Availability, consistency and evidence-base of policies and guidelines on the use of mask and respirator to protect hospital health care workers: a global analysis
BMC Research Notes
Availability, consistency and evidence-base of policies and guidelines on the use of mask and respirator to protect hospital health care workers: a global analysis
Abrar Ahmad Chughtai 0
Holly Seale 0
Chandini Raina MacIntyre 0
0 School of Public Health and Community Medicine, UNSW Medicine, University of New South Wales , Sydney 2052 , Australia
Background: Currently there is an ongoing debate and limited evidence on the use of masks and respirators for the prevention of respiratory infections in health care workers (HCWs). This study aimed to examine available policies and guidelines around the use of masks and respirators in HCWs and to describe areas of consistency between guidelines, as well as gaps in the recommendations, with reference to the WHO and the CDC guidelines. Methods: Policies and guidelines related to mask and respirator use for the prevention of influenza, SARS and TB were examined. Guidelines from the World Health Organization (WHO), the Center for Disease Control and Prevention (CDC), three high-income countries and six low/middle-income countries were selected. Results: Uniform recommendations are made by the WHO and the CDC in regards to protecting HCWs against seasonal influenza (a mask for low risk situations and a respirator for high risk situations) and TB (use of a respirator). However, for pandemic influenza and SARS, the WHO recommends mask use in low risk and respirators in high risk situations, whereas, the CDC recommends respirators in both low and high risk situations. Amongst the nine countries reviewed, there are variations in the recommendations for all three diseases. While, some countries align with the WHO recommendations, others align with those made by the CDC. The choice of respirator and the level of filtering ability vary amongst the guidelines and the different diseases. Lastly, none of the policies discuss reuse, extended use or the use of cloth masks. Conclusion: Currently, there are significant variations in the policies and recommendations around mask and respirator use for protection against influenza, SARS and TB. These differences may reflect the scarcity of level-one evidence available to inform policy development. The lack of any guidelines on the use of cloth masks, despite widespread use in many low and middle-income countries, remains a policy gap. Health organizations and countries should jointly evaluate the available evidence, prioritize research to inform evidence gaps, and develop consistent policy on masks and respirator use in the health care setting.
Infectious diseases; Seasonal influenza; Pandemic influenza; Sever Acute Respiratory Syndrome (SARS); Tuberculosis (TB); Masks; Respirators
To maintain the functionality and capacity of the
healthcare workforce during outbreaks or pandemics of
emerging infections, such as influenza, health care workers
(HCWs) need to be protected. Medical masks (“masks”)
and respirators are commonly used to protect HCWs
from respiratory infections. In the healthcare setting,
masks are used to prevent HCWs acquiring respiratory
infections, from splashes of blood and body fluids and to
reduce transfer of potentially infectious body fluids in
the sterile area. Alternatively, they may be used by the
HCW and coughing patient to prevent the spread of
infection in the ward, referred to as “source control” [
Masks were not designed to provide respiratory
protection , as they have consistently lower filtration
efficiency than respirators [
]. A respirator is a fitted
device that protects the wearer against inhalation of
small and large airborne particles, that is, it protects the
wearer from others who are or might be infected .
High-income countries have established infection
control programs which can be implemented with good
resourcing. The guidelines and advice underlying these
control programs have been produced by high-income
countries for their own social, economic, and health
environments. Low and middle income countries may not
have the ability or finances to adopt generic infection
control or pandemic guidelines, equivalent to those
originating from high income countries. The practices
occurring in low/middle income countries may be driven
by a number of factors other than available scientific
evidence – such as available resources, Occupational
Health and Safety (OHS) legislation, culture, logistics
and cost considerations.
Whilst much has been written about available policies
issued by the World Health Organization (WHO), and
the United States Centers for Disease Control and
Prevention (CDC), little is known about the consistency in
policies from low and middle income countries, and
country-specific issues which can drive different needs.
In light of ongoing threats from influenza (H1N1, H5N1
and H7N9) and other emerging infections, it is essential
to examine the policies and guidelines of various
organizations and countries to examine whether they are
evidence based, and whether there are any issues with the
recommendations. This study aimed to examine
available policies and guidelines around the use of masks and
respirator for HCWs, for the prevention of influenza,
SARS and TB; and to describe areas of consistency and
inconsistency between guidelines, as well as gaps, with
reference to the WHO and the CDC guidelines.
The guidelines of two large public health organizations,
three high-income countries and six low/middle income
countries were purposely selected for inclusion in this
study. We included guidelines from two major health
organizations which are commonly used internationally as
a reference, namely the World Health organization
(WHO) and the US Centers for Disease Control (CDC).
Guidelines from three high income countries (Australia,
Canada and UK) and six middle/low income countries
(Bangladesh, China, India, Indonesia, Pakistan and
Vietnam) were also selected. The main reasons for
purposively selecting these guidelines was that the six low/
middle income countries account for 47% of the world’s
population and represent areas where emerging infectious
diseases are likely to arise from. Most of these guidelines
were publically available or were accessed through known
key contacts, and were available in a language which could
be readily translated in-house.
We selected guidelines related to influenza, SARS and
TB for this review. Given that influenza has the potential
to cause both seasonal infections and pandemics; it was
chosen as the primary infection of interest. TB was
selected as an example of a chronic but highly infectious
disease. In contrast to influenza, TB has a long
incubation and infection period. Lastly, SARS was selected as
an example of emerging infectious disease, which
required a rapid response.
Information relating to mask and respirator use was
extrapolated from the following sources: a) general
infection control guidelines; b) disease specific infection
control guidelines (influenza, SARS and TB); c) personal
protective equipment guidelines; d) mask/respirator use
guidelines and e) position statements. Documents
published in the last twelve years in any language were
screened with key words for applicability. In the event
that two versions of the guideline were found, the most
recent version was included. Four strategies were
utilized to locate relevant documents. Firstly, websites
including the WHO (plus regional offices), CDC, selected
countries health departments and other relevant
websites were screened. Secondly, a key word search was
conducted using Google, with 10 results per page set
and the first two pages of hits reviewed. The policies
and guidelines were also searched in the native
languages of the selected countries through advance search
settings in Google. The search results were narrowed
down by selecting region (e.g. India), site or domain (e.g.
gov) and file type (e.g. pdf ). Google translator was used
to screen the documents in the native languages and
then the selected documents were translated by native
language speaking colleagues. Policies and guideline
documents were also searched for using Medline, Embase,
National Guidelines Clearinghouse, and Google Scholar
through key words. Lastly, key personal contacts in the
selected countries were contacted in regards to the
availability of guidelines in the country. Most of the contacts
are employed in Government organizations or health
Collection and analysis
The predefined criteria were used to screen the
guidelines for their eligibility. Title and summaries were firstly
assessed by AAC and then validated by HS and CRM.
The following information was extracted from each of
the selected guidelines; country/organization,
department, publication year, language, title and
recommendation on mask/respirator use. The terminology used in
different countries and guidelines varied, so a
classification system was devised (Table 1).
In most of the guidelines reviewed, the rationale for
the recommendations around mask and/or respirator
use is not discussed and evidence is rarely provided. The
WHO, the CDC and most of the countries recommend
masks and/or respirator on the basis of the mode of
transmission of influenza, SARS and TB. However,
various types of masks and respirators are recommended in
the guidelines for low and high risk situations. Although
most of the guidelines discuss the importance of training
and fit testing for respirators use, very few documents
High risk situations described in TB guidelines:
Exposure to drugs resistant organism; culture/DST
and other high risk procedures in laboratory, high
risk areas; specialized treatment centers and
emergency surgery of infectious cases.
Low risk situations
High risk situations
provide detail on those procedures. Furthermore, most
guidelines do not discuss recommendations on how long
masks and respirators should be used for and whether
reuse is recommended. Only a few mentioned that a
single mask could be used for 4 hours [
], 8 hours [
or even for an entire shift [
]. Although cloth masks
are also commonly used in resource limited settings, the
use and reuse of cloth masks is not discussed in any
A lack of consistency was identified in regards to the
nomenclature used in the documents. The WHO
frequently uses the term “medical masks” [
], while the
CDC uses the term “facemask”. Various terms were also
used in the country specific guidelines reviewed. For
example, Pakistan uses medical masks, surgical masks is
used in the UK, Canada, Australia and India document,
procedure masks also in the Canadian document and
finally facemasks is the term used in Vietnam. The
description of low and high risk situations also varied
among the general and disease specific infection control
guideline (Table 1).
For seasonal influenza, the WHO [
] and the CDC
] recommends that masks be used in low risk
situations and respirators in high risk situations. The
recommendations from the UK [
], Australia [
], India [
and Pakistan [
] are aligned with those from the WHO
and the CDC. However Canada [
] and Vietnam [
have a different policy, which recommends masks in
both low and high risk situations for seasonal influenza.
Regarding the choice of respirator, the WHO, the CDC
and most of the selected countries recommend an N95
or its equivalent (FFP2 or P2) respirator for seasonal
influenza. The UK, however, recommends FPP3 respirators.
Though the WHO and the CDC have the same policy
for seasonal influenza, they differ in their
recommendations for pandemic influenza. During an influenza
pandemic, the WHO recommends mask use in low risk
situations and respirators in high risk situations [
whereas, the CDC recommends respirators in both
]. The guidelines of the UK [
], Canada [
], China [
], India [
] and Pakistan [
are aligned with those of the WHO (Table 2). For
pandemic influenza, the WHO recommends a range of
respirators (e.g. P2, P3, FFP2, FFP3, N95, N99 and N100)
and the CDC recommend N95 or higher respirators.
Canada and most of the low/middle income countries
recommend N95 or its equivalent respirators. The UK
recommends only FFP3, while Australia recommends P2
or Powered Air Purifying Respirator (PAPR).
The WHO and the CDC have different policies when
coming in contact with a patient with SARS. The WHO
recommends masks in low risk situations and respirators
in high risk situations [
], whereas the CDC
recommends that respirators be used in both low and high risk
]. The UK [
], Canada [
], Australia [
] and Vietnam [
] also recommend
respirators be used by HCWs for protecting themselves from
SARS. Only China has the same policy as the WHO [
(Table 2). The CDC and most of the countries prefer
N95 or equivalent respirators in low risk situations in
SARS, while the UK recommends a FFP3.
Respirators are recommended by the WHO [
the CDC [
] for protection against TB for HCWs in
both low and high risk situations. Canada [
] and China [
] have the same policy as previously
outlined. In contrast, respirators are recommended only
in certain high risk situations in the UK [
], Pakistan [
] Bangladesh [
] and Vietnam [
(Table 2). The WHO and most of the selected countries
recommend N95 or equivalent respirators for HCWs
during low and high risk exposure to TB bacillus. Though
the CDC also recommends N95 respirators in low risk
situation, elastomeric respirators or PAPR are preferred
during the high risk procedures (Table 2).
The seasonal influenza guidelines of China, Indonesia
and Bangladesh, SARS guidelines of India, Indonesia and
Bangladesh and TB guidelines of Indonesia could not be
located; and pandemic guidelines of Indonesia [
] and Vietnam [
] did not make clear
recommendation on masks and respirator use.
Almost all guidelines emphasized the importance of
hand hygiene and strongly recommended HCWs to
wash their hands before and after patients’ contact to
prevent the spread of respiratory infections. The role of
other PPEs was also discussed in most of the guidelines.
The WHO and the CDC recommended gloves, gown
and goggles for seasonal influenza and pandemic
influenza in accordance with the standard precaution, i.e.
while in contact with infectious material or risk splash
on face or body [
]. However in the case of SARS
and other newly emerging infections, both organizations
strongly recommended the use of gloves, gown and
goggles in all patient contact [
Considerable variation was observed amongst the
policies and guidelines of the selected health organizations
and countries in regards to the use of masks and
respirators. The WHO and the CDC have a similar policy for
seasonal influenza and TB; however, they have different
recommendations when dealing with pandemic
influenza and SARS. There is also a vast amount of variation
between the various country recommendations for the
three diseases. We found that influenza related policies
of the selected countries were generally in line with the
WHO, while SARS related policies were aligned with
those from the CDC. The exceptions were the
seasonal influenza policies of Canada and Vietnam and the
Chinese SARS policy. The previous experience of these
three countries with SARS may be a factor influencing
the variation in recommendations. TB related policies of
high-income countries are in line with the WHO and
the CDC, however the policies of the low/middle-income
countries are not consistent with either organization.
Various terms were also used in the guidelines
reviewed in relation to the products. This indicated that
there is no standard terminology or classification for
masks. Although the general term “respirator” is
constantly used in the guidelines, products with various
filtration capacities were recommended for the same
diseases. This was especially apparent with regards to the
selection of respirators for use during high risk
procedures. In some cases, a particular type of respirator
recommended by one country was actually discouraged
by another country. For example, the CDC and Australia
recommend PAPR for high risk situations during SARS,
whereas, Canada and UK discourage PAPR use due to
the risk of self-contamination [
respirators or PAPR were only recommended for use by the
CDC and the high income countries.
The availability of resources/funding and more
stringent OHS regulations in these high-income settings may
be factors influencing this trend. Aside from the
variation in terminology previously described, some low and
high risk situations were classified in a different way. For
example, the CDC and Canada recommend respiratory
protection within 2 meters of an influenza case, which is
different from the WHO policy (1 meter). OSHA also
recommends a 2 meter distance [
]. The rationale for 2
meters is not provided in either guideline. Similarly, the
Canadian pandemic plan considers it high risk if patients
cough forcefully, and/or if patients do not comply with
respiratory hygiene [
] and the Australian pandemic
plan defines high risk when an infected patient may not
able to use masks [
]. However, neither plan provides
evidence to support these recommendations.
The WHO and all selected countries have the same
policy for pandemic influenza, as for seasonal influenza.
The WHO policies are flexible and probably take into
account the possibility of resource issues which could
occur. In comparison, the CDC policy is different from
the WHO and other countries. Due to a lack of
preexisting immunity to pandemic influenza strains, and
the potential for the occurrence of severe disease and a
high mortality, the CDC recommends respirators. The
CDC policies are relatively stringent and may be
influenced by the Occupations Health and Safety
Administration (OSHA) recommendations. In the USA, the
OSHA respiratory protection standard regulates the use
of respirators at workplace. Under the regulation 29
CFR 1910.134, employers are required to provide
respirators to the employees for protection from respiratory
]. The OSHA recommends using N95 or
higher respirators for HCWs exposed to pandemic
] and SARS [
As highlighted in the results, the use of mask and
respirator is not discussed in pandemic plans of some
countries. Our findings corroborate with the WHO which
identified during a comparative review of pandemic plans
that only 33/76 (45%) of the national plans, discuss the
role of masks, respirators and other PPEs [
]. Masks may
be effective during early stages of a pandemic, when the
mode of transmission and virulence characteristics are
uncertain, and when pharmaceutical measure; such as a
vaccine and/or antiviral, may not be available or delayed
]. Studies have demonstrated that masks reduce
shedding of virus from the wears month and could be as a
mean of source control . Therefore, mask use will not
only protect HCWs but also prevent spread of infections
from them to patients and other people surrounding
Uncertainty around the primary mode of transmission
of influenza may be another reason contributing to the
variations between the recommendations made by each
country. Currently the relative contribution and
significance of the each transmission mode is not known
]. Most of the information regarding the mode
of transmission of influenza is based on old
experiments, observational studies during the outbreaks or on
other in-direct research, for example drug and vaccine
]. Droplet and contact is thought to be the
main modes of transmission for seasonal influenza
]. Droplet transmission is via large particles
(typically > 5 um) that do not suspend in the air, while
airborne transmission occurs through the dissemination
of small virus containing particles (typically < 5 um) or
droplet nuclei in the air. However some researchers
argue that the evidence regarding droplet and contact
being the main modes of transmission is not adequate
] and there is more proof available in favor of the
transmission of influenza through the aerosol mode
]. Given the ongoing debate about the
transmission, it is perhaps not surprising that none of the
guidelines justify the selection of masks to evidence around
Droplet and contact are thought to be primary modes
of transmission of SARS [
], yet the use of respirators
is highly recommended by the CDC and most of the
countries in both low and high risk situations. In
comparison, the WHO currently recommends masks for low
risk situations and respirators for high risk. Low levels of
evidence may be contributing to this difference. Most of
the SARS guidelines are based on retrospective,
observational studies conducted during the 2003–04 SARS
outbreak. During that period, the WHO recommended
HCWs to use respirator [
]. However, WHO updated
its policy in 2007 and stated, “The current evidence
suggests that SARS transmission in health care settings
occurs mainly by droplet and contact routes. Therefore a
medical mask is adequate for routine care”. The CDC,
however, maintains its position and continues to
recommend a respirator [
]. In the CDC guideline, the
rationale of the airborne precautions for SARS is discussed in
detail. Respirators are recommended due to the potential
for the airborne transmission, frequently performed
aerosol generating procedures (AGPs) and high case
fatality among the HCWs. Unlike the WHO, the CDC
discussed studies which favor airborne transmission of
There was also a lack of evidence based guidelines in
regards to the use of masks/respirators when treating
TB patients. The WHO quoted 13 studies on masks and
respirator use for TB patients and concluded that there
is little evidence on the effectiveness of respirators [
However the guideline states that “The available
evidence, although weak and indirect, generally favors
respirator use for protecting the wearer from TB”. High
prevalence of TB in low income countries and increase
chances of exposure due to respiratory aerosol in the
healthcare facility setting could be an explanation for
this recommendation. However, only the
recommendations from Canada, Australia and China are aligned with
the WHO and the CDC. Most of the low income
countries recommended the use of respirators only when
undertaking high risk procedures on patients with TB.
Interestingly, the selective use of respirators when
treating this patient group was also recommended in the UK
policy. The UK recommendations have not been
amended since 1994, when the British Thoracic Society (BTS)
issued guidelines on the control and prevention of
tuberculosis in the UK [
Regardless of the mode of disease transmission, all
guidelines recommended the use of respirators while
performing high risk procedures on influenza, SARS or
TB patients. Studies have demonstrated that respiratory
aerosols are produced more during AGPs. For example,
the risk of influenza and SARS have been shown to
increase after tracheal intubation and non-invasive
] and risk of TB increases after bronchoscopy
and sputum induction . Therefore respirators are
preferred during high risk procedures, as they filter small
particles and designed to provide respiratory protection.
Breathing air passes through the respirator filter and
small respiratory aerosols are captured through diffusion
and electrostatic mechanisms [
Training and fit testing are important components of a
respiratory protection program and the efficacy of
respirator use improves after being fit tested [
risk of inhalation of infective particles is reduced if
respirators are properly fitted to the face . Although the
WHO and the CDC discusses the role of fit testing in
most of their guidelines, very few countries explain the
procedure in detail. Guidelines from the low and middle
income countries largely ignored this issue. Many of the
guidelines reviewed also did not specify the maximum
duration a single mask could be used for, while others
varied in the times suggested. Advice pertaining to the
reuse and extended of a mask/respirator was also not
covered in most of the guidelines.
Even though the use/reuse of cloth masks is common,
especially in low resource countries such as, for example
in China [
] and Vietnam [
], none of the
guidelines reviewed covered the use of these products.
Currently, there is a lack of data to either support or refute
the effectiveness of woven cloth masks in blocking
influenza or virus transmission and fluid resistance.
Regulatory standards require that surgical masks not permit
blood or other potentially infectious fluids to pass
through to or reach the wearer’s skin, mouth or other
mucous membranes under normal conditions and for
the duration of time that the protective equipment will
be used. As it is not clear that cloth masks or improvised
masks can meet the standards set by regulatory bodies
and without better testing and more research, cloth
masks or improvised masks generally have not been
recommended as effective respiratory protective devices,
or as devices to prevent exposure to splashes .
Currently there is no clinical trial data on the efficacy
of cloth masks and most of the available studies are
]. Available evidence suggest that cloth
masks may provide some protection, it is assumed to be
considerable less when compared to the use of surgical
masks and respirators . However, it is theorized that
some types of cloth fabric may provide better protection
]. In a report by the National Institute of Health’s
(NIH) Committee on the development of reusable
facemasks for use during an influenza pandemic, the
members were hesitant to discourage the use of cloth masks,
but suggested caution around their use as they were
not likely to be as protective as surgical masks or
This review has some limitations. Firstly, the
guidelines from some countries could not be located, while
others did not specifically address the use of masks and
respirators. Secondly, while we tried to search for the
most updated version of guidelines; some countries may
have updated the documents and not made them
publicly available. Finally, this study focused on selected
high, middle and low income countries, but did not
analyze every country. The situation may be different in
these countries. For example, France recommends FFP2
and Austria recommends FFP3 for the HCWs in low
and high risk situations during pandemics [
policies are in line with the CDC policy. On the other
hand, policies of the European CDC around the use
masks and respirators are the same as those of the
Health care organizations and countries have different
policies and guidelines around mask and respirator use
for influenza, SARS and TB. These policies not only vary
regarding the choice of product used but also the
application and specifications. These differences may reflect
the relative lack of level-one evidence available to inform
policy development. For the end user in a healthcare
facility setting, the availability of conflicting guidance
about mask use from different sources (such as WHO
and in-country guidelines) may be confusing. Health
organizations and countries should jointly evaluate
the available evidence and develop a uniform policy on
masks and respirator use in the health care setting. The
situation in low income settings should be considered and
various options should be explored. There is a need to
conduct further studies to generate better evidence to
inform policy and current practices. Currently there are
major gaps around the modes of transmission of
respiratory viruses, the efficacy of cloth masks and the impact of
extended and re-use of masks/respirators.
Professor Raina MacIntyre receives funding from influenza vaccine
manufacturers GSK and CSL Biotherapies for investigator-driven research.
Dr Holly Seale holds an NHMRC Australian based Public Health Training
Fellowship (1012631). Payment for presentations: Dr Seale has received
funding from Sanofi Pasteur, GSK and CSL Biotherapies for investigator
driven research and for conference presentations.
AAC, HS and CRM contributed to the design of the study. AAC undertook
the search strategy and made the initial selections which were subsequently
validated by HS and CRM. AAC developed the first draft of the manuscript
and HS and CRM extensively reviewed the paper. All authors read and
approved the final manuscript.
We acknowledge the support we received from the focal points and key
informants in the selected countries. We also wish to thank our UNSW
colleagues for translating the policies and guidelines from other languages.
1School of Public Health and Community Medicine, UNSW Medicine,
University of New South Wales, Sydney 2052, Australia. 2National Centre for
Immunization Research and Surveillance of Vaccine Preventable Diseases
(NCIRS), The Children’s Hospital, Westmead, Australia.
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