The Occurrence and Prevention of Infections Associated with Gastrointestinal Endoscopy

The Effectiveness of Immersion Disinfection for Flexible Fiberoptic Laryngoscopes

OBJECTIVE: We sought to determine whether highlevel disinfection renders fiberoptic laryngoscopes free of nonviral infectious microorganisms.

METHODS: Six flexible fiberoptic laryngoscopes in heavy use were subjected to surveillance cultures at the beginning, middle, and end of the clinical workday after high-level disinfection to determine if microorganisms could be recovered. Control cultures were obtained by direct contamination of the endoscope with saliva. The rate of microorganism recovery from the endoscopes after high-level disinfection was determined and compared with control specimens.

RESULTS: Among a total of 48 cultures submitted from in use but disinfected fiberoptic laryngoscopes, 1 positive culture (positive rate, 2.1%) for mold species was recovered. No positive bacterial cultures occurred. Eleven of 11 (100%) control cultures were positive for bacterial species ( P < 0.001). The confidence interval for the risk of microorganism contamination of a disinfected laryngoscope ranged from 0.11% to 11.6%.

CONCLUSION: High-level disinfection provides a reasonably effective method of reducing bacterial and fungal contamination of flexible fiberoptic laryngoscopes. Appropriate surveillance technique should be used in each clinical setting with flexible fiberoptic scopes to ensure adequate disinfection effectiveness. (Otolaryngol Head Neck Surg 2004; 130:681-5.)

Screening for Human Immunodeficiency Virus, Hepatitis B Virus, Hepatitis C Virus, and Treponema pallidum by Blood Testing Using a Bio-Flash Technology-Based Algorithm before Gastrointestinal Endoscopy

Currently, conventional enzyme immunoassays which use manual gold immunoassays and colloidal tests (GICTs) are used as screening tools to detect Treponema pallidum (syphilis), hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus type 1 (HIV-1), and HIV-2 in patients undergoing surgery. The present observational, cross-sectional study compared the sensitivity, specificity, and work flow characteristics of the conventional algorithm with manual GICTs with those of a newly proposed algorithm that uses the automated Bio-Flash technology as a screening tool in patients undergoing gastrointestinal (GI) endoscopy. A total of 956 patients were examined for the presence of serological markers of infection with HIV-1/2, HCV, HBV, and T. pallidum The proposed algorithm with the Bio-Flash technology was superior for the detection of all markers (100.0% sensitivity and specificity for detection of anti-HIV and anti-HCV antibodies, HBV surface antigen [HBsAg], and T. pallidum) compared with the conventional algorithm based on the manual method (80.0% sensitivity and 98.6% specificity for the detection of anti-HIV, 75.0% sensitivity for the detection of anti-HCV, 94.7% sensitivity for the detection of HBsAg, and 100% specificity for the detection of anti-HCV and HBsAg) in these patients. The automated Bio-Flash technology-based screening algorithm also reduced the operation time by 85.0% (205 min) per day, saving up to 24 h/week. In conclusion, the use of the newly proposed screening algorithm based on the automated Bio-Flash technology can provide an advantage over the use of conventional algorithms based on manual methods for screening for HIV, HBV, HCV, and syphilis before GI endoscopy.

Survey of endoscope reprocessing in Korea

Background/Aims

There is a growing emphasis on quality management in endoscope reprocessing. Previous surveys conducted in 2002 and 2004 were not practitioner-oriented. Therefore, this survey is significant for being the first to target actual participants in endoscope reprocessing in Korea.

Methods

This survey comprised 33 self-filled questions, and was personally delivered to nurses and nursing auxiliaries in the endoscopy departments of eight hospitals belonging to the society. The anonymous responses were collected after 1 week either by post or in person by committee members.

Results

The survey included 100 participants. In the questionnaire addressing compliance rates with the reprocessing guideline, the majority (98.9%) had a high compliance rate compared to 27% of respondents in 2002 and 50% in 2004. The lowest rate of compliance with a reprocessing procedure was reported for transporting the contaminated endoscope in a sealed container. Automated endoscope reprocessors were available in all hospitals. Regarding reprocessing time, more than half of the subjects replied that reprocessing took more than 15 minutes (63.2%).

Conclusions

The quality management of endoscope reprocessing has improved as since the previous survey. A national survey expanded to include primary clinics is required to determine the true current status of endoscope reprocessing.

Recent update of gastrointestinal endoscope reprocessing

As infection-related issues have become one of the most important concerns in endoscopy centers, proper reprocessing of endoscopes has attracted great interest. Compliance with established guidelines for reprocessing is critical to prevent pathogen transmission. However, hospital compliance with guidelines has not been satisfactory. To increase compliance, efforts have focused on developing new and more innovative disinfectants and an automated endoscope reprocessor. Reprocessing must be performed by appropriately trained personnel and regular monitoring of reprocessing is essential for quality assurance to improve compliance.

Endoscope disinfection using chlorine dioxide in an automated washer-disinfector

Although 2% glutaraldehyde is often the first-line agent for endoscopic disinfection, its adverse reactions are common among staff and it is less effective against certain mycobacteria and spore-bearing bacteria. Chlorine dioxide is a possible alternative and an automated washer-disinfector fitted with this agent is currently available. This study was conducted to evaluate the effectiveness of chlorine dioxide in endoscopic disinfection after upper gastrointestinal examination. In vitro microbicidal properties of chlorine dioxide solutions were examined at high (600 ppm) and low (30 ppm) concentrations against various microbes including Pseudomonas aeruginosa, Helicobacter pylori, Mycobacterium avium-intracellulare and Bacillus subtilis in the presence or absence of bovine serum albumin (BSA). Immediately following endoscopic procedures and after application to the automated reprocessor incorporating chlorine dioxide at 30 ppm for 5 min, endoscopic contamination with infectious agents, blood, H. pylori ureA gene DNA and HCV-RNA was assessed by cultivation, sensitive test tape, polymerase chain reaction (PCR) and reverse transcriptase-PCR analysis, respectively. Chlorine dioxide at 30 ppm has equivalent microbicidal activity against most microbes and faster antimicrobial effects on M. avium-intracellulare and B. subtilis compared with 2% glutaraldehyde, but contamination with BSA affected the microbicidal properties of chlorine dioxide. Endoscopic contamination with microbes, blood and bacterial DNA was eliminated after application of the automated reprocessor/chlorine dioxide system. Thus, chlorine dioxide is a potential alternative to glutaraldehyde. The use of automated reprocessors with compatibility to chlorine dioxide, coupled with thorough pre-cleaning, can offer effective, faster and less problematic endoscopic disinfection.