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Contamination of endoscopes used in AIDS patients
P J Hanson1, D Gor, J R Clarke
1Brompton Hospital, London.
Abstract:
Contamination of twenty endoscopes used in patients with AIDS was assessed. The suction-biopsy, air, and water channels and the insertion tube were sampled after use, after washing in detergent, and after disinfection for 2 min in 2% alkaline glutaraldehyde. The polymerase chain reaction with Southern blotting, cell cultures, and antigen immunoassay were used to detect human immunodeficiency virus (HIV). Samples were also examined for cytomegalovirus, adenoviruses, enteroviruses, herpes simplex virus, myxoviruses, hepatitis B surface antigen, fungi, and bacteria. Seven of twenty unwashed endoscopes were contaminated by HIV. Commensal bacteria were found in all endoscopes, Candida albicans in six, Staphylococcus aureus in five, and Pseudomonas aeruginosa in five. Washing alone removed all detectable organisms from 66 of 68 contaminated sites; Neisseria spp were recovered from two air channels after washing but not after disinfection. Washing achieved a mean reduction of 4.93 (95% confidence interval 3.69-6.17) colony forming units per ml.
Insights
Endoscopes used in AIDS patients can harbor human immunodeficiency virus (HIV). Thorough washing effectively removed most contaminants, including HIV, from endoscopes, ensuring patient safety.
Area of Science:
- Microbiology
- Infectious Diseases
- Gastroenterology
Background:
- Endoscopes are critical for diagnosing gastrointestinal conditions but pose infection risks.
- Patients with Acquired Immunodeficiency Syndrome (AIDS) may have specific microbial shedding patterns.
- Proper disinfection protocols are essential to prevent cross-contamination.
Purpose of the Study:
- To assess the contamination levels of endoscopes used in patients with AIDS.
- To evaluate the efficacy of washing and disinfection in eliminating pathogens, including human immunodeficiency virus (HIV).
Main Methods:
- Sampling of endoscope channels (suction-biopsy, air, water) and insertion tubes.
- Detection of human immunodeficiency virus (HIV) using polymerase chain reaction (PCR), Southern blotting, cell cultures, and antigen immunoassay.
- Microbiological examination for other viruses, fungi, and bacteria.
Main Results:
- Seven of twenty unwashed endoscopes were contaminated with HIV.
- Commensal bacteria, Candida albicans, Staphylococcus aureus, and Pseudomonas aeruginosa were frequently detected.
- Washing alone removed detectable organisms from 66 of 68 contaminated sites.
- Neisseria spp. persisted in two air channels post-washing but were eliminated after disinfection.
Conclusions:
- Endoscopes used in patients with AIDS can be contaminated with HIV and other microorganisms.
- Standard washing procedures are highly effective in reducing microbial load.
- Disinfection is crucial for complete elimination of potential pathogens, ensuring endoscope safety.