Preventing infection from reusable medical equipment: a systematic review

Background: In 2000, the World Health Organization (WHO) had eight sets of conflicting

recommendations for decontaminating medical equipment. We conducted a systematic review of

observational studies to assist WHO in reconciling the various guidelines. This paper summarises

the methods developed and illustrates the results for three procedures – alcohol, bleach and

povidone iodine.

Methods: We developed a Medline search strategy and applied inclusion criteria specifying the

decontamination procedures of interest and an outcome of microbial destruction for a set of

marker organisms. We developed protocols to assess the quality of studies and categorised them

according to the reliability of the methods used. Through an iterative process we identified best

practice for the decontamination methods and key additional factors required to ensure their

effectiveness. We identified 88 published papers for inclusion, describing 135 separate studies of

decontamination.

Results: For disinfection with alcohol, best practice was identified from 23 studies as an exposure

to 70–80% ethanol or isopropanol for at least 5 minutes. Bleach was effective for sterilization at a

concentration of 5000 ppm for 5 minutes and for disinfection at 1000 ppm for 10 minutes (33

studies). Povidone iodine was only partially effective for disinfection at a concentration of 1% for

15 minutes (15 studies).

Conclusions: Our findings provide an evidence base for WHO guidelines on decontaminating

medical equipment. The results support the recommended use of bleach and show that alcohol

could be used more widely than current guidelines suggest, provided best practice is followed. The

effectiveness of povidone iodine is uncertain.