Preventing infection from reusable medical equipment: a systematic review.
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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. (+info)
Anaerobic and aerobic skin bacteria before and after skin-disinfection with chlorhexidine: an experimental study in volunteers.
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The amount, composition, and localization of anaerobic and aerobic bacteria in the normal skin before and after disinfection were the subject of a volunteer study. The superficial bacterial flora were sampled by velvet pad imprints, and the deep flora were determined from whole skin biopsies. Only one anaerobic species, Propionebacterium acnes, was encountered even though other and more strict anaerobic bacteria could have been grown with the anaerobic technique employed. Staphylococcus albus dominated among the aerobic superficial bacteria, while diphtheroids, Micrococcus spp., and lactobacilli occurred sporadically. The deep aerobic bacteria were present in a significantly greater amount than the anaerobic. A two-step cleansing/disinfection procedure was evaluated in vivo in volunteers as well as in surgical patients, and aqueous cetrimide/chlorhexidine (Savlon) followed by chlorhexidine in alcohol (Hibitane) almost eradicated both the superficial and deep anaerobic and aerobic skin flora. (+info)
Comparative resistance of phage isolates of four genotypes of f-specific RNA bacteriophages to various inactivation processes.
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The effect of natural inactivation in freshwater, chlorination, ammonia, extreme pHs, temperature, and salt content on phage inactivation was evaluated on mixtures of F-specific RNA bacteriophage isolates belonging to genotypes I, II, III, and IV. The bacteriophages studied were previously but recently isolated from natural samples, characterized as F-specific RNA bacteriophages and genotyped by plaque hybridization with genotype-specific probes. Natural inactivation in river water was modeled by in situ incubation of bacteriophages inside submerged dialysis tubes. After several days bacteriophages of genotype I showed the highest persistence, which was significantly different from that of bacteriophages of genotype II, IV, or III. The pattern of resistance of phages belonging to the various genotypes to extreme pHs, ammonia, temperature, salt concentration, and chlorination was similar. In all cases, phages of genotype I showed the highest persistence, followed by the phages of genotypes II, III, and IV. The phages of genotypes III and IV were the least resistant to all treatments, and resistance of genotypes III and IV to the treatments was similar. Bacteriophages of genotype II showed intermediate resistance to some of the treatments. The resistance of four phages of genotype I to natural inactivation and chlorination did not differ significantly. These results indicate that genotypes III and IV are much more sensitive to environmental stresses and to treatments than the other genotypes, especially than genotype I. This should be taken into consideration in future studies aimed at using genotypes of F-specific RNA bacteriophages to fingerprint the origin of fecal pollution. (+info)
Closure of traumatic wounds without cleaning and suturing.
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BACKGROUND: In less than ideal situations wounds have to be closed without extensive cleaning using sterile adhesive strips (Steristrips). This prospective analyses the efficiency of this technique and compares it to the more conventional approach. METHODS: Altogether 147 lacerations were closed with sterile strips with no wound cleaning. Patients were subsequently followed up for a minimum of three months. RESULTS: The sepsis rate in compliant patients was 1.4% with a total complication rate of 2.7%. CONCLUSION: This technique, while contradicting the "sacred tenets" of wound closure, is a cheap, quick, and effective alternative to routine closure of traumatic wounds in a casualty department. (+info)
Identification of bacteria in drinking and purified water during the monitoring of a typical water purification system.
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BACKGROUND: A typical purification system that provides purified water which meets ionic and organic chemical standards, must be protected from microbial proliferation to minimize cross-contamination for use in cleaning and preparations in pharmaceutical industries and in health environments. METHODOLOGY: Samples of water were taken directly from the public distribution water tank at twelve different stages of a typical purification system were analyzed for the identification of isolated bacteria. Two miniature kits were used: (i) identification system (api 20 NE, Bio-Merieux) for non-enteric and non-fermenting gram-negative rods; and (ii) identification system (BBL crystal, Becton and Dickson) for enteric and non-fermenting gram-negative rods. The efficiency of the chemical sanitizers used in the stages of the system, over the isolated and identified bacteria in the sampling water, was evaluated by the minimum inhibitory concentration (MIC) method. RESULTS: The 78 isolated colonies were identified as the following bacteria genera: Pseudomonas, Flavobacterium and Acinetobacter. According to the miniature kits used in the identification, there was a prevalence of isolation of P. aeruginosa 32.05%, P. picketti (Ralstonia picketti) 23.08%, P. vesiculares 12.82%,P. diminuta 11.54%, F. aureum 6.42%, P. fluorescens 5.13%, A. lwoffi 2.56%, P. putida 2.56%, P. alcaligenes 1.28%, P. paucimobilis 1.28%, and F. multivorum 1.28%. CONCLUSIONS: We found that research was required for the identification of gram-negative non-fermenting bacteria, which were isolated from drinking water and water purification systems, since Pseudomonas genera represents opportunistic pathogens which disperse and adhere easily to surfaces, forming a biofilm which interferes with the cleaning and disinfection procedures in hospital and industrial environments. (+info)
Diarrhea prevention through household-level water disinfection and safe storage in Zambia.
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A water quality intervention that consists of water treatment, safe storage, and community education was field tested in Kitwe, Zambia. A total of 166 intervention households were randomly selected from one community and 94 control households from another. Baseline surveys were conducted and the intervention was distributed. Weekly active diarrhea surveillance, biweekly water testing, and a follow-up survey were conducted. Compliance was high in intervention households: 97% reported using disinfectant and 72-95% had measurable chlorine in their water in biweekly testing. The percentage of intervention households storing water safely increased from 41.5% to 89.2%. Stored water in intervention households was significantly less contaminated with Escherichia coli than water in control households (P < 0.001). Diarrheal disease risk for individuals in intervention households was 48% lower than for controls (95% confidence interval = 0.3, 0.9). This intervention is a useful tool for preventing waterborne diseases in families in developing countries who lack access to potable water. (+info)
Comparative inactivation of enteroviruses and adenovirus 2 by UV light.
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The doses of UV irradiation necessary to inactivate selected enteric viruses on the U.S. Environmental Protection Agency Contaminant Candidate List were determined. Three-log reductions of echovirus 1, echovirus 11, coxsackievirus B3, coxsackievirus B5, poliovirus 1, and human adenovirus type 2 were effected by doses of 25, 20.5, 24.5, 27, 23, and 119 mW/cm(2), respectively. Human adenovirus type 2 is the most UV light-resistant enteric virus reported to date. (+info)
Cleaning patient shower facilities: a novel approach to reducing patient exposure to aerosolized Aspergillus species and other opportunistic molds.
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We previously have demonstrated that the hospital water-distribution system could be a reservoir for airborne molds that leads to secondary aerosolization of these molds in patient shower facilities. In this report, we show that cleaning the floors of patient shower facilities in a bone marrow transplantation unit reduced the mean air concentrations of molds, including Aspergillus species (from 12 cfu/m3 to 4 cfu/m3; P=.0047). (+info)