Proposal for a EN 149 acceptable reprocessing method for FFP2 respirators in times of severe shortage

Integrity and filtration efficiency of decontaminated N95/PFF2 masks to protect health care professionals against COVID-19: A systematic literature review and meta-analysis

BACKGROUND

To evaluate the evidence related to maintaining the integrity and filtration efficiency of N95 and/or PFF2 respirators after decontamination in health care professionals' protection against COVID-19.

METHODS

Systematic review, developed based on the guidelines from Joanna Briggs Institute for syntheses focusing on effectiveness evidence. The protocol was registered on the International Prospective Register of Ongoing Systematic Reviews platform, under the number CRD42022354256. This study report was developed in accordance with the guidelines recommended by the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Publications between January 2020 and August 2022 were selected of Embase, Medline, CINAHL, Web of Science, Cochrane, SciELO and Virtual Health Library databases. Joanna Briggs critical appraisal tool for nonrandomized experimental tests was used to evaluate the evidence quality.

RESULTS

Seven articles were included in the data extraction and critical evaluation, and 3 in the meta-analysis. Four studies evaluated the integrity by visual inspection and 2 by electron microscopy. There was no association between the number of cycles increase and the reduction in filtration in up to 10 cycles. None study was considered of high methodological quality.

CONCLUSIONS

There is some evidence that integrity and filtration capacity were maintained after decontamination of N95/PFF2 respirators to prevent COVID-19.

Evaluating the effects of air disinfectants in decontamination of COVID-19 aerosols

Introduction

Airborne transmission is the most  crucial mode of COVID-19 transmission. Therefore, disinfecting the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) aerosols float can have important implications in limiting COVID-19 transmission. Herein, we aimed to review the studies that utilized various disinfectants to decontaminate and inactivate the SARS-CoV-2 aerosols.

Methods

This study was a review that studied related articles published between December 1, 2019 and August 23, 2022. We searched the online databases of PubMed, Scopus, Web of Science, Cochrane, on August 23, 2021. The studies were downloaded into the EndNote software, duplicates were removed, and then the studies were screened based on the inclusion/exclusion criteria. The screening process involved two steps; first, the studies were screened based on their title and abstract and then their full texts. The included studies were used for the qualitative analysis.

Results

From 664 retrieved records, only 31 met the inclusion criteria and were included in the final qualitative analysis. Various materials like Ozone, H₂O₂, alcohol, and TiO₂ and methods like heating and using Ultraviolet were described in these studies to disinfect places contaminated by COVID-19. It appeared that the efficacy of these disinfectants varies considerably depending on the situation, time, and ultimately their mode of application.

Conclusion

Following reliable protocols in combination with the proper selection of disinfectant agents for each purpose would serve to achieve desired elimination of the SARS-CoV-2 transmission.

Large-scale decontamination of disposable FFP2 and FFP3 respirators by hydrogen peroxide vapour, Finland, April to June 2020

BackgroundThe shortage of FFP2 and FFP3 respirators posed a serious threat to the operation of the healthcare system at the onset of the COVID-19 pandemic.AimOur aim was to develop and validate a large-scale facility that uses hydrogen peroxide vapour for the decontamination of used respirators.MethodsA multidisciplinary and multisectoral ad hoc group of experts representing various organisations was assembled to implement the collection and transport of used FFP2 and FFP3 respirators from hospitals covering 86% of the Finnish population. A large-scale decontamination facility using hydrogen peroxide vapour was designed and constructed. Microbiological tests were used to confirm efficacy of hydrogen peroxide vapour decontamination together with a test to assess the effect of decontamination on the filtering efficacy and fit of respirators. Bacterial and fungal growth in stored respirators was determined by standard methods.ResultsLarge-scale hydrogen peroxide vapour decontamination of a range of FFP2 and FFP3 respirator models effectively reduced the recovery of biological indicators: Geobacillus stearothermophilus and Bacillus atrophaeus spores, as well as model virus bacteriophage MS2. The filtering efficacy and facial fit after hydrogen peroxide vapour decontamination were not affected by the process. Microbial growth in the hydrogen peroxide vapour-treated respirators indicated appropriate microbial cleanliness.ConclusionsLarge-scale hydrogen peroxide vapour decontamination was validated. After effective decontamination, no significant changes in the key properties of the respirators were detected. European Union regulations should incorporate a facilitated pathway to allow reuse of appropriately decontaminated respirators in a severe pandemic when unused respirators are not available.

Management of donations of personal protective equipment in response to the massive shortage during the COVID-19 health crisis: providing quality equipment to health care workers

Background

In the COVID-19 pandemic context, a massive shortage of personal protective equipment occurred. To increase the available stocks, several countries appealed for donations from individuals or industries. While national and international standards to evaluate personal protective equipment exist, none of the previous research studied how to evaluate personal protective equipment coming from donations to healthcare establishments. Our aim was to evaluate the quality and possible use of the personal protective equipment donations delivered to our health care establishment in order to avoid a shortage and to protect health care workers throughout the COVID-19 crisis.

Methods

Our intervention focused on evaluation of the quality of donations for medical use through creation of a set of assessment criteria and analysis of the economic impact of these donations.

Results

Between 20th March 2020 and 11th May 2020, we received 239 donations including respirators, gloves, coveralls, face masks, gowns, hats, overshoes, alcohol-based hand rubs, face shields, goggles and aprons. A total of 448,666 (86.3%) products out of the 519,618 initially received were validated and distributed in health care units, equivalent to 126 (52.7%) donations out of the 239 received. The budgetary value of the validated donations was 32,872 euros according to the pre COVID-19 prices and 122,178 euros according to the current COVID-19 prices, representing an increase of 371.7%.

Conclusions

By ensuring a constant influx of personal protective equipment and proper stock management, shortages were avoided. Procurement and distribution of controlled and validated personal protective equipment is the key to providing quality care while guaranteeing health care worker safety.

Development and validation of technologies suitable for the decontamination and re-use of contaminated N95 filtering facepiece respirators in response to the COVID-19 pandemic

Background

Coronavirus disease 2019 (COVID-19) has brought significant challenges to society globally, particularly in the area of healthcare provision. A pressing need existed in protecting those tasked with delivering healthcare solutions during the COVID-19 crisis by providing solutions for preserving adequate supplies of effective personal protective equipment (PPE).

Aim

To evaluate and validate available methods for the decontamination of N95 filtering facepiece respirators (FFRs) while maintaining functionality during re-use.

Methods

Multiple low-temperature steam and vaporized hydrogen peroxide (VHP) technologies were assessed for inactivation of Mycobacterium spp. and feline calicivirus (employed as representatives of the contamination challenge).

Findings

Virus (≥3log₁₀) and Mycobacterium spp. (≥6log₁₀) inactivation was achieved on various types of N95 FFRs using an array of heat (65–71^oC), humidity (>50% relative humidity) and VHP without affecting the performance of the PPE.

Conclusion

The methods have been validated and were authorized by the US Food and Drug Administration under a temporary emergency use authorization. Based on the findings, opportunities exist for development and deployment of decontamination methods made from simple, general purpose materials and equipment should a future need arise.

Stockpiled personal protective equipment and knowledge of pandemic plans as predictors of perceived pandemic preparedness among German general practitioners

BACKGROUND

The COVID-19 pandemic significantly changed the work of general practitioners (GPs). At the onset of the pandemic in March 2020, German outpatient practices had to adapt quickly. Pandemic preparedness (PP) of GPs may play a vital role in their management of a pandemic.

OBJECTIVES

The study aimed to examine the association in the stock of seven personal protective equipment (PPE) items and knowledge of pandemic plans on perceived PP among GPs.

METHODS

Three multivariable linear regression models were developed based on an online cross-sectional survey for the period March-April 2020 (the onset of the pandemic in Germany). Data were collected using self-developed items on self-assessed PP and knowledge of a pandemic plan and its utility. The stock of seven PPE items was queried. For PPE items, three different PPE scores were compared. Control variables for all models were gender and age.

RESULTS

In total, 508 GPs were included in the study; 65.16% believed that they were very poorly or poorly prepared. Furthermore, 13.83% of GPs were aware of a pandemic plan; 40% rated those plans as beneficial. The stock of FFP-2/3 masks, protective suits, face shields, safety glasses, and medical face masks were mostly considered completely insufficient or insufficient, whereas disposable gloves and disinfectants were considered sufficient or completely sufficient. The stock of PPE was significantly positively associated with PP and had the largest effect on PP; the association of the knowledge of a pandemic plan was significant but small. PPE scores did not vary considerably in their explanatory power. The assessment of a pandemic plan as beneficial did not significantly affect PP.

CONCLUSION

The stock of PPE seems to be the determining factor for PP among German GPs; for COVID-19, sufficient masks are the determining factor. Knowledge of a pandemic plans play a secondary role in PP.

Mask decontamination methods (model N95) for respiratory protection: a rapid review

BACKGROUND

N95 respiratory protection masks are used by healthcare professionals to prevent contamination from infectious microorganisms transmitted by droplets or aerosols.

METHODS

We conducted a rapid review of the literature analyzing the effectiveness of decontamination methods for mask reuse. The database searches were carried out up to September 2020. The systematic review was conducted in a way which simplified the stages of a complete systematic review, due to the worldwide necessity for reliable fast evidences on this matter.

RESULTS

A total of 563 articles were retrieved of which 48 laboratory-based studies were selected. Fifteen decontamination methods were included in the studies. A total of 19 laboratory studies used hydrogen peroxide, 21 studies used ultraviolet germicidal irradiation, 4 studies used ethylene oxide, 11 studies used dry heat, 9 studies used moist heat, 5 studies used ethanol, two studies used isopropanol solution, 11 studies used microwave oven, 10 studies used sodium hypochlorite, 7 studies used autoclave, 3 studies used an electric rice cooker, 1 study used cleaning wipes, 1 study used bar soap, 1 study used water, 1 study used multi-purpose high-level disinfection cabinet, and another 1 study used chlorine dioxide. Five methods that are promising are as follows: hydrogen peroxide vapor, ultraviolet irradiation, dry heat, wet heat/pasteurization, and microwave ovens.

CONCLUSIONS

We have presented the best available evidence on mask decontamination; nevertheless, its applicability is limited due to few studies on the topic and the lack of studies on real environments.

Safety in the practice of decontaminating filtering facepiece respirators: A systematic review

BACKGROUND

Considering the new SARS-CoV-2 pandemic and the potential scarcity of material resources, the reuse of personal protective equipment such as filtering facepiece respirators (FFRs) for N95 filtering or higher is being discussed, mainly regarding the effectiveness and safety of cleaning, disinfection and sterilization processes.

AIM

To analyze the available evidence in the literature on the safety in processing FFRs.

METHODS

A systematic review conducted by searching for studies in the following databases: PubMed, CINAHL, LILACS, CENTRAL, EMBASE, Web of Science, and Scopus.

RESULTS

Forty studies were included in this review. The disinfectant/sterilizing agents most frequently tested at different concentrations and exposure periods were ultraviolet irradiation, vaporized hydrogen peroxide and steam sterilization. Microbial reduction was assessed in 21 (52.5%) studies. The only disinfectants/sterilizers that did not caused degradation of the material-integrity were alcohol, electric cooker, ethylene oxide, and peracetic acid fogging. Exposure to ultraviolet irradiation or microwave generated-steam resulted in a nonsignificant reduction in filter performance.

CONCLUSION

There is a complex relationship between the FFR raw materials and the cycle conditions of the decontamination methods, evidencing the need for validating FFRs by models and manufacturers, as well as the process. Some methods may require additional tests to demonstrate the safety of FFRs for use due to toxicity.

A Practical Approach to Filtering Facepiece Respirator Decontamination and Reuse: Ultraviolet Germicidal Irradiation

Purpose of review

Prior outbreaks of respiratory viruses have demonstrated the need for adequate personal protective equipment (PPE) for healthcare workers, particularly filtering facepiece respirators (FFR). Due to shortfalls of PPE during the SARS CoV-2 pandemic, the need for FFR decontamination and reuse (FFR-DR) strategies is paramount. This paper aims to discuss primary decontamination strategies, with an in-depth analysis of ultraviolet germicidal irradiation (UVGI), arriving at the decontamination strategy utilized at the Nebraska Medical Center (NMC).

Methods

Review of the primary literature in regard to FFR-DR as well as a synopsis of the current protocol for FFR-DR at NMC.

Recent findings

UVGI demonstrates effective decontamination of multiple pathogens-including several human respiratory viruses-while maintaining mask integrity and filtering capacity. UVGI was associated with degradation of strap integrity at higher doses than that utilized for decontamination or with reuse beyond 20 times.

Summary

UVGI effectively decontaminates N95 FFRs without significant reduction to fit or strap integrity and can be employed as a strategy for FFR-DR in times of emergency.

A Year of Living Dangerously: Challenges and Recommendations for Safely Performing Ophthalmic Surgery During the COVID-19 Pandemic, from Start to Finish

The COVID-19 pandemic has forced all nations to take an active role in infection control incorporating recommendations and measures to control viral dissemination. The epidemiological impact is very diverse and dynamic, even within the same region. Scientific knowledge regarding SARS-CoV-2 continues to improve every day with protocols needing to be updated and adjusted on a regular basis. Ophthalmology is a medical specialty identified to be at high risk for several reasons: it has very close doctor-patient contact, the virus has been detected in tears, and the ocular surface serves as a gateway to developing the infection. We have reviewed the current information on SARS-CoV-2 in the ophthalmologic field and provide up-to-date recommendations to help create protocols that can adapt to the dynamic situation of ophthalmologic institutions, patient cases, economic situations and access to diagnostic tests. This paper outlines the main recommendations regarding the initial consultation and outpatient clinics, measures to apply in the operating room (OR), and suggestions for post-surgical controls. Triage, according to the patient’s conditions and eye pathology, reduction of the time the patient is at the institution, social distancing, correct use of personal protective equipment (PPE), barrier methods, hygiene, as well as other recommendations mentioned in this document, will allow physicians to take care of the visual health of the patients while reducing the impact of the COVID-19 pandemic.

Decontamination of SARS-CoV-2 contaminated N95 filtering facepiece respirators (FFRs) with moist heat generated by a multicooker

Decontamination of N95 filtering facepiece respirators (FFRs) is a crisis capacity strategy allowed when there are known shortages of FFRs. The application of moist heat is one decontamination method that has shown promise and is the approach approved in the Steris Steam Emergency Use Authorization (EUA). This effort examines the use of multicookers to apply moist heat, as they are available in retail stores and more affordable than methods requiring more sophisticated equipment. Four of five multicooker models examined met the acceptance criteria for the test and one model was selected for inactivation testing. Tests were performed on four different FFR models with SARS‐CoV‐2 suspended in culture media, simulated saliva or simulated lung fluid. Moist heat treatment reduced recoverable titres of SARS‐CoV‐2 virus to levels below the limit of detection in all tests. Furthermore, these four FFR models showed no loss in collection efficiency, inhalation resistance or visual damage after up to 10 decontamination cycles. Two (2) FFR models showed a slight change in strap elasticity (<9%). These data show that moist heat treatment using a multicooker is a viable option for FFR decontamination in a crisis capacity strategy.

Exploring options for reprocessing of N95 Filtering Facepiece Respirators (N95-FFRs) amidst COVID-19 pandemic: A systematic review

BACKGROUND

There is global shortage of Personal Protective Equipment due to COVID-19 pandemic. N95 Filtering Facepiece Respirators (N95-FFRs) provide respiratory protection against respiratory pathogens including SARS-CoV-2. There is scant literature on reprocessing methods which can enable reuse of N95-FFRs.

AIM

We conducted this study to evaluate research done, prior to COVID-19 pandemic, on various decontamination methods for reprocessing of N95-FFRs.

METHODS

We searched 5 electronic databases (Pubmed, Google Scholar, Crossref, Ovid, ScienceDirect) and 1 Grey literature database (OpenGrey). We included original studies, published prior to year 2020, which had evaluated any decontamination method on FFRs. Studies had evaluated a reprocessing method against parameters namely physical changes, user acceptability, respirator fit, filter efficiency, microbicidal efficacy and presence of chemical residues post-reprocessing.

FINDINGS AND CONCLUSIONS

Overall, we found 7887 records amongst which 17 original research articles were finally included for qualitative analysis. Overall, 21 different types of decontamination or reprocessing methods for N95-FFRs were evaluated. Most commonly evaluated method for reprocessing of FFRs was Ultraviolet (Type-C) irradiation (UVGI) which was evaluated in 13/17 (76%) studies. We found published literature was scant on this topic despite warning signs of pandemic of a respiratory illness over the years. Promising technologies requiring expeditious evaluation are UVGI, Microwave generated steam (MGS) and based on Hydrogen peroxide vapor. Global presence of technologies, which have been given Emergency use authorisation for N95-FFR reprocessing, is extremely limited. Reprocessing of N95-FFRs by MGS should be considered for emergency implementation in resource limited settings to tackle shortage of N95-FFRs.

SYSTEMATIC REVIEW IDENTIFIER

PROSPERO, PROSPERO ID: CRD42020189684, (https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020189684).