American Journal of Infection Control

ObjectivesThe aim of this observational study was to demonstrate the behaviour and trajectory of exhaled material from an individual wearing an FFP3 mask. Valves allow material release, but we theorised that valve design may direct material downwards towards patient and surrounding environment. Limiting transmission of diseases with aerosolised spread is a current and serious concern within healthcare worldwide. Filtering face piece masks (FFP) are an essential piece of protective equipment when treating patients with ongoing infection. However, valved masks in other settings such as elective theatre and by the general public may have unforeseen negative effects. DesignA heating coil-based vaporiser was used to produce visible water vapour. A healthy test subject was filmed wearing a variety of different masks and exhaling the water vapour. ResultsFlexible pleated and solid-shell FFP masks direct exhaled material downwards in plumes exceeding 25 cm. Duckbill-shaped masks appear to direct exhaled vapour laterally, with a smaller plume. The effect is influenced by mask design and type of valve. Fluid repellent surgical masks reduce material directed downwards, and when used in conjunction with an FFP3 mask, appear to reduce the size and density of the exhaled vapour plume. The use of a visor was ineffective in reducing plume expulsion. InterpretationA properly fit-tested FFP3-rated protective mask may only moderately limit expulsion of aerosolised particles from asymptomatic healthcare workers to patients, particularly in cases where procedures are being performed in close proximity to patients or in cases where mucosal surfaces are exposed. Further research in this area is needed.

BackgroundUsing face masks is one of the possible prevention methods against respiratory pathogens. A number of studies and reviews have been performed regarding the use of medical grade masks like surgical masks, N95 respirators etc. However, the use of cloth masks has received little attention. ObjectivesThe purpose of this review is to analyze the available data regarding the use of cloth masks for the prevention of respiratory infections. We intended to use data from both clinical and non-clinical studies to arrive at our conclusion. MethodsWe used PubMed, Cochrane Library and Google Scholar as our source databases. Both clinical and non-clinical studies, which had data regarding the efficacy of cloth masks, were selected. Articles not containing analyzable data including opinion articles, review articles etc. were excluded. After screening the search results, ten studies could be included in our review. Data relevant to our objective was extracted from each study including clinical efficacy, compliance, filtration efficacy etc. Data from some studies were simplified for the purpose of comparison. Extracted data was summarized and categorized for detailed analysis. Qualitative synthesis of the data was performed. But the heterogeneity between the studies did not allow for a meta-analysis. DiscussionThe review was limited by a lack of sufficient clinical studies. Lack of standardization between studies was another limitation. Although cloth masks generally perform poorer than the medical grade masks, they may be better than no masks at all. Filtration efficacy varied greatly depending on the material used, with some materials showing a filtration efficacy above 90%. However, leakage could reduce efficacy of masks by about 50%. Standardization of cloth masks and appropriate use is essential for cloth masks to be effective. However, result of a randomized controlled trial suggest that they may be ineffective in the healthcare setting.

BackgroundHealthcare-associated infections (HAIs) constitute a significant financial strain on healthcare systems across the world, with surgical site infections (SSIs) being the costliest form. Despite the existence of diverse sources of infection in the operating room (OR), current literature focuses on human and procedural sources of contamination that could lead to an infection. Comparatively, the OR built environment is understudied as a potential disease transmission interface between the environment, patients, and surgical staff. This systematic literature review aims to investigate how the physical characteristics and components of the built environment impact airflow, infection risk, aerosols, particle counts, contamination, and pathogens in operating rooms. Methods and FindingsLiterature searches were conducted in the PubMed and Web of Science Core Collection databases on December 21, 2020, ultimately retrieving 2,965 articles after duplicates were removed. During abstract screening, all abstracts were independently reviewed by two authors and conflicts were resolved by a third author. All articles published since January 1, 2010, that reported primary data investigating an aspect of the built environment inside an OR in relation to airflow, contamination, and/or infection for which the full text in English was available were included. This resulted in the inclusion of 138 articles, which includes studies conducted in ORs during active surgeries, computer modeling studies, and simulations in which a real OR was used for a mock surgical procedure. Six major built environment categories were identified based on the collected literature: OR layout, disinfection systems, surgical lights, doors, ventilation, and portable airflow devices. A survey created on Qualtrics software was used to record the aspect of the built environment and the outcome of each study, as well as the relationship between the two. ConclusionsWhile OR ventilation has been studied extensively, the OR built environment as a whole is understudied in relation to airflow, contamination, and infection. The current literature is inconsistent in both its findings and subsequent recommendations, making it difficult to inform hospital design in the context of SSIs. No articles were identified that discussed respiratory infection transmission in the OR, and very few addressed healthcare worker (HCW) safety in relation to the OR built environment. The significant discrepancies in the literature identified in this review highlight the need for future studies that assess the quality and bias of these studies before firm recommendations can be made. Future work should also focus on addressing the lack information regarding respiratory infection transmission in the OR, especially in the context of HCW safety.

BackgroundHealthcare workers treating patients with SARS-CoV-2 are at risk of infection from patient-emitted virus-laden aerosols. We quantified the reduction of airborne infectious virus in a simulated hospital room when a ventilated patient isolation (McMonty) hood was in use. MethodsWe nebulised 109 plaque forming units (PFU) of bacteriophage PhiX174 virus into a 35.1m3 room with a hood active or inactive. The airborne concentration of infectious virus was measured by BioSpot-VIVAS and settle plates using plaque assay quantification on the bacterial host Escherichia coli C. The particle number concentration (PNC) was monitored continuously using an optical particle sizer. ResultsMedian airborne viral concentration in the room reached 1.41 x 105 PFU.m-3 with the hood inactive. Using the active hood as source containment reduced infectious virus concentration by 374-fold in air samples. This was associated with a 109-fold reduction in total airborne particle number escape rate. The deposition of infectious virus on the surface of settle plates was reduced by 87-fold. ConclusionsThe isolation hood significantly reduced airborne infectious virus exposure in a simulated hospital room. Our findings support the use of the hood to limit exposure of healthcare workers to airborne virus in clinical environments. Lay summaryCOVID-19 patients exhale aerosol particles which can potentially carry infectious viruses into the hospital environment, putting healthcare workers at risk of infection. This risk can be reduced by proper use of personal protective equipment (PPE) to protect workers from virus exposure. More effective strategies, however, aim to provide source control, reducing the amount of virus-contaminated air that is exhaled into the hospital room. The McMonty isolation hood has been developed to trap and decontaminate the air around an infected patient. We tested the efficacy of the hood using a live virus model to mimic a COVID-19 patient in a hospital room. Using the McMonty hood reduced the amount of exhaled air particles in the room by over 109-times. In our tests, people working in the room were exposed to 374-times less infectious virus in the air, and room surfaces were 87-times less contaminated. Our study supports using devices like the McMonty hood in combination with PPE to keep healthcare workers safe from virus exposure at work.

Decontamination of N95 respirators has become critical to alleviate PPE shortages for healthcare workers in the current COVID-19 emergency. The factors that are considered for the effective reuse of these masks are the fit, filter efficiency and decontamination/disinfection level both for SARS-CoV-2, which is the causative virus for COVID-19, and for other organisms of concern in the hospital environment such as Staphylococcus aureus or Clostridium difficile. In its guidance entitled Recommendations for Sponsors Requesting EUAs for Decontamination and Bioburden Reduction Systems for Surgical Masks and Respirators During the Coronavirus Disease 2019 (COVID19) Public Health Emergency (May 2020)[1], the FDA recommends a 6-log10 reduction in either the most resistant bacterial spores for the system or in a mycobacterium species to authorize the use of a decontamination method of N95 respirators for single or multiple users. While the goal is primarily inactivation against SARS-CoV-2, testing of decontamination methods against the virus may not always be available. For decontamination methods considered for only single users, the recommendation is a 6-log10 reduction in the infective virus concentration of 3 non-enveloped viruses or in the concentration of two Gram (+) and two Gram (-) bacteria. Based on these recommendations, we explored the efficacy of vaporized H2O2 (VHP) treatment of N95 respirators against surrogate viruses covering a wide range of disinfection resistance for emergency decontamination and reuse to alleviate PPE shortages for healthcare workers in the COVID-19 emergency.

Decontamination of N95 respirators has become critical to alleviate PPE shortages for healthcare workers in the current COVID-19 emergency. The factors that are considered for the effective reuse of these masks are the fit, filter efficiency and decontamination/disinfection level both for SARS-CoV2, which is the causative virus for COVID-19, and for other organisms of concern in the hospital environment such as Staphylococcus aureus or Clostridium difficile. The efficacy of inactivation or eradication against various pathogens should be evaluated thoroughly to understand the level of afforded disinfection. Methods commonly used in the sterilization of medical devices such as ionizing radiation, vaporized hydrogen peroxide, and ethylene oxide can provide a high level of disinfection, defined as a 6 log10 reduction, against bacterial spores, considered the most resistant microorganisms. CDC guidance on the decontamination and reuse of N95s also includes the use of moist heat (60{degrees}C, 80% relative humidity, 15-30 min) as a possible recommendation based on literature showing preservation of fit efficiency and inactivation of H1N1 on spiked masks. Here, we explored the efficacy of using moist heat under these conditions as a decontamination method for an N95 respirator (3M 1860S, St. Paul, MN) against various pathogens with different resistance; enveloped RNA viruses, Gram (+/-) bacteria, and non-enveloped viruses.

BACKGROUNDExhalation exposure from patients to healthcare workers (HCWs), while using a nasal cannula or simple O2 mask used in treating COVID-19 and other respiratory diseases, is a present and future risk. Little is known on exhalation dispersal through these devices, and on mitigating the viral exposure to those in the vicinity. METHODSRespiration through O2 therapy devices was studied with a supine manikin equipped with a controllable mechanical lung by measuring aerosol density and flow with direct imaging. Dispersal direction and distances were quantified while placing a surgical mask loosely over the devices and contrasted with unmitigated oxygenation device use. Exhalation jets were examined over the entire range of oxygenation rates used in treatment. RESULTSExhalation jets travel 0.35 {+/-} 0.02 m upward while wearing a nasal cannula, and 0.29 {+/-} 0.02 m laterally while wearing a simple O2 mask posing significant inhalation risk. Placing a surgical facemask loosely over the oxygenation device is demonstrated to alleviate exposure by reducing and deflecting the exhalation jets from being launched forward, and by reducing exhalations from being launched directly higher over a supine patient. Less than 12% of the exhaled breath is observed to reach above a masked face where HCWs would be present, independent of oxygen flow rates. CONCLUSIONSExhalation jets from both the nasal cannula or simple O2 mask were found to concentrate aerosol-laden exhalations directly in front of a patients face. Exposure is effectively mitigated with a surgical mask which reduces and redirects the exhalation downward away from HCWs.

BackgroundIn long-term care facilities (LTCFs), close-contact identification often relies on staff recall and monitoring records because residents may be unable to self-report reliably. How these different record-generation processes relate to proximity-based sensor measurements in routine LTCF workflow remain unclear, and how such differences may influence contact-based decision-making in outbreak response is not well understood. MethodsWe conducted a five-day observational study in a Japanese LTCF using ultra-wideband (UWB) indoor positioning. Twenty-seven participants wore UWB tags, including 16 residents and 11 staff members; 10 staff members completed questionnaires. We compared UWB-derived proximity with questionnaire-derived contacts from staff self-report and monitoring-based proxy records, and assessed directional discrepancies under multiple distance-time thresholds. ResultsQuestionnaire-based records and UWB-derived proximity showed different patterns of discrepancy across contact types. Within this facility, resident-related monitoring-based proxy records showed relatively small directional discrepancies, whereas staff self-reports tended to identify additional resident-staff contacts under the baseline threshold ([≤]1.0 m for [≥]15 min). Several alternative thresholds were associated with discrepancies closer to zero than the baseline, although the apparent ranking varied by summary metric. ConclusionsIn this single-facility observational study, different contact-list generation processes were associated with different patterns of discrepancy relative to a proximity-based operational measure. These findings support interpretation in terms of workflow-specific contact-list generation rather than a single universally optimal threshold and may help inform facility-level review of contact identification practices in LTCFs. These findings support aligning contact identification strategies with facility-specific workflows to improve the feasibility and effectiveness of IPC practices in LTCFs.

We conducted a systematic review of hygiene intervention effectiveness against SARS-CoV-2, including developing inclusion criteria, conducting the search, selecting articles for inclusion, and summarizing included articles. We reviewed 104,735 articles, and 109 articles meeting inclusion criteria were identified, with 33 additional articles identified from reference chaining. Herein, we describe results from 58 mask disinfection and reuse studies, where the majority of data were collected using N95 masks. Please note, no disinfection method consistently removed >3 log of virus irrespective of concentration, contact time, temperature, and humidity. However, results show it is possible to achieve >3 log reduction of SARS-CoV-2 using appropriate concentrations and contact times of chemical (ethanol, hydrogen peroxide, peracetic acid), radiation (PX-UV, UVGI), and thermal (autoclaving, heat) disinfection on N95 masks. N95 mask reuse and failure data indicate that hydrogen peroxide, heat, and UV-GI are promising for mask reuse, peracetic acid and PX-UV need more data, and autoclaving and ethanol lead to mask durability failures. Data on other mask types is limited. We thus recommend focusing guidelines and further research on the use of heat, hydrogen peroxide, and UVGI for N95 mask disinfection/reuse. All of these disinfection options could be investigated for use in LMIC and humanitarian contexts. TOC Art O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=106 SRC="FIGDIR/small/20229880v1_ufig1.gif" ALT="Figure 1"> View larger version (22K): org.highwire.dtl.DTLVardef@154383borg.highwire.dtl.DTLVardef@37b888org.highwire.dtl.DTLVardef@33eae1org.highwire.dtl.DTLVardef@818e32_HPS_FORMAT_FIGEXP M_FIG C_FIG SynopsisIn resource-limited contexts, N95s are reused. We recommend using heat, hydrogen peroxide, or UVGI to disinfect and reuse N95 masks.

Current shortages of Filtering Facepiece Respirators (FFRs) have created a demand for effective methods for N95 decontamination and reuse. Before implementing any reuse strategy it is important to determine what effects the proposed method has on the physical functioning of the FFR. Here we investigate the effects of two potential methods for decontamination; dry heat at 95 {degrees}C, and autoclave treatments. We test both fit and filtration efficiency for each method. For the dry heat treatment we consider the 3M 1860, 3M 1870, and 3M8210+ models. After five cycles of the dry heating method, all three FFR models pass both fit and filtration tests, showing no degradation. For the autoclave tests we consider the 3M 1870, and the 3M 8210+. We find significant degradation of the FFRs following the 121 {degrees}C autoclave cycles. The molded mask tested (3M 8210+) failed fit testing after just 1 cycle in the autoclave. The pleated (3M 1870) mask passed fit testing for 5 cycles, but failed filtration testing. The 95 {degrees}C dry heat cycle is scalable to over a thousand masks per day in a hospital setting, and is above the temperature which has been shown to achieve the requisite 3 log kill of SARS-CoV-2[1], making it a promising method for N95 decontamination and reuse.

The current COVID-19 pandemic has highlighted global supply chain shortcomings in the US hospital delivery system, most notably personal protective equipment (PPE) and COVID-19 is found on these masks [~]7 days. Recent work from our group has shown two promising disinfection methods for N95 facial masks, dry heat (hot air (75 {degrees}C, 30 min) and UVGI which is UVGI 254 nm, 8W, 30 min. Using N95 five models of N95 masks from three different manufacturers we determined the following: 1) Hot air treated N95 masks applied over 5 cycles did not degrade the fit of masks (1.5% change in fit factor, p = .67), 2) UVGI treated N95 masks applied over 10 cycles were significantly degraded in fit and did not pass quantitative fit testing using OSHA testing protocols on a human model (-77.4% change in fit factor, p = .0002). NOTEWe would like to share our results with the community as soon as possible. Be mindful that this report is a pilot study and a work in progress. We will have more results in the coming days and weeks. We recommend that O_SCPLOWHOSPITALC_SCPLOWO_SCPCAP C_SCPCAPO_SCPLOWPOLICYC_SCPLOW and O_SCPLOWPROCEDURESC_SCPLOW be respected and adhered to. Do not use anything in your home to disinfect contaminated equipment. Please do not heat your masks in a home oven!

IntroductionOne of the important measures to prevent spread of COVID-19 in community is use of face mask. Though the debate is going on regarding the airborne transmission of SARS-CoV-2 it makes reasonable point for universal use of face masks. A large variety of face masks are available in the market or people can make their own using household items. The efficacy of masks depends upon the type of cloth and number of layers of the cloth. Material and methodsWe have created an innovative mask with two layers of cotton and an impervious layer. The impervious layer made from polypropylene coated with polyurethane was applied on the outer side in the middle half of the mask in front of mouth and nose. The efficacy of this test mask was measured against N95FFR (reference standard), triple layer surgical masks and single layer cotton mask. A manikin was used wearing these masks/respirator and aerosols/droplets of diluted red coloured carbol fuchsin and fluorescent Auramine O were sprayed from distance of 1m and 2m. We also tested use of face shield. Both macroscopic and microscopic examination of the dissected masks and respirator was performed. ResultsThe N95FFR was able to block the aerosols/droplets by its front layer. One triple layer surgical mask showed microscopic presence of stain in its innermost layer while the other blocked it with middle layer. The single layer cotton mask was not able to protect as we observed stain on the face itself. The test mask blocked most of the stain on impervious layer and also on the front cotton layer on lateral sides, where impervious layer was absent. When fluorescent stain was used, ultraviolet examination demonstrated that the whole area covered by test mask was clean while the other non covered area was fluorescent. ConclusionWe believe that our innovation can be used in the community as well as in general areas of the hospital like, offices, labs, etc. and can be a better alternative to single use triple layer surgical masks. Further testing may be done by other organizations to rule out bias in our study.

ObjectiveTo describe four unique models of implementing Wastewater Based Surveillance (WBS) for SARS-CoV-2 in jails of graduated sizes and differing architectural designs. MethodsThis study summarizes how jails of Cook County (Illinois, average daily population [ADP] 6000), Fulton County (Georgia, ADP 3000, Washington DC (ADP 1600) and Middlesex County (Massachusetts, ADP 875) initiated WBS between 2020 and 2023. ResultsPositive signal for SARS-CoV-2 via WBS can herald new onset of infection in a previously uninfected housing unit of a jail. Challenges in implementing WBS included political will and realized value, funding, understanding of the building architecture, and the need for granularity in the findings. ConclusionsWBS has been effective for detecting outbreaks of SARS-CoV-2 in differing sized jails, both those with dorm-based and cell-based architectural design. Policy implicationsGiven its effectiveness in monitoring SARS-CoV-2, WBS provides a model for population-based surveillance in carceral facilities for future infectious disease outbreaks.

BackgroundThere is a significant transmission of contaminants in the healthcare setting. Daily disinfection utilizing ammonium and chlorine-based products can lead to adverse health effects such as asthma, cancer, and other serious health issues. MethodsThis study evaluated the effectiveness of eraDOCator-60 in a health care facility. This randomized trial took place at Copley Hospital in Morristown, Vermont. Separate areas of the hospital were cleaned and disinfected in one step with eraDOCator-60. A Charm analyzer was utilized to evaluate the efficacy of disinfection before and after 1 minute application of eraDOCator-60. The Charm analyzer detects Adenosine Triphosphate (ATP) presence measured in Relative Light Units (RLUs). ResultsThe median number of RLUs decreased from 52,874 s to 0 RLUs after one-minute eraDOCator-60 dwell time in the emergency room; 18.611 RLUs to 0 RLUs in the medical-surgical unit, 41,507 RLUs to 0 RLUs in the cafeteria; 24,932 RLUs to 0 RLUs in the birthing center. ConclusionsEraDOCator-60 reduced contamination levels on all surfaces in the acute care setting down to a value of zero following a 1-minute dwell time in less than 5% soil load.

BackgroundAirborne microorganisms contribute significantly to hospital-associated infections (HAIs), particularly causing respiratory tract infections (RTIs). Multi-drug resistant (MDR) airborne pathogens pose a global clinical threat, challenging existing air decontamination technologies. While current methods effectively trap microbes, they often lack microbicidal properties. Exploitation of Zeta potential of microbes which are naturally charged could be a potential strategy for air decontamination, independent of their antimicrobial resistance. In this study, we tested the efficacy of ZeBox technology which relies on zeta potential to trap and eliminate airborne pathogens such as clinically isolated, MDR Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Escherichia coli of respiratory origin and a non RTI isolate Staphylococcus aureus. MethodsFive MDR bacterial pathogens which include K. pneumoniae (2 nos), A. baumannii, P. aeruginosa, and E. coli from patients with RTI and one pus isolate of S. aureus were included in the study. These isolates were aerosolized in a certified BSL-2 setting containing a ZeBox-powered Air Sterilization device. Viable bacteria were enumerated before and after exposure to the Zebox powered device. Clinical and laboratory isolated bacterial strains were assessed for zeta potential variations to understand its association with antibiotic resistance and pathogenicity. ResultsOur analyses revealed that Zeta potential is species specific, but independent of the pathogenicity and antibiotic susceptibility of the tested bacteria. Exposure to Zebox powered device for 5 mins resulted in a remarkable decline of microbial load with a minimum 5 log reduction (99.999%) of all the tested isolates, irrespective of their species. Zeta potential measurements further indicated a consistent killing mechanism of MDR pathogens by Zebox technology. ConclusionsThe current study underscores the reliability of zeta potential based air decontamination strategies for potential elimination of diverse, air borne MDR bacteria in healthcare settings. HighlightsO_LIZeta potential value of bacteria is not influenced by AST or pathogenicity of bacteria. C_LIO_LIZeta potential driven device traps and kills airborne MDR bacteria with 99.999% efficiency. C_LIO_LIThe efficacy of ZeBox technology is consistent across pathogens. C_LI

Structured abstractO_ST_ABSObjectivesC_ST_ABSWe aimed to design and produce a low-cost, ergonomic, hood-integrated Powered Air-Purifying Respirator (Bubble-PAPR) for pandemic healthcare use, offering optimal and equitable protection to all staff. We hypothesised that participants would rate Bubble-PAPR more highly than current FFP3 face mask respiratory protective equipment (RPE). DesignRapid design and evaluation cycles occurred based on the identified user needs. We conducted diary card and focus group exercises to identify relevant tasks requiring RPE. Lab-based safety standards established against British Standard BS-EN-12941 and EU2016/425. Questionnaire-based usability data from participating frontline healthcare staff before (usual RPE) and after using Bubble-PAPR. SettingOverseen by a trial safety committee, evaluation progressed sequentially through laboratory, simulated, low-risk, then high-risk clinical environments of a single tertiary NHS hospital. Participants15 staff completed diary cards and focus groups. 91 staff from a range of clinical and non-clinical roles completed the study, wearing Bubble-PAPR for a median of 45 minutes (IQR 30-80 [15-120]). Participants self-reported a range of heights (mean 1.7m [SD 0.1, range 1.5-2.0]), weights (72.4kg [16.0, 47-127]) and body mass indices (25.3 [4.7,16.7-42.9]). Outcome measuresPrimary: "How comfortable do you feel in your PPE?" (Likert scale bounded by 1 [very uncomfortable] to 7 [very comfortable]). Secondary outcomes: perceived safety, communication, anxiety, discomfort, and performance. ResultsBubble-PAPR mean comfort score was 5.64(SD 1.55) versus usual FFP3 2.96(1.44) (mean difference 2.68 (95% CI 2.23-3.14, p<0.001). There was a significant difference in favour of Bubble-PAPR across all secondary outcomes. ConclusionsBubble-PAPR achieved its primary purpose of keeping staff safe from airborne particulate material whilst improving comfort and the user experience. The design and development of Bubble-PAPR were conducted using a careful evaluation strategy addressing key regulatory and safety steps, in contrast to many devices rapidly developed and deployed during the pandemic. Trial registrationIRAS ID:288493, REC Ref:21/WA/0018. ClinicalTrials.gov (NCT04681365). Strengths and limitations of this studyO_LIWe employed user-centred design, engineering optimisation and staged feasibility testing to develop a novel Powered Air-Purifying Respirator (Bubble-PAPR) for use specifically in frontline healthcare settings. C_LIO_LIDiverse, frontline healthcare staff compared Bubble-PAPR with usual FFP3 face masks. C_LIO_LIThe design and development of Bubble-PAPR were conducted using a careful strategy addressing key regulatory and safety steps, in contrast to many devices rapidly developed and deployed during the pandemic. C_LIO_LIBubble-PAPR is an excellent example of developing a cosmopolitan network that could become a key feature of future system resilience. C_LI

During the Covid-19 pandemic, pristine and reprocessed N95 respirators are crucial equipment towards limiting nosocomial infections. The NIOSH test certifying the N95 rating, however, poorly simulates aerosols in healthcare settings, limiting our understanding of the exposure risk for healthcare workers wearing these masks, especially reprocessed ones. We used experimental conditions that simulated the sizes, densities and airflow properties of infectious aerosols in healthcare settings. We analyzed the penetration and leakage of aerosols through pristine and reprocessed N95 respirators. Seven reprocessing methods were investigated. Our findings suggest that pristine and properly reprocessed N95 respirators effectively limit exposure to infectious aerosols, but that care must be taken to avoid the elucidated degradation mechanisms and limit noncompliant wear.

BackgroundFace shields are used as an alternative to facemasks, but their effectiveness in mitigating the spread of SARS-CoV-2 is unclear. The goal of this study is to compare the performance of face shields, surgical facemasks, and cloth facemasks for mitigation of droplet transmission during close contact conditions. MethodsA novel test system was developed to simulate droplet transmission during close contact conditions using two breathing headforms (transmitter and receiver) placed 4 feet apart with one producing droplets containing a DNA marker. Sampling coupons were placed throughout the test setup and subsequently analyzed for presence of DNA marker using quantitative PCR. ResultsAll PPE donned on the transmitter headform provided a significant reduction in transmission of DNA marker to the receiver headform: cloth facemask (78.5%), surgical facemask (89.4%), and face shield (96.1%). All PPE resulted in increased contamination of the eye region of the transmitter headform (9,525.4% average for facemasks and 765.8% for the face shield). Only the face shield increased contamination of the neck region (207.4%), with the cloth facemask and surgical facemask resulting in reductions of 85.9% and 90.2%, respectively. ConclusionsThis study demonstrates face shields can provide similar levels of protection against direct droplet exposure compared to surgical and cloth masks. However, all PPE tested resulted in release of particles that contaminated surfaces. Contamination caused by deflection of the users exhalation prompts concerns for contact transmission via surfaces in exhalation flow path (e.g., face, eyeglasses, etc.).

BackgroundHospital-acquired infections are a major public health problem, as they increase hospitalization, cost, morbidity, mortality and antibiotic resistance. AimTo assess the level of knowledge and practices of health professionals about hospital infections in surgical clinics and investigate possible determinants that affects their compliance with international protocols for prevention and control of hospital infections. MethodsA cross-sectional study with a convenience sample was conducted. Study population included 106 health professionals from medical and nursing staff in surgical clinics of a general hospital in Attica. Data collection was conducted during October and December 2019. We used the Healthcare-Associated Infections questionnaire to measure knowledge and practices of health professionals about hospital infections. ResultsThe mean overall knowledge score for hospital infections was 59.4, indicating a moderate level of knowledge. The highest level of knowledge was about the safety of healthcare professionals, while the lowest level was about the source of hospital infections. The results of the multivariate linear regression showed that participants who were aware of the infection control program at their hospital and knew they had to wash their hands following the six steps of the hand hygiene protocol had a higher level of knowledge score regarding hospital infections. In contrast, participants who felt that their hospital was following a good infection control and prevention strategy had a lower level of knowledge. In addition, healthcare professionals who washed their hands before and after examining patients, after using medical equipment for patient care, throughout and after the end of the shift, and after removing disposable gloves had a higher level of knowledge for hospital infections. ConclusionsThe findings of the present study are consistent with the international literature on the existence of a moderate level of knowledge regarding international prevention guidelines. Compliance of healthcare professionals is essential to achieve universal, quality and safe healthcare and a safe working environment.

COVID-19 has demonstrated the devastating consequences of the rapid spread of an airborne virus in residential aged care. We report the use of CO2-based ventilation assessment to empirically identify potential "super-spreader" zones within an aged care facility, and determine the efficacy of rapidly implemented, inexpensive, risk reduction measures.