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Sterilization of implantable medical devices is of most importance to avoid surgery related complications such as infection and rejection. Advances in biotechnology fields, such as tissue engineering, have led to the development of more sophisticated and complex biomedical devices that are often composed of natural biomaterials. This complexity poses a challenge to current sterilization techniques which frequently damage materials upon sterilization. The need for an effective alternative has driven research on supercritical carbon dioxide (scCO 2 ) technology. This technology is characterized by using low temperatures and for being inert and non-toxic. The herein presented paper reviews the most relevant studies over the last 15 years which cover the use of scCO 2 for sterilization and in which effective terminal sterilization is reported. The major topics discussed here are: microorganisms effectively sterilized by scCO 2 , inactivation mechanisms, operating parameters, materials sterilized by scCO 2 and major requirements for validation of such technique according to medical devices' standards., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Allogeneic hematopoietic cell transplantation (HCT) is part of the standard of care for many hematological diseases. Over the last decades, significant advances in patient and donor selection, conditioning regimens as well as supportive care of patients undergoing allogeneic HCT leading to improved overall survival have been made. In view of many new treatment options in cellular and molecular targeted therapies, the place of allogeneic transplantation in therapy concepts must be reviewed. Most aspects of HCT are well standardized by national guidelines or laws as well as by certification labels such as FACT-JACIE. However, the requirements for human resources, construction and layout of a unit treating patients during the transplantation procedure and for different complications are not well defined. Here, we describe the process of planning a transplant unit in order to open a discussion that could lead to more precise guidelines in the field of personnel and infrastructural requirements for hospitals caring for people with severe immunosuppression., (Copyright © 2018 Société Française du Cancer. Published by Elsevier Masson SAS. All rights reserved.)

Background: The acquisition of reusable surgical instruments (RSIs) through loaner system is a worldwide phenomenon, particularly in orthopaedic surgeries. Loaner sets contain high-complex design RSIs, which are very difficult to clean, and also include single use implants, such as screws, that remain in the surgical tray and are subjected to multiple reprocessing until they are implanted. Inadequate cleaning of SI and various exposures of single-use implants to physical, chemical and biological agents can compromise their quality/safety and promote biofilm formation. The difficulty in cleaning is compounded in middle and low-income countries where automated cleaning infrastructure at sterilizing service units is often unavailable, and thus manual cleaning only is performed. Thus, we aimed to determine the condition of orthopaedic loaned sets when delivered to the hospital, assess the quality of complex-design RSIs reprocessed by manual cleaning, and evaluate the effect of multiple reprocessing on single-use implant (screw)., Methods: Flexible medullary reamers (FMRs), depth gauges and screws used for femur intramedullary nailing, in clinical use for >1 year, were obtained from three Brazilian loaner companies and assessed for residual ATP, protein, bacterial contamination, endotoxin and/or biofilm at delivery at the hospital, following cleaning and steam sterilisation., Results: Before cleaning, blood was visible on a RSIs tray, and RSIs/screws were contaminated with high amounts of ATP, protein and bacteria. Visible soil was released during brushing of a FMR lumen and, following cleaning, the inner layer of 34/40 were visible soiled, and over 5/8 were protein test positive. Following sterilisation, biofilm and soil, including fragments appearing to be bone, were detected by scanning electron microscopy on RSIs/screws. A sterilised FMR revealed visible soil on the inner layer. Endotoxin tests were negative., Conclusion: The contaminated condition of loaned-complex-designed RSIs/screws upon arrival at the hospital and after reprocessing points to the insufficiency of manual reprocessing and management practices related to this instruments/implants. A multidisciplinary approach involving expert in design/manufacture, regulating, managing, reprocessing and surgeons is suggested to improve RSIs manufacture that enables complete decontamination and maintain the surgical patient safety., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Background: Our objective is to show the effect that standardization of surgical trays has on the number of instruments sterilized and on cost., Methods: We reviewed our most commonly used surgical trays with the 3 general thoracic surgeons in our division and agreed upon the least number of surgical instruments needed for mediastinoscopy, video-assisted thoracoscopic surgery, robotic thoracic surgery, and thoracotomy., Results: We removed 59 of 79 instruments (75%) from the mediastinoscopy tray, 45 of 73 (62%) from the video-assisted thoracoscopic surgery tray, 51 of 84 (61%) from the robotic tray, and 50 of 113 (44%) from the thoracotomy tray. From January 2016 to December 2016, the estimated savings by procedure were video-assisted thoracoscopic surgery (n = 398) $21,890, robotic tray (n = 231) $19,400, thoracotomy (n = 163) $15,648, and mediastinoscopy (n = 162) $12,474. Estimated total savings were $69,412. The weight of the trays was reduced 70%, and the nonsteamed sterilization rate (opened trays that needed to be reprocessed) decreased from 2% to 0%. None of the surgeons requested any of the removed instruments., Conclusions: Standardization of thoracic surgical trays is possible despite having multiple thoracic surgeons. This process of lean (the removal of nonvalue steps or equipment) reduces the number of instruments cleaned and carried and reduces cost. It may also reduce the incidence of "wet loads" that require the resterilization of instruments., (Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Study Objective: To describe the type and quantity of bacteria found intraoperatively on the abdomen, vagina, surgical gloves, instrument tips, and uterus at distinct time points during total laparoscopic hysterectomy (TLH)., Design: Observational study (Canadian Task Force classification III)., Setting: Academic affiliated hospital., Patients: Thirty-one women undergoing TLH for benign indications in 2016., Interventions: After antibiotic prophylaxis and chlorhexidine preparation, swabs were collected from the vaginal fornices and abdomen. During subsequent TLH, additional swabs were collected from the following sites: surgeon's gloves after placement of the uterine manipulator, tips of instruments used to close the vaginal cuff, uterine fundus after extraction, and surgeon's gloves after removal of the uterus. A calibrated loop was used to inoculate each specimen onto 5% blood and chocolate agars for growth of aerobes and onto Brucella blood, phenylethyl alcohol, kanamycin vancomycin, and Bacteroides bile esculin agars for growth of anaerobes. Manual colony counts were tabulated for all positive cultures and reported in colony-forming units per milliliter (CFU/mL)., Measurements and Main Results: Anaerobic growth was not seen on the instrument tips, in the vagina, or on the abdomen of any patient. Aerobic bacterial growth was not seen in the vagina of any patient. On the surgeon's gloves after uterine manipulator placement, no patients demonstrated sufficient bacterial growth to potentially cause surgical site infection (≥5000 CFU/mL). On the surgeon's gloves following uterine extraction, 1 patient demonstrated sufficient growth to potentially cause infection. None of the patients developed surgical site infections postoperatively., Conclusion: Cultures from multiple operative sites yielded bacterial growth, but the bacterial concentrations did not exceed the threshold for infection in 98.9% of cultures. Given absent growth from vaginal cultures and rare growth from abdominal cultures, chlorhexidine gluconate 4% is considered an appropriate surgical preparation for use in laparoscopic hysterectomy., (Copyright © 2017 AAGL. Published by Elsevier Inc. All rights reserved.)

Reuse of medical device is accepted worldwide. Benefits of reuse include not only cost saving but a favorable impact on environment. However, certain requirements should be met for reuse to be safe and effective. The devices, which can be reused, should be clearly defined, a meticulous process for dis-infection and sterilization followed and its functionality ascertained before use. Further, an appropriate consent should be obtained where necessary and the cost saving entailed should be directly passed on to the patient., (Copyright © 2017 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.)

Background: Surgical instrument processing is critical to safe, high-quality surgical care but has received little attention in the medical literature. Typical hospitals have inventories in the tens of thousands of surgical instruments organized into thousands of instrument sets. The use of these instruments for multiple procedures per day leads to millions of instrument sets being reprocessed yearly in a single hospital. Errors in the processing of sterile instruments may lead to increased operative times and costs, as well as potentially contributing to surgical infections and perioperative morbidity., Methods: At Virginia Mason Medical Center (Seattle), a quality monitoring approach was developed to identify and categorize errors in sterile instrument processing, through use of a daily defect sheet. Lean methods were used to improve the quality of surgical instrument processing through redefining operator roles, alteration of the workspace, mistake-proofing, quality monitoring, staff training, and continuous feedback. To study the effectiveness of the quality improvement project, a before/after comparison of prospectively collected sterile processing error rates during a 37-month time frame was performed., Results: Before the intervention, instrument processing errors occurred in 3.0% of surgical cases, decreasing to 1.5% at the final follow-up (p < .001). Improvements were observed in multiple categories of error types, particularly the assembly errors of packaging (from 0.66 to 0.24 errors per hundred cases, p = .004), and foreign objects (0.17 to 0.02 errors per hundred cases, p = .025)., Conclusion: Surgical instrument processing errors are a barrier to the highest quality and safety in surgical care but are amenable to substantial improvement using Lean techniques.

Introduction: Orthopaedic surgical treatments emphasizing immobilization using open reduction and internal fixation with osteosynthesis devices are widely accepted for their efficacy in treating complex fractures and reducing permanent musculoskeletal deformity. However, such treatments are profoundly underutilized in low- and middle-income countries (LMIC), partially due to inadequate availability of the costly osteosynthesis devices. Orthopaedic surgeons in some LMIC regularly re-use osteosynthesis devices in an effort to meet treatment demands, even though such devices typically are regulated for single-use only. The purpose of this study is to report a reprocessing protocol applied to explanted osteosynthesis devices obtained at a leading trauma care hospital., Methods: Explanted osteosynthesis devices were identified through a Register of Explanted Orthopaedic Prostheses. Guidelines to handle ethical issues were approved by the local Ethical Committee and informed patient consent was obtained at the time of explant surgery. Primary acceptance criteria were established and applied to osteosynthesis devices explanted between 2005 and 2008. A rigorous protocol for conducting decontamination and visual inspection based on specific screening criteria was implemented using simple equipment that is readily available in LMIC., Results: A total of 2050 osteosynthesis devices, including a large variety of plates, screws and staples, were reprocessed using the decontamination and inspection protocols. The acceptance rate was 66%. Estimated labour time and implementation time of the protocol to reprocess a typical osteosynthesis unit (1 plate and 5 screws) was 25 min, with an estimated fixed cost (in Italy) of €10 per unit for implementing the protocol, plus an additional €5 for final sterilization at the end-user hospital site., Discussion: This study was motivated by the treatment demands encountered by orthopaedic surgeons providing medical treatment in several different LMIC and their need for access to basic osteosynthesis devices. The rigorous decontamination protocol and generalized inspection criteria proved useful for efficiently screening a large volume of devices. Given that re-used osteosynthesis devices can yield satisfactory results, this study addresses potential complications of re-used devices and valid concerns that relate to patient safety. Implementing this defined reprocessing protocol into existing re-use practises in LMIC helps to limit the risks of inadequate sterilization and structural failure without adding additional risks to patients receiving re-used devices., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

A control technique based on Reinforcement Learning is proposed for the thermal sterilization of canned foods. The proposed controller has the objective of ensuring a given degree of sterilization during Heating (by providing a minimum temperature inside the cans during a given time) and then a smooth Cooling, avoiding sudden pressure variations. For this, three automatic control valves are manipulated by the controller: a valve that regulates the admission of steam during Heating, and a valve that regulate the admission of air, together with a bleeder valve, during Cooling. As dynamical models of this kind of processes are too complex and involve many uncertainties, controllers based on learning are proposed. Thus, based on the control objectives and the constraints on input and output variables, the proposed controllers learn the most adequate control actions by looking up a certain matrix that contains the state-action mapping, starting from a preselected state-action space. This state-action matrix is constantly updated based on the performance obtained with the applied control actions. Experimental results at laboratory scale show the advantages of the proposed technique for this kind of processes., (Copyright © 2010 ISA. Published by Elsevier Ltd. All rights reserved.)

Background: Catheter-related bloodstream infection (CRBSI) is a preventable cause of a potentially lethal ICU infection. The optimal method to teach health-care providers correct sterile techniques during central vein catheterization (CVC) remains unclear., Methods: We randomly assigned second- and third-year internal medicine residents trained by a traditional apprenticeship model to simulation-based plus video training or video training alone from December 2007 to January 2008, with a follow-up period to examine CRBSI ending in July 2009. During the follow-up period, a simulation-based training program in sterile techniques during CVC was implemented in the medical ICU (MICU). A surgical ICU (SICU) where no residents received study interventions was used for comparison. The primary outcome measures were median residents' scores in sterile techniques and rates of CRBSI per 1,000 catheter-days., Results: Of the 47 enrolled residents, 24 were randomly assigned to the simulation-based plus video training group and 23 to the video training group. Median baseline scores in both groups were equally poor: 12.5 to 13 (52%-54%) out of maximum score of 24 (P = .95; median difference, 0; 95% CI, 0.2-2.0). After training, median score was significantly higher for the simulation-based plus video training group: 22 (92%) vs 18 (75%) for the video training group (P < .001; median difference, 4; 95% CI, 3-6). During the follow-up period, there was a significantly lower rate of CRBSI in the MICU (1.0 per 1,000 catheter-days) compared with the SICU (3.4 per 1,000 catheter-days) (P = .03). The incidence rate ratio derived from the Poisson regression (0.30; 95% CI, 0.10-0.91) indicated there was a 70% reduction in the incidence of CRBSI in the postintervention MICU compared with the preintervention MICU and the postintervention SICU., Conclusions: Simulation-based training in sterile techniques during CVC is superior to traditional training or video training alone and is associated with decreased rate of CRBSI. Simulation-based training in CVC should be routinely used to reduce iatrogenic risk., Trial Registry: ClinicalTrials.gov; No.: NCT00612131; URL: clinicaltrials.gov.

Background: Traditionally anaesthetic drugs for obstetrics are prepared as a contingency and stored until they are required for emergency use or have expired. Expiry is based on presumed reduction in sterility and efficacy although evidence for this is inconsistent. Preparation in advance introduces the risk of error and potential for tampering by a third party. Discarding and re-preparing drugs daily represents significant wastage with associated cost implications. We predicted that practice of drug preparation would differ widely across the UK, so conducted a national survey., Method: A postal questionnaire was sent to lead consultant obstetric anaesthetists at each of the 223 consultant-led UK obstetric units enquiring about the preparation of anaesthetic drugs for obstetric emergencies., Results: The response rate was 75%; 87% of units routinely draw up emergency drugs, most commonly thiopental and succinylcholine. Only 10% routinely use commercially-prepared succinylcholine syringes, although a further 8% would use them if available. Thiopental is prepared by anaesthetists in 78% of units, operating department practitioners in 8% and pharmacy in <7% of cases. Drugs are changed every 24h in 80% of units and weekly in 6%. With one exception, all units changing drugs weekly use pharmacy-prepared thiopental., Conclusion: The majority of UK obstetric units routinely draw up emergency drugs every 24h. With conflicting evidence regarding sterility and efficacy this represents tremendous wastage and potential for drug error and tampering. We propose that nationwide introduction of commercially- and pharmacy-prepared drugs with long shelf lives would improve safety and cost effectiveness.

Allografts used in orthopedic surgery have steadily increased. With concerns regarding tissue safety and processing, governing entities have increased their regulation. This review articles discusses current testing and processing of allografts as well as the rules of their handling.

Secondary sterilization of musculoskeletal allografts may use chemicals, radiation, or combinations of these. No sterilization techniques have been definitively proven to be more effective than others, and their biomechanical and biological effects on allograft tissue remain largely unknown. The current risk of an allograft infection appears to be much less than the risk of infection surrounding the surgical procedure itself. With appropriate donor screening, improved donor testing--including nucleic acid testing (NAT), and adherence to AATB standards--the risk of disease transmission or infections can be eliminated or substantially decreased.

Purpose: First to audit local adherence to a protocol of use of an alcohol wipe for each tonometry, and secondly to assess current practice nationally in the UK., Method: The audit was carried out at two units: The West Kent Eye Centre at the Princess Royal University Hospital (Orpington, UK) and Queen Mary's Hospital (Sidcup, UK). The standard set for this audit was 100% sterilisation. During a 1-week period in November 2005, the number of alcohol wipes was counted in each consultation room after outpatient clinics, with the doctors being assessed blind to the survey. The number of Goldman applanation tonometry intra-ocular pressures recorded by each clinician was counted by inspection of the medical records of patients seen. Secondly, departments listed in the UK Directory of Training Posts were contacted by telephone and the senior nurse was interviewed. They were asked directly about their department's tonometer prism sterilisation and management., Results: The local audit showed only 54% of tonometry measurements were associated with sterilisation using an alcohol-impregnated wipe. The national survey included 140 of the 152 UK training departments. Thirty-three (23.6%) departments used disposable tonometer prisms routinely. The remaining 107 (76.4%) used non-disposable prisms. Eighty-five (60.7%) departments provided sodium hypochlorite for prism sterilisation, with 69 (81.2%) of these departments providing more than one prism/clinician to allow full exposure to the disinfectant. Twenty-two (15.7%) departments used alcohol wipes. Only 8 (7.5%) of the 107 departments using non-disposable prisms tracked these prisms, despite Royal College of Ophthalmologists guidelines that they should be. These same 8 (7.5%) departments replaced the non-disposable prisms as per manufacturer guidelines. 19.3% of charge nurses were aware of a policy for tonometry in patients with, or at risk of, prion disease., Conclusions: This study highlights that sterilisation of tonometer prisms was inconsistent in a local audit. Nationally, practices were varied. The majority of ophthalmology departments continued to use non-disposable tonometer prisms, but few seemed aware of the Royal College of Ophthalmologists' recommendation that disposable prisms are used in patients at risk of prion disease, and few track tonometer heads or replace them according to manufacturers guidelines. Use of disposable tonometer prisms would seem to reduce concerns about sterilisation, as well as prevent spread of common pathogens.

Stem cells for transplantation are obtained from bone marrow, umbilical cord blood, and peripheral blood. A rare complication of hematopoietic stem cell transplantation is donor cell-derived leukemia (DCL). The donors remain cancer free and the causes of these DCL are unknown. Stem cells must repopulate the bone marrow and then give rise to all hematopoietic cells for the rest of the transplant recipient's life. No procedure is acceptable that might introduce precancerous or cancerous mutations in cells performing such a critical function. Medical disposable sets consisting of bags, tubing sets and freezing containers are used to collect, purify and store stem cells. Sterilization of disposables with ethylene oxide is widespread, even though those sets unavoidably retain residual amounts of ethylene oxide which is a potent, direct-acting mutagen and clastogen that has been demonstrated to induce hematopoietic cancer in mice, rats and human beings. Potential exposure levels to ethylene oxide during processing under proposed US FDA guidelines for residual ethylene oxide would be biologically active and present a significant risk factor for DCL. For direct-acting mutagens, there is no recognized "no effect" dose using currently accepted cancer risk assessment models. The safety concerns with ethylene oxide can be eliminated by the use of alternative technologies including electron beam, gamma irradiation, or steam for the sterilization of all products used for stem cell processing and storage.

Until the establishment of the PREM Bank (Perron Rotary Express Milk Bank) donor human milk banking had not occurred in Australia for the past 20 years. In re-establishing donor human milk banking in Australia, the focus of the PREM Bank has been to develop a formal and consistent approach to safety and quality in processing during the operation of the human milk bank. There is currently no existing legislation in Australia that specifically regulates the operation of donor human milk banks. For this reason the PREM Bank has utilised existing and internationally recognised management practices for managing hazards during food production. These tools (specifically HACCP) have been used to guide the development of Standard Operating Procedures and Good Manufacturing Practice for the screening of donors and processing of donor human milk. Donor screening procedures are consistent with those recommended by other human milk banks operating internationally, and also consistent with the requirements for blood and tissue donation in Australia. Controlled documentation and record keep requirements have also been developed that allow complete traceability from individual donation to individual feed dispensed to recipient and maintain a record of all processing and storage conditions. These operational requirements have been developed to reduce any risk associated with feeding pasteurised donor human milk to hospitalised preterm or ill infants to acceptable levels.

Understanding how cells sense their environment and are able to regulate their metabolism is of great importance for the success of biomaterials implantation. Self assembled monolayers (SAMs) are in use nowadays to model the surface of such materials. They permit the control of different surface parameters (like chemistry, surface energy and topography) enabling to get a greater insight in cells behaviour when interacting with surfaces and thus, in the future, to enhance surface properties of biomaterials. As sterilisation is the compulsory step for in vitro and in vivo assays with living biological materials, it is important to know how SAMs react under sterilisation techniques in use on biomaterials. In this work, the effect of three types of sterilisation techniques: gamma-irradiation, mostly used on biomaterials, dry heat and steam autoclaving, have been investigated on NH2 and CH3 terminated SAMs. Gamma-irradiation destructs drastically the NH2 and partially the CH3 monolayers by producing oxidative compounds (COOH, C=O, C-OH). The main product induced by gamma-irradiation on NH2 monolayers is carboxylic acid, whereas CH3 shows an important increase in the amount of alcoholic groups. This difference in deterioration is assumed to be due to the higher stability of the CH3 monolayer. Steam autoclaving to a lesser extent gives the same results on NH2 monolayers. Dry heat seems to be the most reliable technique, which can be used on such surfaces as it removes physically adsorbed organic contaminants without affecting the integrity of the surface.

Sterilisation of fermentation media, inlet and outlet gases and maintenance of aseptic conditions during bioprocessing represents one of the most relevant parts of comprehensive upstream processing. The present chapter reviews various sterilisation techniques and methods for sterilisation of inlet gases, liquids, including sterilisation of small and large industrial equipment and validation of sterilisation procedures. Various methods for sterilisation using different kinds of filters, filter cartridges and membrane filters are also presented. Liquid sterilisation methods by filtration as well as heat sterilisation are discussed. Sterilisation of small and industrial scale equipment by chemical agents and physical methods as ionising radiation and dry heat sterilisation including the validation of sterilisation are discussed.

Background: It has been recommended that bronchoscopists familiarize themselves with national recommendations for bronchoscope reprocessing practices, but the extent of guideline awareness is unclear., Methods: We distributed a survey to practicing bronchoscopists at two meetings. Questions addressed infection control issues related to bronchoscopy and specific reprocessing recommendations., Results: A total of 46 surveys were completed by medical directors of bronchoscopy suites (26%) and attending bronchoscopists (74%) who had graduated from medical school a median of 22 years ago and performed a median of 19 procedures per month. Sixty-five percent of respondents, including 55% of directors, were not familiar with national reprocessing recommendations, and 39% did not know the approach to reprocessing at their own institution. Respondents who did > 20 procedures per month trended toward being more likely to be aware of guidelines (54% vs 26%, p = 0.09) and were less likely to answer "do not know" to more than one question about specific reprocessing details (25% vs 70%, p = 0.003). Seventy-eight percent of respondents did not know local practices for at least one of the reprocessing details. Forty-six percent of respondents stated their institutions followed recommendations that records be kept of the specific bronchoscope used in each case., Conclusions: Many experienced bronchoscopists are unfamiliar with national guidelines and local practices related to bronchoscope reprocessing. Publication of bronchoscope-specific, comprehensive reprocessing guidelines in the pulmonary literature may help increase familiarity with this crucial process.

Background: Although widely used, commercially available automated culture methods are not US Food and Drug Administration-approved for sterility testing of cell-therapy products. For cell-therapy products regulated under Section 351 of the Public Health Service Act, sterility testing must be performed by the methods described in 21 CFR 610.12 and USP <71> (CFR/USP method), or by methods demonstrated to be equivalent., Methods: Two automated methods, BacT/Alert (BTA; bioMerieux) and Bactec (Becton Dickinson), were compared with the CFR/USP method. Representative mononuclear cell (MNC) products were formulated using six different product media. MNC product aliquots containing 10-50 x 10(6) cells in a 0.5 mL volume were seeded with organisms, and cultured for 14 days in aerobic and anaerobic bottles of each system. Ten different organisms at target concentrations of 10 and 50 colony-forming units (CFU) per bottle were tested., Results: Positives were detected in a mean (range) of 72% (7-100%) of cultures for CFR/USP, 82% (0-100%) for BTA, and 93% (57-100%) for Bactec. For nine of the 10 organisms tested, overall detection rates for BTA and Bactec were equivalent to or higher than CFR/USP. Of the six product media tested, detection of organisms was impaired only by the medium containing multiple antibiotics: this occurred in all three systems. Both BTA and Bactec had shorter times to detection than the CFR/USP method, with overall means (ranges) of 87 (24-264) h for CFR/USP, 24 (12-54) h for BTA, and 33 (12-80) h for Bactec. Detection occurred consistently within 7 days for both BTA and Bactec, but not for CFR/USP., Discussion: Both BTA and Bactec are superior to the CFR/USP method for overall detection and time to detection of organisms in MNC products suspended in commonly used media. These data support general use of either BTA or Bactec for sterility testing of a variety of cell-therapy products, and suggest that a 7-day culture period is sufficient to detect clinically relevant organisms. These results confirm the need for bacteriostasis and fungistasis testing of antibiotic-containing products, even when antibiotic-binding substances are used.

Spores of Bacillus subtilis ATCC 6051 and Bacillus stearothermophilus NCTC 10003 were immobilized in monodisperse alginate beads (diameter, 550 microm +/- 5%), and the capacity of the immobilized bioindicators to provide accurate and reliable F-values for sterilization processes was studied. The resistance of the beads to abrasion and heat was strong enough to ensure total retention of the bioindicators in the beads in a sterilization cycle. D- and z-values for free spores were identical to those for immobilized spores, which shows that immobilization does not modify the thermal resistance of the bioindicators. A D(100 degrees C) value of 1.5 min was found for free and immobilized B. subtilis spores heated in demineralized water, skimmed milk, and milk containing 4% fat, suggesting that a lipid concentration as low as 4% does not alter the thermal resistance of B. subtilis spores. Providing that the pH range is kept between 3.4 to 10 and that sufficiently low concentrations of Ca2+ competitors or complexants are present in the medium, immobilized bioindicators may serve as an efficient, accurate, and reliable tool with which to validate the efficiency of any sterilization process. The environmental factors (pH, media composition) affecting the thermoresistance of native contaminants are intrinsically reflected in the F-value, allowing for a sharper adjustment of the sterilization process. Immobilized spores of B. stearothermophilus were successfully used to validate a resonance and interference microwave system that is believed to offer a convenient alternative for the sterilization of temperature-sensitive products and medical wastes.

In this study the decontamination procedures of laryngoscopes in Dutch hospitals are described, based on a structured telephone questionnaire. There were substantial differences between decontamination procedures in Dutch hospitals and the standards of the APIC (Association of Professionals in Infection Control and Epidemiology), CDC (Centers of Disease Control) and ASA (American Society of Anesthesiology) were met in full in 19.4% of the hospitals. The standards of manual decontamination, used in 78% of the 139 hospitals, were particularly disappointing; manual cleaning was considered inadequate in 22.9% of these hospitals and manual disinfection did not meet the standards of the APIC, CDC or ASA in any of these hospitals. Decontamination by instrument cleaning machines as a standard procedure was used in 30 (22%) hospitals. In three of these hospitals the blades were subsequently sterilized. We suggest adherence to the infection control guidelines of the CDC, APIC and ASA, until the safety of less conservative infection control practices are demonstrated.

The purpose of this study is to determine whether prepared epidural solutions remain sterile when refrigerated prior to use. The sterility of all epidural solutions prepared by an outpatient pharmacy of a tertiary level cancer facility was tested both at the time of preparation and after 14 days of refrigeration. Over a seven-month interval, we found no incidence of epidural solution colonization in 84 submitted samples prepared for four patients. All four patients had good relief of pain with ambulatory epidural infusion, and none developed clinical evidence of infection. We conclude that selected ambulatory patients with severe cancer pain, who are managed in the home environment with permanent epidural catheters, can use preservative-free epidural solutions that have been prepared with the sterile technique and stored in a standard domestic refrigerator for up to 14 days.

Using the Food and Drug Administration's protocol for testing health care sterilizers, the author investigated the ability of chemical vapor and steam to sterilize handpieces. Five internal sites of six high-speed handpiece models and four internal positions of one low-speed handpiece model were each inoculated with 10(6) Bacillus stearothermophilus spores. Half-cycle challenges were conducted with Chemiclave models EC 5500 and 8000 (Barnstead/Thermolyne) and with two autoclaves, Tuttnauer 2540M (large chamber) (Tuttnauer USA Co., Ltd.) and Statim Cassette (SciCan USA). Experiments with spores either openly exposed or partially enclosed prove that chemical vapor is an excellent lethal agent, but strongly suggest penetration weakness [corrected].

There is increasing interest amongst general practitioners in carrying out minor surgical procedures but it is unclear what resources are available for this. We decided to assess the level of knowledge of sterilization and the use of benchtop sterilisers in general practice by circulating a postal questionnaire to the 883 general practices in the Trent Regional Health Authority. The response rate was 49%. Minor surgical procedures were performed in 86% of practices but less than half of respondents understood what was meant by sterilization, 28% considered that the floor of the surgery should be disinfected or sterilised and 13% believed that immersion in 2% glutaraldehyde for 10 min constituted sterilization. 93% had a benchtop steriliser, only a quarter kept a log book, and approximately a third had it serviced at intervals of one year or longer. Less than 50% understood the correct position in which a bowl or kidney dish should be placed and 41% had used or had access to a local sterile services department. The concept of sterilization is not clearly understood and the use of benchtop sterilisers in Trent is suboptimal. On-going education of staff in primary care is required and consideration should be given to a system of accreditation.

The epidemiology of AIDS in Africa is discussed. Serological and clinical data on virology and population genetics are related to current theories of heterosexual transmission and to cultural practices involving the exchange or transmission of body fluids between individuals, such as female and male genital mutilation and indigenous or 'folk' medicine, as well as non-Western medical uses of medical syringes. A review of the relationship of autoimmune conditions, graft-vs-host disease and the retrovirus/oncogene involvement is presented. These data place in a new perspective concepts of widespread heterosexual infection and transmission of HIVs as well as their relation to AIDS in the context of the evolution of the human immune system.

Under existing COSPAR policy adopted in 1984, missions to Mars (landers, probes, and some orbiters) are designated as Category IV missions. As such, the procedures for implementing planetary protection requirements could include trajectory biasing, cleanrooms, bioload reduction, sterilization of hardware, and bioshields. In 1992, a U.S. National Research Council study recommended that controls on forward contamination of Mars be tied to specific mission objectives. The report recommended that Mars landers with life detection instruments be subject to at least Viking-level sterilization procedures for bioload reduction, while spacecraft (including orbiters) without life detection instruments be subject to at least Viking-level pre-sterilization procedures for bioload reduction but need not be sterilized. In light of this, it is proposed that the current policy's Category IV and its planetary protection requirements be divided into two sub-categories as follows: Category IVa, for missions comprising landers and probes without life detection experiments, which will meet a specified bioburden limit for exposed surfaces, and Category IVb, for landers and probes with life detection experiments, which will require sterilization of landed systems. In addition, Category III orbiter mission specifications are expanded to be consistent with these recommendations.

Over the last several years, the nature of the surface conditions on the planet Mars, our knowledge of the growth capabilities of Earth organisms under extreme conditions, and future opportunities for Mars exploration have been under extensive review in the United States and elsewhere. As part of these examinations, in 1992 the US Space Studies Board made a series of recommendations to NASA on the requirements that should be implemented on future missions that will explore Mars. In particular, significant changes were recommended in the requirements for Mars landers, changes that significantly alleviated the burden of planetary protection implementation for these missions. In this paper we propose a resolution implementing this new set of recommendations, for adoption by COSPAR at its 30th meeting in Hamburg. We also discuss future directions and study areas for planetary protection, in light of changing plans for Mars exploration.

Two tasks must be accomplished to provide planetary protection for Mars return missions: (1) sterilization of the scientific module to be landed on Mars and (2) reliable sterilization of all material returned to Earth, while ensuring the scientific integrity of martian samples. This paper examines similarity and differences between these two tasks, and includes a discussion of technological implementation conditions and the nature of terrestrial and hypothesized martian microflora. The feasibility of a number of chemical and physical (ultraviolet and ionizing radiation and heating) methods of sterilization for use on the ground and onboard are discussed and compared. A combination of different methods will probably be selected as the most appropriate for ensuring planetary protection on the return mission.

An interlaboratory comparison of two extraction methods and one thermal desorption test method for the quantification of ethylene oxide (EO) by gas chromatography in two common medical device materials, high density polyethylene (HDPE) and plasticized polyvinyl chloride (PVC), was conducted by 15 laboratories. The three procedures included extraction with water, extraction with acetone, and headspace gas analysis, respectively. Materials were processed through an industrial EO cycle and aerated for various periods to achieve target levels of a low (5 micrograms/g), medium (10 micrograms/g), and high (25 micrograms/g) residual determination following extraction or thermal desorption. The results of this study, using only the data from the laboratories that did not deviate from the procedure, showed that the average estimated total coefficient of variation ranged from 3.63 to 12.42% for the three different methods. Each of the methods is suitable for use as a reference test method for determining residual EO in polymeric materials in the concentration range 2.8-42.3 micrograms/g.

The paper discusses the use of ozone in space applications for the elimination of pathogens, and the enhancement of the oxidation potential of ozone using hydrogen peroxide and ultraviolet radiation. These combinations will be possible to set up in space conditions. The sterilizing effect versus free radical generation is an important equilibrium to establish when specific pathogen free conditions are wanted in aqueous solutions containing organic matter. In situ sterilization of plant roots in hydroponic systems, as well as the oxidation of root exudates, will be discussed. The paper will contain examples of the chemical interaction of ozone with some of the other compounds found in hydroponic systems.

Achieving maximum equipment sterilization is critical. Factors that contribute to sterilization efficiency are covered, including sterilization accuracy level, chamber loading and biological indicators.

A primary scientific theme for the Space Exploration Initiative (SEI) is the search for life, extant or extinct, on Mars. Because of this, concerns about Planetary Protection (PP), the prevention of biological cross-contamination between Earth and other planets during solar system exploration missions, have arisen. A recent workshop assessed the necessity for, and impact of, PP requirements on the unmanned and human missions to Mars comprising the SEI. The following ground-rules were adopted: 1) information needed for assessing PP issues must be obtained during the unmanned precursor mission phase prior to human landings; 2) returned Mars samples will be considered biologically hazardous until proven otherwise; 3) deposition of microbes on Mars and exposure of the crew to Martian materials are inevitable when humans land; and, 4) human landings are unlikely until it is demonstrated that there is no harmful effect of Martian materials on terrestrial life forms. These ground-rules dictated the development of a conservative PP strategy for precursor missions. Key features of the proposed strategy include: 1) for prevention of forward contamination, all orbiters will follow Mars Observer PP procedures for assembly, trajectory, and lifetime. All landers will follow Viking PP procedures for assembly, microbial load reduction, and bioshield; and, 2) for prevention of back contamination, all sample return missions will have PP requirements which include fail-safe sample sealing, breaking contact chain with the Martian surface, and containment and quarantine analysis in an Earth-based lab. In addition to deliberating on scientific and technical issues, the workshop made several recommendations for dealing with forward and back contamination concerns from non-scientific perspectives.

In a double-blind study the fiberoptic bronchoscope was contaminated with five pathogenic organisms, each at a concentration of 10(9) organisms per milliliter. The shaft and inner channel of the bronchoscope were cleansed with five antiseptic regimens. Each regimen included equal 120-ml aliquots of one, two, or three solutions, respectively. The five different regimens were as follows: (1) physiologic saline solution; (2) 70 percent solution of isopropyl alcohol, followed by physiologic saline solution; (3) alkaline glutaraldehyde, followed by 70 percent solution of isoproply alcohol, followed by physiologic saline solution; (4) benzalkonium chloride, followed by 70 percent isopropyl alcohol, followed by physiologic saline solution; and (5) povidone-iodine solution, followed by 70 percent solution of isopropyl alcohol, followed by physiologic saline solution. The four regimens involving solutions other than saline solution alone were effective in reducing the count of residual bacterial colonies to 10(4) colonies per milliliter or less.

Between January, 1979, and January, 1980, hepatitis B developed in three women within 6 months of their undergoing gynaecological surgery at a community hospital in Mississippi. Subsequent investigation revealed another case of hepatitis B associated with gynaecological surgery. The gynaecologist who carried out all four operations (gynaecologist A) was a chronic carrier of hepatitis B. Hepatitis B surface antigen subtyping on serum from gynaecologist A and from one of the hepatitis B patients gave identical results. Patients of gynaecologist A who underwent total abdominal hysterectomies or bilateral salpingo-oophorectomies were at a greater risk of acquiring hepatitis B than were patients in whom the same procedures were carried out by a control group of gynaecologists. After gynaecologist A modified his surgical technique and began wearing two pairs of gloves during surgery, there was no further hepatitis B transmission to his surgical patients.

The value of adding chlorhexidine to urine drainage bags of male patients treated with indwelling catheters after prostatectomy and other transurethral operations was assessed in a randomised, prospective, controlled was assessed in a randomised, prospective, controlled study. Chlorhexidine kept the contents of all drainage bags sterile, but the frequency of urinary infection in the chlordexidine group (51%) did not differ significantly from that in the control group (45%). Most infections were endogenous, caused by organisms which probably came from the patient's own urethra. It was concluded that the method has no value in urology units where standards of catheter care and closed drainage are properly maintained. Controlled studies in other types of catheterised patients are needed, especially when the risks of cross-infection are high.