Disinfection Procedures of Fiberscopes in Endoscopy Departments

Abstract

Disinfection of fibre endoscopes was examined in 5 endoscopy departments during endoscopy sessions. On the endoscopes, especially in the instrument channels, Pseudomonas aeruginosa and Proteus species could be regularly found, in some cases also Enterobacter cloacae and Candida albicans. With the results of disinfection experiments, proposals are made to reduce the infection risk due to insufficiently disinfected instruments in endoscopy departments.

Bacterial spores and chemical sporicidal agents

“…In the microbiological context, the dialdehyde has chiefly been used for the chemical sterilization of medical equipment which cannot be sterilized by physical methods (84,163,185,186,216,222). The main advantages claimed for its use as a chemosterilizer are (i) its broad spectrum of activity, especially good sporicidal properties; (ii) its activity in the presence of organic matter; (iii) its rapid antimicrobial action, although spores are considerably less susceptible than nonsporing bacteria; (iv) its noncorrosive action towards metals, rubber, lenses, and most materials, although some formulations may not fulfil these criteria (9, 11); (v) its lack of harmful effects on cement or lenses of bronchoscopes, cystoscopes, or telescopes; and (vi) its ease of use.…”

“…Rittenbury and Hench (164) and Haselhuhn et al (95) recommended glutaraldehyde for the cold sterilization of hemostats, cystoscopes, food containers, and anesthesia equipment. The aldehyde has also been found to be completely satisfactory for the routine sterilization of urological instruments and endoscopes (133,145) and has proved highly effective for the rapid and safe disinfection of gastrointestinal endoscopy equipment (216). Despite inadequate sterilization with glutaraldehyde, because of the short time periods often used in hospital practice, infection transmission appears to be rare, presumably because very few potentially pathogenic spores are to be found on cleaned endoscopes (9, 11).…”

Disinfection of upper gastrointestinal fibreoptic endoscopy equipment: an evaluation of a cetrimide chlorhexidine solution and glutaraldehyde.

“…after storage as reported by Axon et al (1974) and Tolon et al (1976) apart from the suction channel and shelf below the biopsy valve. We attribute out findings to thorough drying of the instrument before it is replaced in the storage cupboard overnight as this seems to be independent of which disinfection procedure has been used.…”

“…Many endoscopists, however, remain complacent about the need to disinfect upper gastrointestinal instruments between successive examinations despite advice from instrument manufacturers and previous reports (Axon et al, 1974;Elson et al, 1975;Raines et al, 1975;Shull et al, 1975;Tolon et al, 1976;Dunkerley et al, 1977;Noy et al, 1977). Although the extreme situation of fatal septicaemia after endoscopy in granulopenic patients (Greene et al, 1974) is comparatively rare, the risks of bacteraemia and cross-infection when successive patients are examined with the same instrument are high (Elson et al, 1975;Raines et al, 1975;Shull et al, 1975).…”

“…To our knowledge there have been only five reported studies of disinfection of upper gastrointestinal endoscopes (Axon et al, 1974;Elson et al, 1975;Tolon et al, 1976;Dunkerley et al, 1977;Noy et al, 1977), four of which suggest that activated glutaraldehyde is an effective agent as has been shown with other instruments (Ross, 1966;Mitchell and Alder, 1975). Recommended procedures for disinfecting instru-Received for publication 24 April 1978 ments with glutaraldehyde have ranged from 'thorough irrigation' (Noy et al, 1977) to immersion times of from 10 minutes (American Hospital Association, 1974;Axon et al, 1974;Salmon, 1974;Elson et al, 1975;Tolon et al, 1976) to 20 minutes (Blumgart, 1975;KeyMed (personal communication)) and 30 minutes (Haglof, 1976), although it has been shown that vegecidal activity is present after only two minutes (Stonehill et al, 1963;Borick et al, 1964). Tuberculocidal and virucidal activity require 10 minutes' exposure (Stonehill et al, 1963;Klein, 1963), but sporicidal activity requires at least three hours (Stonehill et al, 1963;Lowbury et al, 1975).…”