This is a Gram positive bacillus that produces spores and requires anaerobic conditions for growth. It forms part of the normal intestinal flora in children less than one year old.
Transmission is via the faecal-oral route and can occur from patient to patient from the contaminated environment or the hands of HCW's.
The spores of Clostridium difficile are able to survive for long periods of time in the environment.
There are several reports of possible endoscopic transmission of C. difficile but none have been definite.
C. difficile spores are less resistant to a variety of chemical disinfectants than test spores used in standard analytical chemical sporicidal tests. Exposure for 10 minutes to 2% glutaraldehyde has been shown to inactivate C. difficile spores.
A spiral shaped bacteria with the human gastric mucosa being its major habitat. It is not routinely cultured in most diagnostic microbiology laboratories because of the organism's very specific growth requirements.
Most probably acquired by oral-oral transmission
Helicobacter pylori transmission by contaminated biopsy forceps has been demonstrated. It is probable that endoscopic transmission of H. pylori has been more frequent than has been recognised because of:
It has been suggested that a significant proportion of "adult reinfection" in some research studies is due to reinfection by inadequately processed biopsy forceps.
An increased occupational risk to endoscopy staff of H. pylori infection has been postulated.
A gram negative bacillus that is widely distributed in warm, wet environments and is of particular concern in air-conditioning cooling towers and hot water systems.
Legionellosis can be acquired by:
Pseudoepidemics have occured where L. pneumophilia has been found in broncheoalveolar lavage specimens due to contaminated water used to rinse disinfected bronchoscopes, either because of use of tap water for the final rinsing or because of inadequate maintenance of water filters.
The main issue in relation to resistant organisms such as MRSA, VRE and MDRTB in connection with endoscopy is the potential risk for contamination of the environment by an infected or colonised patient. If this occurs cross infection to subsequent patients may result.
To prevent this it is important to adhere to the infection control guidelines of your particular facility in relation to the patients infected or colonised with these resistant organisms.
Additional precautions (contact transmission) are recommended for patients with MRSA and VRE and additional precautions (airborne transmission ) should be observed for patients with MDRTB.
Gram negative bacilli that live in water and are capable of prolonged survival in moist and dry environments. The species most commonly encountered is Pseudomonas aeruginosa but there are many other species of Pseudomonas that can cause problems in endoscopy.
Pseudomonas is a common hospital environmental pathogen that can cause:
Transmission is almost always as a result of contact with environmental reservoirs or from person to person via HCW's
Endoscopy and accessory contamination has almost invariably been acquired from the hospital environment rather than from previous patients. Historically, endoscopy-associated Pseudomonas infections have largely been confined to E.R.C.P
Clinical infections with Pseudomonas, however, may become significant in the severely immunosuppressed patient, particularly when procedures invloving tissue disruption are undertaken. Colonisation of automatic disinfectors has resulted in serious disease transmission to patients.
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This is a Gram negative bacillus that can be found in the gut of humans and almost all animals throughout the world.
Gastroenteritis is
Typhoid is
Salmonella spp. that cause gastroenteritis are transmitted by the faecal-oral route most commonly via food such as eggs, meats and dairy products. The most likely reservoirs of endoscopy related health care associated infections with this organism are other patients.
Historically, salmonella and related species have been the most common causes of infections transmitted by endoscopy. Many of the older literature reports of such infections occurred with cleaning and disinfection regimens that would not be considered acceptable by today's standards. Some reports of salmonella outbreaks have been associated with inadequate cleaning of accessories, particularly the failure to adequately ultrasonically clean spiral wound wire accessories. Increasing chemical immersion time was ineffective in at least one of these outbreaks and the problem was only terminated when proper cleaning procedures were employed.
This is a Gram negative rod that thrives in moist environments. It frequently contaminates solutions and hospital equipment and the human reservoirs are the urinary and respiratory tracts as well as the gastrointestinal tract of children.
The picture below demonstrates the typical red pigmented colonies of Serratia marcescens.
Significant cause of health care associated pulmonary, urinary, and surgical site infections.
The organism is usually transmitted from person to person via the nahds of HCW's or from environmental reservoirs to patients.
If more evidence is required ofthe pivotal role of adequate mechanical cleaning in endoscope reprocessing then it is provided by Serratia marcescens. Several outbreaks of S. marcescens infection have been tracked to bronchoscopic transmission. In an outbreak involving three fatalities, the instrument had been inadequately cleaned but then subjected to a full ethylene oxide sterilising process, underlining the fact that any attempts at sterilisation or disinfection are likely to be ineffective in the presence of inadequate cleaning.
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