Physical interventions to interrupt or reduce the spread of respiratory viruses: Systematic review

Article (PDF Available)inBMJ (online) 336(7635):77-80 · February 2008with52 Reads
DOI: 10.1136/bmj.39393.510347.BE · Source: PubMed
Abstract
To systematically review evidence for the effectiveness of physical interventions to interrupt or reduce the spread of respiratory viruses. Search strategy of the Cochrane Library, Medline, OldMedline, Embase, and CINAHL, without language restriction, for any intervention to prevent transmission of respiratory viruses (isolation, quarantine, social distancing, barriers, personal protection, and hygiene). Study designs were randomised trials, cohort studies, case-control studies, and controlled before and after studies. Of 2300 titles scanned 138 full papers were retrieved, including 49 papers of 51 studies. Study quality was poor for the three randomised controlled trials and most of the cluster randomised controlled trials; the observational studies were of mixed quality. Heterogeneity precluded meta-analysis of most data except that from six case-control studies. The highest quality cluster randomised trials suggest that the spread of respiratory viruses into the community can be prevented by intervening with hygienic measures aimed at younger children. Meta-analysis of six case-control studies suggests that physical measures are highly effective in preventing the spread of SARS: handwashing more than 10 times daily (odds ratio 0.45, 95% confidence interval 0.36 to 0.57; number needed to treat=4, 95% confidence interval 3.65 to 5.52); wearing masks (0.32, 0.25 to 0.40; NNT=6, 4.54 to 8.03); wearing N95 masks (0.09, 0.03 to 0.30; NNT=3, 2.37 to 4.06); wearing gloves (0.43, 0.29 to 0.65; NNT=5, 4.15 to 15.41); wearing gowns (0.23, 0.14 to 0.37; NNT=5, 3.37 to 7.12); and handwashing, masks, gloves, and gowns combined (0.09, 0.02 to 0.35; NNT=3, 2.66 to 4.97). The incremental effect of adding virucidals or antiseptics to normal handwashing to decrease the spread of respiratory disease remains uncertain. The lack of proper evaluation of global measures such as screening at entry ports and social distancing prevent firm conclusions being drawn. Routine long term implementation of some physical measures to interrupt or reduce the spread of respiratory viruses might be difficult but many simple and low cost interventions could be useful in reducing the spread.

Figures

RESEARCH
Physical interventions to interrupt or reduce the spread of
respiratory viruses: systematic review
Tom Jefferson, coordinator,
1
Ruth Foxlee, trials search coordinator,
2
Chris Del Mar, dean,
3
Liz Dooley, review group coordinator,
4
Eliana Ferroni, researcher,
5
Bill Hewak, medical student,
3
Adi Prabhala, medical student,
3
Sree Nair, professor of biostatistics,
6
Alex Rivetti, trials search coordinator
1
ABSTRACT
Objective To systematically review evidence for the
effectiveness of physical interventions to interrupt or
reduce the spread of respiratory viruses.
Data extraction Search strategy of the Cochrane Library,
Medline, OldMedline, Embase, and CINAHL, without
language restriction, for any intervention to prevent
transmission of respiratory viruses (isolation, quarantine,
social distancing, barriers, personal protection, and
hygiene). Study designs were randomised trials, cohort
studies, case-control studies, and controlled before and
after studies.
Data synthesis Of 2300 titles scanned 138 full papers
were retrieved, including 49 papers of 51 studies. Study
quality was poor for the three randomised controlled trials
and most of the cluster randomised controlled trials; the
observational studies were of mixed quality.
Heterogeneity precluded meta-analysis of most data
except that from six case-control studies. The highest
quality cluster randomised trials suggest that the spread
of respiratory viruses into the community can be
prevented by intervening with hygienic measures aimed
at younger children. Meta-analysis of six case-control
studies suggests that physical measures are highly
effective in preventing the spread of SARS: handwashing
more than 10 times daily (odds ratio 0.45, 95%
confidence interval 0.36 to 0.57; number needed to
treat
=
4, 95% confidence interval 3.65 to 5.52); wearing
masks (0.32, 0.25 to 0.40; NNT
=
6, 4.54 to 8.03); wearing
N95 masks (0.09, 0.03 to 0.30; NNT
=
3, 2.37 to 4.06);
wearing gloves (0.43, 0.29 to 0.65; NNT
=
5, 4.15 to
15.41); wearing gowns (0.23, 0.14 to 0.37; NNT
=
5, 3.37
to 7.12); and handwashing, masks, gloves, and gowns
combined (0.09, 0.02 to 0.35; NNT
=
3, 2.66 to 4.97). The
incremental effect of adding virucidals or antiseptics to
normal handwashing to decrease the spread of
respiratory disease remains uncertain. The lack of proper
evaluation of global measures such as screening at entry
ports and social distancing prevent firm conclusions
being drawn.
Conclusion Routine long term implementation of some
physical measures to interrupt or reduce the spread of
respiratory viruses might be difficult but many simple and
low cost interventions could be useful in reducing the
spread.
INTRODUCTION
Although respiratory viruses usually cause minor dis-
ease, epidemics can occur. Mathematical models esti-
mate that about 36 000 deaths and 226 000 admissions
to hospital in the United States annually are attributa-
ble to influenza,
1
and with incidence rates as high as
50% during major epidemics worldwide, respiratory
viruses strain health services,
2
are responsible for
excess deaths,
23
and result in massive indirect costs
owing to absenteeism from work and school.
4
Concern
is now increasing about serious pandemic viral infec-
tions. In 2003 an epidemic of the previously unknown
severe acute respiratory syndrome (SARS) caused by a
coronavirus affected about 8000 people worldwide,
with 780 deaths (disproportionately high numbers
were in healthcare workers), and causing a social and
economic crisis, especially in Asia.
5
A new avian influ-
enza pandemic caused by the H5N1 virus strain threa-
tens greater catastrophe.
6
High viral load and high viral infectiousness prob-
ably drive virus pandemics,
7
hence the need for inter-
ventions to reduce viral load. Mounting evidence
suggests, however, that single measures, particularly
the use of vaccines or antivirals, will be insufficient to
interrupt the spread of influenza. Agent specific drugs
are also not available for other viruses.
7-10
A recent trial found handwashing to be effective in
lowering the incidence of pneumonia in the develop-
ing world.
w1
Clear evidence has also shown a link
between personal (and environmental) hygiene and
infection.
11
We systematically reviewed the evidence
for the effectiveness of combined public health mea-
sures such as personal hygiene, distancing, and barriers
to interrupt or reduce the spread of respiratory
viruses.
12 13
We did not include vaccines and antivirals
because these have been reviewed.
4 10 14-18
METHODS
We considered trials (individual level, cluster rando-
mised, or quasirandomised), observational studies
(cohort and case-control), and any other comparative
design in people of all ages provided some attempt had
been made to control for confounding.
We included any intervention to prevent the trans-
mission of respiratory viruses from animals to humans
1
Cochrane Vaccines Field,
Alessandria, Italy
2
Cochrane Wounds Gr oup,
Department of Health Sciences,
University of York
3
Faculty of Health Sciences and
Medicine, Bond University,
GoldCoast,4229,Qld,Australia
4
Cochrane Acute Respiratory
Infections Group, Faculty of Health
Sci ences and Medic ine,
Bon d Univ ersity
5
Public Health Agency of Lazio
Region, Rome
6
Department of Statist ics, Manipal
Academy of Higher Education,
Manipal, India
Correspondence to: C Del Mar
cdelmar@bond.edu.au
doi: 10.1136/bmj.39393.510347.BE
BMJ | ONLINE FIRST | bmj.com page 1 of 9
or from humans to humans (isolation, quarantine,
social distancing, barriers, personal protection, and
hygiene) compared with no intervention or with
another intervention. We excluded vaccines and anti-
virals.
The outcome measures were deaths; numbers of
cases of viral illness; severity of viral illness, or proxies
for these; and other measures of burden, such as admis-
sions to hospital.
Search strategy
We searched the Cochrane Central Register of Con-
trolled Trials (Cochrane Library issue 4, 2006), Medline
(1966 to November 2006), OldMedline (1950-65),
Embase (1990 to November 2006), and CINAHL
(1982 to November 2006). See bmj.com for details of
our search terms for Medline and the Cochrane regis-
ter (modified for OldMedline, Embase, and
CINAHL). We applied no language restrictions.
Study design filters included trials; cohort, case-con-
trol, and cross-over studies; and before and after and
time series. We scanned the references of included stu-
dies to identify other potentially relevant studies.
We scanned the titles and abstracts of potentially
relevant studies: when studies seemed to meet our elig-
ibility criteria (or when information was insufficient to
exclude them), we obtained the full text articles. We
used a standardised form to assess the eligibility of
each study, on the basis of the full article.
Quality assessment
We analysed randomised and non-randomised studies
separately. Randomised studies were assessed accord-
ing to the effectiveness of the randomisation method,
the generation of the allocation sequence, allocation
concealment, blinding, and follow-up. Non-rando-
mised studies were assessed for the presence of poten-
tial confounders using the appropriate Newcastle-
Ottawa Scales
19
for case-control and cohort studies,
and a three point checklist was used for controlled
before and after studies.
20
Using quality at the analysis stage as a means of inter-
pretation of the results we assigned risk of bias cate-
gories on the basis of the number of items judged
inadequate in each study: low risk of bias, up to one
inadequate item; medium risk of bias, up to three
inadequate items; and high risk of bias, more than
three inadequate items.
Data extraction
Two authors (TJ, CDM) independently applied inclu-
sion criteria to all identified and retrieved articles. Four
authors (TJ, EF, BH, AP) extracted data from included
studies and checked their accuracy on standard field
forms used by Cochrane groups for vaccines, super-
vised and arbitrated by CDM.
Aggregation of data depended on study design;
types of comparisons; sensitivity; and homogeneity
of definitions of exposure, populations, and outcomes
used. We calculated the statistic I
2
for each pooled esti-
mate to assess the impact on heterogeneity.
21 22
When possible we did a quantitative analysis and
summarised effectiveness as an odds ratio with 95%
confidence intervals, expressing absolute intervention
effectiveness when significant as a percentage using the
formula: intervention effectiveness=1odds ratio. For
studies that could not be pooled we used effect mea-
sures reported by the authors (such as relative risk or
incidence rate ratio, with 95% confidence intervals or,
when not available, relevant P values). We calculated
numbers needed to treat (NNT) using the formula 1/
absolute risk reduction whenever we thought the data
were robust enough to allow it.
RESULTS
Overall, 2300 titles of reports of potentially relevant
studies were identified and screened. In total, 2162
were excluded and 138 full papers retrieved, totalling
49 reports of 51 studies (fig 1).
The quality of the methods of included studies
w1-w51
varied (tables 1-5). Considerable loss of information
resulted from incomplete or no reporting of
randomisation,
w3
blinding,
w5
numerators and
denominators,
w4 w6
interventions, outcomes,
w39
attri-
tion of participants,
w34
confidence intervals,
w33
and
cluster coefficients in the relevant trials.
w4
The impact
of potential biases (such as cash incentives given to
participants
w39
) were not discussed. Some authors con-
fused the cohort design with a before and after design,
which provided conclusions unsupported by the
data.
w34
The quality of methods was sometimes eroded
by the need to deliver behavioural interventions in the
midst of service delivery.
w37
Even when suboptimal
designs were selected, authors rarely articulated poten-
tial confounders. A common confounder specific to
this area is the huge variability in viral incidence over
time, commonly ignored.
w19 w41
Sometimes this was
tackled in the study design,
w30
even in controlled
before and after studies (one attempted correlation
between admissions for respiratory syncytial virus
and respiratory syncytial virus circulating in the
community
w21
; another attempted linking exposure
measured as nasal excretion
and infection rate in the
periods before and after intervention
w14
). Inadequate
blinding or adjustment for confounders is a well
known factor in exaggerating the effects of an inter-
vention.
23
Inappropriate interventions for comparison caused
problems with study designs: in some studies these
Potentially relevant studies (n=2300)
Full papers retrieved (n=138)
Excluded on
basis of titles or
abstracts (n=2162)
Excluded (n=89)
Papers reviewed (n=49, 51 studies)
Fig 1
|
Flow of papers through study
RESEARCH
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Table 1
|
Characteristics of included randomised trials
Study Participants Interventions v comparisons Outcomes Risk of bias (notes)
Randomised controlled
trials:
Gwaltney 1980
w2
15and20participantsin
two experiments
Painting of hands with iodine v placebo
(Ivory soap; Procter and Gamble,
Cincinnati, OH), before experiment
Reduction in experimental rhinovirus
infection (P
=
0.06)
High (poor description of randomisation
process, concealment, and allocation)
Turner 2004
w3
85 participants; 122
participants
Use of salicylic acid v salicylic acid and
pyroglutamic acid, and v
placebo
substance
; use of skin cleanser wipe
containing 4% pyroglutamic acid
formulated with 0.1% benzalkonium
chloride v skin cleanser wipe containing
ethanol
Reduction in experimental rhinovirus
infection (P<0.05); reduction in
experimental rhinovirus infection (not
significant)
High (no description of randomisation
process, concealment, and allocation); high
(no description of randomisation process,
concealment, and allocation)
Cluster randomisedtrials:
Carabin 1999
w4
1729 children aged
18-36 months
Training session (1 day) with washing
hands, cleaning toys, opening windows,
cleaning sandpits, and repeated requests
to wash hands v standard practice
Reduced incidence of colds (incidence rate
ratio 0.80, 95% CI 0.68 to 0.93)
High (no description of randomisation; partial
reporting of outcomes, numerators, and
denominators)
Farr 1988
w5
186 families;98 families Use of virucidal tissues (Kimberly-Clark,
Neenah, WI) over 26 weeks v placebo
tissues, and v no tissues (no placebo);
use of virucidal tissues (Kimberly-Clark) v
placebo tissues
Acute respiratory infections. Total illness
rate was lower in families using virucidal
tissues than in either of other two groups,
but only overall difference between active
and placebo groups was significant
(illnesses per person 3.4 v 3.9 for placebo
groupP
=
0.04, and 3.6 for no tissues control
group P
=
0.2, and overall 14% to 5%
reduction); acute respiratory infections
reduced incidence per person per week in
household by 5% (not significant)
High (failure of blinding); high (failure of
blinding)
Kotch 1994
w6
389 children aged
3 years in day care for at
least 20 h/wk
Structured handwashing (disinfectant
scrub Cal Stat donated by Calgon Vestal
Laboratories, Merck) and disinfecting
programme of environment (surfaces,
sinks, toilets, and toys) with waterless
liquid v standard practice
Acute respiratory infections (defined): No
significant reduction (relative risk 0.94,
95% CI
2.43 to 0.66)
High (poor reporting of randomisation,
outcomes, numerators, and denominators)
Sandora 2005
w7
292 families with
children (6 months to
5years)inchildcare(
10
h/wk)
Alcohol based hand sanitiser (Purell
Instant Hand Sanitizer; Gojo Industries,
Akron, OH) with biweekly hand hygiene
educational materials over five months v
biweekly educational material on healthy
diet
Acute respiratory infections. No significant
reduction (relative risk 0.97, 95% CI 0.72 to
1.30)
Medium (relatively high attrition rate and
confounder in respiratory droplet
transmission route)
Ladegaard 1999
w8
0-6 year olds Educational programme: message on T
shirts
Clean hands
yes, thank you
,
performance of a fairytale
Princess who
did not want to wash her hands,
exercises in handwashing; and
importance of clean and fresh air
34% decrease in
sickness
(probably
mostly gastroenteritis)
Limited data only available
Longini 1988
w9
143 households
randomised to virucidal
tissues during season of
high circulating
influenzaH3N2virusand
rhinoviruses
Disposable three layered virucidaltissues
containing sodium lauryl sulphate
sandwiched between citric and malic
acids (Kimberly-Clark) v placebo (succinic
acid in tissue sandwich)
Acute respiratory infections reduced from
18.7% to 11.8% (NS)
High (inappropriate choice of placebo)
Luby 2005
w1
Householders living in
slums in Karachi
Instruction programme and antibacterial
bar soap containing 1.2% triclocarban
(Safeguard Bar Soap; Procter and
Gamble,Cincinnati,OH) v ordinarysoap to
be used throughout the day by
householders v usual behaviour
Incidence of pneumonia: relative risk
between soap and usual behaviour 0.50
(95% CI 0.65 to 0.34) in children aged <
5years
Low (cluster coefficients reportedand analysis
by unit of randomisation carried out)
Morton 2004
w10
253 school children,
(ages not reported) from
kindergarten to third
grade
Alcohol gel plus handwashing
(AlcoSCRUB; Erie Scientific, Portsmouth,
NH) v handwashing alone
Absenteeism from school reduced by 43% High (no description of randomisation; partial
reporting of outcomes, numerators, and
denominators)
Roberts 2000
w11
Children aged
3 years Handwashing programme (GloGerm,
Moab, UT) including nursery rhymes and
count to 10 seconds when handwashing
or rinsing
Acute respiratory infections (defined)
reduced in children aged
24 months
(relative risk 0.90, 95% CI 0.83 to 0.97) but
not in older children (0.95, 0.89 to 1.01)
Low (cluster coefficients reportedand analysis
by unit of randomisation carried out)
White 2001
w12
769 5-12 year olds Pump activated antiseptic hand rub with
benzalkonium chloride (SAB formulation
sanitiser; Woodward Laboratories) pump
activated antiseptic hand rub plus water
and soap handwash placebo
Acute respiratory infections (defined)
relative risk for illness incidence 0.69,
duration 0.71. Acute asthma.
Gastrointestinal and other illnesses
High (no description of randomisation; partial
reporting of outcomes, numerators, and
denominators)
RESEARCH
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Table 2
|
Characteristics of included controlled before and after studies
Study Participants Interventions Outcomes Risk of bias
Simon 2006
w13
Paediatric inpatients with diagnosis of
respiratory syncytical virus admitted for
at least 24 hours in Germany
Enhanced surveillance and feedback,
rapid diagnosis, barriers and isolation,
disinfection of surfaces
Nosocomial infection with respiratory
syncytical virus decreased from 1.7
(year 1) to 0.2 per 1000 patient days
(Year 3)
Low (reasonably reported study with
incidence data presented by sex, age
group, and birth weight to minimisebias)
Leclair 1987
w14
695 children aged 5 days to 4 years and
11 months
Infection control intervention to
increase use of gloves and gowns
Nosocomial infection with respiratory
syncytical virus reduced by relative risk
of 3 (95% CI 1.5 to 5.7)
Low (although prone to selection bias,
study was better designed than some of
its peers as attempt was made at
adjusting for different levels of
respiratory syncytical virus circulation by
subanalysis of virus shedding days in
infected participants)
Macartney 2000
w15
1604 children in four seasons before
and 2065 children after intervention
seasons (aged about 1 year) with
community acquired respiratory
syncytical virus infection: inpatient
children exposed to infected children,
Philadelphia, USA
Education, high index of suspicion for
case finding, barriers (not goggles or
masks), and handwashing for patients
and staff in contact with infected
patients; two weeks
isolation when
possible: cohorting patients (assigning
them to wards) and staff according to
risk or symptoms, with enhanced
surveillanceand restrictionofvisits,and
discouragingstaffwithacuterespiratory
infections from working unprotected
Infection with respiratory syncytical
virus reduced (relative risk 0.61, 95% CI
0.53 to 0.69)
Medium (study well reported and
conclusions reasonable, but no
information given on background rate of
infection and impact of intervention on
morbidity in healthcare workers not
analysed)
Gala 1986
w16
74childrenand40staffin beforephase;
77 children and 41 staff in after phase
Use of disposable plastic eye-nose
goggle and procedures for control of
respiratory infections v procedures for
control of respiratory infections alone
(cohorting, isolation, and
handwashing)
Infection with respiratory syncytical
virus reduced from 42% (before) to 6%
(after)
High (heavy play of confounders, missed
opportunity for randomisation)
Hall 1981
w17
31 volunteers caring for children with
respiratory syncytical virus in hospital
Exposure to infants admitted with acute
respiratory infection during community
outbreak of respiratory syncytical virus
Rates of respiratory syncytical virus
infection: 5/7 children cuddled, 4/10
children touched, and 0/14 kept away
from their carers
Low (results are of low generalisability)
Hall 1981
w18
162 inpatients with suspected
respiratory syncytical virus infections
from infants
Additional use of gowns and masks v
standard infection control procedures
(handwashing, isolation of affected
cohorts)
Rates of respiratory syncytical virus
infection increased from 32% to 41%
High (poor reporting)
Heymann 2004
w19
186 094 children aged 6-12 years in
Israel
Effect of school closure coinciding with
influenza
outbreak
Decreases in acute respiratory
infections (42%), visits to doctor and
emergency room (28%), and purchase
of drugs (35%)
High (observed effect may result from
school closure or possibly lower
circulation of viruses)
Snydman 1988
w20
Healthcare workers and patients in
special care baby unit
Active surveillance: gown, mask, and
gloves used on contact; restricted
visiting policy; and isolation of cohorts
of cases, suspected cases, and staff
Rate of respiratory syncytical virus
infection decreased from 8 (confirmed)
cases to 0 cases per 1000 patient days
High (no denominators provided and
exposure generically quantified by
aggregate patient days of exposure.
Unclear how circulation of respiratory
syncytical virus outside related to
claimed success of measures, as no
information provided)
Krasinski 1990
w21
All in-hospital paediatric patients
regarded as potentially infected with
respiratory syncytical virus
Isolation of screening cohort for
respiratory syncytical virus and service
education programme v normal care
Respiratory syncyticalvirus infections to
other children reduced from 5 to 3
infections per 1000 patient days
Medium (attempt at correlation between
admissions with respiratory syncytical
virus and circulation of virus in
community)
Krilov 1996
w22
33 children with Down
s syndrome
(ages 6 weeks to 5 years) in special
needs day care centre with staff-child
ratio >5:1
Training (reinforced by intensive
monitoring of classroom behaviour),
handwashing programme, and
disinfectants on school buses,
appliances, and toys
Decreased mean episodes per child per
month: acuterespiratoryinfection0.7to
0.4 (P<0.07), visits to doctor 0.5 to 0.3
(P<0.05), antibiotic courses0.33to 0.28
(P<0.05), days missed from school per
study period from infection 0.8 to 0.4
(P<0.05)
High (disinfectants provided, and study
sponsored, by manufacturer)
Pang 2003
w23
2521 probable cases of SARS, mostly
people admitted to hospital in Beijing,
China
Management training and provision of
gowns, gloves, and masks; and
screening of port of entry
SARS public health measures (barriers,
quarantine, screening, contact tracing);
only 12 cases identified out of 13 000
000 screened
Low (efforts made to minimise impact of
confounding)
Pelke 1994
w24
230 infants, aged 22-42 weeks, of birth
weight 464-6195 g
Additional use of gowns plus standard
procedures (handwashing) v
handwashing alone
No decrease in rates of respiratory
syncytical virus infection, other
infections, or death (1.2 v 1.4 deaths/
100 patient days)
Medium (17% loss to follow-up)
Ryan 2001
w25
136 225 naval recruits (mainly men,
aged 19-20 years) undergoing training
over three years compared with about
30 000 recruits for phase II of study
Structured
‘‘
top-down
’’
, military ordered
programme of handwashing (>4 times
daily) v no programme of handwashing
(that is, standard practice)
Three stratified samples of recruits:
decreased self reported episodes of
acute respiratory infections (4.7 v 3.2
per recruit, odds ratio 1.5, 95% CI 1.2 to
1.8) and fewer admissions to hospital
(odds ratio 0.09, 95% CI 0.63 to 0.006)
Low (attempt at correlating effects in
intervention cohort with viral circulation
in non-intervention population on same
military base)
RESEARCH
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Table 3
|
Characteristics of included prospective cohort studies
Study Participants Interventions v comparisons Outcomes Risk of bias (notes)
Agah 1987
w26
168 healthcare workers
caring for children aged <
5 years with differential
diagnosis of respiratory
syncytical virus infection
Mask and goggles (sometimes gowns) v
normal care
Respiratory syncytial virus illness symptoms
reduced from 61% (controls) to 5%
(intervention)
Low (reasonably reported despite difficulties of
carrying out study; standard procedures such as
handwashing should not have acted as confounder
given 100% coverage among healthcare workers)
Derrick
2005
w27
Six volunteers in
experimental laboratory
setting
Pleated rectangular three ply surgical
masks worn singly up to five thick,
subject to range of neck and head
movements
Poor filtration of particles through masks High (report too brief to allow assessment)
Dick 1986
w28
Eight men with laboratory
inducedcoldusing R16virus
(donors) and 12 antibody
free men (recipients)
Use of virucidal paper handkerchiefs
(Kleenex Mansize tissues; Kimberly-
Clark, Neenah, WI), containing citricacid
and other virucidal ingredients to stop
spread of R16 virus v normal cotton
handkerchiefs
0% transmission of R16 virus in intervention
groups compared with 42% of controls
developing colds
Low (small, well designed and controlled study)
Dyer 2000
w29
420 children aged
5-12 years in private school
in California; cluster open
label crossover cohort study
over 10 weeks
Educational programme, surfactant,
allontoin and benzal konium chloride
spray hand sanitiser (CleanHands), and
use of soap and water at will for
handwashing v normal care
Absenteeism reduced by 41.9%; respiratory
illnesses by 49.7%
Medium (authors described limitations of study as
limited socioeconomic diversity in study population,
limitation to single study site, and lack of blinding.
Further washing using soap and water was not
monitored. Generalisability of results questionable as
participants underwent educational programme)
Falsey
1999
w30
Three adult day care centres
with97 staff and 204 elderly
people
Addition of virucidal hand foam as
supplement (Alcare Plus; Calgon Vestal
Laboratories, St Louis, MO) v normal
handwashing and educational
programme
Rates of respiratory infection fell from 14.5
to 10.4 per 100 person months to 5.7
(P<0.001) in last four years, with
accompanying decline in viral isolates
(influenza, respiratory syncytial virus,
coronavirus, parainfluenza virus,
rhinovirus)
Low (one of few identified studies reporting circulating
viruses in day care setting, in both staff and patients.
Decline in flu-like illness episodes across four study
years reflected in decline in viral isolates, suggesting
that aspecific measures such as handwashing are
effective against main respiratory viruses)
Kimel 1996
w31
199 children of kindergarten
and first grade (primary)
schools
Handwashing and educational
programme v no intervention
Absenteeism as a result of acute respiratory
infections was about double that in control
arm (P
=
0.01)
Medium (study did not control for health and hygiene
practicesat homeor exposureto flu-like illness outside
school. In addition student population was generally
healthy, probably because families were able to
provide adequate health and hygiene resources. Flu
season was later than usual (February), therefore a
confounder. Surveys of teachers indicated problems
with handwashing facilities
Leung
2004
w32
26 healthcare workers
caring for probable or
suspected peoplewithSARS
in Hong Kong
Triage and isolation for ultra high risk of
SARS and strict infection control
procedures v similar triage and isolation
but less strict infection control
procedures
No healthcare workers infected with SARS Low (well done and clearly reported study in midst of
major outbreak with previously unknown agent. Prince
of Wales Hospital had previously experienced an
outbreak in which index patient had infected 138
healthcare workers)
Madge
1992
w33
Four paediatric wards in one
hospital; children had
differential diagnosis of
respiratory syncytial virus
Gowns, gloves, and isolated nursing of
cohorts of suspected cases v normal
care
Nosocomial infection with respiratory
syncytialvirus reduced(odds ratiosreduced
to between 0.76 and 0.013 of the baseline)
Low (possible
ward effect
not accounted for as
confounder in study design. For practical reasons two
wards continued with same policy over first two years
of study. Possibility that another ward had been
effective at implementing the assigned policy)
Makris
2000
w34
Eight private, freestanding,
long term care facilities in
USA
Infection control education programme
reinforcing handwashing and other
hygienic measures v normal care
Reported
reduced number of organisms
present on hands and surfaces, and ARIs
;
however, data showed incidence rate of
4.15 per 1000 patient days in test homes v
3.15per 1000 patientdays in controlhomes
High (internal inconsistencies)
Master
1997
w35
305 healthy, predominantly
upper middle class children
aged 5-12 years
Handwashing programme v usual
practice
Acute respiratory infections: no reduction of
absenteeism (relative risk 0.79, P>0.75)
High (discrete population without socioeconomically
diverse backgrounds, single institution, lack of blind
assessment, low specificity of symptoms, lack of
accurate symptom definition)
Murphy
1981
w36
58 health workers caring for
infants with respiratory
infections
Handwashing, masks, and gowns (28
health workers) v handwashing only
(n
=
30)
Viral infections (including respiratory
syncytial virus) not reduced (5 in
intervention arm v 4 in controls, P>0.20)
Medium (small study with potential confounders:
heavy exposure of adults to respiratory viral illness in
community; poor compliance with study protocol,
modes of virus spread not able to be blocked by masks
or gowns)
Niffenegger
1997
w37
Eight teachers and 26
children (aged 3-5 years) in
test group
Three weekly cycles of teaching
handwashing routine; encouragement
for children, parents, and staff; and
correct procedure for sneezing and
coughing v unclear comparator
During first 11 weeks of study, test centre
haddoublethe incidenceof coldscompared
with that of the control centre (19.4% v
12.7%, P<0.05)
High (wide range of infection incidence and unclear
comparator)
Somogyi
2004
w38
One participant Three masks; two without air filter and
allowing external exhalation, one with
manifold and air filter
Plumes of droplets observed and
photographed: masks poor at preventing
droplet spread
Low (small but simple, safe, and effective study)
White 2003
w39
188 university students in
communal residences
Education programme and alcohol gel
hand sanitiser (Purell; Gojo Industries,
Akron, OH) adjunct to handwashing in
residence halls v standard hygiene
Acute respiratory infection reduced by
14.8% to 39.9%, and absenteeism from
lectures reduced by 40%
Medium (unexplained attrition and unknown effect of
cash incentives; relatively unclear definition of illness
with hint of sensitivity analysis in footnote to table)
RESEARCH
BMJ | ONLINE FIRST | bmj.com page 5 of 9
outcome
w9
; in two studies blinding may have failed
because placebo handkerchiefs were impregnated
with a dummy compound that stung the users
nostrils.
w5
Some interventions were tested under impractical
and unrealistic situations: participants allocated to the
intervention hand cleaner (organic acids) were not
allowed to use their hands between cleaning and chal-
lenge with virus, so the effect of normal use of the hands
on the intervention remains unknown,
w3
and 2% aqu-
eous iodine is a successful antiviral intervention when
painted on the hands but it stains and is impractical for
all but the highest risk of epidemic contagion.
w51
Compliance with interventions
especially educa-
tional programmes
was problematic for several stu-
dies, despite the importance of many such low cost
interventions.
The most impressive effects came from high quality
cluster randomised trials in preventing the spread of
respiratory virus into the community using hygienic
measures aimed at younger children. One study
reported a significant decrease in respiratory illness in
children up to age 24 months (relative risk 0.90, 95%
confidence interval 0.83 to 0.97), although the
decrease was not significant in older children (0.95,
0.89 to 1.01).
w11
Another study reported a 50% (95%
confidence interval 65% to 34%) lower incidence of
pneumonia in children aged less than 5 years in a
developing country.
w1
Additional benefit from
reduced transmission to other household members is
broadly supported by the results of other study designs
although the potential for confounding is greater.
Six case-control studies assessed the impact of public
health measures to curb the spread of the SARS epi-
demic in China, Singapore, and Vietnam in 2003.
Homogeneity of case definition, agent, settings, and
outcomes made meta-analysis possible, using a fixed
effects model because no comparisons showed
significant heterogeneity (fig 2 and table 6). Only bin-
ary data were pooled despite the availability of contin-
uous data because the variables differed or were
measured in different units, and standard deviations
were usually missing. The data suggest that implement-
ing barriers to transmission, isolation, and hygienic
measures are effective and relatively cheap inter-
ventions to contain epidemics of respiratory viruses,
such as SARS, with estimates of effect ranging from
55% to 91%: washing hands more than 10 times daily
(odds ratio 0.45, 95% confidence interval 0.36 to 0.57,
NNT=4, 95% confidence interval 3.65 to 5.52); wear-
ing masks (0.32, 0.25 to 0.40, NNT=6, 4.54 to 8.03);
wearing N95 masks (0.09, 0.03 to 0.30, NNT=3, 2.37
to 4.06); wearing gloves (0.43, 0.29 to 0.65, NNT=5,
4.15 to 15.41); wearing gowns (0.23, 0.14 to 0.37,
NNT=5, 3.37 to 7.12); and handwashing, masks,
gloves, and gowns combined (0.09, 0.02 to 0.35,
NNT=3, 2.66 to 4.97). All studies selected hospital
cases, except one
w45
in which the cases were people
with probable SARS reported to the Department of
Health in the territory of Hong Kong up to 16 May
2003. Evidence was limited for the superior effective-
ness of barrier devices to droplets such as the N95
masks (respirators with 95% filtration capability
against non-oily particulate aerosols
w48
) over simple
surgical masks. An incremental effect was found for
decreased burden of respiratory disease by adding vir-
ucidals or antiseptics to normal handwashing in atypi-
cal settings, but the extra benefit may have been, at
least partly, from confounding additional routines.
Studies on interventions to prevent the transmission
of respiratory syncytical virus and similar viruses in
more typical settings suggested good effectiveness,
although doubt was cast on the findings because of
method quality inherent in controlled before and
after studies, especially different virus infection rates.
Table 4
|
Characteristics of included retrospective cohort studies
Study Participants Interventions v comparisons Outcomes Risk of bias (notes)
Doherty 1998
w40
Children aged <2 years with
differential diagnosis of
respiratory syncytial virus
infection
Diagnosis of respiratory syncytial virus
infection and cohorting v normal care
RSV infection reduced
(but data did not
support conclusion)
High (poor descriptions)
Isaacs 1991
w41
Children aged <2 years with
differential diagnosis of
respiratory syncytial virus
infection
Isolation and handwashing with alcohol
based hand rubs (Amphisept 80;
GoldsCHmidt) v normal care
Respiratory syncytial virus infection
reduced by
up to 60%
High (poor descriptions)
Ou 2003
w42 w43
171 cases of SARS and 1210
people quarantined from
selected districts in China
Quarantineat home or hospital for 14 days
after exposure: comparisons between
reductions of incidence (95% CIs) of SARS
for carers 31% (20% to 44%), visitors 9%
(3% to 22%), and cohabiting contacts 5%
(2% to 9%)
SARS attack rates reduced for all groups
except non-cohabitants living in same
building; carers of cases duringincubation
period (quarantine therefore not
necessary)
High (non-random basis for sample,
selection bias of sample and responders,
recall bias of responders, and absence of
laboratory confirmed diagnosis may have
affected conclusion. Overall, insufficient
denominator data, or data on non-exposed
people, precluded data extraction or
calculation of odds ratios)
Yen 2006
w44
One intervention military
hospital (459 healthcare
workers) and 86 control
hospitals in Taiwan
Integrated infection control strategy: triage
and barrier trafficflow into hospital, zoning
of risk, negative pressure areas of
isolation, personal hygiene, and barrier
interventions v normal isolation
procedures
Only two healthcare workers infected with
SARS, compared with 50 probable cases
and 43 suspected cases in control
hospitals
High (sketchily reported study with missing
denominators and data on exposure to
SARS. Not clear how intervention differed
from high risk isolation procedures)
RESEARCH
page 6 of 9 BMJ | ONLINE FIRST | bmj.com
Few studies reported on resource consumption for
the physical intervention evaluated. One case-control
study
w45
concluded that handwashing needs to be car-
ried out more than 10 times daily to be effective. One
study,
w25
in a military training setting, reported a need
to wash hands more than four times daily. During one
month of the respiratory syncytical virus season on a
ward containing 22 cribs, one study reported that
5350 gowns and 4850 masks were used.
w18
Proper evaluation of global and highly resource
intensive measures such as screening at entry ports
and social distancing was lacking. The handful of stu-
dies (mostly done during the SARS epidemic) did not
allow firm conclusions to be drawn.
DISCUSSION
In this systematic review we found that physical bar-
riers such as handwashing, wearing a mask, and
Table 5
|
Characteristics of included case-control studies
Study Participants Interventions v comparisons Outcomes Risk of bias (notes)
Lau 2004
w45
330 probable cases of
SARS reported to
Department of Health,
Hong Kong
Natural exposure to SARS during serious epidemic Community transmission of SARS reduced (odds ratio
0.30, 95% CI 0.23 to 0.39)
Medium (inconsistenciesin
text: controls not
described)
Nishiura 2005
w46
29 survivors of laboratory
confirmed SARS; cases
admitted to hospital and
retained or transferred
Handwashing before contact with patient infected with
SARS; handwashingafter contact with infected patient;
masks; gloves; gowns; all measures combined
Masks (odds ratio 0.3, 95% CI 0.1 to 0.7) and gowns
(0.2, 0.0 to 0.8) were significantly associated with
protectionfrom SARS during phase 1 trials but in phase
2 trials masks (0.1, 0.0 to 0.3) and all measures (0.1,
0.0 to 0.3) were associated with protection probably
because of increased awareness of danger of outbreak
and increased use of measures
Low (well written and
reported study)
Seto 2003
w47
13 healthcare workers
infected with confirmed
SARS within 2-7 days of
exposure, with no
community exposure
Handwashing, masks, gloves, and gowns Handwashing, masks, and gowns (odds ratio 5, 95% CI
1 to 19) were effective, but only masks (13, 3 to 60)
were significant using logistic regression, possibly
through lack of power
Medium (inconsistenciesin
text: lack of description of
controls)
Teleman 2004
w48
36 healthcare workers
caring for patients with
probable or suspected
SARS
Distance from source of infection <1 m, duration of
exposure
60 minutes, wearing N95 mask, wearing
gloves, wearing gown, touched patients, touched
patients
personal belongings, contact with respiratory
secretions,did venepuncture, carried out or assisted in
intubation, carried out suction of body fluids, gave
oxygen; washed hands after contact with each patient
Three factors were associated with significant risks or
protectionagainst SARS: wearing N95 mask (oddsratio
0.1, 95% CI 0.02 to 0.86), contact with respiratory
secretions (21.8, 1.7 to 274.8), and handwashing after
contact with each patient (0.07, 0.008 to 0.66)
Low (well written and
reported study)
Wu 2004
w49
94 patients with probable
or suspected SARS
admitted to hospital
Always wearing a mask, intermittently wearing a mask,
washing hands after returning home, owning a pet,
visited farmers
market, visited clinics, eaten out, or
used taxis
Always wearing a mask was strongly protective (70%
reduction in risk, odds ratio 0.3, 95% CI 0.2 to 0.7) and
wearing one intermittently (0.5, 0.2 to 0.9) or always
washing hands after returning home (0.3, 0.2 to 0.7)
showed smaller significant reductions in risk. Of great
interest was role of fever clinics in spreading the
disease, probably because of poorly implemented
isolation and triage procedures (13.4, 3.8 to 46.7),
having eaten out (2.3, 1.2 to 4.5), or used taxis more
than once a week (3.2, 1.3 to 8.0)
Medium (inconsistenciesin
text: controls not
described)
Yin 2004
w50
77 healthcare workers
caring for patients with
probable or suspected
SARS
Mouthmasks, thick mouthmasks (>12 layersof cloths),
one-off paper mouth mask, wearing eye mask when
indicated, protection for mucosa of nose and eyes,
shoes, gloves, barrier gown, gloves, rinsing out mouth,
bathing, fresh clothes before going home, checking
mouth mask, taking oseltamivir orally, avoiding eating
or smoking in ward, hand washing and disinfection,
nose clamps, taking herbal Banlangen (Indigowoad
Root) orally
Single measures such as wearing masks (odds ratio
0.78, 95% CI 0.60 to 0.99), goggles (0.20, 0.10 to
0.41), and footwear (0.58, 0.39 to 0.86) were effective
against SARS
Medium (inconsistenciesin
text: controls not
described)
Table 6
|
Pooled estimates of effect of public health interventions to interrupt transmission of SARS from case-control studies
Intervention No of studies (references) Odds ratio (95% CI)
Intervention
effectiveness* (%)
Number needed to treat
(95% CI)
Frequent handwashing (>10 times daily) 6 (w48, w45-w47, w49, w50) 0.45 (0.36 to 0.57) 55 4.00 (3.65 to 5.52)
Wearing mask 5 (w45-w47, w49, w50) 0.32 (0.25 to 0.40) 68 6.00 (4.54 to 8.03)
Wearing N95 mask 2 (w45, w47) 0.09 (0.03 to 0.30) 91 3.00 (2.37 to 4.06)
Wearing gloves 4 (w46, w47 w45, w50) 0.43 (0.29 to 0.65) 57 7.00 (4.15 to 15.41)
Wearing gown 4 (w45, w46, w47, w50) 0.23 (0.14 to 0.37) 77 5.00 (3.37 to 7.12)
Handwashing, mask, gloves, and gown
combined
2 (w46, w47) 0.09 (0.02 to 0.35) 91 3.00 (2.66 to 4.97)
*Odds ratio
1.
Number needed to treat to prevent one case.
RESEARCH
BMJ | ONLINE FIRST | bmj.com page 7 of 9
isolation of potentially infected patients were effective
in preventing the spread of respiratory virus infections.
It is not surprising that methods of the included studies
were at risk of bias as these types of interventions are
difficult to blind, are often set up hurriedly in emer-
gency situations, and funding is less secure than for
profit making interventions. Hasty design of inter-
ventions to minimise public health emergencies,
particularly the six included case-control studies, is
understandable but not when no randomisation (not
even of clusters) was done in the several unhurried
cohort and before and after studies, despite randomisa-
tion leading to minimal disruption to service delivery.
Inadequate reporting often made interpretation of
before and after studies difficult.
The settings of the studies, carried out over four dec-
ades, were heterogeneous, ranging from suburban
schools
w4 w37 w29
to military barracks,
w25
intensive care
units, paediatric wards
w14 w16
in industrialised coun-
tries, slums in developing countries,
w1
and day care
centres for children with special needs.
w22
Few attempts
were made to obtain socioeconomic diversity by, for
example, involving several schools in the evaluations
of one programme.
w29
We identified few studies from
developing countries where the most burden lies and
where cheap interventions are needed. Even in Israel,
the decrease in acute respiratory tract infections subse-
quent to school closure may have been related to aty-
pical features: the high proportion of children in the
population (34%) and limited access to over the coun-
ter drugs, which together with the national universal
comprehensive health insurance means that sympto-
matic treatment is generally prescribed by doctors.
w19
Compliance with interventions
especially educa-
tional programmes
was a problem for several studies,
despite the importance of such low cost interventions.
Routine long term implementation of some would be
problematic
particularly maintaining strict hygiene
and barrier routines for long periods, probably only
feasible in highly motivated environments such as hos-
pitals without the threat of an epidemic.
Global and highly resource intensive measures such
as screening at entry ports and social distancing lacked
proper evaluation. The handful of studies (mostly done
during the SARS epidemic) did not allow us to reach
any firm conclusions, although a recent analysis of his-
torical and archival data from the 1918-9 influenza
pandemic in the United States suggests an effect of
social distancing measures such as school closures
and bans on public gatherings.
24
Nevertheless our systematic review of available
research does provide some important insights. Per-
haps the impressive effect of the hygienic measures
aimed at younger children derives from their poor cap-
ability with personal hygiene.
w1 w11
Simple public health measures seem to be highly
effective at reducing the transmission of respiratory
viruses, especially when they are part of a structured
programme including instruction and education and
when they are delivered together. Further large prag-
matic trials are needed to evaluate the best combina-
tions. In the meantime we recommend implementing
the following interventions combined to reduce the
transmission of respiratory viruses: frequent hand-
washing (with or without antiseptics), barrier measures
(gloves, gowns, and masks), and isolation of people
with suspected respiratory tract infections.
Frequent handwashing
Lau 2004
w45
Nishiura 2005
w46
Seto 2003
w47
Teleman 2004
w48
Wu 2004
w49
Y
in 2004
w50
Total (95% CI)
Total events: 214 (cases), 901 (control)
Test for heterogeneity: χ
2
=4.58, df=5, P=0.47, I
2
=0%
Test for overall effect: z=6.56, P<0.001
57.26
4.62
2.55
4.57
13.45
17.56
100.00
0.1 0.2 0.5 1 2 5 10
Study or subcategory Weight
(%)
0.45 (0.32 to 0.62)
0.91 (0.37 to 2.25)
0.21 (0.05 to 0.83)
0.26 (0.07 to 0.93)
0.38 (0.21 to 0.72)
0.49 (0.28 to 0.85)
0.45 (0.36 to 0.57)
Odds ratio
(fixed) (95% CI)
Odds ratio
(fixed) (95% CI)
61/330
15/25
10/13
27/36
73/94
28/77
575
Cases
n/N
222/660
56/90
227/241
46/50
253/281
97/180
1502
Wearing masks
Lau 2004
w45
Nishiura 2005
w46
Seto 2003
w47
Wu 2004
w49
Y
in 2004
w50
Total (95% CI)
Total events: 194 (cases), 773 (control)
Test for heterogeneity: χ
2
=9.62, df=4, P=0.05, I
2
=58.4%
Test for overall effect: z=9.52, P<0.001
71.85
4.00
2.10
17.22
4.82
100.00
0.28 (0.21 to 0.37)
0.74 (0.29 to 1.90)
0.14 (0.01 to 2.34)
0.48 (0.29 to 0.80)
0.08 (0.02 to 0.40)
0.32 (0.25 to 0.40)
93/330
8/25
0/13
25/94
68/77
539
388/660
35/90
51/241
121/281
178/180
1452
Control
n/N
Favours
intervention
Favours
control
Wearing gloves
Nishiura 2005
w46
Seto 2003
w47
Teleman 2004
w48
Y
in 2004
w50
Total (95% CI)
Total events: 59 (cases), 305 (control)
Test for heterogeneity: χ
2
=4.33, df=3, P=0.23, I
2
=30.6%
Test for overall effect: z=4.07, P<0.001
12.18
11.39
18.27
58.15
100.00
0.94 (0.36 to 2.43)
0.47 (0.14 to 1.57)
0.49 (0.20 to 1.23)
0.30 (0.17 to 0.52)
0.43 (0.29 to 0.65)
8/25
4/13
10/36
37/77
151
30/90
117/241
22/50
136/180
561
Wearing gowns
Nishiura 2005
w46
Seto 2003
w47
Teleman 2004
w48
Y
in 2004
w50
Total (95% CI)
Total events: 34 (cases), 249 (control)
Test for heterogeneity: χ
2
=2.10, df=3, P=0.55, I
2
=0%
Test for overall effect: z=5.99, P<0.001
12.82
11.29
12.02
63.87
100.00
0.23 (0.05 to 1.03)
0.07 (0.00 to 1.20)
0.46 (0.15 to 1.43)
0.22 (0.12 to 0.39)
0.23 (0.14 to 0.37)
2/25
0/13
5/36
27/77
151
25/90
83/241
13/50
128/180
561
Fig 2
|
Evidence from case-control studies on effect of frequent handwashing or wearing of
masks, gloves, or gowns on prevention of severe respiratory syndrome (SARS)
RESEARCH
page 8 of 9 BMJ | ONLINE FIRST | bmj.com
We thank Peter Doshi, Anne Lyddiatt, Stephanie Kondos, Tom Sandora, Kathryn
Glass, Max Bulsara, and Allen Cheng for commenting on the draft protocol;
J
ø
rgen Lous for translating a Danish paper and extracting data; Taixiang Wu for
translating Chinese text; and Ryuki Kassai for translating Japanese text.
Contributors: RF and AR constructed the search strategy. TJ, CDM, and LD
drafted the protocol. LD, CDM, and RF incorporated the referees
comments. TJ,
FE, BH, and AP extracted study data. SN carried out the analyses. TJ and CDM
wrote the final report and are the guarantors for the paper. All authors
contributed to the final paper.
Funding: Cochrane Collaboration Steering Group, UK, and each author
s
institution.
Competing interests: None declared.
Ethical approval: Not required.
Provenance and peer review: Not commissioned; externally peer
reviewed.
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issue 3.
24 Markel H, Lipman HB, Navarro JA, et al. Nonpharmaceutical
interventions implemented by US cities during the 1918-1919
influenza pandemic. JAMA 2007;298:644-54.
Accepted: 23 October 2007
WHAT IS ALREADY KNOWN ON THIS TOPIC
People are increasingly concerned about pandemics of virus infections such as avian
influenza and SARS
Preparation against pandemics includes developing vaccines and stockpiling antiviral agents
interventions that are virus specific and of unknown effectiveness in epidemic disease
WHAT THIS STUDY ADDS
Several physical barriers, especially handwashing, masks, and isolation of potentially
infected people, were effective in preventing the spread of respiratory virus infections
Such interventions should be better evaluated and given higher priority in preparation for
pandemics
RESEARCH
BMJ | ONLINE FIRST | bmj.com page 9 of 9
    • "Das Ausmaß des präventiven Werts des Atemschutzes kann nur schwer abgeschätzt werden, da entsprechende gut geplante und durchgeführte Studien fehlen. Metaanalysen verschiedener retrospektiver Untersuchungen zeigen jedoch eine signifikante Reduktion der Verbreitung respiratorischer Erkrankungen, wenn ein Atemschutz in die Präventionsmaßnahmen einbezogen war106107108109110111. Ein Review zur Infektionsübertragung durch Aerosol-generierende medizinische Maßnahmen zeigte, dass das höchste Risiko einer Übertragung bei trachealer Intubation , nicht-invasiver Beatmung, Tracheotomie und der Beatmung mit Beatmungsbeutel und Maske vor der Intubation entsteht [79]. "
    Article · Oct 2015
    • "vaccination) and non-pharmaceutical public health interventions. Research suggests that non-pharmaceutical respiratory infection control may provide simple, lowcost , effective ways of reducing the transmission and minimising impact of acute respiratory infections in pandemic and non-pandemic contexts456. In the early stages of an emerging respiratory infection outbreak or pandemic, it is unlikely that there will be immediate and sufficient availability of a vaccine on a global scale due to the novelty of the virus [7]. "
    [Show abstract] [Hide abstract] ABSTRACT: Background Non-pharmaceutical public health interventions may provide simple, low-cost, effective ways of minimising the transmission and impact of acute respiratory infections in pandemic and non-pandemic contexts. Understanding what influences the uptake of non-pharmaceutical interventions such as hand and respiratory hygiene, mask wearing and social distancing could help to inform the development of effective public health advice messages. The aim of this synthesis was to explore public perceptions of non-pharmaceutical interventions that aim to reduce the transmission of acute respiratory infections. Methods Five online databases (MEDLINE, PsycINFO, CINAHL, EMBASE and Web of Science) were systematically searched. Reference lists of articles were also examined. We selected papers that used a qualitative research design to explore perceptions and beliefs about non-pharmaceutical interventions to reduce transmission of acute respiratory infections. We excluded papers that only explored how health professionals or children viewed non-pharmaceutical respiratory infection control. Three authors performed data extraction and assessment of study quality. Thematic analysis and components of meta-ethnography were adopted to synthesise findings. Results Seventeen articles from 16 studies in 9 countries were identified and reviewed. Seven key themes were identified: perceived benefits of non-pharmaceutical interventions, perceived disadvantages of non-pharmaceutical interventions, personal and cultural beliefs about infection transmission, diagnostic uncertainty in emerging respiratory infections, perceived vulnerability to infection, anxiety about emerging respiratory infections and communications about emerging respiratory infections. The synthesis showed that some aspects of non-pharmaceutical respiratory infection control (particularly hand and respiratory hygiene) were viewed as familiar and socially responsible actions to take. There was ambivalence about adopting isolation and personal distancing behaviours in some contexts due to their perceived adverse impact and potential to attract social stigma. Common perceived barriers included beliefs about infection transmission, personal vulnerability to respiratory infection and concerns about self-diagnosis in emerging respiratory infections. Conclusions People actively evaluate non-pharmaceutical interventions in terms of their perceived necessity, efficacy, acceptability, and feasibility. To enhance uptake, it will be necessary to address key barriers, such as beliefs about infection transmission, rejection of personal risk of infection and concern about the potential costs and stigma associated with some interventions.
    Full-text · Article · Jun 2014
    • "According to the WHO recommendations in case of epidemics and pandemics, along with other preventive measures to protect human health, one of the key measures is the implementation of respiratory protection [12, 13]. At the individual level, respiratory protection is achieved by wearing different types of masks, half masks, respirators or other physical barriers [14]. The mask should be worn at all occasions where there is a possibility of air contamination by viruses and bacteria due to a large number of sick or even healthy individuals (healthy carriers) in enclosed spaces, public places and other places of assembly [15]. "
    Full-text · Article · Jan 2014 · BMC Public Health
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