A pre‐systematic review on the use of masks as a protection material for SARS‐COV‐2 during the COVID‐19 pandemic – Wiley

PubMed ¹⁶

To evaluate the effectiveness of protective equipment (UK)¹²

Effectiveness of protective equipment

1 volunteer (healthy)

Three tests: Hat, goggles, mask and gown (Test 1); Hat, goggles, mask, gown and visor (Test 2); and High-necked full-body suit and full-face visor (Test 3).

A colloidal solution (brown cornstarch-based) was sprayed at arms-length.

It was observer droplet contamination of exposed skin.

Droplet spray forehead, bridge of nose, cheeks and neck (Test 1). It was possible to observe exposition (Test 2). Elimination of droplet skin contamination (Test 3).

Extra protective equipment is recommended, such as additional neck, face and hair protection, namely a full-face visor and a high neck hooded overall suit.

Limitations: Only one volunteer.

To evaluate the efficacy of three types of masks (N95 masks, medical masks and homemade masks) and instant hand wiping using the avian influenza virus to mock (China)²⁴

Effectiveness of protective equipment

Not applicable Virus quantification (avian influenza): real-time reverse transcription-polymerase chain reaction. Instant hand wiping respectively using a wet towel 1.00% soap powder, 0.05% active chlorine or 0.25% active chlorine (from sodium hypochlorite) removed the virus from hands: 98.36%, 96.62% and 99.98%. N95 masks, medical masks and homemade masks (four-layer kitchen paper and one-layer cloth) could block 99.98%, 97.14% and 95.15% of the virus in aerosols.

It was proposed mask-wearing and hand hygiene to slow the exponential spread of the virus.

Limitations: Experiments were not performed with SARS-CoV-2, thus the calculated mask efficiency may not be the same (eg, different viruses present different morphologic characteristics).

To evaluate the effectiveness of surgical and cotton masks in filtering SARS–CoV-2 (South Korea)²⁵

Effectiveness of protective equipment

4 patients (SARS-CoV-2 positive) Comparison: disposable surgical masks vs 100% cotton masks. Using the following sequence of masks: no mask, surgical mask, cotton mask and no mask. Patients were required to cough five times into a petri dish with viral transport media. Median viral loads of nasopharyngeal and saliva samples (4 participants): 5.66 log copies/mL and 4.00 log copies/mL, respectively. Median viral loads after coughs were, as follows: 2.56 log copies/mL (without a mask), 2.42 log copies/mL (with a surgical mask) and 1.85 log copies/mL (1.85 log copies/mL).

During coughing, both surgical and cotton masks not effectively filtered SARS–CoV-2 to the environment and external mask surface.

Limitations: The number of participants is limited.

To describe the infection control measures undertaken for coronavirus disease in the first 42 d after the announcement of a cluster of pneumonia in China, on December 31, 2019 (day 1) (Hong Kong)²⁶

Impact of infection control measures in hospitals and epidemiological tracing

43 public hospitals: 1275 patients; 42 cases of COVID-19 Hospitals: active and enhanced laboratory surveillance, early airborne infection isolation, rapid molecular diagnostic testing and tracing of healthcare workers with unprotected exposure. For confirmed cases: epidemiological characteristics, environmental and air samples were collected and analysed. 42 (3.3%) were confirmed cases of COVID-19; zero nosocomial transmission of SARS-CoV-2 after the importation of the first confirmed case on day 22 in Hong Kong. Examples of specific measures: provision of surgical masks to all health workers, patients and visitors in clinical areas (day 5) and use of personal protective equipment amongst health workers performing aerosol-generating procedures, even if caring for patients without clinical features/epidemiological exposure risk in general wards.

It was possible to prevent nosocomial transmission of SARS-CoV-2 through the application of appropriate hospital infection control measures.

Limitations: Not all medical staff and patients were tested in relation to SARS-CoV-2.

To present an investigation about a patient (COVID-19 positive) who has received nursing assistance in an open cubicle of a general ward before diagnosis (Hong Kong)¹

Impact of infection control measures in hospitals and epidemiological tracing

1 patient (SARS-CoV-2 positive) All contacts were identified and categorised into two groups: ‘close’ or ‘casual’. Quarantine and/or medical surveillance was adopted. Collection of respiratory specimens (test for SARS-CoV-2): contacts with fever and/or respiratory symptoms. Number of contacts (total): 71 staff and 49 patients; close contacts: 7 staff and 10 patients. Surveillance 28 d: 76 tests in 52 contacts were carried out (all were negative).

It seems nosocomial transmission of SARS-CoV-2 is prevented through usual infection control measures, such as wearing surgical masks, hand and environmental hygiene.

Limitations: The number of participants is limited.

To define recommendations for obstetric care (Italy)²⁷

Clinical guidance

42 labours (SARS-CoV-2 positive)

An obstetrics task force was constituted.

Overall, interstitial pneumonia in 20 women, with seven requiring respiratory support; two premature labours. All cases did well in comparison with the usual 10-15 d, which are necessary to overcome the critical phase of SARS-CoV-2 pneumonia.

Breastfeeding:

• – All women breastfeed while wearing a surgical mask.
• – COVID-19-positive mothers with mild or no symptoms can breastfeed.
• – COVID-19-positive and symptomatic mothers are separated from their newborns, and women can use pumps to express breast milk.

Defined recommendations in labour:

• – During labour the midwife and labouring woman wear surgical masks.
• – During the second stage of labour the midwife wears appropriate personal protective equipment.
• – A woman’s partner is permitted to attend during labour and delivery but is not permitted on the postpartum ward.

A set of rules of protection for healthcare providers were extended to all labouring women, including breastfeeding.

Limitations: laboratorial findings were not divulgated.

To report the 1st case of a woman (SARS-CoV-2 positive) delivering a baby through cesarean section at 37 + 6 wk of pregnancy (Republic of Korea)²⁸

Clinical guidance

1 (SARS-CoV-2 positive)

1 case report

Woman with mild symptoms; conservative treatment without medication.

Labour was anticipated due to obstructed labour with incomplete rotation of the foetal head. The mother was discharged. Baby (3.13 kg) was born with Apgar scores at 1 and 5 min of 9 and 10, respectively. The SARS-CoV-2 PCR results (placenta, amniotic fluid and cord blood) were negative. Nasopharyngeal swab of the baby was negative on two consecutive SARS-CoV-2 RT-PCR tests.

Suggested conditions for a safe delivery: negative pressure operating room, skillfull medical team and enhanced personal protective equipment including N95 masks, surgical cap, double gown, double gloves, shoe covers and powered air-purifying respirator. Medical staff was reported negative.

Limitations: The number of participants is limited.

To apply online surveying to determine knowledge and perceptions of COVID-19) amongst the general public (United States and the United Kingdom)²⁹

Questionnaires

3000 adults (United States) and 3000 adults (United Kingdom)

Online survey (February 23 and March 2, 2020)

Questionnaire completion: 2986 (United States; 64.4% tertiary education) and 2988 (United Kingdom; 51.5% tertiary education)

General good knowledge: disease transmission and common symptoms. Misconceptions: prevention of infection and care-seeking behaviour. For instance, almost half of UK and US participants thought that using a surgical mask was “highly effective” in protecting them from acquiring COVID-19.

Online questionnaires seem to be useful tools to inform public health authorities, as well as, to take public health and politique measures during infectious disease outbreaks.

Limitations: Middle- and low-income countries were not involved.

To evaluate how nursing students will face patients with severe acute respiratory syndrome (Hong Kong)³⁰

Questionnaires

102 nursing students Questionnaire survey. 96.1% of students disagree to be involved in the intubation of severe acute respiratory syndrome patients if N95 mask and gown were not available, 37.3% agree with a distribution of N95 masks should be by casting lot (if there are insufficient N95 masks) and 94.1% agree with an intensive care unit specifically for severe acute respiratory syndrome patients.

Training on infection control practice and isolation facilities during outbreaks of infectious diseases should be considered in nursing education programmes.

Limitations: Other health professions, such as physicians and graduated health professionals were not enrolled.

Google Scholar ¹⁷

To divulge data on facemask use prevalence in international airports in Asia, Europe and the Americas, March 2020 (USA)³

Universal use of face masks plus other protective measures in community

1797 (health state unknown) Photo Frames Presence of facemask (number of Faces identified): Airport of Bangkok, Thailand (n = 279; 46%; March 6, 2020); Airport of Paris, France (n = 356; 4%; March 7, 2020); Airport of Boston, USA (n = 371; 3%; March 7, 2020); Airport of Atlanta, USA (n = 554; 2%; March 7, 2020) and Airport Lima, Peru (n = 237; 27%; March 12, 2020).

Clear variations in facemask use rates between regions were detected, which support the need for additional research on the possibility of facemask use, as well, as to provide uniform recommendations to all persons.

Limitations: The type of mask or the number of infected individuals were not quantified.

To assess the association between COVID-19 diagnoses per inhabitant and the national promotion of face masks in Public (Belgium)¹¹

Universal use of face masks plus other protective measures in community

Not applicable

Linear regression: 8 of the 49 countries with available data and supporting the wearing face masks in public.

China, Czechia, Hong Kong, Japan, Singapore, South Korea, Thailand and Malaysia.

Face mask wear was negatively associated with the number of COVID-19 cases/inhabitant (coef. −326, 95% CI −601 to −51, P =.021).

Face mask usage may

reduce the transmission and acquisition of respiratory viral infections because of SARS-CoV-2.

Limitations: Residual confounding should be evaluated

To evaluate the impact of self-imposed prevention measures (handwashing, mask-wearing and social distancing) on the spread of COVID-19 (Netherlands)²²

Universal use of face masks plus other protective measures in community

Not applicable A transmission model was developed (a deterministic compartmental model). Handwashing, mask-wearing and social distancing can be effective strategies to mitigate and delay the epidemic. The peak can only be delayed (by at most 7 mo for a 3-mo intervention) by early implementation of short-term government interventions. This delay seems to be precious for healthcare systems to prepare for facing an increasing COVID-19 burden.

To report a typical case of cluster outbreak caused by public transportation exposure (China)¹⁵

Impact of infection control measures in hospitals and epidemiological tracing

1 patient (SARS-CoV-2 positive) Epidemiological survey. First bus: 39 other passengers (2 h and 10 min). Second bus (minibus): 14 other passengers (50 min). This patient has transmitted the infection to five people in the first vehicle (he does not wears a face mask), but no one was infected later in the second vehicle (he wears a face mask)

Trips should be avoided by infected persons (or if there is a suspicious of infection). The use of a face mask may have contributed to prevent transmission of infection. The authors suggest further research “should focus on assessing the efficacy of face masks against COVID-

19, investigating reuse of face masks and assessing compliance”.

Limitations: only one case. The real dimensions of the buses were not described (eg, average space per passenger).

To develop a “Personal Respirator – Southampton” (PeRSo); PeRso delivers air (HEPA filtered) using a battery through a lightweight hood/face mask (United Kingdom)¹³

Development of new personal protective equipment

Healthcare Worker Feedback (the number was not detailed) Fit and Air-Tightness Tests: 3 M FT-30 & FT-32 solution and spray apparatus. Biological filtration efficacy: settle plates according to ISO14698.

PeRSo can be worn for several hours. Usability tests with doctors and nurses: PeRSo prototype was preferred to standard N95/FFP3 masks.

Preliminary tests indicate that the device removes microbes and passes the “fit tests” widely used to evaluate face masks.

PreRso may constitute an alternative to traditional face masks. Possible advantage of PrePso: it may not need to be changed as often.

Limitations: Safety and efficacy of PreRso for the prevention of SARS-CoV-2 infections are not established, for instance, tests with SARS-CoV-2 were not carried out. In addition, information on how to sanitise PreRso was not presented.

To develop a 3D printed reusable N95 comparable respirator that can be used with multiple filtration units (US)²¹

Development of new personal protective equipment

Prototype respirator model Candidate mask: a respirator (found on an open-source maker website) and developed with PLA (printer filament), a removable cap, a removable filtration unit (two layers of MERV 16 sandwiched between MERV 13) and removable elastics. Candidate mask: passed a suction test protocol to evaluate leakage and passed a qualitative Bitrix N95 fit test. Seal against face, comfort and sizing are still being developed.

A prototype respirator model was developed: 3D printed N95 reusable respirators could provide a viable alternative to N95 masks. 3D printing procedures should ensure that this type of candidate masks fit the individual, since all air needs to pass through the filter to reach the wearer’s face with no leaks.

Limitations: It seems the safety and efficacy of this prototype wer not evaluated in SARS-CoV-2 settings.

Process for Decontamination and Reuse of N95 Filtering Facemask Respirator Ultraviolet Germicidal Irradiation (UVGI) (US)⁶

Sanitisation of facemask

Not applicable Decontamination procedure involving the delivery of UVGI to used N95 (exposure of 60 mJ/cm²); RNA virus may be inactivated by UVGI exposure of 2-5 mJ/cm² in general. The number of times a mask has gone through decontamination is controlled through the application of a mark. After the decontamination procedure masks are redistributed. It was planed to decontaminant and reuse N95 FFRs multiple times until respirator fit is impacted

It seems decontamination and Reuse of N95 Filtering Facemask Respirator is possible.

Limitations: It seems that control quality measures have not been implemented, ie, it is necessary to prove the microbiologic decontamination, as well as, the integrity of facemask after the decontamination procedures.

To test four different decontamination methods to decontaminate four different N95 masks of experimental contamination with SARS-CoV-2 or vesicular stomatitis virus as a surrogate, as well as, to evaluate functional integrity (Canada)⁷

Sanitisation of facemask

4 types of N95 masks

Decontamination methods: autoclave treatment, ethylene oxide gassing, ionised hydrogen peroxide fogging and vapourized hydrogen peroxide exposure.

Tested masks (4 types): 3 M’s 1860, 1870 and VFlex 1804 respirator models (3 M Company, St. Paul, Minnesota) as well as AO Safety 1054S (Pleats Plus) Respirator (Aearo Company, Indianapolis). Effectiveness of decontamination (potential virus was eluted from mask after decontamination and transferring each into 1 mL of virus culture medium) and impact of decontamination on structural and functional integrity was evaluated (TSI PortaCount 8038+ to assess functional integrity).

4 tested methods: one cycle of treatment was effective in decontamination without structural/functional deterioration; vapourized hydrogen peroxide treatment was tolerated to at least five cycles by masks; standard autoclave treatment was associated with no loss of structural or functional integrity to a minimum of 10 cycles for the three pleated mask models.

It seems decontamination and Reuse of N95 Filtering Facemask Respirator is possible.

Limitations: Only four types of N95 were evaluated; thus, standardisation procedures, for instance at the hospital level, may require tight quality control, including evaluation of effectiveness of decontamination and the impact of decontamination on structural and functional integrity. Additionally, the present test not considered the rough handling of these masks by health care workers.

To test Hydrogen Peroxide Vapour sterilisation of N95 respirators for reuse (US)⁸

Sanitisation of facemask

1 type of mask Hydrogen Peroxide vapour decontamination of respirators using a Clarus C system (Bioquell, Horsham, PA) which normally is used to fumigate hospital rooms. Inoculation of 3 M 1870 N95 respirators (3 M, St. Paul, MN) with three aerosolised bacteriophages (classified as proxies for SARS-CoV-2). Virucidal activity was measured by a standard plaquing assay prior to and after sterilisation. A single Hydrogen Peroxide vapour cycle: complete eradication of phage from masks (limit of detection 10 PFU). After five cycles, the respirators appeared like new (no deformity).

It seems decontamination and Reuse of N95 Filtering Facemask Respirator may be possible, namely trough using a Bioquell machine. This machine can be scaled to allow simultaneous sterilisation of many used but otherwise intact respirators.

Limitations: Previous contamination of mask specifically with SARS-CoV-2 was not performed. It seems impact of decontamination on structural and functional integrity was not evaluated through the application of specific tests.

To evaluate Cobalt-60 (60Co) gamma irradiation as a possible method of sterilisation of masks (US)⁹

Sanitisation of facemask

3 M 8210 and 9105 masks (3 masks of each type) Masks were irradiated to doses of 0 kiloGray (kGy), 10 kGy and 50 kGy of approximately 1.3 MeV gamma radiation from cobalt sources (dose rate of 2.2 kGy per hour). However, tested masks passed OSHA Gerson Qualitative Fit Test QLFT 50 (saccharin apparatus), masks’ filtration of 0.3 µm particles was significantly degraded.

Findings suggest against gamma and possibly all ionising radiation, as a method of disposable N95 sterilisation, as well as, the qualitative fit test alone to assess mask integrity cannot be used.

Limitations: It seems gamma irritation and possibly all ionising radiation are not proper methods to decontaminate and reuse N95 Filtering Facemasks, since filtration of particles was significantly degraded.

To evaluate aerosol-spread in cardiopulmonary resuscitation (CPR) using different methods of airway management (Germany)²³

Clinical guidance

Not applicable

Resuscitation dummy: ultraviolet sensitive detergents were nebulised into the artificial airway of a resuscitation dummy. Cadaver model: nebulised detergents into human cadavers by an endotracheal tube (a laryngeal tube with and without a connected airway filter was used).

After, CPR was performed and a camera was used to register the spread of the visualised aerosol.

The insertion of a laryngeal tube connected to an airway filter leads to a remarkable reduction of aerosol-spread, which mostly occurred during CPR compression. The use of a surgical mask deflected the spread.

The early insertion of a laryngeal tube connected to an airway filter before CPC is advisable to treat hypoxemia, as well as, to protect health professionals during CPR.

Limitations: It seems more studies are required to prove that the use of surgical masks in CPR plus the application of a laryngeal tube connected to an airway filter is enough to prevent a potential infection by SARS-CoV-2.

DOAJ ¹⁸

To provide guidance for surgery during the COVID-19 crisis (USA, Germany, Italy, Philippines, Spain, Guatemala, Portugal, Poland, Israel, Turkey, Brazil, Iran, Ecuador, Australia, Austria)³¹

Clinical guidance

Not application Various scientists and clinicians from diverse specialties were involved. Surgery includes surgical procedures by distinct surgical disciplines such as cancer surgery, cardiothoracic surgery, emergency, general surgery, gynaecology, neurosurgery, orthopaedics, paediatric surgery, reconstructive and plastic surgery, surgical critical care, trauma surgery, etc

Amongst others, recommendations on personal protective equipment are here highlighted.

Personal Protective Equipment for Low-risk patients (LRP = Double gloves, booties, surgical gown, FFP3 (N99) or P3 (N100) face mask, Face shield (± googles), head cover.

Personal Protective Equipment for High-risk patients: As in LRP plus overalls under surgical gown, gowns (plastic ponchos) and train dressing/undressing and supervision.

The guidance is relevant for surgical procedures in different surgical settings. SciELO ¹⁹ — — — — —

Source of this news: https://onlinelibrary.wiley.com/doi/10.1111/ijcp.14215