Anatomical three-dimensional model with peri-implant defect for in vitro assessment of dental implant decontamination.

OBJECTIVES: Access to the implant surface plays a significant role in effective mechanical biofilm removal in peri-implantitis treatment. Mechanical decontamination may also alter the surface topography of the implant, potentially increasing susceptibility to bacterial recolonization. This in vitro study aimed to evaluate a newly developed, anatomically realistic, and adaptable three-dimensional (3D)printed model with a peri-implant bone defect to evaluate the accessibility and changes of dental implant surfaces after mechanical decontamination treatment. MATERIAL AND METHODS: A split model of an advanced peri-implant bone defect was prepared using 3D printing. The function of the model was tested by mechanical decontamination of the exposed surface of dental implants (Standard Implant Straumann AG) coated with a thin layer of colored occlusion spray. Two different instruments for mechanical decontamination were used. Following decontamination, the implants were removed from the split model and photographed. Image analysis and fluorescence spectroscopy were used to quantify the remaining occlusion spray both in terms of area and total amount, while scanning electron microscopy and optical profilometry were used to analyze alteration in the implant surface morphology. RESULTS: The 3D model allowed easy placement and removal of the dental implants without disturbing the implant surfaces. Qualitative and quantitative assessment of removal of the occlusion spray revealed differences in the mechanism of action and access to the implant surface between tested instruments. The model permitted surface topography analysis following the decontamination procedure. CONCLUSION: The developed 3D model allowed a realistic simulation of decontamination of implant surfaces with colored occlusion spray in an advanced peri-implant defect. 3D printing allows easy adaptation of the model in terms of the shape and location of the defect. The model presents a valuable tool for in vitro investigation of the accessibility and changes of the implant surface after mechanical and chemical decontamination.

Effectiveness of a low-cost UVGI chamber for decontaminating filtering facepiece respirators to extend reuse.

In emergencies like the COVID-19 pandemic, the reuse or reprocessing of filtering facepiece respirators (FFRs) may be required to mitigate exposure risk. Research gap: Only a few studies evaluated decontamination effectiveness against SARS-CoV-2 that are practical for low-resource settings. This study aimed to determine the effectiveness of a relatively inexpensive ultraviolet germicidal irradiation chamber to decontaminate FFRs contaminated with SARS-CoV-2. A custom-designed UVGI chamber was constructed to determine the ability to decontaminate seven FFR models including N95s, KN95, and FFP2s inoculated with SARS-CoV-2. Vflex was excluded due to design folds/pleats and UVGI shadowing inside the chamber. Structural and functional integrity tolerated by each FFR model on repeated decontamination cycles was assessed. Twenty-seven participants were fit-tested over 30 cycles for each model and passed if the fit factor was ≥100. Of the FFR models included for testing, only the KN95 model failed filtration. The 3M™ 3M 1860 and Halyard™ duckbill 46727 (formerly Kimberly Clark) models performed better on fit testing than other models for both pre-and-post decontaminations. Fewer participants (0.3 and 0.7%, respectively) passed fit testing for Makrite 9500 N95 and Greenline 5200 FFP2 and only two for the KN95 model post decontamination. Fit testing appeared to be more affected by donning & doffing, as some passed with adjustment and repeat fit testing. A ≥ 3 log reduction of SARS-CoV-2 was achieved for worn-in FFRs namely Greenline 5200 FFP2. Conclusion: The study showed that not all FFRs tested could withstand 30 cycles of UVGI decontamination without diminishing filtration efficiency or facial fit. In addition, SARS-CoV-2 log reduction varied across the FFRs, implying that the decontamination efficacy largely depends on the decontamination protocol and selection of FFRs. We demonstrated the effectiveness of a low-cost and scalable decontamination method for SARS-CoV-2 and the effect on fit testing using people instead of manikins. It is recognized that extensive experimental evidence for the reuse of decontaminated FFRs is lacking, and thus this study would be relevant and of interest in crisis-capacity settings, particularly in low-resource facilities.

Sensitive microscopic quantification of surface-bound prion infectivity for the assessment of surgical instrument decontamination procedures.

BACKGROUND: Pathogenic prions (PrPSc) are amyloid-rich hydrophobic proteins which bind avidly to surgical surfaces and represent some of the most difficult targets during the reprocessing of reusable surgical instruments. In-vitro methods to amplify and detect the presence of otherwise undetectable prion contamination are available, but they do not measure associated infectivity. Most of these methods rely on the use of proteinase K, however this can lead to the loss of a substantial portion of PrPSc, potentially producing false negatives. AIM: To develop a sensitive in-situ method without proteinase treatment for the dynamic quantification of amyloid accumulation in N2a #58 cells following 22L-prion infection from infected tissues and spiked stainless-steel surfaces. METHODS: We spiked cultures of N2a #58 cells with the 22L prion strain in solution or dried on stainless-steel wires and directly measured the accumulation of prion amyloid aggregates over several passages using highly sensitive fluorescence microscopy. FINDINGS: We demonstrated a 10-log dynamic range using our method to test residual prion infectivity, that was validated to show variable decontamination efficacy against prions from commercially available cleaning chemistries. CONCLUSIONS: The new cell-based infectivity method presented here avoids partial or possibly total proteinase K digestion of PrPSc in samples for greater sensitivity, in addition to low cost, no ethical concerns, and adaptability to detect different prion strains. This method can be used to test cleaning chemistries' efficacy with greater sensitivity than measuring total residual proteins, which may not correlate with residual prion infectivity.

Efficacy of hydrogen peroxide wipes for decontamination of AZD1222 adenovirus COVID-19 vaccine strain on pharmaceutical industry materials.

This study aimed to evaluate the performance of accelerated hydrogen peroxide® wipes (HPW) for decontamination of the chimpanzee adenovirus AZD1222 vaccine strain used in the production of recombinant COVID-19 vaccine in a pharmaceutical industry. Two matrices were tested on stainless-steel (SS) and low-density-polyethylene (LDP) surfaces: formulated recombinant COVID-19 vaccine (FCV) and active pharmaceutical ingredient (API). The samples were spiked, dried and the initial inoculum, possible residue effect (RE) and titre reduction after disinfection with HPW were determined. No RE was observed. The disinfection procedure with HPW resulted in complete decontamination the of AZD1222 adenovirus strain in FCV (≥7·46 and ≥7·49 log10 infectious unit [IFU] ml-1 for SS and LDP carriers respectively) and API (≥8·79 and ≥8·78 log10 IFU ml-1 for SS and LDP carriers respectively). In conclusion, virucidal activity of HPW was satisfactory against the AZD1222 adenovirus strain and can be a good option for disinfection processes of SS and LPD surfaces in pharmaceutical industry facilities during recombinant COVID-19 vaccine production. This procedure is simple and can be also applied on safety unit cabins and sampling bags made of LDP as well.

Assessment of a novel, easy-to-implement, aerosolized H2O2 decontamination method for single-use filtering facepiece respirators in case of shortage.

The COVID-19 pandemic has affected the world and caused a supply shortage of personal protection equipment, especially filtering facepiece respirators (FFP). This has increased the risk of many healthcare workers contracting SARS-CoV-2. Various strategies have been assessed to tackle these supply issues. In critical shortage scenarios, reusing single-use-designed respirators may be required. Thus, an easily applicable and reliable FFP2 (or alike) respirator decontamination method, allowing safe re-use of FFP2 respirators by healthcare personnel, has been developed and is presented in this study. A potent and gentle aerosolized hydrogen peroxide (12% wt) method was applied over 4 hr to decontaminate various brands of FFP2 respirators within a small common room, followed by adequate aeration and storage overnight. The microbial efficacy was tested on unused respirator pieces using spores of Geobacillus stearothermophilus. Further, decontamination effectiveness was tested on used respirators after one 12-hr shift by swabbing before and after the decontamination. The effects of up to ten decontamination cycles on the respirators' functionality were evaluated using material properties, the structural integrity of the respirators, and fit tests with subjects. The suggested H2O2 decontamination procedure was proven to be (a) sufficiently potent (no microbial recovery, total inactivation of biological indicators as well as spore inoculum on critical respirator surfaces), (b) gentle as no significant damage to the respirator structural integrity and acceptable fit factors were observed, and (c) safe as no H2O2 residue were detected after the defined aeration and storage. Thus, this easy-to-implement and scalable method could overcome another severe respirator shortage, providing enough flexibility to draft safe, effective, and logistically simple crisis plans. However, as highlighted in this study, due to the wealth of design and material used in different models and brands of respirators, the decontamination process should be validated for each FFP respirator model before its field implementation.

Assessment of Surface Disinfection Effectiveness of Decontamination System COUNTERFOG® SDR-F05A+ Against Bacteriophage ɸ29.

The experience of COVID19 pandemic has demonstrated the real concern of biological agents dispersed in the air and surfaces environments. Therefore, the need of a fast and large-scale disinfection method has arisen for prevention of contagion. COUNTERFOG® is an innovative technology developed for large-scale decontamination of air and surfaces. The objective of this study is to assess experimentally the effectiveness of COUNTERFOG® in disinfecting viral-contaminated surfaces. We also aim to measure the necessary time to disinfect said surfaces. Stainless steel surfaces were contaminated with bacteriophage φ29 and disinfected using COUNTERFOG® SDR-F05A+, which uses a sodium hypochlorite solution at different concentrations and for different exposure times. A log reduction over 6 logs of virus titer is obtained in 1 min with 1.2% sodium hypochlorite when the application is direct; while at a radial distance of 5 cm from the point of application the disinfection reaches a reduction of 5.5 logs in 8 min. In the same way, a higher dilution of the sodium hypochlorite concentration (0.7% NaOCl) requires more exposure time (16 min) to obtain the same log reduction (> 6 logs). COUNTERFOG® creates, in a short time and at a distance of 2 m from the point of application, a thin layer of disinfectant that covers the surfaces. The selection of the concentration and exposure time is critical for the efficacy of disinfection. These tests demonstrate that a concentration between 0.7- 1.2% sodium hypochlorite is enough for a fast and efficient ɸ29 phage inactivation. The fact that ɸ29 phage is more resistant to disinfection than SARS-CoV-2 sustains this disinfection procedure.

Decontamination Assessment of Nanofiber-based N95 Masks.

As the world battles with the outbreak of the novel coronavirus, it also prepares for future global pandemics that threaten our health, economy, and survivor. During the outbreak, it became evident that use of personal protective equipment (PPE), specially face masks, can significantly slow the otherwise uncontrolled spread of the virus. Nevertheless, the outbreak and its new variants have caused shortage of PPE in many regions of the world. In addition, waste management of the enormous economical and environmental footprint of single use PPE has proven to be a challenge. Therefore, this study advances the theme of decontaminating used masks. More specifically, the effect of various decontamination techniques on the integrity and functionality of nanofiber-based N95 masks (i.e. capable of at least filtering 95% of 0.3 µm aerosols) were examined. These techniques include 70% ethanol, bleaching, boiling, steaming, ironing as well as placement in autoclave, oven, and exposure to microwave (MW) and ultraviolet (UV) light. Herein, filtration efficiency (by Particle Filtration Efficiency equipment), general morphology, and microstructure of nanofibers (by Field Emission Scanning Electron microscopy) prior and after every decontamination technique were observed. The results suggest that decontamination of masks with 70% ethanol can lead to significant unfavorable changes in the microstructure and filtration efficiency (down to 57.33%) of the masks. In other techniques such as bleaching, boiling, steaming, ironing and placement in the oven, filtration efficiency dropped to only about 80% and in addition, some morphological changes in the nanofiber microstructure were seen. Expectedly, there was no significant reduction in filtration efficiency nor microstructural changes in the case of placement in autoclave and exposure to the UV light. It was concluded that, the latter methods are preferable to decontaminate nanofiber-based N95 masks.

The novel application and effect of an ultraviolet light decontamination strategy on the healthcare acquisition of carbapenem-resistant Enterobacterales in a hospital setting.

BACKGROUND: The role of the hospital environment as contributory to healthcare acquisition of multidrug-resistant organisms (MDROs) is increasingly recognized. Ultraviolet light decontamination can minimize the environmental bioburden, thereby potentially reducing healthcare acquisition. This effect has been demonstrated for typical environmental MDROs, e.g. meticillin-resistant Staphylococcus aureus, vancomycin-resistant entero-cocci, and Clostridioides difficile; however, its role in reducing carbapenem-resistant Enterobacterales (CRE) incidence rates is unclear. AIM: To evaluate the impact of continuous ultraviolet light (C-UV) on healthcare acquisition rates of CRE. METHODS: A 26-month pragmatic, prospective interventional study with addition of C-UV decontamination to standard cleaning was conducted in units at high risk for CRE acquisition. Introduction of C-UV followed a 12 month baseline period, with a two-month wash-in period. Implementation included terminal decontamination at discharge and a novel in-use protocol, whereby rooms occupied for ≥48 h were decontaminated during the course of the patients' in-hospital stay. Incidence density rates of CRE during the intervention period were compared to the baseline period using interrupted time series regression. Rates were adjusted for ward/admission prevalence and analysed according to C-UV protocol. FINDINGS: The in-use C-UV protocol demonstrated a significant negative association with the incidence density rate of CRE when adjusting for CRE admission rate (P = 0.0069). CRE incidence density rates decreased significantly during the intervention period (P = 0.042). Non-intervention units demonstrated no change in incidence density rates when adjusting for ward and/or admission prevalence. CONCLUSION: C-UV decontamination can potentially reduce healthcare acquisition of CRE when implemented with an in-use protocol.

Thermal resistance and high-performance microwave decontamination assessment of Bacillus endospores isolated from food-grade herbal extracts.

Generally, endospore contamination can occur from different sources during product manufacturing in many industries and therefore lower its quality by affecting physicochemical properties and shelf-life. Bacterial endospores can germinate inside the product and produce several enzymes, which can cause several undesirable changes. This study assessed the spores thermal resistance and applied a microwave decontamination technique toward herbal extracts (Tilia tomentosa and Centella asiatica) containing ethanol or glycerol. Based on 16S rRNA analysis, the detected contaminant endospores belonged to different Bacillus species, namely B. subtilis, B. zhangzhouensis, and B. pumilus. The thermal resistance assessment using inoculated endospores in the actual products revealed B. pumilus T2 as the most resistant endospore to the heat treatments tested in both T. tomentosa and C. asiatica extracts. Finally, a high-performance microwave technique was used to decontaminate T. tomentosa extract against the mixture of Bacillus spores. Results from the microwave technique indicate that the increase of temperature from 100°C to 105°C not only decontaminated the product but also could dramatically decrease the effective thermal treatment time (10 times), which can benefit the product quality. The results provided in this study considerably contribute to improving an original decontamination method for products containing glycerol and ethanol with the most negligible effect on product quality.

Evaluación del método de Petroff modificado con solución salina para el diagnóstico de micobacterias en el sistema Bact/Alert 3D / Assessment of Petroff method modified with saline solution for the diagnosis of mycobacteria in Bact/Alert 3D system

Introducción: Existen diferentes métodos de descontaminación de muestras pulmonares para el diagnóstico de micobacterias. El Programa Nacional de Control de Tuberculosis recomienda el método de Petroff modificado con solución salina, pero no existen evidencias documentadas que avalen este método. Objetivo: Evaluar el método de Petroff modificado con solución salina para el diagnóstico de micobacterias en el sistema Bact/Alert 3D. Métodos: Se realizó un estudio observacional analítico de pruebas diagnósticas utilizando 100 muestras pulmonares recibidas en el Laboratorio Nacional de Referencia e Investigaciones de Tuberculosis, Lepra y Micobacterias del Instituto Pedro Kourí, abril 2016 enero 2017. La muestra se dividió en 3 alícuotas y se descontaminaron mediante 3 métodos; luego se inocularon en los medios de cultivo sólido y líquido. Se compararon los resultados del cultivo en cuanto: tiempo de detección de crecimiento, tasa de contaminación, por ciento de positividad, además se calcularon indicadores de desempeño. Resultados: Al comparar el método Petroff modificado con solución salina con el Petroff modificado con solución fosfato en Löwenstein Jensen, el tiempo de detección de crecimiento, por ciento de positividad y la tasa de contaminación se comportaron de forma similar y la sensibilidad (93,75 por ciento), concordancia (96,47 por ciento) e índice de Youden (0,91) fueron elevadas. Al compararlo el Petroff modificado con solución salina con el N-Acetil-L-Cisteína, las variables no mostraron diferencias significativas y los Indicadores de Desempeño se comportaron por encima del 93 por ciento, para el medio sólido y líquido. Conclusiones: Los resultados avalan la continuidad del uso del Petroff modificado con solución salina como método de descontaminación de las muestras pulmonares en la red de laboratorios de Cuba y como alternativa en el pretratamiento de las muestras para el medio líquido (Bact/Alert 3D), además constituye un soporte para el Programa Nacional de Control de Tuberculosis(AU)

Introduction: There are different decontamination methods of pulmonary samples for the diagnosis of mycobacteria. The National Program for the Control of Tuberculosis recommends Petroff method modified with saline solution; but there are not documented evidences that endorse it. Objective: Assess Petroff method modified with saline solution for the diagnosis of mycobacteria in Bact / Alert 3D system. Methods: An observational analytic study of diagnostic tests was conducted; there were used 100 pulmonary samples received in the National Laboratory of References and Researches of Tuberculosis, Leprosy and Mycobacteria of Pedro Kourí Institute, from April 2016 to January 2017. The sample was divided in 3 aliquots and those were decontaminated using 3 methods; then, they were inoculated in the solid and liquid culture means. Cultures´ results were compared according to: growth's detection time, contamination rate, percent of positivity; in addition, performance indicators were calculated. Results: When comparing Petroff method modified with saline solution with Petroff method modified with phosphate solution in Löwenstein Jensen, the growth's detection time, the percent of positivity and the rate of contamination behaved similarly, and sensitivity (93,75percent), concordance (96,47percent) and Youden´s index (0,91) were high. When the Petroff method modified with saline solution was compared with N-Acetil-L- Cisteina, the variables did not show significative differences and the behaviour indicators were over 93percent for the solid and liquid mean. Conclusions: The results endorse the continuity of the use of Petroff method modified with saline solution as a decontamination method of pulmonary samples in the network of Cuban laboratories and as alternative to the pre-treatment of the samples for the liquid mean (Bact/Alert 3D); it also constitutes a support for the National Program for the Control of Tuberculosis(AU)

Assessment of saliva interference with UV-based disinfection technologies.

Worldwide shortages of personal protective equipment during COVID-19 pandemic has forced the implementation of methods for decontaminating face piece respirators such as N95 respirators. The use of UV irradiation to reduce bioburden of used respirators attracts attention, making proper testing protocols of uttermost importance. Currently artificial saliva is used but its comparison to human saliva from the UV disinfection perspective is lacking. Here we characterize UV spectra of human and artificial saliva, both fresh and after settling, to test for possible interference for UV-based disinfection. ASTM 2720 artificial saliva recipe (with either porcine or bovine mucin) showed many discrepancies from average (N = 18) human saliva, with different mucins demonstrating very different UV absorbance spectra, resulting in very different UV transmittance at different wavelength. Reducing porcine mucin concentration from 3 to 1.7 g/L brought UVA254 in the artificial saliva to that of average human saliva (although not for other wavelengths), allowing 254 nm disinfection experiments. Phosphate saline and modified artificial saliva were spiked with 8.6 log CFU/ml B. subtilis spores (ATCC 6633) and irradiated at dose of up to 100 mJ/cm2, resulting in 5.9 log inactivation for a saline suspension, and 2.8 and 1.1 log inactivation for ASTM-no mucin and ASTM-1.7 g/L porcine mucin 2 µL dried droplets, respectively. UVC irradiation of spores dried in human saliva resulted in 2.3 and 1.5 log inactivation, depending on the size of the droplets (2 vs 10 µL, respectively) dried on a glass surface. Our results suggest that in the presence of the current standard dried artificial saliva it is unlikely that UVC can achieve 6 log inactivation of B. subtilis spores using a realistic UV dose (e.g. less than 2 J/cm2) and the ATSM saliva recipe should be revised for UV decontamination studies.

Filtering Facepiece Respirator (N95 Respirator) Reprocessing: A Systematic Review.

IMPORTANCE: The COVID-19 pandemic has resulted in a persistent shortage of personal protective equipment; therefore, a need exists for hospitals to reprocess filtering facepiece respirators (FFRs), such as N95 respirators. OBJECTIVE: To perform a systematic review to evaluate the evidence on effectiveness and feasibility of different processes used for decontaminating N95 respirators. EVIDENCE REVIEW: A search of PubMed and EMBASE (through January 31, 2021) was completed for 5 types of respirator-decontaminating processes including UV irradiation, vaporized hydrogen peroxide, moist-heat incubation, microwave-generated steam, and ethylene oxide. Data were abstracted on process method, pathogen removal, mask filtration efficiency, facial fit, user safety, and processing capability. FINDINGS: Forty-two studies were included that examined 65 total types of masks. All were laboratory studies (no clinical trials), and 2 evaluated respirator performance and fit with actual clinical use of N95 respirators. Twenty-seven evaluated UV germicidal irradiation, 19 vaporized hydrogen peroxide, 9 moist-heat incubation, 10 microwave-generated steam, and 7 ethylene oxide. Forty-three types of N95 respirators were treated with UV irradiation. Doses of 1 to 2 J/cm2 effectively sterilized most pathogens on N95 respirators (>103 reduction in influenza virus [4 studies], MS2 bacteriophage [3 studies], Bacillus spores [2 studies], Escherichia virus MS2 [1 study], vesicular stomatitis virus [1 study], and Middle East respiratory syndrome virus/SARS-CoV-1 [1 study]) without degrading respirator components. Doses higher than 1.5 to 2 J/cm2 may be needed based on 2 studies demonstrating greater than 103 reduction in SARS-CoV-2. Vaporized hydrogen peroxide eradicated the pathogen in all 7 efficacy studies (>104 reduction in SARS-CoV-2 [3 studies] and >106 reduction of Bacillus and Geobacillus stearothermophilus spores [4 studies]). Pressurized chamber systems with higher concentrations of hydrogen peroxide caused FFR damage (6 studies), while open-room systems did not degrade respirator components. Moist heat effectively reduced SARS-CoV-2 (2 studies), influenza virus by greater than 104 (2 studies), vesicular stomatitis virus (1 study), and Escherichia coli (1 study) and preserved filtration efficiency and facial fit for 11 N95 respirators using preheated containers/chambers at 60 °C to 85 °C (5 studies); however, diminished filtration performance was seen for the Caron incubator. Microwave-generated steam (1100-W to 1800-W devices; 40 seconds to 3 minutes) effectively reduced pathogens by greater than 103 (influenza virus [2 studies], MS2 bacteriophage [3 studies], and Staphylococcus aureus [1 study]) and maintained filtration performance in 10 N95 respirators; however, damage was noted in least 1 respirator type in 4 studies. In 6 studies, ethylene oxide preserved respirator components in 16 N95 respirator types but left residual carcinogenic by-product (1 study). CONCLUSIONS AND RELEVANCE: Ultraviolet germicidal irradiation, vaporized hydrogen peroxide, moist heat, and microwave-generated steam processing effectively sterilized N95 respirators and retained filtration performance. Ultraviolet irradiation and vaporized hydrogen peroxide damaged respirators the least. More research is needed on decontamination effectiveness for SARS-CoV-2 because few studies specifically examined this pathogen.

Decontaminating N95 respirators during the COVID-19 pandemic: simple and practical approaches to increase decontamination capacity, speed, safety and ease of use.

BACKGROUND: The COVID-19 pandemic has caused a severe shortage of personal protective equipment (PPE), especially N95 respirators. Efficient, effective and economically feasible methods for large-scale PPE decontamination are urgently needed. AIMS: (1) to develop protocols for effectively decontaminating PPE using vaporized hydrogen peroxide (VHP); (2) to develop novel approaches that decrease set-up and take-down time while also increasing decontamination capacity; (3) to test decontamination efficiency for N95 respirators heavily contaminated by make-up or moisturizers. METHODS: We converted a decommissioned Biosafety Level 3 laboratory into a facility that could be used to decontaminate N95 respirators. N95 respirators were hung on metal racks, stacked in piles, placed in paper bags or covered with make-up or moisturizer. A VHP® VICTORY™ unit from STERIS was used to inject VHP into the facility. Biological and chemical indicators were used to validate the decontamination process. FINDINGS: N95 respirators individually hung on metal racks were successfully decontaminated using VHP. N95 respirators were also successfully decontaminated when placed in closed paper bags or if stacked in piles of up to six. Stacking reduced the time needed to arrange N95 respirators for decontamination by approximately two-thirds while almost tripling facility capacity. Make-up and moisturizer creams did not interfere with the decontamination process. CONCLUSIONS: Respirator stacking can reduce the hands-on time and increase decontamination capacity. When personalization is needed, respirators can be decontaminated in labelled paper bags. Make up or moisturizers do not appear to interfere with VHP decontamination.

Assessment of efficacy of postinfusion tubing flushing in reducing risk of cytotoxic contamination.

PURPOSE: Infusion of cytotoxic drugs carries the risk of occupational exposure of healthcare workers. Since disconnecting an infusion line is a source of contamination, flushing of tubing after infusion of cytotoxic agents is recommended, but the optimal volume of rinsing solution is unknown. The objective of this study was to assess whether postinfusion line flushing completely eliminates cytotoxics. METHODS: Infusions were simulated with 3 cytotoxics (gemcitabine, cytarabine, and paclitaxel) diluted in 5% dextrose injection or 0.9% sodium chloride injection in 250-mL infusion bags. Infusion lines were flushed using 5% dextrose injection or 0.9% sodium chloride solution at 2 different flow rates. The remaining concentration of cytotoxics in the infusion line was measured by a validated high-performance liquid chromatography (HPLC) method after passage of every 10 mL of flushing volume until a total of 100 mL had been flushed through. RESULTS: All cytotoxics remained detectable even after line flushing with 80 mL of flushing solution (a volume 3-fold greater than the dead space volume within the infusion set). Gemcitabine and cytarabine were still quantifiable via HPLC even after flushing with 100 mL of solution. Efficacy of flushing was influenced by the lipophilicity of drugs but not by either the flushing solvent used or the flushing flow rate. After 2-fold dead space volume flushing, the estimated amount of drug remaining in the infusion set was within 0.19% to 0.56% of the prescribed dose for all 3 cytotoxics evaluated. CONCLUSION: Complete elimination of cytotoxics from an infusion line is an unrealistic objective. Two-fold dead space volume flushing could be considered optimal in terms of administered dose but not from an environmental contamination point of view. Even when flushed, the infusion set should still be considered a source of cytotoxic contamination.

An Assessment of Decontamination Strategies for Materials Commonly Used in Canine Equipment.

Working canines are frequently exposed to hazardous environments with a high potential for contamination. Environmental contamination may occur in many ways. Contamination may be chemical, biological, radiological, or nuclear. Examples may include a pipeline rupture following an earthquake, microbiological contamination of floodwaters, or exposure to toxic industrial chemical such as hydrogen chloride, ammonia, or toluene. Evidence to support effective methods for decontamination of equipment commonly used by working canines is lacking. Recent work has identified decontamination protocols for working canines, but little data are available to guide the decontamination of equipment used during tactical operations. The objective of our work was to investigate the effects of cleanser, cleaning method, and material type on contaminant reduction for tactical canine equipment materials using an oil-based contaminant as a surrogate for toxic industrial chemical exposure. A contaminant was applied, and effectiveness was represented as either success (= 50% contaminant reduction) or failure (< 50% contaminant reduction). A two-phase study was used to investigate cleanser, method of cleaning, and material types for effective contaminant reduction. In phase 1, Simple Green® cleanser had a higher frequency (P = .0075) of failure, but method and material did not affect contamination reduction (P > .05). In phase 2, Dawn® (P = .0004) and Johnson's® (P = .0414) successfully reduced contamination. High-pressure cleaning (HPC) resulted in successful decontamination (P < .0001). These novel data demonstrate potential techniques for reduction of contaminants on tactical canine equipment.

In vitro assessment of cobalt oxide particle dissolution in simulated lung fluids for identification of new decorporating agents.

Inhalation of 60Co3O4 particles may occur at the work place in nuclear industry. Their low solubility may result in chronic lung exposure to γ rays. Our strategy for an improved therapeutic approach is to enhance particle dissolution to facilitate cobalt excretion, as the dissolved fraction is rapidly eliminated, mainly in urine. In vitro dissolution of Co3O4 particles was assessed with two complementary assays in lung fluid surrogates to mimic a pulmonary contamination scenario. Twenty-one molecules and eleven combinations were selected through an extensive search in the literature, based on dissolution studies of other metal oxides (Fe, Mn, Cu) and tested for dissolution enhancement of cobalt particles after 1-28 days of incubation. DTPA, the recommended treatment following cobalt contamination did not enhance 60Co3O4 particles dissolution when used alone. However, by combining molecules with different properties, such as redox potential and chelating ability, we greatly improved the efficacy of each drug used alone, leading for the highest efficacy, to a 2.7 fold increased dissolution as compared to controls. These results suggest that destabilization of the particle surface is an important initiating event for a good efficacy of chelating drugs, and open new perspectives for the identification of new therapeutic strategies.

Chemical-Biological Terrorism and Its Impact on Children.

Chemical and biological events (including infectious disease outbreaks) may affect children disproportionately, and the threat of a chemical or biological attack remains in the United States and worldwide. Although federal programs and funding support a broad range of federal initiatives for public health preparedness and response, funding at the state and local levels has been flat or is decreasing, potentially leaving communities vulnerable. Consequently, pediatricians need to prepare and be ready to care for children in their communities before, during, and after a chemical or biological event, including during long-term recovery. Some medical countermeasures for particular chemical and biological agents have not been adequately studied or approved for children. The American Academy of Pediatrics provides resources and education on disaster preparedness and response, including information on the pediatrician's role in disasters, pediatric medical countermeasures, and mental health after an event as well as individual and family preparedness. This policy statement addresses the steps that clinicians and policy makers can take to protect children and mitigate the effects of a chemical or biological attack.

Rapid identification of organophosphorus pesticides on contaminated skin and confirmation of adequate decontamination by ambient mass spectrometry in emergency settings.

RATIONALE: Dermal exposure to pesticides may cause severe intoxication and even result in a fatal outcome. To expedite rescue in the emergency department, it is mandatory to develop a point-of-care analytical method for immediate identification of pesticides on the skin of exposed personnel, and to perform immediate dermal decontamination to prevent further harm and optimize the chance for full clinical recovery. METHODS: Four of the most commonly used highly toxic pesticides that contaminate the skin were rapidly characterized by thermal desorption electrospray ionization mass spectrometry. The technique was also applied to confirm the completeness of pesticide decontamination from the skin. Pesticide sampling, desorption, ionization, and detection altogether took less than 30 s. In addition, different fabrics of protective garments worn by farmers were assessed with this efficient ambient mass spectrometric technique for their protective capabilities against dermal exposure to pesticides, and scanning electron microscopy was used to observe their different microstructures. The decontaminating efficacies of different cleansing agents for these skin contaminants were also evaluated by this technical platform. RESULTS: The repeatability of this method had a low relative standard deviation (<22%) for the detection of pesticides on the surface of swine skin. The detection limits of the pesticides in solution were found to be in the range of 3-20 ng/mL. Linearity was observed between the signal intensities and the concentrations of the four pesticides in solution within the range of 50 ng/mL to 50 µg/mL (R2 between 0.9921 and 0.9966). In addition, it was found that PVC fabric is optimal in preventing skin contamination by fenthion and detergent had the best efficiency for fenthion decontamination. CONCLUSIONS: Since the whole analytical process is extremely fast, this technique allows early point-of-care identification of contaminating pesticides on the skin of exposed patients in the emergency room, as well as rapid assessment of the adequacy of decontamination.