The disinfection of clinically contaminated Matburn suction pumps and baby incubators in an 'Aseptor' formalin cabinet

Fifty-millilitre washings from 53 used Matburn suction pumps contained up to 10⁹ organisms per ml. Of 93 isolates, 47 were Pseudomonas species. Apart from some enterobacteria and yeasts, manual washing failed to eliminate these organisms and occasionally introduced further contamination. Machine washing and oven drying greatly reduced the numbers of contaminating bacteria. Exhaust air from pumps was frequently contaminated but at a low level and usually with non-pathogens. Of 27 baby incubators, 19 were contaminated with up to 10⁶ organisms per ml of 50 ml washings despite the presence of residual chlorhexidine activity from ward disinfection.Apart from occasional probable post-disinfection contamination of the machines with diphtheroids, micrococci, coagulase-negative staphylococci and Bacillus spp., disinfection with formalin in an Aseptor 8800 yielded sterile cultures from 51 (96·2 per cent) and 26 (96·3 per cent) of suction pumps and incubators, respectively.