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Background: Recently, face mask sampling (FMS) confirmed detection of Mycobacterium tuberculosis DNA from exhaled breath in adults with tuberculosis. To date, no study has evaluated the use of FMS to detect pulmonary tuberculosis in children. We developed a method for FMS of M. tuberculosis-specific DNA in children and performed a clinical exploration to assess feasibility in children., Methods: Face masks were spiked, analyzed on GeneXpert-Ultra, quantitative polymerase chain reaction, and targeted next-generation sequencing. Children with pulmonary tuberculosis were asked to wear 3 modified FFP2 masks for 30 minutes as part of an exploratory clinical study., Results: Experiments with H37Ra M. tuberculosis strain showed a limit of 95% detection of 3.75 colony-forming units (95% confidence interval, 4.85-3.11) on GeneXpert-Ultra. Ten children with pulmonary tuberculosis participated in the clinical study. M. tuberculosis-specific DNA was detected on none of the face masks., Conclusions: Pediatric FMS has a low limit of detection for M. tuberculosis-specific DNA in vitro. However, M. tuberculosis DNA was not detected in any of 30 masks worn by children with pulmonary tuberculosis. This suggests that FMS in this form may not be more effective for detecting M. tuberculosis in children with tuberculosis than existing methods., Competing Interests: Potential conflicts of interest. All authors: No reported conflicts. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed., (© The Author(s) 2024. Published by Oxford University Press on behalf of Infectious Diseases Society of America. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Introduction: Facemasks were widely mandated during the recent SARS-CoV-2 pandemic. Especially the use by the general population is associated with a higher risk of improper handling of the mask and contamination and potential adverse microbiological consequences., Methods: We investigated and quantified bacterial accumulation in facemasks used by the general population, using 16S rRNA (Sanger Sequencing), culture and biochemical analysis along with Rose Bengal staining. Additionally, a systematic overview of the literature on face mask contamination was undertaken., Results: We found an average bacterial load of 4.24 × 10 4 CFU recovered/mask, with a maximum load of 2.85 × 10 5 CFU. This maximum is 310 times higher than the limit value for contamination of ventilation system outlet surfaces specified by the German standard VDI 6022. Biochemical and molecular identification predominantly found Staphylococcus species (80%), including Staphylococcus aureus , along with endospore-forming Bacillus spp. Literature reports also indicate contamination of masks by bacterial and fungal opportunists of the genera Acinetobacter, Aspergillus, Alternaria, Bacillus, Cadosporium, Candida, Escherichia, Enterobacter, Enterococcus, Klebsiella (including K. pneumoniae ), Micrococcus, Microsporum, Mucor, Pseudomonas, Staphylococcus and Streptococcus . Bacterial counts increase linearly with wearing duration., Discussion: Prolonged use may affect the skin and respiratory microbiomes, promoting consequential eye, skin, oral and airway conditions. These aspects underscore the urgent need for further research and a risk-benefit analysis in respect of mask use, particularly given their unproven efficacy in disrupting the transmission of respiratory viruses and their adverse social consequences., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Kisielinski, Wojtasik, Zalewska, Livermore and Jurczak-Kurek.)

Healthcare-associated infections (HAIs) remain a critical public health issue, as they contribute to prolonged treatment duration, increased healthcare costs, and heightened risks of morbidity and mortality. In head and neck cancer patients undergoing radiotherapy, thermoplastic masks (TMs), which come into direct contact with the skin, represent a potential vector for infection. Additionally, the storage racks where these masks are kept may also facilitate microorganism transmission. Our study aimed to isolate and identify microorganisms from infective skin lesions secondary to radiation dermatitis in head and neck cancer patients, as well as from the TMs and storage racks, and to evaluate the antibiotic resistance profiles of the isolated microorganisms. The study included 71 locally advanced head and neck cancer patients who underwent radiotherapy between August 2022 and November 2023. Patients were monitored daily, and their skin evaluations were made according to Common Terminology Criteria for Adverse Events (CTCAE) version 4.0. Grade 2 and 3 radiodermatitis was observed in 29 of these 71 patients. Samples were collected using sterile swabs from the skin lesions on the head and neck area, the inner surfaces of the TM, and the storage rack from 29 patients. Samples were inoculated into enrichment and selective media. After the growing microorganisms were identified, antimicrobial susceptibility was evaluated using conventional methods and automated systems according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) criteria. At least one type of microorganism was isolated from the skin samples of infected patients, and double growth was detected in two patients. Among the samples, 2 were methicillin-resistant coagulase-negative Staphylococcus (MRCNS), 1 was methicillin-resistant Staphylococcus aureus (MRSA), 1 was Candida albicans (C. albicans), 15 were methicillin-sensitive coagulase-negative Staphylococcus (MSCNS), 1 was methicillin-sensitive Staphylococcus aureus (MSSA), 1 was Bacillus subspecies (Bacillus spp.) and 3 were Corynebacterium diphtheriae (C. diphtheriae). Coagulase-negative Staphylococcus strains were isolated from the skin of 14 of 19 patients with grade 2 radiation dermatitis, whereas CNS strains were isolated from only 2 of 10 patients with grade 3 radiation dermatitis. Among the gram-negative bacteria, 3 Pseudomonas aeruginosa (P. aeruginosa), 2 Enterobacter cloacae (E. cloacae), 1 Klebsiella pneumoniae (K. pneumoniae) and 1 Moraxella catarrhalis (M. catarrhalis) strain were isolated. Sixteen (55.1%) of the TMs used in 29 patients and 20 (68.9%) of the storage racks harbored microorganisms, including HAI agents and flora bacteria. Bacteria colonize TMs and storage racks where they are risk factors for secondary skin infections in radiation dermatitis lesions that develop on the skin of head and neck cancer patients. Decontamination procedures should be meticulously applied to surfaces such as TMs and their storage racks during the course of radiotherapy., Competing Interests: Declarations Competing interests The authors declare no competing interests. Ethics approval and consent to participate The study was reviewed and approved by the institutional ethics board of the Akdeniz University School of Medicine (Decision number: KAEK-441, Date: 20.07.2022) and followed the ethical principles of the 1964 Declaration of Helsinki. All participants provided written informed consent., (© 2024. The Author(s).)

There is insufficient research on bioaerosols in hospital waste decontamination stations. This study aimed to investigate the effect of three-layer and N95 masks in reducing the inhalation risk of bacterial bioaerosols in a waste decontamination station at a teaching hospital. Active sampling was conducted on five different days at three locations: the yard, resting room, and autoclave room in three different modes: without a mask, with a three-layer mask, and with an N95 mask. Bacterial bioaerosols passing through the masks were identified using biochemical tests and polymerase chain reaction (PCR). The median concentration and interquartile range (IQR) of bacterial bioaerosols was 217.093 (230.174) colony-forming units per cubic meter (CFU/m 3 ), which is higher than the recommended amount by Pan American Health Organization (PAHO). The resting room had high contamination levels, with a median (IQR) of 321.9 (793.529) CFU/m 3 of bacterial bioaerosols. The maximum concentration of bioaerosols was also recorded in the same room (2443.282 CFU/m 3 ). The concentration of bacterial bioaerosols differed significantly between using a three-layer or N95 mask and not using a mask (p-value < 0.001). The non-carcinogenic risk level was acceptable in all cases, except in the resting room without a mask (Hazard Quotient (HQ) = 2.07). The predominant bacteria were Gram-positive cocci (33.98%). Micrococci (three-layer mask = 51.28%, N95 mask = 50%) and Coagulase-negative Staphylococci (three-layer mask = 30.77%, N95 mask = 31.82%) were the most abundant bioaerosols passing through the masks. The results obtained are useful for managerial decisions in hospital waste decontamination stations to reduce exposure to bioaerosols and develop useful guidelines., (© 2024. The Author(s).)

Objectives: As face mask wear can result in the redirection of nasal and oral exhalation toward the ocular region, this study investigated the impact of face mask wear on the conjunctiva, eyelid margin, and contact lens (CL) surface microbiome., Methods: In this prospective, cross-over study, experienced CL wearers (N=20) were randomized to wear a face mask for 6 hr/day (minimum) for a week or no mask for a week. The conjunctiva, eyelid, and CLs were then sampled. After a 1-week washout period, participants were crossed over into the alternate treatment for 1 week and sampling was repeated. Sampling was bilateral and randomly assigned to be processed for culturing or 16S ribosomal(r) RNA gene sequencing., Results: Culturing showed no effect of mask wear on the average number of bacterial colonies isolated on the conjunctiva, eyelid, or CL, but there was increased isolation of Staphylococcus capitis on CL samples with mask wear ( P =0.040). Culture-independent sequencing found differences in the taxonomic complexity and bacterial composition between the three sites ( P <0.001), but there was no effect of bacterial diversity within and between sites. Mask wear did not impact dry eye or CL discomfort, but increased ocular surface staining was reported ( P =0.035)., Conclusions: Mask wear did not substantially alter the microbiome of the conjunctiva, eyelid margin, or CL surfaces in uncompromised healthy eyes., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the Contact Lens Association of Opthalmologists.)

Whether in the field of medical care, or in people's daily life and health protection, the importance of masks has been paid more and more attention. Acne, the most common complication after wearing masks, which is also called maskne, has been successfully introduced into the common language as a common topic of dermatologist consultations. This study aims to study the changes of microflora in maskne patients and healthy controls before and after wearing masks. In the summer of 2023, we collected a total of 50 samples from 15 maskne patients and 10 healthy controls before and after wearing surgical masks for a long time. 16 S ribosomal DNA sequencing and identification technology with V3-V4 variable region were adopted to explore the microbiome changes caused by mask wearing, analyze the changes in microbial diversity, and make interaction network. LDA effect size analysis was used to identify which bacteria showed significant changes in their relative abundance from phylum to genus. After wearing a mask, the microbiome of the maskne patients changed significantly more than that of the healthy controls, with both α diversity and β diversity lower than those of maskne patients before wearing masks and those of healthy controls after wearing masks. Co-occurrence network analysis showed that compared with other groups, the network of maskne patients after wearing masks for a long time had the lowest connectivity and complexity, but the highest clustering property, while the opposite was true for healthy controls. Many microbes that are potentially beneficial to the skin decreased significantly after wearing a mask. There was almost no difference in healthy controls before and after wearing a mask., (© 2024. The Author(s).)

Cellulose acetate (CA) is a non-toxic, renewable, and biodegradable polymeric material that can be effectively electrospuned into bacterial filtration efficient nanofiber membrane for face mask application. However, its fragile and non-antibacterial nature influenced its scalability. In this context, natural antibacterial gum rosin (GR) additive can be explored. Therefore, the present study aimed to produce a CA/GR composite nanofibers membrane for the finest bacterial filtration, excellent antibacterial moiety, and improved tensile properties for facemask application. Hence, in this work, we have studied the effect of GR concentrations (0-15 g) on the needleless electrospinning behavior and fibers' morphology through rheology, electrical conductivity, and SEM analysis. These analyses revealed that GR significantly affects the fibers' spinning behavior, morphology, and diameter of the produced fibers. Later, ATR-FTIR spectroscopy mapped the functional changes in the produced nanofibers that affirmed the integration of GR with CA polymer. This modification resulted in a 3-fold rise in tensile strength and an 11-fold decline in elongation% in 15 g CA/GR composite nanofibers membrane than the control sample. Furthermore, it has shown 98.79 ± 0.10% bacterial filtration efficiency and ∼ 93 % reduction in Staphylococcus Aureus and Klebsiella Pneumoniae bacterial growth, elucidating a high-efficiency level for potential facemask application., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Purpose: To investigate the bacterial growth in the surgical face masks used by patients who received intravitreal injections and study the effect of povidone-iodine on the periocular area (PA) of masks., Methods: Forty patients who attended for intravitreal injections were divided in those with less (<4 hours) and more (>4 hours) than 4 hours of mask use. Each group was divided depending on the application or not of povidone-iodine in the PA of the mask. Bacterial load was studied on PA and mouth area samples., Results: The bacterial load in the PA was higher in the >4 hours group compared with the <4 hours group (13.2 vs. 48.75 colony-forming units/μL; P = 0.03). The contamination in the PA significantly decreased after applying povidone-iodine in the >4 hours group (P = 0.01). The use or not of povidone-iodine was strongly correlated to a positive culture (OR = 9.0, P = 0.00. CI 1.63-49.44)., Conclusion: Surgical face masks worn for more than 4 hours present higher contamination in the PA than those with less use. Bacterial load in the PA is reduced with povidone-iodine on masks used for more than 4 hours. This contamination should be considered in the asepsis protocol of intravitreal injections., Competing Interests: The authors declare that there is no conflict of interest.

Background: In healthcare facilities, nosocomial transmissions of respiratory viruses are a major issue. SARS-CoV-2 is not exempt from nosocomial transmission. Our goals were to describe COVID-19 nosocomial cases during the first pandemic wave among patients in a French university hospital and compliance with hygiene measures., Methods: We conducted a prospective observational study in Grenoble Alpes University Hospital from 01/03/2020 to 11/05/2020. We included all hospitalised patients with a documented SARS-CoV-2 diagnosis. Nosocomial case was defined by a delay of 5 days between hospitalisation and first symptoms. Hygiene measures were evaluated between 11/05/2020 and 22/05/2020. Lockdown measures were effective in France on 17/03/2020 and ended on 11/05/2020. Systematic wearing of mask was mandatory for all healthcare workers (HCW) and visits were prohibited in our institution from 13/03/2021 and for the duration of the lockdown period., Results: Among 259 patients included, 14 (5.4%) were considered as nosocomial COVID-19. Median time before symptom onset was 25 days (interquartile range: 12-42). Eleven patients (79%) had risk factors for severe COVID-19. Five died (36%) including 4 deaths attributable to COVID-19. Two clusters were identified. The first cluster had 5 cases including 3 nosocomial acquisitions and no tested HCWs were positive. The second cluster had 3 cases including 2 nosocomial cases and 4 HCWs were positive. Surgical mask wearing and hand hygiene compliance were adequate for 95% and 61% of HCWs, respectively., Conclusions: The number of nosocomial COVID-19 cases in our hospital was low. Compliance regarding mask wearing, hand hygiene and lockdown measures drastically reduced transmission of the virus. Monitoring of nosocomial COVID-19 cases during the first wave enabled us to determine to what extent the hygiene measures taken were effective and patients protected. Trial registration Study ethics approval was obtained retrospectively on 30 September 2020 (CECIC Rhône-Alpes-Auvergne, Clermont-Ferrand, IRB 5891)., (© 2021. The Author(s).)

Background: As the SARS-CoV-2 pandemic accelerates, the supply of personal protective equipment remains under strain. To combat shortages, re-use of surgical masks and filtering facepiece respirators has been recommended. Prior decontamination is paramount to the re-use of these typically single-use only items and, without compromising their integrity, must guarantee inactivation of SARS-CoV-2 and other contaminating pathogens., Aim: We provide information on the effect of time-dependent passive decontamination (infectivity loss over time during room temperature storage in a breathable bag) and evaluate inactivation of a SARS-CoV-2 surrogate and a non-enveloped model virus as well as mask and respirator integrity following active multiple-cycle vaporised hydrogen peroxide (VHP), ultraviolet germicidal irradiation (UVGI), and dry heat (DH) decontamination., Methods: Masks and respirators, inoculated with infectious porcine respiratory coronavirus or murine norovirus, were submitted to passive decontamination or single or multiple active decontamination cycles; viruses were recovered from sample materials and viral titres were measured via TCID50 assay. In parallel, filtration efficiency tests and breathability tests were performed according to EN standard 14683 and NIOSH regulations., Results and Discussion: Infectious porcine respiratory coronavirus and murine norovirus remained detectable on masks and respirators up to five and seven days of passive decontamination. Single and multiple cycles of VHP-, UVGI-, and DH were shown to not adversely affect bacterial filtration efficiency of masks. Single- and multiple UVGI did not adversely affect respirator filtration efficiency, while VHP and DH induced a decrease in filtration efficiency after one or three decontamination cycles. Multiple cycles of VHP-, UVGI-, and DH slightly decreased airflow resistance of masks but did not adversely affect respirator breathability. VHP and UVGI efficiently inactivated both viruses after five, DH after three, decontamination cycles, permitting demonstration of a loss of infectivity by more than three orders of magnitude. This multi-disciplinal approach provides important information on how often a given PPE item may be safely reused., Competing Interests: The authors have declared that no competing interests exist.

Based on the current knowledge of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) transmission, wearing a mask has been recommended during the COVID-19 pandemic. Bacterial filtration efficiency (BFE) measurements enable designing and regulating medical masks to prevent bioaerosol dissemination; however, despite the simplicity of these measurements, several scientific questions remain unanswered regarding BFE tests. Here, we investigated (1) the impact of substituting 100-mm Petri dishes with 90-mm disposable Petri dishes, (2) the impact of colony-counting methods on the bioaerosol aerodynamic size, and (3) the impact of colony-counting methods on the total viable particle counts. We demonstrated that disposable 90-mm Petri dishes can be used to replace the 100-mm dishes. We also showed that an automatic high-resolution colony counter can be used to directly count viable particles on collection substrates and to measure the bioaerosol size parameters. Our results enable possible modernization of the outdated testing methods recommended in the US and European standards for BFE measurements. Specifically, use of a modernized colony counter should be clearly regulated and permitted to avoid the counting of positive holes. The median aerodynamic diameter appears to be the most relevant parameter for characterizing bioaerosol size.

Influenza, pneumonia, and pathogenic infection of the respiratory system are boosted in cold environments. Low temperatures also result in vasoconstriction, restraint of blood flow, and decreased oxygen to the heart, and the risk of a heart attack would increase accordingly. The present face mask fabric fails to preserve its air-filtering function as its electrostatic function vanishes once exposed to water. Therefore, its filtering efficacy would be decreased meaningfully, making it nearly impracticable to reuse the disposable face masks. The urgent requirement for photothermal fabrics is also rising. Nanobased polyethyleneimine-polypyrrole nanopigments (NPP NPs) have been developed and have strong near-infrared spectrum absorption and exceptional photothermal convertible performance. Herein, the mask fabric used PE-fiber-constructed membrane (PEFM) was coated by the binding affinity of the cationic polyethyleneimine component of NPP NPs forming NPP NPs-PEFM. To the best of our knowledge, no study has investigated NPP NP-coated mask fabric to perform infrared red (solar or body) photothermal conversion efficacy to provide biocompatible warming, remotely photothermally captured antipathogen, and antivasoconstriction in vivo . This pioneering study showed that the developed NPP NPs-PEFM could be washable, reusable, breathable, biocompatible, and photothermal conversable for active eradication of pathogenic bacteria. Further, it possesses warming preservation and antivasoconstriction.

Objectives: Non-traditional materials are used for mask construction to address personal protective equipment shortages during the coronavirus disease 2019 (COVID-19) pandemic. Reusable masks made from surgical sterilization wrap represent such an innovative approach with social media frequently referring to them as "N95 alternatives." This material was tested for particle filtration efficiency and breathability to clarify what role they might have in infection prevention and control., Methods: A heavyweight, double layer sterilization wrap was tested when new and after 2, 4, 6, and 10 autoclave sterilizing cycles and compared with an approved N95 respirator and a surgical mask via testing procedures using a sodium chloride aerosol for N95 efficiency testing similar to 42 CFR 84.181. Pressure testing to indicate breathability was also conducted., Results: The particle filtration efficiency for the sterilization wrap ranged between 58% to 66%, with similar performance when new and after sterilizing cycles. The N95 respirator and surgical mask performed at 95% and 68% respectively. Pressure drops for the sterilization wrap, N95 and surgical mask were 10.4 mmH2O, 5.9 mmH2O, and 5.1 mmH2O, respectively, well below the National Institute for Occupational Safety and Health limits of 35 mmH2O during initial inhalation and 25 mmH2O during initial exhalation., Conclusions: The sterilization wrap's particle filtration efficiency is much lower than a N95 respirator, but falls within the range of a surgical mask, with acceptable breathability. Performance testing of non-traditional mask materials is crucial to determine potential protection efficacy and for correcting misinterpretation propagated through popular media.

Many healthcare systems have been forced to outsource simple mask production due to international shortages caused by the COVID-19 pandemic. Providence created simple masks using surgical wrap and submitted samples to an environmental lab for bacterial filtration efficiency testing. Bacterial filtration efficiency rates ranged from 83.0% to 98.1% depending on specific material and ply, and particular filtration efficiency rates ranged from 92.3% to 97.7%. Based on mask configuration, specific surgical wrap selected, and ply, the recommended filtration efficiency for isolation and surgical masks of 95% and 98%, respectively can be achieved. These alternative masks can allow for similar coverage and safety when hospital-grade isolation masks are in short supply., (Copyright © 2020 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.)

Background: Thermoplastic immobilization masks used during radiation therapy treatment have been shown to harbor several different types of bacteria. Recovered bacteria included Staphylococcus aureus, Enterococcus species, Gram-negative rods, coagulase-negative staphylococci, and several different Bacillus species. Two of the recovered Bacillus bacteria were examined for their ability to attach to and survive over time on patient head-only masks from four different manufacturers. B. halosaccharovorans was recovered from a treatment facility's water bath while B. cereus was recovered from a patient mask in the same facility. Bacillus bacteria were chosen for this study due to their capability to form dormant spores., Methods: Inoculums containing either B. halosaccharovorans or B. cereus bacteria were seeded onto predesignated areas of each test mask. Masks were subsequently sampled at intervals of 1-h, 1 week, 2 weeks, 3 weeks, and 4 weeks. Recovered bacterial numbers at each sampling interval were determined using the direct plate count method. Spore stains were made of both bacterial isolates and number of detected spores were enumerated., Results: B. halosaccharovorans attached to each mask type after a 1-h contact time at a number 3X greater than B. cereus. B. halosaccharovorans was also recovered at a number 8.5X greater than B. cereus after 4 weeks. Variation was seen in the attachment capability of each bacterium on tested mask types. Both bacilli were recovered from all 4 masks at each sampling interval including week 4. Examination of spore stains of each bacteria demonstrated nearly a 25:1 ratio of B. halosaccharovorans spores over B. cereus., Discussion: The large variation seen between B. halosaccharovorans and B. cereus capability to attach to each of the four tested masks is revealing, especially when it is combined with determined spore numbers. It suggests that spores play a role in mediating their attachment to mask surfaces. Moreover, the recovery of both bacteria from stored masks after 4 weeks indicates a continued presence of dormant spores since growth-supportive nutrients are lacking. It also implies the potential for their transfer to a patient wearing a contaminated mask during a treatment session., Conclusion: The demonstrated ability of these two Bacillus bacteria to attach to and reside on patient masks presents a dilemma. Routine cleaning with approved disinfectants may not be sufficient to eliminate dormant spores on masks surfaces. This matter requires further investigation. For now, a small modification to the routine mask cleaning procedure before its application may help to reduce the possibility of spore transfer., (Copyright © 2020. Published by Elsevier Inc.)

Novel sampling matrices were manufactured using 3D printing for the detection of respiratory pathogens in expired air. A specific configuration of the matrices was designed using Computer-Aided Design software. Polyvinyl alcohol (PVA) was printed using fused deposition modelling to create a multilayer matrix to enhance the capture of bacteria. The performance of these matrices was compared with gelatine filters that have been used for this work to date. PVA matrices (60 mm diameter) were contaminated with bacteria either by direct inoculation, or by aerosol exposure using an Omron A3 nebuliser. Rough and smooth morphotypes of Mycobacterium abscessus, M. smegmatis and M. bovis BCG, were used in this study to contaminate the matrices. PVA matrices and gelatine sampling filters were contaminated to compare recovery rates for quantitative analyses. These were dissolved in water, bacteria pelleted and DNA extracted followed by a Mycobacterium-specific quantitative Polymerase Chain Reaction (qPCR).The results showed that 3D printed PVA matrices are very effective to capture the bacteria. 3D printed PVA matrix and gelatine filters yielded results of the same order of magnitude for mycobacterial analyses, however, PVA matrix offers several advantages over the latter material. 3D printed PVA is considered as an economic and time-effective matrix as it is cheaper than gelatine filters. PVA is sufficiently robust to be handled and loaded into the surgical masks for sampling, compared to the brittle gelatine filters that required supportive frames. PVA is a synthetic material and it is suitable for DNA-based analyses, whilst gelatine is derived from animal collagen, and carries a high bacterial DNA background that interferes with the target DNA analysis. Furthermore, PVA dissolves in distilled water without requiring chemicals or enzymes, such as the case for gelatine hydrolysis. To summarise, 3D printed PVA sampling matrix is considered a promising tool used for microbiological diagnostic purposes., (Copyright © 2020 Elsevier GmbH. All rights reserved.)

The regeneration of filtering facepiece respirators (FFRs) is of critical importance because of the severe shortage of FFRs during large-scale outbreaks of respiratory epidemics, such as COVID-19. Comprehensive experiments regarding FFR regeneration were performed in this study with model bacteria to illustrate the decontamination performance of the regeneration processes. The results showed that it is dangerous to use a contaminated FFR without any microbe inactivation treatment because the bacteria can live for more than 8 h. The filtration efficiency and surface electrostatic potential of 75% ethanol-treated FFRs were significantly reduced, and a most penetrating particle size of 200 nm was observed. Steam and microwave irradiation (MWI) showed promising decontamination performances, achieving 100% inactivation in 90 and 30 min, respectively. The filtration efficiencies of steam-treated FFRs for 50 and 100 nm particles decreased from 98.86% and 99.51% to 97.58% and 98.79%, respectively. Ultraviolet irradiation (UVI) effectively inactivated the surface bacteria with a short treatment of 5 min and did not affect the filtration performance. However, the UV dose reaching different layers of the FFP2 mask sample gradually decreased from the outermost layer to the innermost layer, while the model bacteria on the second and third layers could not be killed completely. UVI+MWI and steam were recommended to effectively decontaminate the used respirators and still maintain the respirators' filtration efficiency. The present work provides a comprehensive evaluation for FFR regeneration in terms of the filtration efficiencies for 50-500 nm particles, the electrostatic properties, mechanical properties, and decontamination effects.

Introduction: One of the serious consequences of the SARS-CoV-2 pandemic is the shortage of protective equipment for health personnel. N95 masks are considered one of the essential protective equipment in the management of patients with COVID-19. The shortage of N95 masks implies potential health risks for health personnel and significant economic losses for the health institution. The objective of this work was to investigate the disinfection of N95 masks artificially contaminated with SARS-CoV-2 and ESKAPE bacteria by using hydrogen peroxide plasma., Material and Methods: We examined the disinfection capacity of hydrogen peroxide plasma against the SARS-CoV-2 and 2 members of the ESKAPE bacteria (Acinetobacter baumannii and Staphylococcus aureus) through a study of artificial contamination in situ of N95 masks. Amplification of specific genes by real-time reverse transcription polymerase chain reaction of SARS-CoV-2 and microbiological culture of ESKAPE bacteria was performed before and after the disinfection process., Results: SARS-CoV-2 was not detected in all assays using 5 different concentrations of the virus, and A baumannii and S aureus were not cultivable with inoculums of 10 2 to 10 6 CFU after disinfection tests of N95 masks with hydrogen peroxide plasma., Conclusion: Disinfection of N95 masks by using the hydrogen peroxide plasma technology can be an alternative for their reuse in a shortage situation. Implications for the use of disinfection technologies of N95 masks and the safety of health personnel are discussed., (Copyright © 2020 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.)

Respiratory protection is key in infection prevention of airborne diseases, as highlighted by the COVID-19 pandemic for instance. Conventional technologies have several drawbacks (i.e., cross-infection risk, filtration efficiency improvements limited by difficulty in breathing, and no safe reusability), which have yet to be addressed in a single device. Here, we report the development of a filter overcoming the major technical challenges of respiratory protective devices. Large-pore membranes, offering high breathability but low bacteria capture, were functionalized to have a uniform salt layer on the fibers. The salt-functionalized membranes achieved high filtration efficiency as opposed to the bare membrane, with differences of up to 48%, while maintaining high breathability (> 60% increase compared to commercial surgical masks even for the thickest salt filters tested). The salt-functionalized filters quickly killed Gram-positive and Gram-negative bacteria aerosols in vitro, with CFU reductions observed as early as within 5 min, and in vivo by causing structural damage due to salt recrystallization. The salt coatings retained the pathogen inactivation capability at harsh environmental conditions (37 °C and a relative humidity of 70%, 80% and 90%). Combination of these properties in one filter will lead to the production of an effective device, comprehensibly mitigating infection transmission globally.

Background: Tuberculosis remains a global health challenge, with early diagnosis key to its reduction. Face-mask sampling detects exhaled Mycobacterium tuberculosis. We aimed to investigate bacillary output from patients with pulmonary tuberculosis and to assess the potential of face-mask sampling as a diagnostic method in active case-finding., Methods: We did a 24-h longitudinal study in patients from three hospitals in Pretoria, South Africa, with microbiologically confirmed pulmonary tuberculosis. Patients underwent 1 h of face-mask sampling eight times over a 24-h period, with contemporaneous sputum sampling. M tuberculosis was detected by quantitative PCR. We also did an active case-finding pilot study in inhabitants of an informal settlement near Pretoria. We enrolled individuals with symptoms of tuberculosis on the WHO screening questionnaire. Participants provided sputum and face-mask samples that were tested with the molecular assay Xpert MTB/RIF Ultra. Sputum-negative and face-mask-positive individuals were followed up prospectively for 20 weeks by bronchoscopy, PET-CT, and further sputum analysis to validate the diagnosis., Findings: Between Sept 22, 2015, and Dec 3, 2015, 78 patients with pulmonary tuberculosis were screened for the longitudinal study, of whom 24 completed the study (20 had HIV co-infection). M tuberculosis was detected in 166 (86%) of 192 face-mask samples and 38 (21%) of 184 assessable sputum samples obtained over a 24-h period. Exhaled M tuberculosis output showed no diurnal pattern and did not associate with cough frequency, sputum bacillary content, or chest radiographic disease severity. On May 16, 2018, 45 individuals were screened for the prospective active case-finding pilot study, of whom 20 had tuberculosis symptoms and were willing to take part. Eight participants were diagnosed prospectively with pulmonary tuberculosis, of whom six were exclusively face-mask positive at screening. Four of these participants (three of whom were HIV-positive) had normal findings on chest radiography but had treatment-responsive early tuberculosis-compatible lesions on PET-CT scans, with Xpert-positive sputum samples after 6 weeks., Interpretation: Face-mask sampling offers a highly efficient and non-invasive method for detecting exhaled M tuberculosis, informing the presence of active infection both with greater consistency and at an earlier disease stage than with sputum samples. The approach shows potential for diagnosis and screening, particularly in difficult-to-reach communities., Funding: Wellcome Trust, CARA (Council for At-Risk Academics), University of Leicester, the UK Medical Research Council, and the National Institute for Health Research. VIDEO ABSTRACT., (Copyright © 2020 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.)

Background and Aims: Nonuniversal use of facial protection during endoscopy may place endoscopists at risk of exposure to blood and body fluids; however, the frequency of exposure is unknown., Methods: A prospective 6-month study of 4 gastroenterologists using a face shield during endoscopy was undertaken. The face shield was swabbed in a standardized fashion before and at the end of the session. Controls included pre- and post-swabs of face shields placed on the (1) endoscopy suite wall, (2) remote patient intake bay wall, and (3) after deliberate contamination with a colonoscope immediately after colonoscopy. The swabs were cultured for 48 hours, and growth was reported as no growth or by number of colony-forming units (CFUs). The groups were compared for +CFU rate and CFU number., Results: A total of 1100 procedures were performed in 239 endoscopy sessions. The +CFU rate in the pre-endoscopy groups (2%-4.8%, not significant) was significantly lower than the postendoscopist face shield (45.8%, P < .001) and endoscopy suite wall groups (21.4%, P < .001), respectively. Using a cut-off of >15 CFUs as an indicator of definite exposure, the occurrence rate was 5.6 per 100 half days of endoscopy to the endoscopist's face and 3.4 per 100 half days of endoscopy 6 feet away., Conclusions: This is the first study to quantify the rate of unrecognized exposure to the endoscopist's face to potentially infectious biologic samples during endoscopy (5.6/100 days of endoscopy). This exposure may result in transmission of infectious diseases. As such, we recommend the use of universal facial protection during GI endoscopy., (Published by Elsevier Inc.)

Introduction: Nebulized devices are commonly used in the treatment of respiratory infection, and other respiratory diseases. It has been reported nosocomial infections in cystic fibrosis patients as a result of the use of contaminated devices. However, little is known about nosocomial infections secondary to aerosolized therapy in COPD patients admitted for acute exacerbation., Methods: Thirty consecutive patients (13 males) were included. All of them received aerosolized medication. Each patient used their own facemask and nebulizer cup, which were stored in the room after its use. Samples from nebulizer cups were obtained on days 0, 4 and 7. In addition, sputum samples were obtained on day 0 (prior to any nebulization) and on day 7, and cultivated in enriched media., Results: Only nine nebulizer cups had positive microbiological cultures. Coagulase negative staphylococci (CoNS) were isolated in all cases. Sputum samples could be obtained in 27 patients. None grew CoNS after 7 days of aerosolized therapy. Gram-negative non-fermenting bacilli were isolated in three patients without concomitant grown in nebulizer cups., Conclusions: We did not find any nosocomial infection related to aerosolize medications in COPD patients admitted for acute exacerbation.

Background: Although tuberculosis is transmitted by the airborne route, direct information on the natural output of bacilli into air by source cases is very limited. We sought to address this through sampling of expelled aerosols in face masks that were subsequently analyzed for mycobacterial contamination., Methods: In series 1, 17 smear microscopy positive patients wore standard surgical face masks once or twice for periods between 10 minutes and 5 hours; mycobacterial contamination was detected using a bacteriophage assay. In series 2, 19 patients with suspected tuberculosis were studied in Leicester UK and 10 patients with at least one positive smear were studied in The Gambia. These subjects wore one FFP30 mask modified to contain a gelatin filter for one hour; this was subsequently analyzed by the Xpert MTB/RIF system., Results: In series 1, the bacteriophage assay detected live mycobacteria in 11/17 patients with wearing times between 10 and 120 minutes. Variation was seen in mask positivity and the level of contamination detected in multiple samples from the same patient. Two patients had non-tuberculous mycobacterial infections. In series 2, 13/20 patients with pulmonary tuberculosis produced positive masks and 0/9 patients with extrapulmonary or non-tuberculous diagnoses were mask positive. Overall, 65% of patients with confirmed pulmonary mycobacterial infection gave positive masks and this included 3/6 patients who received diagnostic bronchoalveolar lavages., Conclusion: Mask sampling provides a simple means of assessing mycobacterial output in non-sputum expectorant. The approach shows potential for application to the study of airborne transmission and to diagnosis.

Objective: To describe the pathogens found in home nebulizers and in respiratory samples of cystic fibrosis (CF) patients, and to evaluate the effect that a standardized instruction regarding cleaning and disinfection of nebulizers has on the frequency of nebulizer contamination., Methods: We included 40 CF patients (22 males), all of whom used the same model of nebulizer. The median patient age was 11.2 ± 3.74 years. We collected samples from the nebulizer mouthpiece and cup, using a sterile swab moistened with sterile saline. Respiratory samples were collected by asking patients to expectorate into a sterile container or with oropharyngeal swabs after cough stimulation. Cultures were performed on selective media, and bacteria were identified by classical biochemical tests. Patients received oral and written instructions regarding the cleaning and disinfection of nebulizers. All determinations were repeated an average of two months later., Results: Contamination of the nebulizer (any part) was detected in 23 cases (57.5%). The nebulizer mouthpiece and cup were found to be contaminated in 16 (40.0%) and 19 (47.5%), respectively. After the standardized instruction had been given, there was a significant decrease in the proportion of contaminated nebulizers (43.5%)., Conclusions: In our sample of CF patients, nebulizer contamination was common, indicating the need for improvement in patient practices regarding the cleaning and disinfection of their nebulizers. A one-time educational intervention could have a significant positive impact.

Objective: Bacteria on the facepiece of a dust respirator were measured just after use and after 24-hours storage at a room temperature after being worn, and bacteria disinfection methods other than ethanol were examined., Methods: The existence of bacteria on a facepiece of a mask that had been worn for about one hour in a laboratory was investigated. In order to eliminate bacteria before use on the next day, five methods of bacteria disinfection were investigated: wiping with a facial tissue impregnated with ethanol as a control; wiping with a facial tissue wetted with tap water; wiping with a dry facial tissue after wiping with one wetted with tap water; wiping with a dry facial tissue after wiping with one wetted with distilled water; and wiping with a dry facial tissue two times. The tests were carried out using silicone rubber sheets plated with bacteria collected from human skin. The disinfection methods that were as effective as facial paper wetted with ethanol, were then assayed on the facepiece of the dust respirator., Results: Bacteria were detected on the facepiece immediately after it had been worn. Bacteria were also detected on the facepiece after it had been stored at 25°C for 24-hours after being worn. The methods of wiping with a dry facial tissue after wiping with either tap water or distilled water were almost as statistically effective as wiping with ethanol wetted facial paper. Bacteria on the facepiece were decreased by wiping with a dry facial tissue after wiping with one wetted with tap water., Discussion: Colonies of bacteria were detected on a facepiece that had been stored 24 hours after being worn, which suggests that bacteria disinfection just after a respirator has been worn should be recommended. It is very important that the water on the facepiece should be removed after wiping with a wet facial tissue.

Background: The effectiveness of recommended measures, such as "cover your mouth when coughing", in disrupting the chain of transmission of infectious respiratory diseases (IRD) has been questioned. The objective of the current study was to determine the effectiveness of simple primary respiratory hygiene/cough etiquette maneuvers in blocking droplets expelled as aerosol during coughing., Method: In this study, 31 healthy non-smokers performed cough etiquette maneuvers in an effort to cover their voluntarily elicited best effort coughs in an open bench format. A laser diffraction system was used to obtain accurate, non-invasive, quantitative, real time measurements of the size and number of droplets emitted during the assessed cough etiquette maneuvers., Results: Recommended cough etiquette maneuvers did not block the release and dispersion of a variety of different diameter droplets to the surrounding environment. Droplets smaller than one-micron size dominate the total number of droplets leaked when practicing assessed maneuvers., Conclusions: All the assessed cough etiquette maneuvers, performed as recommended, do not block droplets expelled as aerosol when coughing. This aerosol can penetrate profound levels of the respiratory system. Practicing these assessed primary respiratory hygiene/cough etiquette maneuvers would still permit direct, indirect, and/or airborne transmission and spread of IRD, such as influenza and Tuberculosis. All the assessed cough etiquette maneuvers, as recommended, do not fully interrupt the chain of transmission of IRD. This knowledge urges us all to critically review recommended CE and to search for new evidence-based procedures that effectively disrupt the transmission of respiratory pathogens. Interrupting the chain of transmission of IRD will optimize the protection of first responders, paramedics, nurses, and doctors working in triage sites, emergency rooms, intensive care units, and the general public against cough-droplet-spread diseases.

Objective: To investigate the amount of bacterial dispersal associated with speech in a simulated intravitreous injection., Methods: Fifteen volunteers were recruited. Each volunteer was positioned over an open blood agar plate and did the following: read a 5-minute script with a face mask, read a 5-minute script without a face mask, read a 5-minute script with the face turned away from the plate without a face mask, and stood in silence for 5 minutes. Each volunteer then read a 5-minute script while reclined in a standard ophthalmic examination chair with an open blood agar plate secured to the forehead to simulate bacterial dispersal associated with a talking patient. Total numbers of colony-forming bacteria per plate were counted, and the bacteria were identified., Results: Significantly less bacterial growth occurred in the face mask and silence conditions compared with the no face mask condition (both P < .001). Bacterial growth was significantly greater in the reclined condition compared with the room control (P = .02). Oral streptococcal species represented 66.7% to 82.6% of bacterial colonies in the no face mask, face turned, and reclined conditions., Conclusions: During simulated intravitreous injection, wearing a face mask or remaining silent significantly decreases culture plate contamination from talking. Talking from above and talking in the reclined position were associated with a significant increase in culture plate contamination. Physicians performing intravitreous injections should be aware of these patterns of bacterial contamination, should consider either wearing a face mask or minimizing speech, and should encourage patients to minimize speech during the procedure.

An overview of available literature on the use of protective facemasks by children for protection from respiratory infectious agents reveals relatively few articles dealing specifically with the topic, despite their use during recent outbreaks (eg, severe acute respiratory syndrome, pandemic influenza). Little is known about the physiological and psychological burdens imposed by these devices and a child's ability to correctly use and tolerate them. This article focuses on the myriad issues associated with protective facemask use by children in the hope of educating public health personnel, healthcare professionals, and families on their limitations and associated risks, and in the hope of fostering much-needed research.

Objective: To determine whether nebulizers are a source of microbial contamination in patients with cystic fibrosis, as well as whether the technique and frequency of disinfection of these devices is appropriate., Methods: This was a cross-sectional, uncontrolled observational study. Samples were collected from 28 patients with cystic fibrosis. Samples were collected at the homes of the patients, who were not previously informed of the purpose of the visit. Three samples were collected from each patient: one from the nebulizer chamber, one from the mask/mouthpiece, and one from the patient (oropharyngeal swab /sputum). The samples were properly stored and taken for analyses. The patients, their parents, or their legal guardians completed a questionnaire regarding nebulizer cleaning and disinfecting methods., Results: We collected 84 samples from the 28 patients. Of those 28 patients, 15 (53.5%) were male. The median age of the patients was 11 years (range, 1-27 years). Of the 28 patients, 15 presented with positive oropharyngeal swab /sputum sample cultures. The most common bacterial isolates were Staphylococcus aureus (in 8 patients) and Pseudomonas aeruginosa (in 4 patients). Although the samples obtained from the nebulizers presented with various pathogens in culture, no specific species predominated. In 27 cases (96.7%), there were no associations between the samples obtained from the nebulizers and those obtained from the patients in terms of the results of the cultures. Cleaning and disinfection of nebulizers were inappropriate in 22 cases (78.6%)., Conclusions: In this sample of patients, despite the inappropriate disinfection techniques, nebulizers were not found to be a source of microbial contamination.

The study presents first experiences on the controlled use of respiratory masks against Methicillin-resistant Staphylococcus aureus (MRSA) in a multi-person veterinary pig practice. Seven veterinarians entered the trial (five wearing masks, two wearing no masks) after the veterinarians had performed a decolonisation protocol. The pig herds were visited regularly by the veterinarians during the study period. The five "trial" veterinarians wore gloves and respiratory masks for at least 30 days and 30 farm visits. The two "control" veterinarians wore gloves only. Nasal swabs were collected at a seven day interval. Swabs and ten masks per "trial" veterinarian were bacteriologically tested for MRSA including MLST- and spa-typing. The study showed a high MRSA-exposure for the veterinarians, since 68% of the masks were tested positive for MRSA. However, four vets stayed MRSA-negative while using the masks. Only one of the"trial" veterinarians became positive after two weeks. After the masks were not worn any more, two veterinarians returned to colonisation soon again. The two "control" veterinarians turned positive after 26 and 54 days, respectively. The high finding-rates of MRSA in the masks proof an enormous risk of nasal colonisation during routine work.The results of our study do not proof the potential of respiratory masks to prevent nasal colonisation of veterinarians with MRSA. However, there are no hints, that the proper use of masks could be a risk factor for becoming colonised. Further details of the proper use of masks and the quantification of their protective potential need further studies on a larger scale.

Scuba divers typically rinse equipment in communal tanks. Studies show these tanks are contaminated with bacteria, but the types of bacteria have not been studied. We sought to identify bacteria in rinse tanks at a dive facility at San Pedro, Belize, to determine the origin of the bacteria and determine whether the bacteria represented potential threats to human health. The identity of bacteria was investigated using reverse line blot (RLB) assays based on 28 different rDNA probes designed to detect known pathogens of sepsis, as well as by sequencing 23S rDNA from isolates and performing VITEK identification of several isolates. Based on the identities of bacteria in divers' rinse tanks, many likely originate from the ocean, and others likely originate from the divers themselves. None of the bacteria identified would be considered overt human pathogens. However, some of the bacteria found in the tanks are known to be associated with unsanitary conditions and can cause opportunistic infections, which may pose health problems to some individuals. Rinsing scuba equipment in communal tanks has the potential to transmit disease among some divers. Equipment, especially regulators and masks, should be rinsed/cleaned individually and not be placed in communal tanks.

Approximately 6.4 million operative procedures are carried out each year in Germany. Besides nosocomial pneumonia and urinary tract infections, postoperative wound infections account for 16% and are the third most common kind of infection in German hospitals. The spectrum of pathogens depends on the type and localization of the operative procedure. The pathogens can penetrate the wound from outside (exogenic) or from the patient's own skin or mucosal flora (endogenic). There are different kinds of risk factors whereby those of the patient can be influenced in a limited manner and are differentiated from those which can be influenced by preventive actions against infections in the context of the organization of perioperative nursing.

Background: The SARS outbreak in 2003 has spawned a major controversy concerning protective performance facemasks for healthcare workers. This study reports a study on in-vivo protective performance of surgical masks and N95 respirators., Methods: Typical surgical masks and N95 respirators used in Hong Kong hospitals were tested in comparison with those treated with nano-functional materials (called nano-masks) on various physical properties and in-vivo wear filtration efficiency, as well as usability test in hospitals for surgical masks., Results: Tests on physical properties showed that N95 respirators had significantly lower air permeability and water vapor permeability than surgical masks. The in-vivo filtration tests illustrated that N95 respirators filtered out 97% of potassium chloride (KCl) solution, while surgical masks filtered out 95% of KCl solution. Nano-masks show stronger water repellency and antibacterial activities, but no difference in usability, comparing with normal N95 and surgical masks., Conclusions: Surgical masks can provide in-vivo filtration protection of 95% filtration efficiency. N95 respirators provide higher in-vivo filtration efficiency of 97% with significant reduction of air permeability and water vapor permeability. Compared to normal surgical masks/respirators, the nano-masks can provide additional protective functions in stopping capillary diffusion and antibacterial activities.

Aerosols containing microbes from the oral cavity of the patient are created when using modern high-speed rotating instruments in restorative dentistry. How far these aerosols spread and what level of contamination they cause in the dental surgery has become a growing concern as the number of patients with oro-nasal meticillin-resistant Staphylococcus aureus colonization has increased. The present study aimed to determine how far airborne bacteria spread during dental treatment, and the level of contamination. Fall out samples were collected on blood agar plates placed in six different sectors, 0.5-2m from the patient. Restorative dentistry fallout samples (N=72) were collected from rooms (N=6) where high-speed rotating instruments were used, and control samples (N=24) were collected from rooms (N=4) used for periodontal and orthodontic treatment where rotating and ultrasonic instruments were not used. The collection times were 1.5 and 3 h. In addition, samples were taken from facial masks of personnel and from surfaces in the rooms before and after disinfection. After 48 h of incubation at 37 degrees C, colonies were counted and classified by Gram stain. The results showed significant contamination of the room at all distances sampled when high-speed instruments were used (mean 970 colony-forming units/m2/h). The bacterial density was found to be higher in the more remote sampling points. Gram-positive cocci, namely viridans streptococci and staphylococci, were the most common findings. The area that becomes contaminated during dental procedures is far larger than previously thought and practically encompasses the whole room. These results emphasize the need for developing new means for preventing microbial aerosols in dentistry and protection of all items stored temporarily on work surfaces. This is especially important when treating generally ill or immunocompromised patients at dental surgeries in hospital environments.

This study assessed the antimicrobial activity of nanoparticles (consisting of a mixture of silver nitrate and titanium dioxide) and nanoparticle-coated facemasks to protect against infectious agents. The minimum inhibitory concentrations of the nanoparticles against Escherichia coli and Staphylococcus aureus were 1/128 and 1/512, respectively. The antibacterial activity of nanoparticle-coated masks was quantified according to the procedures of AATCC 100-1999. A 100% reduction in viable E. coli and S. aureus was observed in the coated mask materials after 48 h of incubation. Skin irritation was not observed in any of the volunteers who wore the facemasks. Nanoparticles show promise when applied as a coating to the surface of protective clothing in reducing the risk of transmission of infectious agents.

Introduction: Home-nebulizers are a potential source of bacterial infection of the respiratory tract in patients suffering from cystic fibrosis. Recommendations for disinfecting this equipment are often arbitrary and sometimes contradictory., Objective: To assess in vitro the effectiveness of 5 methods of disinfecting this equipment., Methods: 160 mouthpieces and 160 masks of nebulizers were artificially and massively contaminated with 16 strains of germs found in patients with cystic fibrosis (Staphylococcus aureus, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Burkholderia cenocepacia, Alcaligenes xylosoxydans). A controlled comparison was carried out of the five methods of disinfection (hypochlorite solution (0.02% active chlorine), acetic acid 3.5%, Hexanios 0.5%, washing-up detergent 0.5% and a dishwasher), tested with and without drying. Standardised bacteriological sampling took place 4 h after disinfecting., Results: Following treatment, the disappearance of the germ was recorded in 84.1% of cases, and effective disinfecting (reduction>5 log CFU/mL) in another 10.6%. Disinfection failure (5.3%) was found almost only in the case of acetic acid against Staphylococcus aureus., Conclusion: With the exception of acetic acid, the methods of disinfecting tested in this study appeared to be effective against common bacterial pathogens in cystic fibrosis.

Background: Disinfectants for medical devices are uncommonly a cause of iatrogenic adverse effects. Nevertheless, when misused, they can induce severe complications. Three cases of acute respiratory distress in newborns probably induced by glutaraldehyde are reported., Case Reports: Three children born by Caesarean section between 8 and 19 May 1999 in the same hospital presented acute respiratory distress requiring hospitalization in the neonatal intensive care unit; one child was premature. The clinical appearance, which was initially normal, deteriorated with a respiratory distress in 30 to 60 minutes. Recovery was uneventful in all cases. The diagnosis considered was a hyaline membrane disease. The enquiry conducted after this cluster onset identified, as a main contributing factor, the disinfection procedure recently introduced in the surgical theater., Conclusion: Review of toxicologic data on glutaraldehyde shows this is a highly irritating chemical for the respiratory tract, even at low concentrations. Clinical and radiologic features in these three neonates are compatible with a pulmonary sub-edema on an immature alveolar setting. The hypothesis proposed is that glutaraldehyde, the active ingredient of the biocidal formula used to disinfect the respiratory masks, was massively desorbed from the rubber and foam of which masks are made.

Surgical face masks prevent the dispersal of bacteria from the upper airway to surfaces immediately in front of and below the face during talking. However, mask wiggling has been reported to increase dermabrasion and bacterial contamination of surfaces immediately below the face. Facial hair and recent shaving may alter the quantity of particles shed by dermabrasion when the mask is wiggled. We investigated the effect of mask wiggling in 10 bearded and 10 clean-shaven male subjects, and 10 female subjects. Wiggling the mask significantly increased the degree of bacterial shedding onto agar plates 15 cm below the lips in bearded males (p = 0.03) and females (p = 0.03), but not in clean-shaven males. At rest without mask wiggling the bearded subjects shed significantly more bacteria than clean-shaven males (p = 0.01) or females (p = 0.001). To reduce the risks of contamination of the sterile field when face masks are worn females and bearded males should avoid wiggling the face mask. Bearded males may also consider removing their beards.