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1.
ACS Nano ; 14(7): 9188-9200, 2020 07 28.
Article in English | MEDLINE | ID: covidwho-1387153

ABSTRACT

Filtration efficiency (FE), differential pressure (ΔP), quality factor (QF), and construction parameters were measured for 32 cloth materials (14 cotton, 1 wool, 9 synthetic, 4 synthetic blends, and 4 synthetic/cotton blends) used in cloth masks intended for protection from the SARS-CoV-2 virus (diameter 100 ± 10 nm). Seven polypropylene-based fiber filter materials were also measured including surgical masks and N95 respirators. Additional measurements were performed on both multilayered and mixed-material samples of natural, synthetic, or natural-synthetic blends to mimic cloth mask construction methods. Materials were microimaged and tested against size selected NaCl aerosol with particle mobility diameters between 50 and 825 nm. Three of the top five best performing samples were woven 100% cotton with high to moderate yarn counts, and the other two were woven synthetics of moderate yarn counts. In contrast to recently published studies, samples utilizing mixed materials did not exhibit a significant difference in the measured FE when compared to the product of the individual FE for the components. The FE and ΔP increased monotonically with the number of cloth layers for a lightweight flannel, suggesting that multilayered cloth masks may offer increased protection from nanometer-sized aerosol with a maximum FE dictated by breathability (i.e., ΔP).


Subject(s)
Coronavirus Infections/prevention & control , Masks/standards , Pandemics/prevention & control , Personal Protective Equipment/standards , Pneumonia, Viral/prevention & control , Respiratory Protective Devices/standards , Textiles/standards , Aerosols/chemistry , Betacoronavirus/pathogenicity , COVID-19 , Filtration , Humans , Masks/virology , Nanoparticles/chemistry , Nanoparticles/virology , Personal Protective Equipment/virology , Respiratory Protective Devices/virology , SARS-CoV-2 , Textiles/adverse effects , Textiles/virology
2.
J Occup Environ Hyg ; 18(7): 345-360, 2021 07.
Article in English | MEDLINE | ID: covidwho-1269471

ABSTRACT

First responders may have high SARS-CoV-2 infection risks due to working with potentially infected patients in enclosed spaces. The study objective was to estimate infection risks per transport for first responders and quantify how first responder use of N95 respirators and patient use of cloth masks can reduce these risks. A model was developed for two Scenarios: an ambulance transport with a patient actively emitting a virus in small aerosols that could lead to airborne transmission (Scenario 1) and a subsequent transport with the same respirator or mask use conditions, an uninfected patient; and remaining airborne SARS-CoV-2 and contaminated surfaces due to aerosol deposition from the previous transport (Scenario 2). A compartmental Monte Carlo simulation model was used to estimate the dispersion and deposition of SARS-CoV-2 and subsequent infection risks for first responders, accounting for variability and uncertainty in input parameters (i.e., transport duration, transfer efficiencies, SARS-CoV-2 emission rates from infected patients, etc.). Infection risk distributions and changes in concentration on hands and surfaces over time were estimated across sub-Scenarios of first responder respirator use and patient cloth mask use. For Scenario 1, predicted mean infection risks were reduced by 69%, 48%, and 85% from a baseline risk (no respirators or face masks used) of 2.9 × 10-2 ± 3.4 × 10-2 when simulated first responders wore respirators, the patient wore a cloth mask, and when first responders and the patient wore respirators or a cloth mask, respectively. For Scenario 2, infection risk reductions for these same Scenarios were 69%, 50%, and 85%, respectively (baseline risk of 7.2 × 10-3 ± 1.0 × 10-2). While aerosol transmission routes contributed more to viral dose in Scenario 1, our simulations demonstrate the ability of face masks worn by patients to additionally reduce surface transmission by reducing viral deposition on surfaces. Based on these simulations, we recommend the patient wear a face mask and first responders wear respirators, when possible, and disinfection should prioritize high use equipment.


Subject(s)
COVID-19/transmission , Infectious Disease Transmission, Patient-to-Professional/prevention & control , Masks/virology , N95 Respirators/virology , SARS-CoV-2 , Aerosols , Air Microbiology , Ambulances , COVID-19/prevention & control , Computer Simulation , Emergency Responders , Equipment Contamination , Humans , Monte Carlo Method , Respiratory Protective Devices/virology , Risk Reduction Behavior , Transportation of Patients
3.
Infect Control Hosp Epidemiol ; 42(4): 381-387, 2021 04.
Article in English | MEDLINE | ID: covidwho-1189143

ABSTRACT

OBJECTIVE: To characterize associations between exposures within and outside the medical workplace with healthcare personnel (HCP) SARS-CoV-2 infection, including the effect of various forms of respiratory protection. DESIGN: Case-control study. SETTING: We collected data from international participants via an online survey. PARTICIPANTS: In total, 1,130 HCP (244 cases with laboratory-confirmed COVID-19, and 886 controls healthy throughout the pandemic) from 67 countries not meeting prespecified exclusion (ie, healthy but not working, missing workplace exposure data, COVID symptoms without lab confirmation) were included in this study. METHODS: Respondents were queried regarding workplace exposures, respiratory protection, and extra-occupational activities. Odds ratios for HCP infection were calculated using multivariable logistic regression and sensitivity analyses controlling for confounders and known biases. RESULTS: HCP infection was associated with non-aerosol-generating contact with COVID-19 patients (adjusted OR, 1.4; 95% CI, 1.04-1.9; P = .03) and extra-occupational exposures including gatherings of ≥10 people, patronizing restaurants or bars, and public transportation (adjusted OR range, 3.1-16.2). Respirator use during aerosol-generating procedures (AGPs) was associated with lower odds of HCP infection (adjusted OR, 0.4; 95% CI, 0.2-0.8, P = .005), as was exposure to intensive care and dedicated COVID units, negative pressure rooms, and personal protective equipment (PPE) observers (adjusted OR range, 0.4-0.7). CONCLUSIONS: COVID-19 transmission to HCP was associated with medical exposures currently considered lower-risk and multiple extra-occupational exposures, and exposures associated with proper use of appropriate PPE were protective. Closer scrutiny of infection control measures surrounding healthcare activities and medical settings considered lower risk, and continued awareness of the risks of public congregation, may reduce the incidence of HCP infection.


Subject(s)
COVID-19/transmission , Infectious Disease Transmission, Patient-to-Professional/prevention & control , Adult , Aged , COVID-19/prevention & control , Case-Control Studies , Female , Global Health/statistics & numerical data , Humans , Infectious Disease Transmission, Patient-to-Professional/statistics & numerical data , Logistic Models , Male , Middle Aged , Occupational Exposure/prevention & control , Occupational Exposure/statistics & numerical data , Personal Protective Equipment/statistics & numerical data , Personal Protective Equipment/virology , Respiratory Protective Devices/statistics & numerical data , Respiratory Protective Devices/virology , Young Adult
4.
PLoS One ; 16(3): e0248099, 2021.
Article in English | MEDLINE | ID: covidwho-1115311

ABSTRACT

Since the appearance of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the question regarding the efficacy of various hygiene measures and the use of personal protective equipment (PPE) has become the focus of scientific and above all public discussion. To compare respirators, medical face masks, and cloth masks and determine if it is recommendable to wear face masks to protect the individual wearer of the mask from inhaling airborne particles, we challenged 29 different masks with aerosols and tested the pressure drop as a surrogate for breathing resistance owing to the mask material. We found that Type II medical face masks showed the lowest pressure drop (12.9±6.8 Pa/cm2) and therefore additional breathing resistance, whereas respirators such as the KN95 (32.3±7.0 Pa/cm2) and FFP2 (26.8±7.4 Pa/cm2) showed the highest pressure drops among the tested masks. The filtration efficacy of the mask material was the lowest for cloth masks (28±25%) followed by non-certified face masks (63±19%) and certified medical face masks (70±10%). The materials of the different respirators showed very high aerosol retentions (KN95 [94±4%] and FFP2 [98±1%]). For evaluating the as-worn filtration performance simulating real live conditions each mask type was also tested on a standardized dummy head. Cloth masks and non-EN-certified face masks had the worst as-worn filtration efficacies among the tested masks, filtering less than 20% of the test aerosol. Remarkably, certified type II medical face masks showed similar (p>0.5) as-worn filtration results (47±20%) than KN95 masks (41±4%) and FFP2 masks (65±27%), despite having a lower pressure drop. Face shields did not show any significant retention function against aerosols in our experiment. Our results indicate that it seems recommendable to wear face masks for providing base protection and risk reduction against inhaling airborne particles, in low-risk situations. In our study, especially EN 14683 type II certified medical face masks showed protective effectiveness against aerosols accompanied by minimal additional breathing resistance. FFP2 Respirators, on the other hand, could be useful in high-risk situations but require greater breathing effort and therefore physical stress for users.


Subject(s)
COVID-19/transmission , Disease Transmission, Infectious/prevention & control , Masks/trends , Aerosols , COVID-19/epidemiology , Filtration , Humans , Models, Statistical , Occupational Exposure/prevention & control , Personal Protective Equipment/trends , Respiratory Protective Devices/virology , SARS-CoV-2/pathogenicity
5.
Am J Gastroenterol ; 116(1): 202-205, 2021 01 01.
Article in English | MEDLINE | ID: covidwho-1068052

ABSTRACT

INTRODUCTION: During the coronavirus disease 2019 pandemic, whether endoscopy generates aerosols needs to be determined. METHODS: In patients undergoing upper gastrointestinal endoscopy with an enclosure covering their heads, 0.3-10-µm aerosols were measured for 60 seconds before, during, and after endoscopy by an optical counter. Whether aerosols increased in the situation with and without endoscopy was examined. RESULTS: The analysis included 103 consecutive patients undergoing endoscopy and 90 control patients. Aerosols increased significantly during endoscopy compared with the control group. Body mass index and burping were significant factors related to increased aerosols during endoscopy. DISCUSSION: Upper gastrointestinal endoscopy was an aerosol-generating procedure.


Subject(s)
Aerosols/analysis , COVID-19 , Disease Transmission, Infectious/prevention & control , Endoscopy, Gastrointestinal , Gastrointestinal Diseases/diagnosis , Infection Control , Respiratory Protective Devices/virology , Respiratory System , COVID-19/epidemiology , COVID-19/prevention & control , Endoscopy, Gastrointestinal/adverse effects , Endoscopy, Gastrointestinal/methods , Female , Humans , Infection Control/instrumentation , Infection Control/methods , Japan/epidemiology , Male , Materials Testing , Middle Aged , Outcome Assessment, Health Care , Respiratory System/physiopathology , Respiratory System/virology , SARS-CoV-2
6.
Ann Work Expo Health ; 64(8): 775-777, 2020 10 08.
Article in English | MEDLINE | ID: covidwho-1060033

ABSTRACT

Many academics and researchers have responded to the COVID-19 pandemic by forming on-line national and international collaborative groups to rapidly investigate issues of prevention and treatment. This commentary describes the spontaneous formation of an international team of 115 researchers who summarized the literature on safe methods for decontaminating N95 filtering facepiece respirators in response to the supply crisis. The summary reports and fact sheets on the (www.n95decon.org) website have had more than 200 000 unique visits and the organization's webinars have reached health care professionals from more than 50 countries. The team is extending its mission to cover other personal protective equipment. The success of these collaborations may alter how scientific questions are tackled in the future.


Subject(s)
Coronavirus Infections/prevention & control , Decontamination/methods , International Cooperation , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , Respiratory Protective Devices , Betacoronavirus , COVID-19 , Equipment Contamination , Equipment Reuse , Humans , Occupational Exposure/prevention & control , Respiratory Protective Devices/supply & distribution , Respiratory Protective Devices/virology , SARS-CoV-2
7.
J Hosp Infect ; 106(3): 536-553, 2020 Nov.
Article in English | MEDLINE | ID: covidwho-1023641

ABSTRACT

BACKGROUND: In pandemics such as COVID-19, shortages of personal protective equipment are common. One solution may be to decontaminate equipment such as facemasks for reuse. AIM: To collect and synthesize existing information on decontamination of N95 filtering facepiece respirators (FFRs) using microwave and heat-based treatments, with special attention to impacts on mask function (aerosol penetration, airflow resistance), fit, and physical traits. METHODS: A systematic review (PROSPERO CRD42020177036) of literature available from Medline, Embase, Global Health, and other sources was conducted. Records were screened independently by two reviewers, and data was extracted from studies that reported on effects of microwave- or heat-based decontamination on N95 FFR performance, fit, physical traits, and/or reductions in microbial load. FINDINGS: Thirteen studies were included that used dry/moist microwave irradiation, heat, or autoclaving. All treatment types reduced pathogen load by a log10 reduction factor of at least three when applied for sufficient duration (>30 s microwave, >60 min dry heat), with most studies assessing viral pathogens. Mask function (aerosol penetration <5% and airflow resistance <25 mmH2O) was preserved after all treatments except autoclaving. Fit was maintained for most N95 models, though all treatment types caused observable physical damage to at least one model. CONCLUSIONS: Microwave irradiation and heat may be safe and effective viral decontamination options for N95 FFR reuse during critical shortages. The evidence does not support autoclaving or high-heat (>90°C) approaches. Physical degradation may be an issue for certain mask models, and more real-world evidence on fit is needed.


Subject(s)
Coronavirus Infections/prevention & control , Decontamination/standards , Equipment Reuse/standards , Guidelines as Topic , Hot Temperature , Respiratory Protective Devices/virology , Ultraviolet Rays , Humans
8.
J Hosp Infect ; 108: 113-119, 2021 Feb.
Article in English | MEDLINE | ID: covidwho-1014625

ABSTRACT

BACKGROUND: The coronavirus disease 2019 pandemic has caused problems with respirator supplies. Re-use may minimize the impact of the shortage, but requires the availability of an efficient and safe decontamination method. AIM: To determine whether low-temperature-steam-2%-formaldehyde (LTSF) sterilization is effective, preserves the properties of filtering facepiece (FFP) respirators and allows safe re-use. METHODS: Fourteen unused FFP2, FFP3 and N95 respirator models were subjected to two cycles of decontamination cycles. After the second cycle, each model was inspected visually and accumulated residual formaldehyde levels were analysed according to EN 14180. After one and two decontamination cycles, the fit factor (FF) of each model was tested, and penetration tests with sodium chloride aerosols were performed on five models. FINDINGS: Decontamination physically altered three of the 14 models. All of the residual formaldehyde values were below the permissible threshold. Irregular decreases and increases in FF were observed after each decontamination cycle. In the sodium chloride aerosol penetration test, three models obtained equivalent or superior results to those of the FFP classification with which they were marketed, both at baseline and after one and two cycles of decontamination, and two models had lower filtering capacity. CONCLUSION: One and two decontamination cycles using LTSF did not alter the structure of most (11/14) respirators tested, and did not degrade the fit or filtration capacity of any of the analysed respirators. The residual formaldehyde levels complied with EN 14180. This reprocessing method could be used in times of shortage of personal protective equipment.


Subject(s)
Decontamination/methods , Formaldehyde/pharmacology , Respiratory Protective Devices/virology , Sterilization/methods , Adult , Aerosols/adverse effects , COVID-19/diagnosis , COVID-19/epidemiology , COVID-19/prevention & control , COVID-19/virology , Equipment Reuse , Formaldehyde/analysis , Humans , Male , Masks/trends , Masks/virology , Personal Protective Equipment/supply & distribution , Respiratory Protective Devices/supply & distribution , SARS-CoV-2/genetics , Sodium Chloride/analysis , Steam/adverse effects , Ventilators, Mechanical/supply & distribution , Ventilators, Mechanical/virology
9.
Am J Infect Control ; 49(4): 424-429, 2021 04.
Article in English | MEDLINE | ID: covidwho-917197

ABSTRACT

BACKGROUND: Filtering facepiece respirators (FFR) are critical for protecting essential personnel and limiting the spread of disease. Due to the current COVID-19 pandemic, FFR supplies are dwindling in many health systems, necessitating re-use of potentially contaminated FFR. Multiple decontamination solutions have been developed to meet this pressing need, including systems designed for bulk decontamination of FFR using vaporous hydrogen peroxide or ultraviolet-C (UV-C) radiation. However, the large scale on which these devices operate may not be logistically practical for small or rural health care settings or for ad hoc use at points-of-care. METHODS: Here, we present the Synchronous UV Decontamination System, a novel device for rapidly deployable, point-of-care decontamination using UV-C germicidal irradiation. We designed a compact, easy-to-use device capable of delivering over 2 J cm2 of UV-C radiation in one minute. RESULTS: We experimentally tested Synchronous UV Decontamination System' microbicidal capacity and found that it eliminates near all virus from the surface of tested FFRs, with less efficacy against pathogens embedded in the inner layers of the masks. CONCLUSIONS: This short decontamination time should enable care-providers to incorporate decontamination of FFR into a normal donning and doffing routine following patient encounters.


Subject(s)
COVID-19/prevention & control , Decontamination/instrumentation , Point-of-Care Systems , Respiratory Protective Devices/virology , SARS-CoV-2 , Ultraviolet Rays , COVID-19/virology , Decontamination/methods , Equipment Reuse , Humans
11.
J Hosp Infect ; 106(4): 698-708, 2020 Dec.
Article in English | MEDLINE | ID: covidwho-813690

ABSTRACT

BACKGROUND: Coronavirus disease 2019 (COVID-19) has significantly impacted the health of millions of people around the world. The shortage of personal protective equipment, including N95 respirators, in hospital facilities has put frontline healthcare professionals at high risk for contracting this virus. AIM: To develop a reproducible and safe N95 respirator reprocessing method that satisfies all presented regulatory standards and that can be directly implemented by hospitals using existing available equipment. METHODS: A non-toxic gravity steam reprocessing method has been developed for the reuse of N95 respirators consisting of 30 min of steam treatment at 121°C followed by 30 min of heat drying. Samples of model number 1860, 1860s, 1870+, and 9105 N95 respirators were either collected from hospitals (for microbiology testing) or purchased new (for functionality testing), with all functionality tests (i.e. filter efficiency, fit evaluation, and strap integrity) performed at the Centers for Disease Control and Prevention using standard procedures established by the National Institute for Occupational Safety and Health. FINDINGS: All tested models passed the minimum filter efficiency of 95% after three cycles of gravity steam reprocessing. The 1870+ N95 respirator model is the most promising model for reprocessing based on its efficient bacterial inactivation coupled with the maintenance of all other key functional respirator properties after multiple reprocessing steps. CONCLUSIONS: The gravity steam method can effectively reprocess N95 respirators over at least three reprocessing cycles without negatively impacting the functionality requirements set out by regulators. Enabling the reuse of N95 respirators is a crucial tool for managing both the current pandemic and future healthcare crises.


Subject(s)
COVID-19/transmission , Equipment Reuse/standards , N95 Respirators/supply & distribution , Steam/adverse effects , Sterilization/instrumentation , COVID-19/diagnosis , COVID-19/epidemiology , COVID-19/virology , Centers for Disease Control and Prevention, U.S./organization & administration , Decontamination/methods , Disease Transmission, Infectious/prevention & control , Health Facilities/standards , Health Facilities/statistics & numerical data , Humans , N95 Respirators/standards , National Institute for Occupational Safety and Health, U.S./organization & administration , Personal Protective Equipment/supply & distribution , Respiratory Protective Devices/standards , Respiratory Protective Devices/virology , SARS-CoV-2/genetics , United States
12.
J Hosp Infect ; 106(3): 577-584, 2020 Nov.
Article in English | MEDLINE | ID: covidwho-809252

ABSTRACT

BACKGROUND: In the context of the ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, the supply of personal protective equipment remains under severe strain. To address this issue, re-use of surgical face masks and filtering facepiece respirators has been recommended; prior decontamination is paramount to their re-use. AIM: We aim to provide information on the effects of three decontamination procedures on porcine respiratory coronavirus (PRCV)-contaminated masks and respirators, presenting a stable model for infectious coronavirus decontamination of these typically single-use-only products. METHODS: Surgical masks and filtering facepiece respirator coupons and straps were inoculated with infectious PRCV and submitted to three decontamination treatments, ultraviolet (UV) irradiation, vaporized H2O2, and dry heat treatment. Viruses were recovered from sample materials and viral titres were measured in swine testicle cells. FINDINGS: UV irradiation, vaporized H2O2 and dry heat reduced infectious PRCV by more than three orders of magnitude on mask and respirator coupons and rendered it undetectable in all decontamination assays. CONCLUSION: This is the first description of stable disinfection of face masks and filtering facepiece respirators contaminated with an infectious SARS-CoV-2 surrogate using UV irradiation, vaporized H2O2 and dry heat treatment. The three methods permit demonstration of a loss of infectivity by more than three orders of magnitude of an infectious coronavirus in line with the United States Food and Drug Administration policy regarding face masks and respirators. It presents advantages of uncomplicated manipulation and utilization in a BSL2 facility, therefore being easily adaptable to other respirator and mask types.


Subject(s)
Coronavirus Infections/prevention & control , Decontamination/standards , Equipment Reuse/standards , Hot Temperature , Hydrogen Peroxide/standards , Respiratory Protective Devices/virology , Surgical Equipment/standards , Surgical Equipment/virology , Ultraviolet Rays , Guidelines as Topic , Humans
14.
Am J Infect Control ; 48(12): 1457-1461, 2020 12.
Article in English | MEDLINE | ID: covidwho-713731

ABSTRACT

BACKGROUND: To address the shortage of N95 respirators in the wake of the COVID-19 pandemic, some organizations have recommended the decontamination of respirators using vaporized hydrogen peroxide (VHP) sterilizer for up to 10 times. However, these recommendations are based on studies that did not take into account the extended use of respirators, which can degrade respirator fit. METHODS: We investigated the impact of extended use and decontamination with VHP on N95 Respirator Fit. We performed a prospective cohort study to determine the number of times respirators can be decontaminated before respirator fit test failure. The primary outcome was the overall number of cycles required for half of the respirators to fail (either mechanical failure or fit test failure). RESULTS: Thirty-six participants completed 360 hours of respirator usage across 90 cycles. The median number of cycles completed by participants before respirator failure was 2. The overall number of cycles required for half of respirators to fail was 1, 3, 5, and 4 for the 3M 1860(S), 3M 1870+, Moldex 151X and ProGear 88020 respirators, respectively. CONCLUSIONS: The combination of prolonged usage and VHP decontamination was associated with early failure. Decontamination and prolonged usage of respirators must be done cautiously.


Subject(s)
COVID-19/prevention & control , Decontamination/methods , Equipment Reuse , N95 Respirators/virology , Respiratory Protective Devices/virology , Adult , Decontamination/standards , Female , Humans , Hydrogen Peroxide , Male , Prospective Studies , SARS-CoV-2 , Volatilization
15.
J Hosp Infect ; 106(3): 504-521, 2020 Nov.
Article in English | MEDLINE | ID: covidwho-709227

ABSTRACT

BACKGROUND: Decontaminating and reusing filtering facepiece respirators (FFRs) for healthcare workers is a potential solution to address inadequate FFR supply during a global pandemic. AIM: The objective of this review was to synthesize existing data on the effectiveness and safety of using chemical disinfectants to decontaminate N95 FFRs. METHODS: A systematic review was conducted on disinfectants to decontaminate N95 FFRs using Embase, Medline, Global Health, Google Scholar, WHO feed, and MedRxiv. Two reviewers independently determined study eligibility and extracted predefined data fields. Original research reporting on N95 FFR function, decontamination, safety, or FFR fit following decontamination with a disinfectant was included. FINDINGS AND CONCLUSION: A single cycle of vaporized hydrogen peroxide (H2O2) successfully removes viral pathogens without affecting airflow resistance or fit, and maintains an initial filter penetration of <5%, with little change in FFR appearance. Residual hydrogen peroxide levels following decontamination were within safe limits. More than one decontamination cycle of vaporized H2O2 may be possible but further information is required on how multiple cycles would affect FFR fit in a real-world setting before the upper limit can be established. Although immersion in liquid H2O2 does not appear to adversely affect FFR function, there is no available data on its ability to remove infectious pathogens from FFRs or its impact on FFR fit. Sodium hypochlorite, ethanol, isopropyl alcohol, and ethylene oxide are not recommended due to safety concerns or negative effects on FFR function.


Subject(s)
Coronavirus Infections/prevention & control , Decontamination/standards , Disinfectants/administration & dosage , Equipment Reuse/standards , Hydrogen Peroxide/administration & dosage , Respiratory Protective Devices/virology , Sodium Hypochlorite/administration & dosage , Guidelines as Topic , Humans , Ultraviolet Rays
17.
Am J Infect Control ; 49(3): 309-318, 2021 03.
Article in English | MEDLINE | ID: covidwho-679501

ABSTRACT

BACKGROUND: The pandemic coronavirus disease 2019 (COVID-19) has taken a heavy toll on human life and has upended the medical system in many countries. The disease has created a system wide worsening shortage of N95, medical masks, and other personal protective equipment (PPE) that is regularly used by healthcare personnel and emergency service providers for their protection. AIM: Considering the number of infected patients and the stressed supplies of PPE, reuse of PPE can serve as an efficient contingency plan. Multiple studies have investigated the effect of different decontamination methods. METHODS: We chose the most user-friendly, easily scalable viral decontamination methods, including ultraviolet irradiation and heat treatment. In this paper, we investigated a unique approach to reuse the mask by creating a hybrid model that efficiently sanitizes the infected mask. RESULTS: The advantages of the proposed hybrid model as compared to the respective single arms is its decontamination efficacy, operational speed, as well as the number of reuse cycles as verified by mathematical analysis and simulation. This model is mainly intended for medical PPE but can also be used for other domestic and personal sanitization during the COVID-19 pandemic. As per the situation, the hybrid system can be used as standalone systems also. This sanitization process is not only limited to the elimination of Severe acute respiratory syndrome coronavirus 2 but can be extended to any other infectious agents. Thus, our results indicate that the proposed hybrid system is more effective, meets disinfection criterion and time saving for the reuse of respirators and PPE.


Subject(s)
Disinfection/methods , Hot Temperature , Personal Protective Equipment/virology , SARS-CoV-2/radiation effects , Ultraviolet Rays , COVID-19/prevention & control , Decontamination/methods , Equipment Reuse , Humans , Masks/virology , Respiratory Protective Devices/virology
19.
Am J Infect Control ; 49(2): 274-275, 2021 02.
Article in English | MEDLINE | ID: covidwho-645687

ABSTRACT

The use of surgical sterilization wrap for respirator masks during the COVID-19 crisis has become a popularized personal protective equipment alternative option due to claims supporting its ability to meet N95 standards. This study sought to assess these claims using standardized filter testing. The tested material failed to meet N95 standards and suggests its use may place medical personnel at increased risk of harm when managing COVID-19 patients.


Subject(s)
COVID-19/prevention & control , Equipment Design/adverse effects , Masks/virology , Materials Testing/statistics & numerical data , Respiratory Protective Devices/virology , SARS-CoV-2/isolation & purification , Aerosols/isolation & purification , COVID-19/virology , Equipment Design/standards , Health Personnel , Humans , Masks/standards , Respiratory Protective Devices/standards , Sterilization
20.
J Hosp Infect ; 106(1): 10-19, 2020 Sep.
Article in English | MEDLINE | ID: covidwho-635297

ABSTRACT

BACKGROUND: In the wake of the SARS-CoV-2 pandemic and unprecedented global demand, clinicians are struggling to source adequate access to personal protective equipment. Respirators can be in short supply, though are necessary to protect workers from SARS-CoV-2 exposure. Rapid decontamination and reuse of respirators may provide relief for the strained procurement situation. METHOD: In this study, we investigated the suitability of 70°C dry heat and microwave-generated steam (MGS) for reprocessing of FFP2/N95-type respirators, and Type-II surgical face masks. Staphylococcus aureus was used as a surrogate as it is less susceptible than enveloped viruses to chemical and physical processes. RESULTS: We observed >4 log10 reductions in the viability of dry S. aureus treated by dry heat for 90 min at 70°C and >6 log10 reductions by MGS for 90 s. After 3 reprocessing cycles, neither process was found to negatively impact the bacterial or NaCl filtration efficiency of the respirators that were tested. However, MGS was incompatible with Type-II surgical masks tested, as we confirmed that bacterial filtration capacity was completely lost following reprocessing. MGS was observed to be incompatible with some respirator types due to arcing observed around some types of metal nose clips and by loss of adhesion of clips to the mask. CONCLUSION: Considering the advantages and disadvantages of each approach, we propose a reprocessing personal protective equipment/face mask workflow for use in medical areas.


Subject(s)
Coronavirus Infections/prevention & control , Decontamination/methods , Equipment Reuse/standards , Hot Temperature , Masks/virology , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , Respiratory Protective Devices/virology , Steam , Betacoronavirus , COVID-19 , Guidelines as Topic , Humans , Microwaves , SARS-CoV-2
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