APIC guideline for selection and use of disinfectants. 1994, 1995, and 1996 APIC Guidelines Committee. Association for Professionals in Infection Control and Epidemiology, Inc

An evaluation of patient area cleaning in 3 hospitals using a novel targeting methodology

BACKGROUND

Although environmental cleaning and disinfecting practices have become a cornerstone of patient care, assessment of actual compliance with such procedures has not been reported. Using a novel methodology, we developed a means to monitor directly such activities.

METHODS

A nontoxic target solution, which intensely fluoresces with a black light, was formulated to be inconspicuous yet readily removed by housekeeping products. Small volumes of material were confidentially applied to 12 target sites in patient rooms in 3 hospitals following terminal cleaning. The targets were reevaluated following terminal cleaning after several patients had occupied the room.

RESULTS

One hundred fifty-seven rooms and 1404 targets were evaluated. In the 3 hospitals studied, only 45%, 42%, and 56% of targets were removed by routine terminal cleaning/disinfecting activities. The frequency with which various individual sites were cleaned varied widely but was similar in all hospitals.

CONCLUSION

The use of a novel target compound to evaluate housekeeping practices confirmed high rates of cleaning of traditional sites but poor cleaning of many sites that have significant potential for harboring and transmitting microbial pathogens. This methodology has the potential for being used to evaluate objectively the cleaning/disinfecting activities in various health care settings.

Use of germicides in the home and the healthcare setting: is there a relationship between germicide use and antibiotic resistance?

BACKGROUND

The spread of antibiotic-resistant pathogens represents an increasing threat in healthcare facilities. Concern has been expressed that the use of surface disinfectants and antiseptics may select for antibiotic-resistant pathogens.

OBJECTIVE

To review the scientific literature on whether there is a link between use of germicides (ie, disinfectants and antiseptics) and bacterial resistance to antibiotics. In addition, we will review whether antibiotic-resistant bacteria exhibit altered susceptibility to germicides that are recommended for use as disinfectants or antiseptics.

DESIGN

A review of the appropriate scientific literature.

RESULTS

In the laboratory, it has been possible to develop bacterial mutants with reduced susceptibility to disinfectants and antiseptics that also demonstrate decreased susceptibility to antibiotics. However, the antibiotic resistance described was not clinically relevant because the test organism was rarely a human pathogen, the altered level of antimicrobial susceptibility was within achievable serum levels for the antibiotic, or the antibiotic tested was not clinically used to treat the study pathogen. Similarly, wild-type strains with reduced susceptibility to disinfectants (principally, quaternary ammonium compounds) and antiseptics (principally, triclosan) have been reported. However, because the concentration of disinfectants used in the healthcare setting greatly exceeds the concentration required to kill strains with reduced susceptibility to disinfectants, the clinical relevance of these observations is questionable.

CONCLUSION

To date, there is no evidence that using recommended antiseptics or disinfectants selects for antibiotic-resistant organisms in nature. Disinfectants and antiseptics should be used when there are scientific studies demonstrating benefit or when there is a strong theoretical rationale for using germicides.

Precautions in ophthalmic practice in a hospital with a major acute SARS outbreak: an experience from Hong Kong

Many new infectious diseases in humans have been derived from animal sources in the past 20 years. Some are highly contagious and fatal. Vaccination may not be available and antiviral drugs are not effective enough. Infectious control is important in clinical medicine and in Ophthalmology. Severe acute respiratory syndrome (SARS), as an example, is a highly contagious respiratory disease that has recently been reported in Asia, North America, and Europe. Within a matter of weeks, the outbreak has evolved to become a global health threat and more than 30 countries have been afflicted with a novel Coronavirus strain (SARS-CoV) that is the aetiologic agent of SARS. The primary route of transmission of SARS appears involving close person-to-person contact through droplets. Ophthalmologists may be particularly susceptible to the infection as routine ophthalmic examinations like direct ophthalmoscopy and slit-lamp examination are usually performed in a setting that has close doctor-patient contact. Being the Ophthalmology Department of the only hospital in the world that has just gone through the largest outbreak of SARS, we would like to share our strategy, measures, and experiences of preventing contracting or spreading of SARS infection as an infection control model. SARS is one of the many viruses against which personnel will need protecting in an ophthalmic setting. The experiences attained and the measures established might also apply to other infectious conditions spreading by droplets such as the avian influenza with H5N1.

Inconsistencies in endoscope-reprocessing and infection-control guidelines: the importance of endoscope drying

INTRODUCTION

Endoscope reprocessing is a multi-stepped process that renders a contaminated endoscope safe for reuse. Its steps include meticulous cleaning, complete immersion in a liquid chemical sterilant (LCS) or disinfectant to achieve high-level disinfection (or "liquid sterilization"), water rinsing, and proper handling and storage. Surveys and reports indicate that not all health-care facilities dry their endoscopes after reprocessing. Endoscope drying can be easily, quickly, and inexpensively achieved by flushing the endoscope's internal channels, and wiping its external surfaces, with 70-90% ethyl or isopropyl alcohol, to facilitate drying after reprocessing, followed by compressed or forced air.

METHODS

The medical literature was reviewed to evaluate the importance of endoscope drying to the prevention of disease transmission. Several national and international endoscope-reprocessing and infection-control guidelines and a public health advisory were also reviewed and compared for consistency and to evaluate the emphasis each places on endoscope drying. If a guideline recommends endoscope drying, this study clarified whether this step is recommended after reprocessing throughout the day (i.e., between patient procedures), before storage, or both. These guidelines were also reviewed to determine whether any of them recommend reprocessing endoscopes before the first patient of the day.

RESULTS

This review identified several published reports and clinical studies that demonstrate the significant contribution of endoscope drying to the prevention of disease transmission. This review also identified significant differences and inconsistencies regarding the emphasis different published guidelines and a public health advisory place on endoscope drying. Some guidelines recommend drying the endoscope after completion of every reprocessing cycle, both throughout the day and before storage, while others deemphasize its importance and recommend endoscope drying only before storage, if at all. Instead of recommending endoscope drying before storage, some guidelines recommend reprocessing endoscopes before the first patient of the day.

DISCUSSION AND CONCLUSION

The finding that several guidelines are inconsistent with one another and that some are remiss and fail to recommend endoscope drying is of concern. Endoscope drying is as important to the prevention of nosocomial infection as cleaning and high-level disinfection (or "liquid sterilization"). Whereas wet or inadequately dried endoscopes pose an increased risk of contamination and have been associated with transmission of waterborne microorganisms and nosocomial infection, thoroughly dried (and properly cleaned and high-level disinfected) endoscopes have not been linked to nosocomial infection. Moreover, inconsistent guidelines can confuse reprocessing staff members and result in noncompliance, variations in the standard of care, and ineffective reprocessing. To minimize the risk of disease transmission and nosocomial infection, modification and revision of guidelines are recommended as required to be consistent with one another and to unconditionally recommend endoscope drying after completion of every reprocessing cycle, both between patient procedures and before storage, no matter the label claim of the LCS or disinfectant, the label claim of the automated reprocessing system, or the microbial quality of the rinse water. According to the medical literature, adoption of this recommendation may reduce the importance of not only monitoring the microbial quality of the rinse water, but also reprocessing endoscopes before the first patient of the day, both of which can be costly practices that a few guidelines recommend.

Chemical resistance of the gram-negative bacteria to different sanitizers in a water purification system

Background

Purified water for pharmaceutical purposes must be free of microbial contamination and pyrogens. Even with the additional sanitary and disinfecting treatments applied to the system (sequential operational stages), Pseudomonas aeruginosa, Pseudomonas fluorescens, Pseudomonas alcaligenes, Pseudomonas picketti, Flavobacterium aureum, Acinetobacter lowffi and Pseudomonas diminuta were isolated and identified from a thirteen-stage purification system. To evaluate the efficacy of the chemical agents used in the disinfecting process along with those used to adjust chemical characteristics of the system, over the identified bacteria, the kinetic parameter of killing time (D-value) necessary to inactivate 90% of the initial bioburden (decimal reduction time) was experimentally determined.

Methods

Pseudomonas aeruginosa, Pseudomonas fluorescens, Pseudomonas alcaligenes, Pseudomonas picketti, Flavobacterium aureum, Acinetobacter lowffi and Pseudomonas diminuta were called in house (wild) bacteria. Pseudomonas diminuta ATCC 11568, Pseudomonas alcaligenes INCQS , Pseudomonas aeruginosa ATCC 15442, Pseudomonas fluorescens ATCC 3178, Pseudomonas picketti ATCC 5031, Bacillus subtilis ATCC 937 and Escherichia coli ATCC 25922 were used as 'standard' bacteria to evaluate resistance at 25°C against either 0.5% citric acid, 0.5% hydrochloric acid, 70% ethanol, 0.5% sodium bisulfite, 0.4% sodium hydroxide, 0.5% sodium hypochlorite, or a mixture of 2.2% hydrogen peroxide (H₂O₂) and 0.45% peracetic acid.

Results

The efficacy of the sanitizers varied with concentration and contact time to reduce decimal logarithmic (log₁₀) population (n cycles). To kill 90% of the initial population (or one log₁₀ cycle), the necessary time (D-value) was for P. aeruginosa into: (i) 0.5% citric acid, D = 3.8 min; (ii) 0.5% hydrochloric acid, D = 6.9 min; (iii) 70% ethanol, D = 9.7 min; (iv) 0.5% sodium bisulfite, D = 5.3 min; (v) 0.4% sodium hydroxide, D = 14.2 min; (vi) 0.5% sodium hypochlorite, D = 7.9 min; (vii) mixture of hydrogen peroxide (2.2%) plus peracetic acid (0.45%), D = 5.5 min.

Conclusion

The contact time of 180 min of the system with the mixture of H₂O₂+ peracetic acid, a total theoretical reduction of 6 log₁₀ cycles was attained in the water purified storage tank and distribution loop. The contact time between the water purification system (WPS) and the sanitary agents should be reviewed to reach sufficient bioburden reduction (over 6 log₁₀).

Efficacy of hospital germicides against adenovirus 8, a common cause of epidemic keratoconjunctivitis in health care facilities

The inactivation of virus-contaminated nonporous inanimate surfaces was investigated using adenovirus type 8, a common cause of epidemic keratoconjunctivitis. A 10-microl inoculum of adenovirus was placed onto each stainless steel disk (1-cm diameter), and the inoculum was allowed to air dry for 40 min. Twenty-one different germicides (including disinfectants and antiseptics) were selected for this study based on their current uses in health care. After a 1- or 5-minute exposure to 50 microl of the germicide, the virus-germicide test mixture was neutralized and assayed for infectivity. Using an efficacy criterion of a 3-log10 reduction in the titer of virus infectivity and regardless of the virus suspending medium (i.e., hard water, sterile water, and hard water with 5% fetal calf serum), only five disinfectants proved to be effective against the test virus at 1 min: 0.55% ortho-phthalaldehyde, 2.4% glutaraldehyde, 2.65% glutaraldehyde, approximately 6,000 ppm chlorine, and approximately 1,900 ppm chlorine. Four other disinfectants showed effectiveness under four of the five testing conditions: 70% ethanol, 65% ethanol with 0.63% quaternary ammonium compound, 79.6% ethanol with 0.1% quaternary ammonium compound, and 0.2% peracetic acid. Of the germicides suitable for use as an antiseptic, 70% ethanol achieved a 3-log10 reduction under four of the five test conditions. These results emphasize the need for proper selection of germicides for use in disinfecting noncritical surfaces and semicritical medical devices, such as applanation tonometers, in order to prevent outbreaks of epidemic keratoconjunctivitis.

Assessment of materials commonly utilized in health care: implications for bacterial survival and transmission

BACKGROUND

Contaminated environmental surfaces, equipment, and health care workers' hands have been linked to outbreaks of infection or colonization because of vancomycin-resistant enterococci (VRE) and Pseudomonas aeruginosa (PSAE). Upholstery, walls, and flooring may enhance bacterial survival, providing infectious reservoirs.

OBJECTIVES

Investigate recovery of VRE and PSAE, determine efficacy of disinfection, and evaluate VRE transmission from surfaces.

METHODS

Upholstery, flooring, and wall coverings were inoculated with VRE and PSAE and assessed for recovery at 24 hours, 72 hours, and 7 days. Inoculated surfaces were cleaned utilizing manufacturers' recommendations of natural, commercial, or hospital-approved products and methods, and samples were obtained. To assess potential for transmission, volunteers touched VRE-inoculated surfaces and imprinted palms onto contact-impression plates.

RESULTS

Twenty-four hours following inoculation, all surfaces had recovery of VRE; 13 (92.9%) of 14 surfaces had persistent PSAE. After cleaning, VRE was recovered from 7 (50%) surfaces, PSAE from 5 (35.7%) surfaces. After inoculation followed by palmar contact, VRE was recovered from all surfaces touched.

CONCLUSION

Bacteria commonly encountered in hospitals are capable of prolonged survival and may promote cross transmission. Selection of surfaces for health care environments should include product application and complexity of manufacturers' recommendations for disinfection. Recovery of organisms on surfaces and hands emphasizes importance of hand hygiene compliance prior to patient contact.

Inactivation of prions by acidic sodium dodecyl sulfate

Prompted by the discovery that prions become protease-sensitive after exposure to branched polyamine dendrimers in acetic acid (AcOH) (S. Supattapone, H. Wille, L. Uyechi, J. Safar, P. Tremblay, F. C. Szoka, F. E. Cohen, S. B. Prusiner, and M. R. Scott, J. Virol. 75:3453-3461, 2001), we investigated the inactivation of prions by sodium dodecyl sulfate (SDS) in weak acid. As judged by sensitivity to proteolytic digestion, the disease-causing prion protein (PrPSc) was denatured at room temperature by SDS at pH values of < or =4.5 or > or =10. Exposure of Sc237 prions in Syrian hamster brain homogenates to 1% SDS and 0.5% AcOH at room temperature resulted in a reduction of prion titer by a factor of ca. 10(7); however, all of the bioassay hamsters eventually developed prion disease. When various concentrations of SDS and AcOH were tested, the duration and temperature of exposure acted synergistically to inactivate both hamster Sc237 prions and human sporadic Creutzfeldt-Jakob disease (sCJD) prions. The inactivation of prions in brain homogenates and those bound to stainless steel wires was evaluated by using bioassays in transgenic mice. sCJD prions were more than 100,000 times more resistant to inactivation than Sc237 prions, demonstrating that inactivation procedures validated on rodent prions cannot be extrapolated to inactivation of human prions. Some procedures that significantly reduced prion titers in brain homogenates had a limited effect on prions bound to the surface of stainless steel wires. Using acidic SDS combined with autoclaving for 15 min, human sCJD prions bound to stainless steel wires were eliminated. Our findings form the basis for a noncorrosive system that is suitable for inactivating prions on surgical instruments, as well as on other medical and dental equipment.

Recent advances in epidemiology and prevention of gastrointestinal endoscopy related infections

PURPOSE OF REVIEW

This article reviews recent publications relevant to endoscope reprocessing and the potential for transmission of infection during gastrointestinal endoscopy.

RECENT FINDINGS

There have been a number of established reprocessing failures of gastrointestinal endoscopes at various healthcare facilities across the US resulting in patient notifications. These episodes have been associated with user errors and reprocessing equipment failures, highlighting the need for increased compliance with established guidelines. Surveillance cultures may be useful to monitor the outcome of reprocessing, although their use is controversial. New technology to allow point-of-use monitoring is promising. Biofilm accumulation may be an issue when reprocessing gastrointestinal endoscopes. Although peracetic acid has been promoted as superior to aldehyde-type liquid chemical germicides with regard to soil fixation, it may only be a modest improvement. Electrolyzed acid water is an emerging liquid chemical germicide that may be equivalent to currently accepted disinfectants. There appears to be no benefit to an additional reprocessing cycle before use for endoscopes that have been appropriately cleaned, disinfected, and stored.

SUMMARY

With the recent media attention on gastrointestinal endoscope reprocessing failures, despite the absence of documented transmission of infection, increased compliance with existing guidelines and new initiatives to enhance endoscope reprocessing are increasingly important to maintain public confidence.

Microarray analysis of toxicogenomic effects of peracetic acid on Pseudomonas aeruginosa

Hospital-acquired (nosocomial) infection (HAI) represents a serious threat to public health, both in terms of human casualty and in terms of economic impact. On an annual basis, 2 million individuals require prolonged hospitalization, and an estimated 90 000 patients die due to HAI. Economic damages are reported to exceed $4.5 billion, annually. While many disinfectants, including peracetic acid, have been employed to eradicate infectious bacteria, a lack of understanding their mode of action and the corresponding defense mechanisms hinders successful antimicrobial application. We report here the first transcriptome analysis of the response of Pseudomonas aeruginosa, a pathogen infecting those with cystic fibrosis, upon 20 min exposure to a sublethal concentration (1 mM) of peracetic acid. As a result, we identified that 570 out of a total of 5570 P. aeruginosa genes showed statistically significant transcript level changes. Our findings indicate that (i) many genes associated with cellular protective processes were induced, (ii) the transcription of genes involved in primary metabolic pathways was repressed, and (iii) the transcription of genes encoding membrane proteins and small molecule transporters was altered. We also observed that genes within operons were highly cotranscribed in this study. Finally, this global transcriptional profile can help identify signature genes that are also activated with other oxidative disinfectants, which may be used to design new more effective treatments or more efficaciously apply existing compounds.

Health care-associated infections in the neonatal intensive care unit

Neonates represent a unique and highly vulnerable patient population. Advances in medical technology that have occurred over the last few decades have improved the survival and quality of life for neonates, particularly those infants born with extreme prematurity or with congenital defects. Although immunologic immaturity and altered cutaneous barriers play some role in the vulnerability of neonates to nosocomial infections, clearly, therapeutic interventions that have proven to be lifesaving for these fragile infants also appear to be associated with the majority of infectious complications resulting in neonatal morbidity and mortality. Rates of infections in neonatal intensive care units (NICUs) have varied from 6% to 40% of neonatal patients, with the highest rates in those facilities having larger proportions of very low-birth-weight infants (birthweight < or =1000 grams) or neonates requiring surgery. Efforts to protect the vulnerable NICU infants include the following: (1) optimal infection control practices, especially good hand hygiene and good nursery design; (2) prudent use of invasive interventions with particular attention to early removal of invasive devices after they are no longer essential; and (3) judicious use of antimicrobial agents, with an emphasis on targeted (narrow spectrum) rather than broad-spectrum antibiotics and appropriate indications (proven or suspected bacterial infections).

Sporicidal activity in liquid chemical products to sterilize or high-level disinfect medical and dental instruments

BACKGROUND

Various liquid chemical products are commercially available in Mexico under sporicidal label claims. Frequently, information provided on their labels conflicts with published data on active ingredients, use concentrations, or exposure times.

OBJECTIVE

To evaluate sporicidal activity in 8 chemical products sold for the sterilization or high-level disinfection of medical and dental instruments.

METHODS

Bacillus atrophaeus ATCC 9372 spores were suspended (10 6 spores in 50 mL) in each of 4 glutaraldehyde solutions: a super oxidized solution, a hydrogen peroxide formulation, a quaternary ammonium compound, and an ortho -phthalaldehyde solution. After up to a 10-hour exposure, the solutions were passed through 0.22-mum filters, which were then rinsed with 1% sodium bisulfite, washed, and incubated on tryptic soy agar for 5 days at 37 degrees C.

RESULTS

At the use concentrations stipulated on their labels, only 2 of 6 products registered as sterilants showed sporicidal activity when challenged with 6 log 10 : a 2% glutaraldehyde in 10 hours and the hydrogen peroxide solution in 6 hours. Of 2 products registered as high-level disinfectants, only the ortho -phthalaldehyde showed noticeable sporicidal activity after 10-hour exposure.

CONCLUSION

The results show that some chemical products, commercially available in Mexico as "Liquid Chemical Sterilants/High-Level Disinfectants" cannot be used reliably to process instruments between patients.

Considering risks to healthcare workers from glutaraldehyde alternatives in high-level disinfection

Due to concerns over glutaraldehyde's toxicity, two substitutes have recently been introduced; ortho-phthalaldehyde (OPA), and a mixture of hydrogen peroxide and peracetic acid. There is limited information about the health effects for employees from these products. This study assesses the current practices regarding the use of high-level disinfectants in British Columbian hospitals and predicts the relative toxicities of each product. Industry practices were compiled using a comprehensive survey of current practices and decision processes in all hospitals in British Columbia. Of 95 hospitals, 64 returned surveys; 80% of these used high-level disinfection. Among user hospitals, 49% used glutaraldehyde alone and 51% had introduced alternatives. Concern about staff health was the most common reason for substituting, but this was frequently not considered when choosing specific alternatives. Hospitals that involved occupational health, infection control or regional staff in high-level disinfectant decisions used glutaraldehyde alternatives less often. In most hospitals, it was difficult to find individuals who were knowledgeable about the use of disinfectants. Potential health effects associated with each type of high-level disinfectant were assessed by review of the published literature and available manufacturers' data along with qualitative structure-activity relationship analysis. Results indicated that although all products irritate the skin and respiratory tract, OPA is a potential dermal and respiratory sensitizer but hydrogen peroxide and peracetic acid do not cause allergic reactions. Despite little being known about the risks to employees from glutaraldehyde alternatives, their use is widespread. The potential risks of all high-level disinfectants are serious; thus regulators and users are faced with important risk management decisions before and after they have been introduced into the workplace.

Infection control guidelines for the cardiac catheterization laboratory: Society guidelines revisited

In the early years of diagnostic cardiac catheterization, strict sterile precautions were required for cutdown procedures. Thirteen years ago, when the original guidelines were written, the brachial arteriotomy was still frequently utilized, femoral closure devices were uncommon, "implantables," such as intracoronary stents and PFO/ASD closure devices, were in their infancy, and percutaneous valve replacement was not a consideration. In 2005, the cardiac catheterization laboratory is a complex interventional suite with percutaneous access routine and device implantation standard. Despite frequent device implantation, strict sterile precautions are often not observed. Reasons for this include a decline in brachial artery cutdown, limited postprocedure follow-up with few reported infections, limited use of hats and masks in televised cases, and lack of current guidelines. Proper sterile technique has the potential to decrease the patient infection rate. Hand washing remains the most important procedure for preventing infections. Caps, masks, gowns, and gloves help to protect the patient by maintaining a sterile field. Protection of personnel may be accomplished by proper gowning, gloving, and eye wear, disposal of contaminated equipment, and prevention and care of puncture wounds and lacerations. With the potential for acquired disease from blood-borne pathogens, the need for protective measures is as essential in the cardiac catheterization laboratory as is the standard Universal Precautions, which are applied throughout the hospital. All personnel should strongly consider vaccination for hepatitis B. Maintenance of the cardiac catheterization laboratory environment includes appropriate cleaning, limitation of traffic, and adequate ventilation. In an SCAI survey, members recommended an update on guidelines for infection control in the cardiac catheterization laboratory. The following revision of the original 1992 guidelines is written specifically to address the increased utilization of the catheterization laboratory as an interventional suite with device implantation. In this update, infection protection is divided into sections on the patient, the laboratory personnel, and the laboratory environment. Additionally, specific CDC recommendation sections highlight recommendations from other published guidelines.

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Contamination, disinfection, and cross-colonization: are hospital surfaces reservoirs for nosocomial infection?

Despite documentation that the inanimate hospital environment (e.g., surfaces and medical equipment) becomes contaminated with nosocomial pathogens, the data that suggest that contaminated fomites lead to nosocomial infections do so indirectly. Pathogens for which there is more-compelling evidence of survival in environmental reservoirs include Clostridium difficile, vancomycin-resistant enterococci, and methicillin-resistant Staphylococcus aureus, and pathogens for which there is evidence of probable survival in environmental reservoirs include norovirus, influenza virus, severe acute respiratory syndrome-associated coronavirus, and Candida species. Strategies to reduce the rates of nosocomial infection with these pathogens should conform to established guidelines, with an emphasis on thorough environmental cleaning and use of Environmental Protection Agency-approved detergent-disinfectants.

Use of nonsterile instruments for examination for retinopathy of prematurity in the neonatal intensive care unit

OBJECTIVE

Use of nonsterile eyelid speculae and scleral depressors during screening examinations for retinopathy of prematurity (ROP) in the neonatal intensive care unit (NICU) violates existing infection control recommendations. The objective of this study was to characterize current instrument management and to estimate the prevalence of use of nonsterile instruments.

STUDY DESIGN

NICU nurse managers were surveyed. Questionnaires were mailed to 735 NICUs from The United States Neonatologists and Perinatologists Directory.

RESULTS

Of 300 surveys returned, 290 reported ROP examinations in their NICUs. Two hundred ten (72%) of 290 NICUs reported supplying instruments. Seventy-five (36%) of 210 NICUs supplying instruments reported a best practice on the basis of current guidelines. Twenty-six (9%) of 290 NICUs reported eye infections as a result of ROP examinations. Reported infection was more frequent (19%) among NICUs reporting reuse of instruments ( P =.019) and more frequent (17%) among NICUs in which ophthalmologists brought their own instruments ( P =.021). Only one (2%) NICU reporting best practice also reported eye infections ( P =.004).

CONCLUSIONS

ROP instrument management is inconsistent within and between NICUs. Without the exclusive use of sterile instruments, an increased risk of nosocomial infection might exist. Greater attention to sterile instrument management is recommended.

Manual versus automated methods for cleaning reusable accessory devices used for minimally invasive surgical procedures

We undertook a simulated-use study using quantitative methods to evaluate the cleaning efficacy of ported and non-ported accessory devices used in minimally invasive surgery. We chose laparoscopic scissors and forceps to represent worst-case devices which were inoculated with artificial test soil containing 10(6) cfu/mL Enterococcus faecalis and Geobacillus stearothermophilus and allowed to dry for 1 h. Cleaning was performed manually, as well as by the automated SI-Auto Narrow lumen cleaner. Manual cleaning left two- to 50-fold more soil residuals (protein, haemoglobin and carbohydrate) inside the lumen of non-ported versus ported laparoscopic accessory devices. The SI-Auto Narrow lumen cleaner was more efficient than manual cleaning and achieved >99% reduction in soil parameters in both non-ported (using retro-flushing) and ported laparoscopic devices. Only the automated cleaning of ported devices achieved 10(3)-10(4)-fold reduction in bacterial numbers. Sonication alone (no flushing of inner channel) did not effectively remove soil or organisms from the inner channel. Our findings indicate that non-ported accessory devices cannot be as reliably cleaned as ported devices regardless of the cleaning method used. If non-ported accessory devices are reprocessed, they should be cleaned using retro-flushing in an automated narrow lumen cleaner.

Disinfection and sterilization in health care facilities: what clinicians need to know

All invasive procedures involve contact between a medical device or surgical instrument and a patient's sterile tissue or mucous membranes. A major risk of all such procedures is the introduction of pathogenic microbes that could lead to infection. Failure to properly disinfect or sterilize reusable medical equipment carries a risk associated with breach of the host barriers. The level of disinfection or sterilization is dependent on the intended use of the object: critical items (such as surgical instruments, which contact sterile tissue), semicritical items (such as endoscopes, which contact mucous membranes), and noncritical items (such as stethoscopes, which contact only intact skin) require sterilization, high-level disinfection, and low-level disinfection, respectively. Cleaning must always precede high-level disinfection and sterilization. Users must consider the advantages and disadvantages of specific methods when choosing a disinfection or sterilization process. Adherence to these recommendations should improve disinfection and sterilization practices in health care facilities, thereby reducing infections associated with contaminated patient-care items.

Reprocessing endoscopes: United States perspective

Endoscopes are used frequently for the diagnosis and therapy of medical disorders. For example, greater than 10000000 gastrointestinal endoscopic procedures are performed each year in the United States. Failure to employ appropriate cleaning and disinfection/sterilization of endoscopes has been responsible for multiple nosocomial outbreaks and serious, sometimes life-threatening, infections. Flexible endoscopes, by virtue of the site of use, have a high bioburden of microorganisms after use. The bioburden found on flexible gastrointestinal endoscopes following use has ranged from 10(5) to 10(10)CFU/ml, with the highest levels being found in the suction channels. Cleaning dramatically reduces the bioburden on endoscopes. Several investigators have shown a mean log(10) reduction factor of 4 (99.99%) in the microbial contaminants with cleaning alone. Cleaning should be done promptly following each use of an endoscope to prevent drying of secretions, allow removal of organic material, and decrease the number of microbial pathogens. Because the endoscope comes into intimate contact with mucous membranes, high-level disinfection is the reprocessing standard after each patient use. High-level disinfection refers to the use of a disinfectant (e.g., FDA-cleared chemical sterilant or high-level disinfectant) that inactivates all microorganisms (i.e., bacteria, viruses, fungi, mycobacteria) but not high levels of bacterial spores. The disinfection process requires immersion of the endoscope in the high-level disinfectant and ensuring all channels are perfused for the approved contact time (e.g., for ortho-phthaladehyde this is 12 min in the US). Following disinfection, the endoscope and channels are rinsed with sterile water, filtered water, or tapwater. The channels are then flushed with alcohol and dried using forced air. The endoscope should be stored in a manner that prevents recontamination. A protocol that describes the meticulous manual cleaning process, the appropriate training and evaluation of the reprocessing personnel, and a quality assurance program for endoscopes should be adopted and enforced by each unit performing endoscopic reprocessing.

Efficacy and safety of reuse of disposable laparoscopic instruments in laparoscopic cholecystectomy: a prospective randomized study

BACKGROUND

The aim of this prospective randomized study was to investigate the efficacy and safety of the reuse of disposable laparoscopic instruments (DLI) in laparoscopic cholecystectomy.

METHODS

A total of 125 consecutive patients with symptomatic cholelithiasis were randomly assigned to undergo laparoscopic cholecystectomy with single-use DLI (group 1, n = 62) or DLI that were reused (group 2, n = 63) after high-level disinfection by alkalinized 2% glutaraldehyde. Operative and postoperative outcomes were investigated.

RESULTS

There was no significant difference between group 1 and group 2 in mean operating time, linear analogue pain scale score, duration and amount of analgesic administration, or hospital stay. Total incidence of complications (3.2% vs 4.8%, p = 0.50) and infection rates (1.6% vs 3.2%, p = 0.57) were also similar when group 1 was compared to group 2.

CONCLUSION

This study showed that reusing DLI did not change the operative and postoperative outcomes or the infection rate for laparoscopic cholecystectomy when strict rules for disinfection were followed.

Infection control

Information resources from a variety of governmental agencies and professional organizations are available to facilitate development of site-specific infection control programs. Using a strategic approach to organize and apply the information can result in a comprehensive and effective infection control program.

Efficacy of some neutralizers in suspension tests determining the activity of disinfectants

The ability of six mixtures to neutralize glutaraldehyde, o-phthalaldehyde and peracetic acid was tested using four reference strains: Pseudomonas aeruginosa CIP A22, Escherichia coli CIP 54127, Staphylococcus aureus CIP 53154, and Enterococcus faecium CIP 5855. Glutaraldehyde was the hardest to neutralize, and peracetic acid the easiest. The most effective mixture was Tween 80 with sodium bisulphate, sodium thioglycolate, lecithin and cysteine, and the least effective was Tween 80, lecithin and histidine. The efficacy of the neutralizers may indicate a propensity loss of activity from interfering substances when disinfectants are used in practice.

Multi-society guideline for reprocessing flexible gastrointestinal endoscopes. Society for Healthcare Epidemiology of America

Flexible gastrointestinal endoscopy is a valuable diagnostic and therapeutic tool for the care of patients with gastrointestinal and pancreaticobiliary disorders. Compliance with accepted guidelines for the reprocessing of gastrointestinal endoscopes between patients is critical to the safety and success of their use. When these guidelines are followed, pathogen transmission can be effectively prevented. Increased efforts and resources should be directed to improve compliance with these guidelines. Further research in the area of gastrointestinal endoscope reprocessing should be encouraged. The organizations that endorsed this guideline are committed to assisting the FDA and manufacturers in addressing critical infection control issues in gastrointestinal device reprocessing.

SHEA guideline for preventing nosocomial transmission of multidrug-resistant strains of Staphylococcus aureus and enterococcus

BACKGROUND

Infection control programs were created three decades ago to control antibiotic-resistant healthcare-associated infections, but there has been little evidence of control in most facilities. After long, steady increases of MRSA and VRE infections in NNIS System hospitals, the Society for Healthcare Epidemiology of America (SHEA) Board of Directors made reducing antibiotic-resistant infections a strategic SHEA goal in January 2000. After 2 more years without improvement, a SHEA task force was appointed to draft this evidence-based guideline on preventing nosocomial transmission of such pathogens, focusing on the two considered most out of control: MRSA and VRE.

METHODS

Medline searches were conducted spanning 1966 to 2002. Pertinent abstracts of unpublished studies providing sufficient data were included.

RESULTS

Frequent antibiotic therapy in healthcare settings provides a selective advantage for resistant flora, but patients with MRSA or VRE usually acquire it via spread. The CDC has long-recommended contact precautions for patients colonized or infected with such pathogens. Most facilities have required this as policy, but have not actively identified colonized patients with surveillance cultures, leaving most colonized patients undetected and unisolated. Many studies have shown control of endemic and/or epidemic MRSA and VRE infections using surveillance cultures and contact precautions, demonstrating consistency of evidence, high strength of association, reversibility, a dose gradient, and specificity for control with this approach. Adjunctive control measures are also discussed.

CONCLUSION

Active surveillance cultures are essential to identify the reservoir for spread of MRSA and VRE infections and make control possible using the CDC's long-recommended contact precautions.

The effect of mechanical cleaning and thermal disinfection on light intensity provided by fibrelight Macintosh laryngoscopes

The increased use of thermal decontamination procedures for fibrelight laryngoscope blades, to comply with international guidelines, will have considerable economical effects. We evaluated the effect of mechanical cleaning plus thermal disinfection at 90 degrees C, with or without subsequent steam sterilisation at 134 degrees C, on light intensity provided by fibrelight laryngoscopes. After mounting the blades in a special frame with a built-in light source, light intensity was measured using radiometer/photometer. In total, 14 blades provided by 11 companies were tested. The majority of fibrelight laryngoscope blades were fairly resistant to the damaging effects of machine washing plus disinfection at 90 degrees C (mean [range] reduction in light intensity 34.6%[2.1-78.3%]). However, when exposed to an additional sterilisation procedure at 134 degrees C, the majority of blades were unable to withstand the combined treatment for 300 cycles (mean [range] reduction in light intensity 86.5%[32.0-98.7%]). This study stresses the need for fibrelight laryngoscope blades which are more resistant to thermal decontamination procedures than those available at present.

Infection control during gastrointestinal endoscopy

Infection-control issues during gastrointestinal endoscopy, which are becoming increasingly important, can generally be divided into three major areas: (1) infectious complications resulting from a patient's own microbial flora (autologous), (2) infections transmitted from patient to patient by way of the endoscope (exogenous), and (3) infections transmitted between the patient and the health-care provider. The mean frequency of postprocedure bacteremia ranges from 0.5% for flexible sigmoidoscopy to 2.2% for colonoscopy, 4.2% for esophagogastroduodenoscopy, 8.9% for variceal ligation, 11% for endoscopic retrograde cholangiopancreatography, 15.4% for variceal sclerotherapy, and 22.8% for esophageal dilation. Although postprocedure bacteremia is not uncommon, it seldom results in infectious complications. Exogenous infections transmitted during endoscopy, which are extremely rare, generally result from failure to follow accepted guidelines for the cleaning and disinfection of gastrointestinal endoscopes, underscoring the importance of meticulous attention to endoscope reprocessing. Finally, although the risk of patient-staff transmission of infection is also rare, standard infection-control recommendations are important in protecting both patients and health-care providers.