. Based on these results, several considerations and conclusions are provided:

(1)  Culturing Staphylococcus epidermidis and Streptococcus pneumoniae (both of which are gram-positive cocci) from the suction channel and other surfaces of a “patient ready” endoscope indicates that the hospital’s endoscope reprocessing    practices in general and its cleaning step in particular are inadequate. The presence of S. epidermidis on a ready-for-use endoscope could also indicate environmental  contamination, possibly due to improper handling using dirty gloves or unclean hands.

(2)  Hospital  X found during its investigation that the air/water channels and the air/water button of its “patient ready” endoscopes were contaminated with gram-negative bacilli, specifically P. aeruginosa. This result likely indicates that the endoscope was not adequately dried after reprocessing.

This investigation also found that Hospital X was not cleaning, disinfecting (or sterilizing) and drying its reusable irrigation water bottles and tubing sets at the end of the day.  This reprocessing oversight could also explain why P. aeruginosa was cultured from the endoscope’s air/water channels. If improperly reprocessed, the irrigation water bottle and tubing set can become colonized with P. aeruginosa (and other gram-negative bacteria) during overnight storage and recontaminate the sterile water added to it the next day and the endoscope.

Also, if a bacterial filter is used to improve the quality of the rinse water used during endoscope reprocessing, culturing P. aeruginosa from a reprocessed endoscope could indicate that the bacterial water filter is failing (ie, allowing bacteria to pass) and requires replacement. This same result could also indicate that the filter’s housing contains a biofilm and requires decontamination.

(3)  Both P. aeruginosa and Klebsiella pneumonia were cultured from Hospital X’s detergent container.  This finding should not necessarily warrant concern. Detergents are used to clean the endoscope before—not after—chemical immersion. They therefore are not required either to be sterile or bacteria-free. A contaminated detergent container has not been reported to increase the risk of patient infection.  Only if the detergent were to contact and recontaminate the endoscope after reprocessing might the patient be potentially at risk.

(4)  Bordetella bronchiseptica was cultured in the sink used by Hospital X to wash its endoscopes.  But this finding too should not necessarily warrant concern, as this bacterium is commonly isolated on moist surfaces. It could pose a risk to the patient, but only if it were to  contact the endoscope after reprocessing.

(5) Hospital X sampled Lactobacillus, Bacteroides, and Enterococcus on a soiled and dirty endoscope (that is, on an endoscope that had not been reprocessed). This finding is not unexpected. These bacteria are often found in the GI tract’s normal flora and therefore culturing them on a dirty endoscope need not necessarily rouse concern. Culturing these bacteria from a “patient ready” endoscope, however, would be of concern and would indicate that the reprocessing protocol was ineffective.

Conclusions and recommendations

A case study was performed at Hospital X. This investigation was prompted by a GI nurse who observed patient debris on a “patient ready” colonoscope. No patient infections were reported, but fear of the potential for a bacterial outbreak warranted review of the hospital’s infection control and reprocessing practices.

During the investigation, several GI endoscopes and environmental sites were sampled for possible contamination. The results indicated that several essential reprocessing practices were being breached. The endoscopes, cleaning sink and detergent container were found to be contaminated with both gram-negative and gram-positive bacteria.  As part of the investigation, the sampled bacteria were typed to assess patient risk and identify specific breaches in protocol.

Based on the specific types of bacteria cultured by Hospital X, several recommendations are provided to reduce the risk of patient infection.  These recommendations are provided in the more complete (PDF) article that is based on this blog, and they may be read by clicking here.


Article by: Lawrence F Muscarella, PhD, posted on 1-2-2013; updated 6-28-2013.

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