key: cord-1052657-xtmn1n0r
authors: Abboah-Offei, Mary; Salifu, Yakubu; Adewale, Bisi; Bayuo, Jonathan; Ofosu-Poku, Rasheed; Opare-Lokko, Edwina Beryl Addo
title: A rapid review of the use of face mask in preventing the spread of COVID-19
date: 2020-12-05
journal: Int J Nurs Stud Adv
DOI: 10.1016/j.ijnsa.2020.100013
sha: 6ef4aecc81e35d42c72fa5eed81b22343482a7b1
doc_id: 1052657
cord_uid: xtmn1n0r

INTRODUCTION: The original use of face masks was to help protect surgical wounds from staff-generated nasal and oral bacteria. Currently governments across the world have instituted the mandatory use of masks and other face coverings so that face masks now find much broader usage in situations where close contact of people is frequent and inevitable, particularly inside public transport facilities, shopping malls and workplaces in response to the COVID-19. OBJECTIVE: We conducted a rapid review to investigate the impact face mask use has had in controlling transmission of respiratory viral infections. METHOD: A rapid review was conducted in line with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidance. Five electronic databases (CINAHL, Embase, Medline, PsycINFO and Global Health) were searched from database inception to date, using pre-defined search terms. We included all studies of any design and used descriptive analysis to report summary statistics of search results. Data were extracted including sample characteristics, study design, respiratory virus being controlled, type of face masks used and their effectiveness. RESULTS: 58 out of 84 studies met the inclusion criteria, of which 13 were classified as systematic reviews and 45 were quantitative studies (comprising randomised controlled trials, retrospective cohort studies, case control, cross-sectional, surveys, observational and descriptive studies). N = 27 studies were conducted amongst healthcare workers wearing face masks, n = 19 studies among the general population, n = 9 studies among healthcare workers the general population and patients wearing masks, and n = 3 among only patients. Face masks use have shown a great potential for preventing respiratory virus transmission including COVID-19. CONCLUSION: Regardless of the type, setting, or who wears the face mask, it serves primarily a dual preventive purpose; protecting oneself from getting viral infection and protecting others. Therefore, if everyone wears a face mask in public, it offers a double barrier against COVID-19 transmission.

Since Wells ( Wells, 1934 ) first hypothesised droplet nuclei transmission of airborne infections in the 1930s, and many pathogens have been identified as transmittable through airborne routes ( Fiegel et al., 2006 , Eames et al., 2009 . When a contagious person coughs or sneezes, droplets containing infectious particles (bacteria and viruses) are released ( Nicas et al., 2005 , Chao et al., 2009 . Despite the potential public health implications or airborne transmission, it had not garnered serious global attention until the severe acute respiratory syndrome and human swine influenza pandemics in 2003 and 2009 respectively, which revealed the ramifications of such pandemics on global health and economy. After these pandemics, diverse studies have been conducted to investigate ways to control and reduce infections caused by airborne pathogens.

Respiratory infections can be transmitted by droplets of varying sizes: > 5-10 m in diameter (respiratory droplets), and < 5 m in diameter (droplet nuclei) ( World Health Organization, 2014 ) . Airborne transmission, which is the presence of microbes within droplet nuclei, is different from droplet transmission and can remain in the air for long periods of time and be transmitted to others over distances greater than 1 m. Although initial evidence suggested that COVID-19, which was declared a pandemic within three months of its emergence ( World Health Organization, 2020 ) , is primarily transmitted through respiratory droplets and contact routes ( Liu et al., 2020 , Chan et al., 2020 , Huang et al., 2020 , Burke and Midgley, 2020 , more recent research suggests that airborne transmission plays a very significant role in propagating the infection, similar to what was found in severe acute respiratory syndrome coronavirus 1 (SARS-COV1), its predecessor. There are different groups of approaches to control airborne diseases. Ventilation and air flow patterns have been widely investigated to study their influence on droplet transmission ( Li et al., 2007 , Strasser and Schlich, 2020 ) . Active devices such as air cleaners may also be an effective control measure to reduce exposure when they are properly located relative to the infected person ( Chen et al., 2010 ) . Respiratory protective equipment such as facemasks and N95 respirators also provide personal protection against infection ( Jefferson et al., 2009 , van der Sande et al., 2008 . Despite face masks being cheaper and easier to use, more research has been carried out on testing the efficacy of respirators than on face masks ( Ba ł azy et al., 2006 , Beest et al., 2010 .

The original use of face masks was to help protect surgical wounds from staff-generated nasal and oral bacteria ( Meleny and Stevens, 1926 , Romney, 2001 ) , among others. Currently governments across the world have instituted the mandatory use of masks and other face coverings so that face masks now find much broader usage in situations where close contact of people is frequent and inevitable, particularly inside public transport facilities, shopping malls and workplaces in response to the COVID-19 ( GOV.UK, 2020 ). However, despite much research effort, the effectiveness of face masks for preventing the contraction of respiratory virus influenza is still under debate and the results presented are not viewed as conclusive ( van der Sande et al., 2008 , Cowling et al., 2008 , Jacobs et al., 2009 . Nevertheless, some recent research results have observed that face masks significantly reduce the risk of contracting influenzalike illnesses in households ( Perski et al., 2020 ) .

A rapid systematic review of randomised controlled trials using different interventions to assess the efficacy of face masks and respirators against respiratory virus transmission including coronaviruses found masks to be effective in the community; respirators worn by healthcare workers were also found to be effective, but only if worn continually; however, medical and cloth masks were less effective ( MacIntyre and Chughtai, 2020 ) . Owing to these varying medical and public perceptions of the impact of wearing face masks in preventing COVID-19, we aimed to conduct a rapid review of all study designs to investigate the impact face mask use has had in controlling transmission of respiratory viral infections.

1. What useful lessons exist from the use of face masks in controlling respiratory virus transmission in the past? 2. Which group of people would benefit the most from the use of face masks, to guide the efficient use and allocation of limited supplies and save cost? Table 1 Inclusion and exclusion criteria.

Qualitative, quantitative, mixed methods research, systematic reviews and randomised controlled trials, Protocols, opinion, discussion and editorial papers, including letters.

All persons/study participants who have used face masks to prevent the transmission of respiratory viral infections.

Persons wearing face masks for purposes other than the prevention of the transmission of respiratory viral infections. All countries and settings (health institutions, community settings, residential and care homes)

Data selection and extraction.

We conducted a rapid review in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses ( Moher et al., 2009 ).

Relevant studies were identified by searching electronic databases: CINAHL, Embase, Medline, PsycINFO and Global Health, and searching reference lists of included studies to identify additional studies. Studies published in English from inception of these databases to June 2020 were included.

The search strategy combined the keywords i) 'Face mask' OR 'Respiratory protective equipment' OR 'face covering' AND ii) 'Severe Acute Respiratory Syndrome' OR 'Coronavirus/ COVID-19 ′ OR 'Middle East Respiratory Syndrome' OR 'Respiratory virus' OR 'Influenza virus' OR 'Respiratory infection' OR 'Adult respiratory distress syndrome' OR 'Respiratory distress syndrome' AND iii) 'Cough' OR 'Sneeze' OR 'Droplet' AND iv) 'Impact' OR 'Effectiveness'. Multiple keywords were used including the abbreviated names of all respiratory viral infections (SARS-CoV-1, SARS-CoV-2, HIN1, among others) to broaden the search and increase sensitivity to the databases.

The inclusion criteria were primary and secondary studies of all designs including peer-reviewed research studies, review papers, dissertations and grey literature. Details of inclusion and exclusion criteria are listed in Table 1 .

The first reviewer (MA-O) imported all search results to Endnote reference manager version X9, de-duplicated, then screened titles and abstracts of all identified studies. Three authors (MA-O, BA, RO-P) screened retained studies against inclusion/ exclusion criteria, any article for which inclusion was unclear was discussed and adjudicated by authors (JB and YS). Full texts of the articles were obtained if abstracts did not contain sufficient information to determine the relevance of an article. We extracted variables such as sample size and characteristic, aims/objectives, design, respiratory virus being controlled by face mask, type of face mask used, impact/effectiveness of face mask controlling respiratory virus and sample size and final conclusions drawn to a common table (see Table 3 ). Studies not meeting the inclusion criteria were excluded from the analysis.

Summary statistics were used to report the number of published studies and presented in a PRISMA flow diagram in Fig. 1 . We analysed descriptions of types of face masks by comparing masks vs. no masks, N95 vs. surgical/ medical face masks and other respirators; respiratory virus being controlled and effectiveness of face masks in controlling transmission of respiratory pathogens. All studies (qualitative, quantitative and systematic reviews) were analysed descriptively, and then findings synthesised. All studies addressing any type of respiratory virus/ infection and any type of face mask used were retained in the final analysis.

A total of 84 studies were retrieved through database and reference list search as shown in Fig. 1 . Of the 84 studies, 19 irrelevant studies were excluded, leaving 65 studies for full-text review: 7 papers were excluded as they did not meet the inclusion criteria (reasons reported in Fig. 1 ) and 58 studies met the inclusion criteria. These 58 studies were retained for final analysis. Study designs included were mainly systematic reviews and quantitative studies (comprising randomised controlled trials, retrospective cohort studies, case control, cross-sectional, surveys, observational and descriptive studies). Of the 58 papers included in this review, 13 of them were systematic reviews and 45 were quantitative studies. Countries where these studies were conducted included Mainland China ( n = 10); United States of America (USA) ( n = 9); Canada ( n = 4); Hong Kong ( n = 4); South Korea ( n = 4); Australia, Japan, Singapore, Thailand, and Vietnam each have two studies; and France, Germany, Mexico and Saudi Arabia each have one study. 13 systematic reviews were conducted by authors from multiple countries (see Table 3 for details of study designs and respective countries where the studies were conducted). Fig. 2 represents the characteristics of the study samples in the various papers. n = 27 of the papers reported studies conducted amongst healthcare workers wearing face masks, n = 19 studies focused on wearing masks among the general population, n = 9 of the papers focused on a combination of studies of healthcare workers, the general population and patients wearing masks, and n = 3 focused on only patients wearing masks. Table 2 also represents the distribution of the types of face masks that were studied in the various studies reviewed. n = 14 studies did not mention the type of face masks used, n = 13 studies used surgical masks, n = 12 studies used both surgical and N95 masks, n = 10 used N95, n = 5 studied all types face masks (N95, Surgical Masks, Cotton, Paper, Fabrics etc.), n = 2 used paper, cotton and gauze masks, n = 1 used surgical masks and cloth mask, and n = 1 used N95, surgical masks and paper masks.

Majority of the studies ( n = 55) included in the review reported the use of various types of face masks to control the transmission of respiratory viruses. Table 4 summarises the types of masks used to control the various respiratory viruses. Specific mask not mentioned n = 14 Surgical masks n = 13 Both N95 and surgical mask n = 12 N95 n = 10 All types (N95, Surgical Masks, Cotton, Paper, Fabrics etc.) n = 5 Paper, cotton and gauze masks n = 2 Surgical masks and cloth mask n = 1 N95, surgical masks and paper masks n = 1

All studies that compared the use of face mask, irrespective of the type, to non-use of face mask observed a significantly higher rate of infection among the participants who did not use mask. For instance, Wang et al. (2020a) reported no SARS-CoV-2 infection among participants who wore a face mask whilst 10 participants in the no mask group were infected. In similar lines, the risk of contracting SARS-CoV-2 was reported to be 36.9 times higher in those who used no masks ( Wang et al., 2020 a) . In addition, Kim et al. (2016) noted that two participants who did not wear a mask contracted MERS-CoV. Despite the findings above, two studies observed no significant change regarding the use or non-use of face masks in controlling influenza ( GOV.UK 2020 ) or common cold ( Cowling et al., 2008 ) .

Mixed findings were reported by studies that compared N95 to surgical/ medical masks. Six studies observed that both forms of face mask offered similar levels of protection in controlling the transmission of respiratory pathogens ( Benkouiten and Brouqui, 2014 , Johnson et al., 2009 , Ki et al., 2019 , Kim et al., 2016 , Radonovich et al., 2019 , Smith et al., 2016 . Despite the notion of both forms of face masks offering similar levels of protection in controlling the transmission of SARS-CoV, one study observed that this did not apply to H1N1 influenza ( Offeddu et al., 2017 ) . Four studies further highlighted that N95 offered a better form of protection when compared with surgical masks ( Loeb et al., 2009 , MacIntyre et al., 2017 , Scales et al., 2003 , Seto et al., 2003 . Further, in this regard, MacIntyre et al. (2013) observed that it is the continuous use of N95, rather than the intermittent use that offered an effective protection against clinical respiratory illness. Although Inouye et al. ( Jefferson et al., 2011 ) observed that face masks made from paper, cotton gauze or non-woven fabric provided some protection, Offeddu et al. (2017) highlighted that paper or reusable cotton face masks offered no protection and were associated with a higher risk of harbouring various pathogens when compared to N95 or medical masks. Similarly, MacIntyre et al. (2015) also noted that the use of a double-layered cloth face mask led to a high rate of influenza-like illness as compared to those who used other types of masks. These findings notwithstanding, the study findings Compliance with mask wearing in public settings significantly reduces the incidence of COVID-19.

( continued on next page ) N95 has potential superior benefit in high-risk situations but further studies are needed to establish it and identify high-risk situations.

( continued on next page ) The rates of clinical respiratory illness N95 group compared to medical masks. By intention-to-treat analysis, when p-values were adjusted for clustering, non-fit-tested N95 respirators were significantly more protective than medical masks against clinical respiratory illness, but no other outcomes were significant. The rates of all outcomes were higher in the convenience no-mask group compared to the intervention arms. There was no significant difference in outcomes between the N95 arms with and without fit testing.

Rates of infection in the medical mask group were double that in the N95 group. A benefit of respirators is suggested but would need to be confirmed by a larger trial, as this study may have been underpowered. There were 207 laboratory-confirmed influenza infection events in the N95 respirator group and 193 in the medical mask group There were 1556 acute respiratory illness events in the respirator group vs 1711 in the mask group; 679 laboratory-detected respiratory infections in the respirator group vs 745 in the mask group; 371 laboratory-confirmed respiratory illness events in the respirator group vs 417 in the mask group; and 128 influenza-like illness events in the respirator group vs 166 in the mask group. In the respirator group, 89.4% of participants reported "always " or "sometimes " wearing their assigned devices vs 90.2% in the mask group.

N95 respirators vs medical masks as worn by participants in this trial resulted in no significant difference in the incidence of laboratory-confirmed influenza. 

Types of face masks used in controlling respiratory virus.

The use of cloth masks was cautioned as it has a greater moisture retention, likely to be reused and may have poor filtration that may result in increased risk of infection when not properly decontaminated , Offeddu et al., 2017 . Paper mask was identified as the worst of them all because they easily moisten and disintegrate ( Seto et al., 2003 ) . This, therefore, means that when people use cloth mask; it must be washed after each use and dried and or ironed to reduce the risk of contamination. The general use of face masks was recommended in several countries, such as Mainland China, Hong Kong Special Administrative Region, Singapore, Japan, USA, UK, and Germany in the early period of the outbreak of COVID-19 pandemic ( Feng et al., 2020 ) . Additionally, the review findings suggest a need to consider the utilisation of other adjunct measures such as hand hygiene in order to decrease the risk of transmission further. Taken together, the findings offer support to enforce the early and correct use of face masks and meticulous hand hygiene.

Our review shows that wearing a face mask has a great potential in controlling airborne transmitted viruses including COVID-19. This corroborate previous works that indicated that mask use is beneficial to prevent the transmission of COVID-19 ( Greenhalgh et al., 2020 ) . Greenhalgh et al. (2020) concluded that wearing a face mask in public should be encouraged regardless, even if the protection it offers is limited. This they argued, will limit transmission of COVID-19 and save some lives. In a narrative rebuttal to critics who disagreed with the contention by Greenhalgh et al. (2020) that face mask could be used as a 'precautionary measure' when in public, the author maintained that in time of global health and economic crises a reliance on only 'perfect evidence' such as randomised controlled trial evidence, may be the enemy of good policy. A recent rapid systematic review on face mask use and its efficacy against coronavirus and other respiratory viruses found that mask use in public could be beneficial within in the community and clinical settings for the prevention of COVID-19, especially those who have not yet started showing clinical symptoms ( MacIntyre and Chughtai, 2020 ). Their study also indicated that mask use offered respiratory protection from patients (source control) to others. Although this review focused only on randomised controlled trial, which is widely believed to be the 'gold standard' for evidence, we contend that for people to accept the use of mask, they do not only need the evidence for its use, but also require the potential and actual problems associated with mask use to be addressed. This study addresses this loophole, since it included all study designs.

We are also cognisant of all the systematic reviews conducted on the use of face masks and other face-covering ( MacIntyre and Chughtai, 2020 , Bartoszko et al., 2020 , Benkouiten and Brouqui, 2014 , Bin-Reza et al., 2012 , Jefferson et al., 2011 , Liang et al., 2020 , MacIntyre and Chungtai, 2015 , MacIntyre et al., 2017 , Offeddu et al., 2017 , Saunders-Hastings et al., 2017 , Smith et al., 2016 , Xiao et al., 2020 . These reviews have mainly focused on: (a) a combination of different primary study designs ( Bartoszko et al., 2020 , Benkouiten and Brouqui, 2014 , Bin-Reza et al., 2012 , Jefferson et al., 2011 , Liang et al., 2020 , Offeddu et al., 2017 , Saunders-Hastings et al., 2017 , Smith et al., 2016 ; (b) only randomised controlled trials ( MacIntyre and Chughtai, 2020 , MacIntyre and Chungtai, 2015 , MacIntyre et al., 2017 , Xiao et al., 2020 ; (c) studied multiple interventions in addition to face-covering ( Bin-Reza et al., 2012 , Liang et al., 2020 , Offeddu et al., 2017 ; (d) only healthcare workers and general population ( Bin-Reza et al., 2012 , Jefferson et al., 2011 , Liang et al., 2020 , MacIntyre and Chungtai, 2015 , Saunders-Hastings et al., 2017 ; (e) only healthcare workers ( Bartoszko et al., 2020 , MacIntyre et al., 2017 , Offeddu et al., 2017 , Smith et al., 2016 ); (f) only general population ( Benkouiten and Brouqui, 2014 , Xiao et al., 2020 ) ; and (g) a combination of healthcare workers, general population and patients ( MacIntyre and Chughtai, 2020 ). Therefore, the findings from this study which reviewed all study designs (including systematic reviews), focusing on all types of study population (healthcare workers, general population and patients), and using face mask to prevent all types of respiratory viral transmission will reinforce the evidence presented in the above reviews. Additionally, these findings could help in drawing a holistic conclusion of the impact of face masks in preventing the spread of respiratory viral infection in order to make policy recommendation for their use. Wearing face masks will not only protect lives but can protect the economy because people can engage in their work, less likely to be infected, are able to prevent possible future lockdowns, and ensure people stay healthy enough to work.

The study findings have significant bearing on nursing practice particularly, regarding the education of the populace and patients on the early and continuous use of appropriate face masks, in addition to other measures (such as hand hygiene) as we navigate the pandemic. As nurses continue to play critical roles as frontline workers, the findings of this review can enhance infection control measures instituted during the COVID-19 pandemic. As noted in the review, the efficacy of some face masks used such as those made from paper and cloth has not been established therefore, further research is required in this regard to strengthen the evidence base. Additionally, the effectiveness of reusable face masks after being washed is another area requiring more evidence. Despite the extensiveness of the current review, some limitations are noteworthy, including reviewing only studies published and reported in English thereby missing out on grey literature and studies published in other languages.

This rapid review highlights the impact of face mask use in preventing respiratory virus transmission among healthcare workers, patients and the general population. Findings demonstrate that, regardless of the type, setting, or who wears the face mask, it serves primarily a dual preventive purpose; protecting oneself from getting viral infection and protecting others. Therefore, if everyone wears a face mask in public, it offers a double barrier against COVID-19 transmission. In addition, this review reveal that the prolonged/ continuous use of face masks may affect a person's oxygen concentration level and may lead to dizziness due to repeated rebreathing of carbon dioxide retention. Consequently, we recommended that any future study conducted on the use of masks, investigates the length at which mask can be used at a particular time in order to mitigate these negative health effects.

Controlling the spread of COVID-19 could save lives, prevent possible reintroduction of lockdowns, and ensure that health systems are not overwhelmed with severe cases of COVID-19.

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Surgical/ medical face mask Influenza ( MacIntyre and Chughtai, 2020 , Aiello et al., 2012 , Barasheed et al., 2014 , Bartoszko et al., 2020 , Cowling et al., 2009 , GOV.UK 2020 , Heinzerling et al., 2020 , Jefferson et al., 2011 , Lau et al., 2008 a, Lau et al., 2004 , Loeb et al., 2009 , MacIntyre et al., 2011 , MacIntyre et al., 2013 , MacIntyre et al., 2016 , MacIntyre et al., 2017 , Milton et al., 2013 , Radonovich et al., 2019 , Saunders-Hastings et al., 2017 , Smith et al., 2016 , Simmerman et al., 2011 , Suess et al., 2012 , Xiao et al., 2020 , Laosiritaworn, 2014 ) Surgical mask, N95 mask SARS-CoV, SARS-CoV-2, influenza ( MacIntyre and Chughtai, 2020 , Benkouiten and Brouqui, 2014 , Liu et al., 2009 , Liung et al., 2020 , Scales et al., 2003 , Teleman et al., 2004 , Tuan et al., 2007 , Wang et al., 2020 a, b , Wilder-Smith et al., 2005 , Chou et al., 2020 .

Not specified ( Bin-Reza et al., 2012 , Loeb et al., 2004 ) Surgical mask, N95 mask/respirator Influenza ( Bischoff et al., 2007 , Johnson et al., 2009 , Ki et al., 2019 , MacIntyre and Chungtai, 2015 ( Offeddu et al., 2017 ) by Smith et al. (2016) offers a caution to healthcare professionals as the authors noted that nurses/ physicians are more likely to contaminate their faces while wearing the N95 mask due to the discomfort associated with their use.

Beside N95 and surgical facemasks, the use of other advanced respirators were noted in the review. One study reported the enhanced efficacy of the Powered Air-Purifying Respirator in controlling/ preventing the transmission of MERS-CoV in comparison to N95 ( Larson et al., 2010 ) . The use of other advanced respirators also protected healthcare professionals from contracting SARS-CoV ( Park et al., 2004 ) .

Five studies evaluated the combined effects of face masks and hand hygiene in reducing transmission ( Aiello et al., 2012 , Barasheed et al., 2014 , Heinzerling et al., 2020 , Lau et al., 2008a , Suess et al., 2012 . Three studies observed that the utilization of mask and hand hygiene significantly lowered the transmission of influenza-like illness ( Aiello et al., 2012 , Barasheed et al., 2014 , Heinzerling et al., 2020 . Although Suess et al. (2012) did not observe a statistically significant difference on the combined effects of mask and hand hygiene, the authors noted that commencement of these interventions within 36hours of symptom onset of the index case led to lower rates of transmitting secondary infection among contacts.

Findings suggest that the correct and early use of facemask or face covering could save many more lives than when it is not used. Mask use could lower the risk of COVID-19 transmission ( MacIntyre and Chughtai, 2020 , Christie et al., 1995 , Hogg et al., 2006 , Loeb et al., 2004 , SARS ( Inouye et al., 2006 ) , Influenza ( Ki et al., 2019 , Laosiritaworn, 2014 , MERS ( Kim et al., 2015 ) and recommended for use in the public ( Condon and Sinha, 2009 ). Additionally, N95 masks seem to provide a better form of protection from influenza-like illness than the other types of masks when used continuously, rather than intermittently ( Maclntyre et al., 2009 , MacIntyre et al., 2013 , MacIntyre et al., 2017 and a multi-layered mask offered better protection ( Liung et al., 2020 ) . However, in a randomised controlled trial Smith et al. (2016) concluded that the process of wearing N95 respirators might lead to contamination due to the following factors; 1) N95 is mostly uncomfortable to wear, 2) may be worn improperly and 3) may be adjusted often. This will have implication for clinical practice where the setting could lead to transmission of disease to vulnerable patients, and therefore proper hand washing should be ensured in addition to mask use ( Adhikari et al., 2020 ) .

I acknowledge all authors for their contribution to this rapid review. This review was conceived and designed by ………………, and …………. The first reviewer imported all search results to Endnote reference manager version X9, de-duplicated, then all authors screened titles and abstracts of all identified studies, any article for which inclusion was unclear were discussed and if necessary adjudicated by the last reviewer. All authors critically appraised and contributed to the manuscript.

None.

No external funding