Event-based surveillance at health ... - BMJ Global Health · 2 KuehnefiA etfial BMJ Global Health...
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1 Kuehne A, et al. BMJ Global Health 2019;4:e001878. doi:10.1136/bmjgh-2019-001878 Event-based surveillance at health facility and community level in low- income and middle-income countries: a systematic review Anna Kuehne , 1,2,3 Patrick Keating , 1,3 Jonathan Polonsky , 4,5 Christopher Haskew , 4 Karl Schenkel , 4 Olivier Le Polain de Waroux , 1,2,3 Ruwan Ratnayake 3 Research To cite: Kuehne A, Keating P, Polonsky J, et al. Event-based surveillance at health facility and community level in low- income and middle-income countries: a systematic review. BMJ Global Health 2019;4:e001878. doi:10.1136/ bmjgh-2019-001878 Handling editor Seye Abimbola Received 30 July 2019 Revised 26 August 2019 Accepted 30 August 2019 1 UK Public Health Rapid Support Team, London, United Kingdom 2 Public Health England, London, United Kingdom 3 Department of Infectious Disease Epidemiogy, London School of Hygiene and Tropical Medicine, London, United Kingdom 4 Department of Health Emergency Information and Risk Assessment, World Health Organization, Geneva, Switzerland 5 Faculty of Medicine, University of Geneva, Geneva, Switzerland Correspondence to Dr Anna Kuehne; [email protected] © Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ. Key questions What is already known? ► Event-based surveillance (EBS) aims to contribute to rapid detection of acute public health events, and supplements indicator-based surveillance (IBS), the backbone of national surveillance systems. ► To date, no assessment of evidence for best prac- tices exists. What are the new findings? ► The scope of EBS is broader than IBS in several aspects: (1) In outbreaks, EBS was able to identi- fy outbreak-disease cases and programming gaps helping to guide the response; (2) EBS was able to rapidly identify outbreaks and other health hazards that were not detected by IBS, or before they were detected by IBS; (3) EBS was able to reach remote areas and was most used where health facilities were scarce. ► Good communication with communities and other stakeholders were described as key; in addition, linkage to IBS surveillance and rapid response was described as essential for all systems as every ver- ified event needs an assessment and potentially a response. What do the new findings imply? ► EBS is a valuable source of data that can strengthen the early warning function of national surveillance systems, if integrated into existing surveillance and linked to response structures. ► Priority in the implementation of EBS should be given to settings that would particularly benefit from EBS’ strengths such as areas most prone to outbreaks, where access to the formal health system is limited, where traditional ‘routine’ surveillance is suboptimal and where timeliness of notification of epidemic- prone diseases is of particular importance to mount- ing a rapid response. ABSTRACT Background The International Health Regulations require member states to establish “capacity to detect, assess, notify and report events”. Event-based surveillance (EBS) can contribute to rapid detection of acute public health events. This is particularly relevant in low-income and middle- income countries (LMICs) which may have poor public health infrastructure. To identify best practices, we reviewed the literature on the implementation of EBS in LMICs to describe EBS structures and to evaluate EBS systems. Methods We conducted a systematic literature search of six databases to identify articles that evaluated EBS in LMICs and additionally searched for grey literature. We used a framework approach to facilitate qualitative data synthesis and exploration of patterns across and within articles. Results We identified 778 records, of which we included 15 studies concerning 13 different EBS systems. The 13 EBS systems were set up as community-based surveillance, health facility-based surveillance or open surveillance (ie, notification by non-defined individuals and institutions). Four systems were set up in outbreak settings and nine outside outbreaks. All EBS systems were integrated into existing routine surveillance systems and pre-existing response structures to some extent. EBS was described as useful in detecting a large scope of events, reaching remote areas and guiding outbreak response. Conclusion Health facility and community-based EBS provide valuable information that can strengthen the early warning function of national surveillance systems. Integration into existing early warning and response systems was described as key to generate data for action and to facilitate rapid verification and response. Priority in its implementation should be given to settings that would particularly benefit from EBS strengths. This includes areas most prone to outbreaks and where traditional ‘routine’ surveillance is suboptimal. BACKGROUND The International Health Regulations (IHR) require member states to have “the capacity to detect, assess, notify and report events”. 1 An event is defined as “a manifestation of disease or an occurrence that creates a potential for disease”. 1 Event-based surveillance (EBS) is the organised collection, monitoring, assessment on October 7, 2020 by guest. Protected by copyright. http://gh.bmj.com/ BMJ Glob Health: first published as 10.1136/bmjgh-2019-001878 on 10 December 2019. Downloaded from
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1Kuehne A, et al. BMJ Global Health 2019;4:e001878. doi:10.1136/bmjgh-2019-001878
Event- based surveillance at health facility and community level in low- income and middle- income countries: a systematic review
Anna Kuehne ,1,2,3 Patrick Keating ,1,3 Jonathan Polonsky ,4,5 Christopher Haskew ,4 Karl Schenkel ,4 Olivier Le Polain de Waroux ,1,2,3 Ruwan Ratnayake 3
Research
To cite: Kuehne A, Keating P, Polonsky J, et al. Event- based surveillance at health facility and community level in low- income and middle- income countries: a systematic review. BMJ Global Health 2019;4:e001878. doi:10.1136/bmjgh-2019-001878
Handling editor Seye Abimbola
Received 30 July 2019Revised 26 August 2019Accepted 30 August 2019
1UK Public Health Rapid Support Team, London, United Kingdom2Public Health England, London, United Kingdom3Department of Infectious Disease Epidemiogy, London School of Hygiene and Tropical Medicine, London, United Kingdom4Department of Health Emergency Information and Risk Assessment, World Health Organization, Geneva, Switzerland5Faculty of Medicine, University of Geneva, Geneva, Switzerland
Correspondence toDr Anna Kuehne; anna. kuehne@ lshtm. ac. uk
© Author(s) (or their employer(s)) 2019. Re- use permitted under CC BY- NC. No commercial re- use. See rights and permissions. Published by BMJ.
Key questions
What is already known? ► Event- based surveillance (EBS) aims to contribute to rapid detection of acute public health events, and supplements indicator- based surveillance (IBS), the backbone of national surveillance systems.
► To date, no assessment of evidence for best prac-tices exists.
What are the new findings? ► The scope of EBS is broader than IBS in several aspects: (1) In outbreaks, EBS was able to identi-fy outbreak- disease cases and programming gaps helping to guide the response; (2) EBS was able to rapidly identify outbreaks and other health hazards that were not detected by IBS, or before they were detected by IBS; (3) EBS was able to reach remote areas and was most used where health facilities were scarce.
► Good communication with communities and other stakeholders were described as key; in addition, linkage to IBS surveillance and rapid response was described as essential for all systems as every ver-ified event needs an assessment and potentially a response.
What do the new findings imply? ► EBS is a valuable source of data that can strengthen the early warning function of national surveillance systems, if integrated into existing surveillance and linked to response structures.
► Priority in the implementation of EBS should be given to settings that would particularly benefit from EBS’ strengths such as areas most prone to outbreaks, where access to the formal health system is limited, where traditional ‘routine’ surveillance is suboptimal and where timeliness of notification of epidemic- prone diseases is of particular importance to mount-ing a rapid response.
AbsTrACTbackground The International Health Regulations require member states to establish “capacity to detect, assess, notify and report events”. Event- based surveillance (EBS) can contribute to rapid detection of acute public health events. This is particularly relevant in low- income and middle- income countries (LMICs) which may have poor public health infrastructure. To identify best practices, we reviewed the literature on the implementation of EBS in LMICs to describe EBS structures and to evaluate EBS systems.Methods We conducted a systematic literature search of six databases to identify articles that evaluated EBS in LMICs and additionally searched for grey literature. We used a framework approach to facilitate qualitative data synthesis and exploration of patterns across and within articles.results We identified 778 records, of which we included 15 studies concerning 13 different EBS systems. The 13 EBS systems were set up as community- based surveillance, health facility- based surveillance or open surveillance (ie, notification by non- defined individuals and institutions). Four systems were set up in outbreak settings and nine outside outbreaks. All EBS systems were integrated into existing routine surveillance systems and pre- existing response structures to some extent. EBS was described as useful in detecting a large scope of events, reaching remote areas and guiding outbreak response.Conclusion Health facility and community- based EBS provide valuable information that can strengthen the early warning function of national surveillance systems. Integration into existing early warning and response systems was described as key to generate data for action and to facilitate rapid verification and response. Priority in its implementation should be given to settings that would particularly benefit from EBS strengths. This includes areas most prone to outbreaks and where traditional ‘routine’ surveillance is suboptimal.
bACKgroundThe International Health Regulations (IHR) require member states to have “the capacity to detect, assess, notify and report events”.1 An event is defined as “a manifestation of disease
or an occurrence that creates a potential for disease”.1 Event- based surveillance (EBS) is the organised collection, monitoring, assessment
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rotected by copyright.http://gh.bm
j.com/
BM
J Glob H
ealth: first published as 10.1136/bmjgh-2019-001878 on 10 D
ecember 2019. D
ownloaded from
2 Kuehne A, et al. BMJ Global Health 2019;4:e001878. doi:10.1136/bmjgh-2019-001878
BMJ Global Health
Table 1 Systematic and grey literature review on event- based surveillance in the field: definitions
EBS For the purpose of this review, we defined EBS as “the organised collection, monitoring, assessment and interpretation of information of mainly unstructured ad hoc information regarding health events or risks, which may represent an acute risk to human health”2 and require rapid reporting and assessment.2 3 The events can relate to the occurrence of epidemic- prone diseases and other chemical and environmental hazards in humans (eg, cluster of cases of disease, unusual disease patterns, unexplained deaths, chemical spills) or related to potential exposure for humans (eg, mass deaths among animals).2 3
We included EBS systems (as distinct from IBS2) characterised by the following attributes: (1) the source of signal can be a report from the general public, healthcare workers, community- level volunteers and it is not limited to the use of data and other information that arrive via a formal IBS system; (2) notifiable events are not defined by symptoms or syndromes but by (specified or unspecified) events related to health threats; (3) notification from the field to the EBS system is immediate (rather than planned weekly or monthly); (4) every notified signal requires rapid verification; (5) every verified event requires a timely response.EBS as defined by WHO2 can include an epidemic intelligence component that is based on the systematic automated analysis of various media sources (such as Epidemic Intelligence from Open Sources29 and the Global Public Health Intelligence Network30 on global scale). However, given the difference in structure and remit, we restricted our review to field- based EBS sourced from informants in health facilities or in the community.
Signal A signal is reported data or information which represent a potential acute risk to human health. It is transmitted immediately and has not yet been verified to meet the event definition of the EBS system.2
Event The IHR define an event as “(…)a manifestation of disease or an occurrence that creates a potential for disease; (…)”.1 In the context of event- based surveillance, an ‘event’ refers to ‘a signal’ that has been verified to meet the event definition of the EBS system.2
Alert In this document (as in the WHO guidance 20142), “an alert will refer to a public health event that has been (i) verified and (ii) risk assessed and (iii) requires an intervention (an investigation, a response or a communication).”2
Community- based surveillance (CBS)
“CBS is the systematic detection and reporting of events of public health significance within a community by community members”.11 It is a surveillance system (IBS or EBS) that relies on defined individuals from the community (often called community volunteers) who received special training on event definition (for EBS) or case definitions (for IBS) and who notify signals to the surveillance system.
Health facility–based surveillance
A surveillance system (IBS or EBS) that relies on health professionals notifying signals to a next level in the surveillance system.
Open surveillance We use the term ‘open surveillance’ to describe systems that did not specify who can notify signals but were open to receive signals from anyone (including lay people, media, NGOs, health professionals, teachers etc).
Outbreak setting Refers to a setting in which EBS was implemented during an outbreak to enhance outbreak- specific surveillance.
Routine setting Refers to a setting in which the purpose of the EBS system is to contribute to routine surveillance of defined or undefined events to detect outbreaks and other public health emergencies outside outbreaks.
CBS, community- based surveillance; EBS, event- based surveillance; IBS, indicator- based surveillance; IHR, International Health Regulations; NGO, non- government organisation; WHO, World Health Organisation.
and interpretation of mainly unstructured, ad hoc informa-tion regarding health events or risks, which may represent an acute risk to human health.2 EBS should be monitored and responded to in real- time. EBS, alongside indicator- based surveillance (IBS), is a component of the early warning, alert and response (EWAR) function of a national surveillance system.2 The objective of EWAR is to support the early detection of, and rapid response to, acute public health events of any origin.2 Thus, EWAR is a key function of surveillance, particularly in low- income and middle- income country (LMIC) settings and for humanitarian emergencies where the epidemic risk is high and other elements of the surveillance architecture may be limited or absent.2 EBS may provide the earliest detection of any acute public health event, particularly those that are not well detected by IBS, or not detected rapidly enough.
Guidance documents discuss the implementation of EBS within national surveillance systems, prior to and during humanitarian emergencies.2–6 However, to date no assessment of evidence for best practices exists. We evaluated the peer- reviewed and grey literature relating to the implementation of EBS for outbreak detection in
LMICs in both emergency and non- emergency settings in order to provide a systematic description of EBS and to evaluate the strengths and weaknesses of EBS across both contexts.
MeTHodsKey outcomesThe key outcomes included summaries of the (1) quality of available evaluations, (2) EBS system structure and event definitions in use, and (3) evaluations of surveil-lance attributes of the EBS systems.
search strategyFollowing PRISMA guidelines, we conducted a systematic review to identify peer- reviewed literature that presented data collected by EBS systems in LMICs and/or evalu-ated EBS systems in LMICs. We searched six databases: MEDLINE (Ovid MEDLINE and Epub Ahead of Print, In- Process & Other Non- Indexed Citations and Daily), EMBASE, Global Health, Northern Light Life Sciences Conference Abstracts, CINAHL Plus with full text
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rotected by copyright.http://gh.bm
j.com/
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J Glob H
ealth: first published as 10.1136/bmjgh-2019-001878 on 10 D
ecember 2019. D
ownloaded from
Kuehne A, et al. BMJ Global Health 2019;4:e001878. doi:10.1136/bmjgh-2019-001878 3
BMJ Global Health
Figure 1 Systematic and grey literature review on event- based surveillance in the field: PRISMA flow chart for systematic literature review (black ink letters) and grey literature search (blue ink letters) and backward citation search (green ink letters) describing identification, screening, eligibility and inclusion. EBS, event- based surveillance; IBS, indicator- based surveillance; LMIC, low- income and middle- income countries.
and Africa Wide Information. We included literature published since the earliest date indexed in each data-base up to 20 August 2018 in English, French, German, Portuguese or Spanish. The search terms were related to (1) event- based surveillance and early warning alert and response, or (2) different types and channels of surveil-lance that are used to detect outbreaks or epidemics and (3) LMICs and regions (online supplementary file 1). The search strategies included indexed terms where possible and the list of LMICs was adapted from the standard list available at OVID MEDLINE based on World Bank Group classification 2017–2018.7 We adapted the search strategy for MEDLINE and tailored it to each database. Furthermore, we conducted a backward citation search and searched the references for each included article for relevant literature. We repeated all steps of the system-atic assessment of titles and abstracts and full texts for all cited references.
Additional grey (unpublished) literature was retrieved by contacting epidemiologists at agencies and networks known to be involved in implementation or evaluation of EBS at the London School of Hygiene and Tropical Medicine, Médecins Sans Frontières, Norwegian Red Cross, CARE, US Centers for Disease Control (US CDC), WHO, and the Training Programs in Epidemiology and Public Health Interventions Network (TEPHINET).
definitionsWe defined the terms EBS and associated terminology in accordance with WHO guidance2 3 (table 1).
selection of literatureFollowing the elimination of duplicates, two researchers independently assessed the potential relevance of all papers, starting with titles and abstracts (screening) and full text (data extraction) using set inclusion and exclu-sion criteria. A consensus was reached for any discrep-ancy through discussion between the two researchers. For conference abstracts that were identified during the literature search, we contacted the corresponding author to obtain additional information.
Inclusion criteriaThe full text referred to EBS as defined above and to LMICs as defined by the World Bank Group 2017–2018.7
Exclusion criteriaWe excluded any full texts that described the EBS system but did not provide any data (quantitative or qualitative) on its functioning or effectiveness. We excluded any full texts that referred exclusively to (1) either case- based or syndromic IBS systems, or (2) systems using thresholds (of numbers of observations) to generate an alert. We excluded full texts that described mixed surveillance systems (IBS and EBS)
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rotected by copyright.http://gh.bm
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J Glob H
ealth: first published as 10.1136/bmjgh-2019-001878 on 10 D
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BMJ Global Health
Tab
le 2
S
yste
mat
ic a
nd g
rey
liter
atur
e re
view
on
even
t- b
ased
sur
veill
ance
in t
he fi
eld
: sum
mar
y of
typ
es o
f stu
die
s (n
=15
) and
con
text
and
set
ting
of e
vent
- bas
ed
surv
eilla
nce
syst
ems
(17
pub
licat
ions
on
15 s
tud
ies)
Pub
licat
ion
Co
ntex
t an
d s
etti
ngM
etho
do
log
y
Tit
leTy
pe
of
pub
licat
ion
Pla
ce a
nd s
cop
eC
oun
try,
are
a an
d
po
pul
atio
nT
ime,
sca
le a
nd
freq
uenc
y o
f re
po
rtin
gTy
pe
of
dat
aM
etho
ds
and
att
rib
utes
eva
luat
ed
Outbreak setting
Rat
naya
ke R
, et
al (2
016)
. “A
sses
smen
t of
Com
mun
ity
Eve
nt- B
ased
Ssu
rvei
llanc
e fo
r E
bol
a V
irus
Dis
ease
, S
ierr
a Le
one,
201
5.”
Em
ergi
ng In
fect
ious
Dis
ease
s 22
(8):
1431
–143
719 a
nd E
RC
(201
5) E
valu
atio
n of
the
Fu
nctio
nalit
y an
d E
ffect
iven
ess
of C
omm
unity
Eve
nt-
Bas
ed S
urve
illan
ce (C
EB
S) i
n S
ierr
a Le
one20
Pee
r- re
view
ed p
ublic
atio
n.
Eva
luat
ion
of E
BS
.S
ierr
a Le
one.
Em
erge
ncy
sett
ing/
outb
reak
. Prim
arily
rur
al a
rea.
C
omm
unity
- bas
ed.
Sie
rra
Leon
e, 9
/14
dis
tric
ts. P
opul
atio
n 3.
9 m
illio
n.
Feb
201
5–S
ep 2
015
in
nine
dis
tric
ts. E
xhau
stiv
e su
rvei
llanc
e. Im
med
iate
re
por
ting.
►
Qua
ntita
tive
EB
S
dat
a.
►Q
uant
itativ
e co
mp
aris
on w
ith
othe
r su
rvei
llanc
e d
ata.
Des
crip
tion
of o
vera
ll ty
pe
of s
igna
ls o
ver
time,
use
fuln
ess:
id
entifi
catio
n of
EV
D a
nd o
ther
out
bre
aks,
PP
V (c
onfir
med
ca
ses/
all s
usp
ect,
pro
bab
ly, c
onfir
med
cas
es),
sens
itivi
ty
of C
EB
S (C
EB
S c
ases
/all
confi
rmed
cas
es).
Des
crip
tion
of
Kam
bia
CE
BS
cas
es w
ith n
o ep
i lin
k: s
ensi
tivity
of C
EB
S
(CE
BS
cas
es/a
ll co
nfirm
ed c
ases
), tim
elin
ess
(day
s): o
nset
to
det
ectio
n.
Sto
ne E
, et
al (2
016)
. “C
omm
unity
Eve
nt- B
ased
S
urve
illan
ce fo
r E
bol
a V
irus
Dis
ease
in S
ierr
a Le
one:
Im
ple
men
tatio
n of
a N
atio
nal-
Leve
l Sys
tem
Dur
ing
a C
risis
.” P
LoS
cur
rent
s 8.
and
ER
C (2
015)
Eva
luat
ion
of t
he F
unct
iona
lity
and
Effe
ctiv
enes
s of
Com
mun
ity
Eve
nt- B
ased
Sur
veill
ance
(CE
BS
) in
Sie
rra
Leon
e20
Pee
r- re
view
ed p
ublic
atio
n.
Eva
luat
ion
of E
BS
.S
ierr
a Le
one.
Em
erge
ncy
sett
ing/
outb
reak
. Prim
arily
rur
al a
rea.
C
omm
unity
- bas
ed.
Sie
rra
Leon
e, 9
/14
dis
tric
ts. P
opul
atio
n 3.
9 m
illio
n.
Mar
201
5–A
ug 2
015.
E
xhau
stiv
e su
rvei
llanc
e.
Imm
edia
te r
epor
ting.
►
Qua
ntita
tive
EB
S
dat
a.
►Q
uant
itativ
e su
rvey
am
ong
per
sonn
el.
Qua
litat
ive
inte
rvie
ws
amon
g p
erso
nnel
.
Des
crip
tion
of d
ata
qua
lity
(pro
por
tion
of c
omm
unity
hea
lth
mon
itor
(CH
M) w
ho c
orre
ctly
rec
alle
d t
rigge
r ev
ents
), ac
cep
tab
ility
(pro
por
tion
of C
HM
rep
ortin
g w
eekl
y an
d
pro
por
tion
of d
istr
ict
stak
ehol
der
s fin
din
g C
EB
S u
sefu
l),
othe
r: p
roce
ss e
valu
atio
n of
imp
lem
enta
tion.
Lee
CT,
et
al. (
2016
). "E
valu
atio
n of
a N
atio
nal C
all
Cen
tre
and
a L
ocal
Ale
rts
Sys
tem
for
Det
ectio
n of
New
C
ases
of E
bol
a V
irus
Dis
ease
—G
uine
a, 2
014–
2015
.”
MM
WR
. Mor
bid
ity a
nd M
orta
lity
Wee
kly
Rep
ort
65(9
): 22
7–23
018
Pee
r- re
view
ed p
ublic
atio
n.
Eva
luat
ion
of E
BS
.G
uine
a. E
mer
genc
y se
ttin
g/ou
tbre
ak. C
ount
ryw
ide.
Any
one
(per
son/
agen
cy) c
an n
otify
eve
nt.
Gui
nea.
Pop
ulat
ion
11.8
mill
ion.
Nov
201
4–A
ug 2
015.
E
xhau
stiv
e su
rvei
llanc
e.
Imm
edia
te r
epor
ting.
►
Qua
ntita
tive
EB
S
dat
a.
►Q
uant
itativ
e co
mp
aris
on w
ith
othe
r su
rvei
llanc
e d
ata.
Des
crip
tion
of n
umb
er o
f sig
nals
ove
r tim
e, s
ensi
tivity
of (
1)
Nat
iona
l Cal
l Cen
tre
and
(2) L
ocal
Ale
rts
Sys
tem
.
Mill
er L
A, e
t al
(201
5). “
Use
of a
nat
ionw
ide
call
cent
re
for
Eb
ola
resp
onse
and
mon
itorin
g d
urin
g a
3 d
ay
hous
e- to
- hou
se c
amp
aign
—S
ierr
a Le
one,
Sep
tem
ber
20
14.”
MM
WR
. Mor
bid
ity a
nd M
orta
lity
Wee
kly
Rep
ort
64(1
): 28
–2921
Pee
r- re
view
ed p
ublic
atio
n.
Ass
essm
ent
of E
BS
res
pon
se.
Sie
rra
Leon
e. E
mer
genc
y se
ttin
g/ou
tbre
ak. C
ount
ryw
ide.
Any
one
(per
son/
agen
cy) c
an n
otify
eve
nt.
Sie
rra
Leon
e. P
opla
tion
7 m
illio
n.19
–21
Sep
201
4.
Exh
aust
ive
surv
eilla
nce.
Im
med
iate
rep
ortin
g.
►
Qua
ntita
tive
EB
S
dat
a.
►Q
uant
itativ
e su
rvey
am
ong
lay
peo
ple
w
ho n
otifi
ed a
lert
s.
Des
crip
tion
of n
umb
er o
f sig
nals
ove
r tim
e, o
ther
: res
pon
se:
pro
por
tion
calls
tha
t re
sulte
d in
act
ion
(ass
essm
ent
of t
he
situ
atio
n on
site
).
San
ta- O
lalla
P e
t al
(201
3). “
Imp
lem
enta
tion
of a
n al
ert
and
res
pon
se s
yste
m in
Hai
ti d
urin
g th
e ea
rly s
tage
of
the
resp
onse
to
the
chol
era
epid
emic
.” T
he A
mer
ican
Jo
urna
l of T
rop
ical
Med
icin
e an
d H
ygie
ne 8
9(4)
: 68
8–69
725
Pee
r- re
view
ed p
ublic
atio
n.
Des
crip
tion
of E
BS
.H
aiti.
Em
erge
ncy
sett
ing/
outb
reak
fo
llow
ing
natu
ral d
isas
ter
(UN
cl
uste
rs a
ctiv
ated
). C
ount
ryw
ide.
A
nyon
e (p
erso
n/ag
ency
) can
not
ify
even
t.
Hai
ti. P
opul
atio
n 10
mill
ion.
Nov
201
0–N
ov 2
011.
E
xhau
stiv
e su
rvei
llanc
e.
Imm
edia
te r
epor
ting.
►
Qua
ntita
tive
EB
S
dat
a.
►Q
uant
itativ
e co
mp
aris
on w
ith
othe
r su
rvei
llanc
e d
ata.
►
Cas
e st
udy.
Des
crip
tion
of n
umb
er o
f sig
nals
ove
r tim
e an
d t
ype
of a
lert
s, u
sefu
lnes
s: a
ctio
n ta
ken
bas
ed o
n E
BS
’ dat
a q
ualit
y: p
rop
ortio
n of
doc
umen
ted
res
pon
ses
and
val
idity
: co
mp
aris
on w
ith IB
S d
ata,
acc
epta
bili
ty: t
rans
ition
to
loca
l ow
ners
hip
, flex
ibili
ty: c
hang
e of
cas
e d
efini
tions
, oth
er: e
xit
stra
tegy
.C
ase
stud
y ill
ustr
atin
g se
nsiti
vity
and
tim
elin
ess.
Routine setting
Cla
ra A
et
al: F
acto
rs In
fluen
cing
Com
mun
ity E
vent
- b
ased
Sur
veill
ance
: Les
sons
Lea
rned
from
Pilo
t Im
ple
men
tatio
n in
Vie
tnam
. Hea
lth S
ecur
ity V
olum
e 16
, Num
ber
S1,
201
8. D
OI:
10.1
089/
hs.2
018.
0066
(not
p
ublis
hed
yet
)13
Pee
r- re
view
ed p
ublic
atio
n.
Eva
luat
ion
of E
BS
.V
ietn
am. R
outin
e se
ttin
g. U
rban
an
d r
ural
are
a. C
omm
unity
- bas
ed.
Vie
tnam
, 6/6
3 p
rovi
nces
. Pop
ulat
ion
8 m
illio
n; 9
% o
f the
V
ietn
ames
e p
opul
atio
n.
Sep
201
6–D
ec 2
017.
E
xhau
stiv
e su
rvei
llanc
e.
Imm
edia
te r
epor
ting.
►
Qua
ntita
tive
EB
S
dat
a.
►Q
uant
itativ
e su
rvey
am
ong
per
sonn
el.
Incl
udin
g on
ly n
ew in
form
atio
n (c
omp
ared
with
pre
viou
s p
ublic
atio
n):
Des
crip
tion
of t
ype
of s
igna
ls a
nd e
vent
inci
den
ce o
ver
time,
vill
age
heal
th w
orke
r ch
arac
teris
tics,
PP
V (s
igna
l:eve
nt
ratio
), ac
cep
tab
ility
: will
ingn
ess
to p
artic
ipat
e vi
a q
uant
itativ
e q
uest
ionn
aire
.E
valu
atio
n of
fact
ors
influ
enci
ng e
vent
inci
den
ce r
ate
(MVA
).
Cla
ra A
, et
al (2
018)
. “E
vent
- Bas
ed S
urve
illan
ce
at C
omm
unity
and
Hea
lthca
re F
acili
ties,
Vie
tnam
, 20
16–2
017.
” E
mer
ging
Infe
ctio
us D
isea
ses
24(9
): 16
49–1
658.
14
Pee
r- re
view
ed p
ublic
atio
n.
Eva
luat
ion
of E
BS
.V
ietn
am. R
outin
e se
ttin
g. U
rban
an
d r
ural
are
a. C
omm
unity
- bas
ed.
Vie
tnam
, 4/6
3 p
rovi
nces
. Pop
ulat
ion
6 29
2 80
0; 7
% o
f the
V
ietn
ames
e p
opul
atio
n.
Sep
201
6–M
ay 2
017.
E
xhau
stiv
e su
rvei
llanc
e.
Imm
edia
te r
epor
ting.
►
Qua
ntita
tive
EB
S
dat
a.
►Q
uant
itativ
e su
rvey
am
ong
per
sonn
el.
►
Qua
litat
ive
inte
rvie
ws
amon
g p
erso
nnel
►
Cas
e st
udy.
Des
crip
tion
of s
igna
ls o
ver
time
and
sou
rces
of s
igna
ls,
usef
ulne
ss: p
rop
ortio
n ag
reei
ng E
BS
sup
por
ts o
utb
reak
d
etec
tion
via
qua
ntita
tive
que
stio
nnai
re, P
PV:
eve
nts/
sign
al,
acce
pta
bili
ty (a
nd s
usta
inab
ility
): w
illin
gnes
s to
par
ticip
ate
via
qua
ntita
tive
que
stio
nnai
re a
nd m
otiv
atio
n vi
a Q
I and
FG
D, t
imel
ines
s (h
ours
): d
etec
tion
to n
otifi
catio
n an
d
det
ectio
n to
res
pon
se.
Eva
luat
ion
of e
vent
defi
nitio
ns v
ia Q
I and
FG
D.
Cas
e st
udy
from
det
ectio
n to
res
pon
se.
Con
tinue
d
on October 7, 2020 by guest. P
rotected by copyright.http://gh.bm
j.com/
BM
J Glob H
ealth: first published as 10.1136/bmjgh-2019-001878 on 10 D
ecember 2019. D
ownloaded from
Kuehne A, et al. BMJ Global Health 2019;4:e001878. doi:10.1136/bmjgh-2019-001878 5
BMJ Global Health
Pub
licat
ion
Co
ntex
t an
d s
etti
ngM
etho
do
log
y
Tit
leTy
pe
of
pub
licat
ion
Pla
ce a
nd s
cop
eC
oun
try,
are
a an
d
po
pul
atio
nT
ime,
sca
le a
nd
freq
uenc
y o
f re
po
rtin
gTy
pe
of
dat
aM
etho
ds
and
att
rib
utes
eva
luat
ed
Mer
ali S
, et
al (2
018)
. “Le
sson
s Le
arne
d fr
om
Com
mun
ity E
vent
- Bas
ed S
urve
illan
ce Im
ple
men
tatio
n in
G
hana
.” IC
EID
. 26.
–29.
08.2
018
Atla
nta
Con
fere
nce
pre
sent
atio
n.
Des
crip
tion
of E
BS
.G
hana
. Rou
tine
sett
ing.
Urb
an a
nd
rura
l are
a. C
omm
unity
- bas
ed.
Gha
na, 2
pilo
t d
istr
icts
. P
opul
atio
n 26
4 53
6.Ju
n 20
17–A
ug 2
018.
E
xhau
stiv
e su
rvei
llanc
e.
Imm
edia
te r
epor
ting.
►
Qua
ntita
tive
EB
S
dat
a.
►C
ase
stud
y.
Des
crip
tion
of t
ype
of s
igna
ls, P
PV
(sig
nals
- eve
nts-
re
spon
ses)
, oth
er: l
esso
ns le
arnt
. Cas
e st
udy
from
det
ectio
n to
res
pon
se.
Lars
en T
M e
t al
(201
7). "
Red
Cro
ss v
olun
teer
s’
exp
erie
nce
with
a m
obile
com
mun
ity e
vent
- bas
ed
surv
eilla
nce
(CE
BS
) sys
tem
in S
ierr
a Le
one
dur
ing-
and
af
ter
the
Eb
ola
outb
reak
—a
qua
litat
ive
stud
y”. H
ealth
P
rim C
ar 1
(3):1
–715
and
(201
6). “
A Q
ualit
ativ
e S
tud
y of
Vo
lunt
eer
Exp
erie
nces
With
a M
obile
Com
mun
ity E
vent
b
ased
Sur
veill
ance
(CE
BS
) Sys
tem
In S
ierr
a Le
one.
” IJ
ID 5
3 S
upp
l: S
11616
Pee
r- re
view
ed p
ublic
atio
n an
d c
onfe
renc
e p
rese
ntat
ion.
E
valu
atio
n of
EB
S.
Sie
rra
Leon
e. R
outin
e se
ttin
g (p
ost-
outb
r eak
). P
rimar
ily r
ural
ar
ea. C
omm
unity
- bas
ed.
Sie
rra
Leon
e, 3
/14
dis
tric
ts. P
opul
atio
n no
t sp
ecifi
ed
Jul 2
015/
Dec
201
5/Ja
n 20
16. E
xhau
stiv
e su
rvei
llanc
e. Im
med
iate
re
por
ting.
– Q
ualit
ativ
e in
terv
iew
s am
ong
per
sonn
el.
Des
crip
tion
of a
ccep
tanc
e, e
xper
ienc
es o
f vol
unte
ers.
Toya
ma
Y e
t al
(201
5). “
Eve
nt- b
ased
sur
veill
ance
in
nort
h- w
este
rn E
thio
pia
: exp
erie
nce
and
less
ons
lear
nt
in t
he fi
eld
.” W
este
rn P
acifi
c S
urve
illan
ce a
nd R
esp
onse
Jo
urna
l: W
PS
AR
6 (3
): 22
–2722
Pee
r- re
view
ed p
ublic
atio
n.
Eva
luat
ion
of E
BS
.E
thio
pia
. Rou
tine
sett
ing.
Rur
al
area
. Com
mun
ity- b
ased
.E
thio
pia
, Am
hara
re
gion
, 3 z
ones
with
175
H
ealth
Cen
tres
(HC
s).
Pop
ulat
ion
4.5
mill
ion.
Oct
201
3–N
ov 2
014.
S
entin
el s
urve
illan
ce in
59
HC
, eac
h se
rvin
g 25
000
p
opul
atio
n. Im
med
iate
re
por
ting.
►
Qua
ntita
tive
EB
S
dat
a.
►Q
uant
itativ
e co
mp
aris
on w
ith
othe
r su
rvei
llanc
e d
ata.
– D
escr
iptio
n of
typ
e si
gnal
s an
d s
ourc
es o
f sig
nals
, us
eful
ness
: act
ion
take
n b
ased
on
EB
S, d
ata
qua
lity:
co
mp
lete
ness
of r
umou
r lo
g b
ooks
and
val
idity
of m
easl
es
sign
als,
PP
V: p
rop
ortio
n of
ver
ified
rum
ours
, sen
sitiv
ity:
com
par
ison
with
IBS
dat
a, a
ccep
tab
ility
: pro
por
tion
of
rum
ours
tha
t w
ere
notifi
ed b
y th
e co
mm
unity
, tim
elin
ess
(day
s): o
nset
to
rep
ortin
g an
d r
epor
ting
to r
esp
onse
.
Oum
S e
t al
(200
5). “
Com
mun
ity- b
ased
sur
veill
ance
: a
pilo
t st
udy
from
rur
al C
amb
odia
.” T
rop
ical
Med
icin
e &
In
tern
atio
nal H
ealth
10(
7): 6
89–6
9726
Pee
r- re
view
ed p
ublic
atio
n.
Eva
luat
ion
of E
BS
.C
amb
odia
. Rou
tine
sett
ing.
Rur
al
area
. Com
mun
ity- b
ased
.C
amb
odia
, 7
com
mun
ities
; ser
ved
b
y fo
ur h
ealth
cen
tres
. P
opul
atio
n 30
000
.
Sep
200
0–A
ug 2
002.
E
xhau
stiv
e su
rvei
llanc
e.
Imm
edia
te r
epor
ting.
►
Qua
ntita
tive
EB
S
dat
a.
►Q
uant
itativ
e co
mp
aris
on w
ith
othe
r su
rvei
llanc
e d
ata.
Des
crip
tion
of t
ype
of s
igna
ls, P
PV:
pro
por
tion
of v
erifi
ed
outb
reak
s, o
ther
: res
ourc
es: c
osts
, tra
inin
g an
d t
ime,
ad
diti
onal
ind
icat
ors
for
IBS
com
pon
ent
of t
he s
yste
m
eval
uate
d b
ut n
ot c
onsi
der
ed h
ere.
Nas
er A
M, e
t al
(201
5). “
Inte
grat
ed c
lust
er-
and
cas
e-
bas
ed s
urve
illan
ce fo
r d
etec
ting
stag
e III
zoo
notic
p
atho
gens
: an
exam
ple
of N
ipah
viru
s su
rvei
llanc
e in
Ban
glad
esh.
” E
pid
emio
logy
& In
fect
ion
143(
9):
1922
–193
024
Pee
r- re
view
ed p
ublic
atio
n.
Eva
luat
ion
of E
BS
.B
angl
ades
h. R
outin
e se
ttin
g.
Pre
dom
inan
tly r
ural
are
a. H
ealth
fa
cilit
y b
ased
.
Ban
glad
esh,
10
sent
inel
ho
spita
ls. P
opul
atio
n no
t sp
ecifi
ed.
Feb
200
6–S
ep 2
011.
S
entin
el s
urve
illan
ce.
Imm
edia
te r
epor
ting.
►
Qua
ntita
tive
EB
S
dat
a.
►Q
uant
itativ
e co
mp
aris
on w
ith
othe
r su
rvei
llanc
e d
ata.
Des
crip
tion
of: n
umb
er o
f Nip
ah c
lust
ers
and
non
- Nip
ah
clus
ters
iden
tified
, PP
V: p
rop
ortio
n of
Nip
ah c
lust
ers/
non-
N
ipah
clu
ster
s, s
ensi
tivity
: men
ingo
- enc
epha
litis
cas
es
iden
tified
with
clu
ster
sur
veill
ance
am
ong
all m
enin
go-
ence
pha
litis
cas
es.
Sha
rma
R e
t al
(200
9). “
Com
mun
icab
le d
isea
se
outb
reak
det
ectio
n b
y us
ing
sup
ple
men
tary
too
ls t
o co
nven
tiona
l sur
veill
ance
met
hod
s un
der
Inte
grat
ed
Dis
ease
Sur
veill
ance
Pro
ject
(ID
SP
), In
dia
.” J
ourn
al o
f C
omm
unic
able
Dis
ease
s 41
(3):
149–
15927
Pee
r- re
view
ed p
ublic
atio
n.
Des
crip
tion
of E
BS
.In
dia
. Rou
tine
sett
ing.
C
ount
ryw
ide.
Hea
lth fa
cilit
y b
ased
.In
dia
. Pop
ulat
ion
1.2
bill
ion.
Ap
r 20
08–J
un 2
009.
E
xhau
stiv
e su
rvei
llanc
e.
Imm
edia
te r
epor
ting.
– Q
uant
itativ
e E
BS
dat
a.D
escr
iptio
n of
num
ber
of c
alls
rec
eive
d o
ver
time.
Fur
ther
su
rvei
llanc
e sy
stem
s ou
tsid
e th
e sc
ope
of t
his
revi
ew.
Tant
e S
et
al (2
015)
. “W
hich
sur
veill
ance
sys
tem
s w
ere
oper
atio
nal a
fter
Typ
hoon
Hai
yan?
” W
este
rn
Pac
ific
Sur
veill
ance
and
Res
pon
se J
ourn
al: W
PS
AR
6(
Sup
ple
men
t 1)
: 66–
7023
Pee
r- re
view
ed p
ublic
atio
n.
Eva
luat
ion
of E
BS
.P
hilip
pin
es. R
outin
e E
BS
su
rvei
llanc
e ev
alua
ted
in
emer
genc
y se
ttin
g/na
tura
l dis
aste
r. A
reas
affe
cted
by
typ
hoon
. A
nyon
e (p
erso
n/ag
ency
) can
not
ify
even
t.
Phi
lipp
ines
(3 r
egio
ns
incl
udin
g 11
sur
veill
ance
un
its a
ffect
ed b
y ty
pho
on).
Pop
ulat
ion
not
spec
ified
.
18 w
eeks
follo
win
g 11
Aug
20
13 (d
ay t
ypho
on h
it).
Exh
aust
ive
surv
eilla
nce.
Im
med
iate
rep
ortin
g.
– Q
uant
itativ
e su
rvey
am
ong
per
sonn
el.
Des
crip
tion
of s
tab
ility
: op
erat
iona
lity
by
area
(yes
/no)
and
fu
nctio
nalit
y on
Lik
ert
scal
e (1
–5),
othe
r: c
omp
lem
enta
ry
func
tion
on L
iker
t sc
ale.
Dag
ina
R e
t al
(201
3). “
Eve
nt- b
ased
sur
veill
ance
in
Pap
ua N
ew G
uine
a: s
tren
gthe
ning
an
Inte
rnat
iona
l H
ealth
Reg
ulat
ions
(200
5) c
ore
cap
acity
.” W
este
rn
Pac
ific
Sur
veill
ance
and
Res
pon
se J
ourn
al: W
PS
AR
4
(3):
19–2
528
Pee
r- re
view
ed p
ublic
atio
n.
Eva
luat
ion
of E
BS
.P
apua
New
Gui
nea.
Rou
tine
sett
ing.
Cou
ntry
wid
e. A
nyon
e (p
erso
n/ag
ency
) can
not
ify e
vent
.
Pap
ua N
ew G
uine
a.
Pop
ulat
ion
~7
mill
ion.
Sep
200
9–N
ov 2
012.
E
xhau
stiv
e su
rvei
llanc
e.
Imm
edia
te r
epor
ting.
– Q
uant
itativ
e E
BS
dat
a.D
escr
iptio
n of
typ
e of
sig
nals
ove
r tim
e an
d s
ourc
es o
f si
gnal
s, u
sefu
lnes
s: a
ctio
n ta
ken
bas
ed o
n E
BS
, PP
V:
pro
por
tion
of v
erifi
ed e
vent
s, t
imel
ines
s (d
ays)
: ons
et t
o re
por
ting
and
rep
ortin
g to
ver
ifica
tion,
oth
er: l
abor
ator
y co
nfirm
atio
n of
sig
nals
.
Yello
w: E
BS
sys
tem
s in
out
bre
ak s
ettin
gs; B
lue:
EB
S s
yste
ms
in r
outin
e se
ttin
gs. T
he c
olor
s ar
e al
read
y la
bel
led
in a
ll ta
ble
s.C
BS
, com
mun
inty
- bas
ed s
urve
illan
ce; C
EB
S, C
omm
unity
- eve
nt- b
ased
sur
veill
ance
; CH
M, C
omm
unity
Hea
lth M
onito
r; E
BS
, eve
nt- b
ased
sur
veill
ance
; FG
D, F
ocus
gr o
up d
iscu
ssio
n; IB
S, i
ndic
ator
- bas
ed s
urve
illan
ce; M
V A, m
ulti
varia
ble
ana
lysi
s; P
PV,
Pos
itive
pre
dic
tive
valu
e; Q
I, Q
ualit
ativ
e in
terv
iew
s.
Tab
le 2
C
ontin
ued
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BMJ Global Health
if the evaluation did not provide detailed information on the EBS component. In addition, descriptions of EBS that focused on animal health without any link to the human health were excluded. Finally, we did not include global EBS that relied on algorithms for detection of media or social media activity only.
In the case of multiple publications based on the same EBS system/dataset, the quality and content were assessed simultaneously. Structure and components are described by EBS system (and not by publication or by dataset).
Assessment of quality of studiesWe assessed the quality of the evidence using the GRADE approach.8 In addition, we developed a score to eval-uate the quality of the evaluation based on the guidance by CDC for evaluating surveillance systems.9 We based our approach on the eight key elements of surveillance system evaluation described by CDC9 and added two additional categories: “response mechanism described” and “feedback mechanism to stakeholders described”. We scored the quality of description of the surveillance system (0–2 points). Zero points applied for “not stated/missing information”, one point for “incomplete descrip-tion” and two points for “comprehensive description”. We calculated a summary score (0–20 points) for the quality of description. In addition, we graded each attribute eval-uated and the comprehensiveness of evaluation using a simple colour scheme (green: comprehensively evalu-ated; yellow: partly evaluated; red: not evaluated).
data extractionWe extracted information for each study using a stand-ardised form assessing quality of the description, context, event definitions, characteristics and attributes evaluated.
data synthesisWe used a framework approach10 to facilitate qualita-tive data synthesis and exploration of patterns within and across articles. We summarised quantitative results without pooling the data as the lack of standardisation between surveillance systems and evaluations does not allow for the calculation of quantitative summary meas-ures. Following an inductive process, we developed typol-ogies of EBS systems separately for outbreak and routine contexts. We synthesised available information for each of 10 defined attributes of surveillance systems9 using the framework approach.10
Patient involvementDesign, literature search, data synthesis and interpreta-tion were done without patient involvement.
resulTsselection of literatureAfter deduplication, we screened titles and abstracts of 778 records (systematic literature search, grey search and backwards search combined) (figure 1). We screened full texts for 90 records, of which we included 17 (figure 1).
Among the 17 included records were 13 peer- reviewed publications, one manuscript under peer review, two conference abstracts including presentations and one agency report.
All full texts assessed and the reason for exclusion are available in online supplementary file 2.
Quality assessmentThe 17 identified records referred to 15 studies (based on individual sets of data) and 13 different EBS systems.8–24 For the quality appraisal, we assessed each of the 15 studies. Three studies were of low evidence (observa-tional studies with comparison groups) and 12 were of very low evidence (observational studies without any comparison group), according to GRADE.
The quality of description of the EBS system varied from a summary score of 5/20 to 20/20 (online supple-mentary file 3). All 15 studies described the objective of the surveillance system, the event(s) under surveillance and the components of the EBS system to some extent (online supplementary file 3). With regards to the attri-butes described, 9 of the 17 studies described the positive predictive value of signals to events for the EBS system to some extent. All other attributes were rarely described (online supplementary file 3).
data extractionType of studies and context of EBS systemsOf the 15 included studies, 11 studies were evaluations of EBS systems, three were descriptions of EBS systems and one was an assessment of the response to EBS alerts (table 2).
Structure, components and functioning of EBS systemsEvent definitions were disease specific in the four EBS systems in outbreak settings and one routine EBS system. In other routine surveillance systems, definitions were a mix of events targeting emerging diseases, unusual events and early detection of outbreaks (table 3).
Trained lay community volunteers (CVs) notified events for 6/13 EBS systems, healthcare workers notified events in 2/13 EBS systems, and any member of the public was able to notify events using the two public telephone hotlines and in the three centralised surveillance systems (table 4). A verification and risk assessment mechanism was described for 11/13 EBS systems and a standardised algorithm for verification was mentioned in 3/13 EBS systems (table 4). All EBS systems were integrated into the routine surveillance system to some extent (table 4). Routine surveillance staff were involved in the response in all systems that specified the responding body (12/13). Six of 13 EBS systems specified a feedback mechanism to stakeholders (table 4).
data synthesisTypes of EBS systems in outbreak contextsCommunity-based surveillance in outbreak contextsWe identified one community event- based surveillance (CEBS) system operating during an outbreak: the Sierra
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BMJ Global Health
Tab
le 3
S
yste
mat
ic a
nd g
rey
liter
atur
e re
view
on
even
t- b
ased
sur
veill
ance
in t
he fi
eld
: eve
nt d
efini
tions
as
des
crib
ed in
iden
tified
EB
S s
yste
ms
(n=
13)
Pub
licat
ion
Set
ting
: ro
utin
e/o
utb
reak
co
ntex
tE
vent
Eve
nt d
efini
tio
nOutbreak setting
Rat
naya
ke e
t al
(2
016)
19 a
nd S
tone
et
al (2
016)
17 a
nd E
RC
(2
015)
20
Com
mun
ity- b
ased
/tra
ined
vo
lunt
eers
not
ify e
vent
s.Tr
igge
r ev
ents
for
EV
D
tran
smis
sion
.(1
) >2
sick
or
dea
d m
emb
ers
in a
hou
seho
ld, (
2) a
sic
k or
dea
d p
erso
n af
ter
an u
nsaf
e b
uria
l or
corp
se w
ashi
ng, (
3) a
sic
k or
dea
d h
ealth
wor
ker
or t
rad
ition
al h
eale
r, (4
) a s
ick
or d
ead
tra
velle
r, (5
) a s
ick
or d
ead
con
tact
of a
n E
VD
pat
ient
, (6)
an
unsa
fe b
uria
l or
corp
se w
ashi
ng, (
7) ‘o
ther
’ w
as in
clud
ed s
o th
at c
omm
unity
hea
lth m
onito
rs c
ould
rep
ort
and
des
crib
e ot
her
unus
ual e
vent
s th
at d
id n
ot fa
ll un
der
any
of t
he s
ix d
efine
d
trig
ger
even
ts.
Lee
et a
l (20
16)18
Any
one
(per
son/
agen
cy) c
an n
otify
ev
ents
.A
ny c
omm
unity
dea
ths
and
sus
pec
t E
bol
a ca
ses.
No
furt
her
spec
ifica
tion.
Mill
er e
t al
(201
5)21
Any
one
(per
son/
agen
cy) c
an n
otify
ev
ents
.P
ossi
ble
Eb
ola
case
s an
d d
eath
s an
d a
ny
Eb
ola
info
rmat
ion.
No
furt
her
spec
ifica
tion.
San
ta- O
lalla
et
al
(201
3)25
Any
one
(per
son/
agen
cy) c
an n
otify
ev
ents
.C
hole
ra e
vent
req
uirin
g im
med
iate
res
pon
se.
Unu
sual
eve
nts.
(1) F
irst
case
s or
dea
ths
(in p
revi
ousl
y ch
oler
a- fr
ee a
reas
); (2
) dea
ths
in t
he c
omm
unity
(cho
lera
or
othe
r ca
use)
; (3)
sig
nific
ant
incr
ease
s of
nu
mb
ers
of c
ases
or
dea
ths
(in a
reas
with
con
firm
ed c
ases
of c
hole
ra a
s in
dic
ated
by
loca
l par
tner
s an
d/o
r fie
ld t
eam
mem
ber
s); (
4) in
suffi
cien
t tr
eatm
ent
cap
acity
(hos
pita
ls, C
TCs
and
CTU
s); (
5) n
eed
for
par
tner
s, d
rugs
, and
/or
equi
pm
ent
sup
plie
s or
sta
ff fo
r th
e C
TCs,
CTU
s or
OR
Ps;
(6
) lac
k of
acc
ess
to h
ealth
care
ser
vice
s an
d/o
r p
otab
le w
ater
; (7)
lack
of a
san
itatio
n st
rate
gy (b
ody
man
agem
ent
and
dis
pos
al a
nd w
aste
m
anag
emen
t); (8
) lac
k of
tra
inin
g (e
g, in
cas
e m
anag
emen
t or
pre
vent
ion)
.A
ny e
vent
tha
t co
uld
pos
e a
pub
lic h
ealth
ris
k us
ing
the
fram
ewor
k es
tab
lishe
d b
y th
e IH
R (2
005)
.
Routine setting
Cla
ra e
t al
(201
8)14
an
d (2
018)
13C
omm
unity
- bas
ed/t
rain
ed
volu
ntee
rs n
otify
eve
nts.
Em
ergi
ng n
ew d
isea
ses,
ra
bie
s, a
vian
influ
enza
, va
ccin
e- p
reve
ntab
le
dis
ease
s, c
hole
ra (n
o sp
ecifi
catio
n w
hich
in
dic
ator
for
whi
ch
even
t). R
evis
ed A
ug
2017
.
>2
hosp
italis
ed p
erso
ns a
nd/o
r d
eath
with
sim
ilar
typ
e of
sym
pto
ms
occu
rrin
g in
the
sam
e co
mm
unity
, sch
ool,
or w
orkp
lace
in t
he s
ame
7 d
ays.
Une
xpec
ted
larg
e nu
mb
ers
of c
hild
ren
abse
nt fr
om s
choo
l bec
ause
of t
he s
ame
illne
ss in
the
sam
e 7-
day
per
iod
, sal
es a
t p
harm
acie
s of
man
y p
eop
le b
uyin
g m
edic
ines
for
the
sam
e ki
nd o
f illn
ess,
peo
ple
sic
k w
ith t
he s
imila
r ty
pe
of s
ymp
tom
s at
the
sam
e tim
e, d
eath
s of
pou
ltry
or o
ther
d
omes
tic a
nim
als.
A d
og t
hat
is s
usp
ecte
d t
o b
e ra
bid
or
a si
ck d
og t
hat
has
bitt
en s
omeo
ne o
r an
y d
og t
hat
has
bitt
en >
2 p
erso
ns in
the
pas
t 7
day
s.on
e ch
ild <
15 y
ears
of a
ge w
ith s
udd
en w
eakn
ess
of li
mb
s or
feve
r, ra
sh, r
esp
irato
ry in
fect
ion
and
pos
sib
ly r
ed e
yes.
A s
ingl
e ca
se s
ever
e en
ough
to
req
uire
hos
pita
l ad
mis
sion
or
caus
ing
dea
th o
f any
of t
he fo
llow
ing:
>3
rice
wat
ery
stoo
ls in
24
hour
s in
any
p
erso
n >
5 ye
ars
of a
ge w
ith d
ehyd
ratio
n, a
new
res
pira
tory
infe
ctio
n w
ith fe
ver
in a
per
son
who
has
tra
velle
d a
bro
ad in
the
pas
t 14
day
s, a
ne
w r
esp
irato
ry in
fect
ion
with
feve
r af
ter
cont
act
with
live
pou
ltry,
illn
ess
with
in 1
4 d
ays
afte
r va
ccin
atio
n, il
lnes
s ne
ver
seen
bef
ore
or r
are
sym
pto
ms
in t
he c
omm
unity
.*
Mer
ali e
t al
(201
8)C
omm
unity
- bas
ed/t
rain
ed
volu
ntee
rs n
otify
eve
nts.
Unu
sual
hea
lth e
vent
s.U
nexp
ecte
d la
rge
num
ber
s of
chi
ldre
n ab
sent
from
sch
ool d
ue t
o th
e sa
me
illne
ss.
Incr
ease
in n
umb
er o
f ani
mal
dea
ths,
incl
udin
g p
oultr
y, w
ithin
1 w
eek.
Tw
o or
mor
e p
erso
ns p
rese
ntin
g w
ith s
imila
r ill
ness
es in
the
sam
e co
mm
unity
with
in 1
wee
k. T
wo
or m
ore
per
sons
tha
t p
ass
wat
ery
stoo
ls a
nd/o
r vo
miti
ng a
fter
eat
ing/
drin
king
at
a gi
ven
sett
ing
(eg,
wed
din
g,
fune
ral,
fest
ival
, can
teen
, foo
d s
elle
rs e
tc).
Two
or m
ore
per
sons
dyi
ng in
the
sam
e co
mm
unity
with
in 1
wee
k.A
ny p
erso
n w
ho h
as b
een
bitt
en, s
crat
ched
or
who
se w
ound
has
bee
n lic
ked
by
a d
og, c
at o
r ot
her
anim
al.
Any
per
son
with
feve
r an
d r
ash,
any
per
son
with
wor
ms
emer
ging
from
any
par
t of
the
bod
y. A
ny p
erso
n 5
year
s or
mor
e w
ith lo
ts o
f wat
ery
dia
rrho
ea a
nd s
omet
imes
vom
iting
pro
fuse
ly a
s w
ell.
In c
ase
of a
n ou
tbre
ak a
nyb
ody
who
pas
ses
wat
ery/
loos
e st
ool.
Any
new
bor
n w
ho is
ab
le t
o su
ck a
nd c
ry a
t b
irth
and
the
n, a
fter
2 d
ays,
is u
nab
le t
o su
ck o
r fe
ed a
nd b
ecom
es s
tiff.
Any
per
son
with
feve
r an
d n
eck
stiff
ness
. Any
p
erso
n w
ho d
evel
ops
sud
den
wea
knes
s in
the
lim
bs.
Lars
en e
t al
(201
7)15
an
d (2
016)
16C
omm
unity
- bas
ed/t
rain
ed
volu
ntee
rs n
otify
eve
nts.
6 co
mm
unity
eve
nts.
VH
F in
clud
ing
Eb
ola+
Lass
a, A
WD
as
pro
xy fo
r ch
oler
a, m
easl
es, c
omm
unity
dea
ths,
floo
ds,
fire
. No
furt
her
spec
ifica
tion.
Toya
ma
et a
l (20
15)22
Com
mun
ity- b
ased
/tra
ined
vo
lunt
eers
not
ify e
vent
s.U
nusu
al e
vent
s.A
ny c
omm
unic
able
dis
ease
out
bre
aks
and
unu
sual
hea
lth e
vent
s, p
artic
ular
ly e
vent
s w
ith m
ultip
le d
eath
s fr
om u
nkno
wn
caus
es.
Oum
et
al. (
2005
)26C
omm
unity
- bas
ed/t
rain
ed
volu
ntee
rs n
otify
eve
nts.
Clu
ster
of c
ases
.A
gro
up o
f five
or
mor
e si
mila
r ca
ses
occu
rrin
g un
usua
lly c
lose
ly t
oget
her
in a
ny v
illag
e w
ithin
a w
eek.
Nas
er e
t al
(201
5)24
Hea
lth fa
cilit
y–b
ased
/hea
lth w
orke
rs
notif
y ev
ents
.S
usp
ect
men
ingo
- en
cep
halit
is c
lust
er.
≥2 m
enin
go- e
ncep
halit
is c
ases
, age
d ≥
5 ye
ars,
livi
ng w
ithin
30
min
wal
king
dis
tanc
e of
eac
h ot
her
who
dev
elop
ed il
lnes
s w
ithin
3 w
eeks
of o
ne
anot
her.
Sha
rma
et a
l (20
09)27
Hea
lth fa
cilit
y–b
ased
/hea
lth w
orke
rs
notif
y ev
ents
.A
ny u
nusu
al h
ealth
ev
ents
.N
o fu
rthe
r sp
ecifi
catio
n.
Tant
e et
al (
2015
)23A
nyon
e (p
erso
n/ag
ency
) can
not
ify
even
ts.
Rar
e, u
nusu
al e
vent
s.N
o fu
rthe
r sp
ecifi
catio
n.
Dag
ina
et a
l (20
13)28
Any
one
(per
son/
agen
cy) c
an n
otify
ev
ents
.P
oten
tial p
ublic
hea
lth
even
ts.
No
furt
her
spec
ifica
tion.
*The
sys
tem
incl
uded
IBS
com
mun
ity- c
ase
defi
nitio
ns, i
n ad
diti
on t
o E
BS
eve
nt d
efini
tions
.A
WD
, acu
te w
ater
y d
iarr
hoea
; CTC
, cho
lera
tre
atm
ent
cent
re; C
TU, c
hole
ra t
reat
men
t un
it; E
BS
, eve
nt- b
ased
sur
veill
ance
; EV
D, E
bol
a vi
rus
dis
ease
; IH
R, I
nter
natio
nal H
ealth
Reg
ulat
ions
; OR
P, o
ral r
ehyd
ratio
n p
oint
s; V
HF,
vira
l hae
mor
rhag
ic fe
ver.
on October 7, 2020 by guest. P
rotected by copyright.http://gh.bm
j.com/
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J Glob H
ealth: first published as 10.1136/bmjgh-2019-001878 on 10 D
ecember 2019. D
ownloaded from
8 Kuehne A, et al. BMJ Global Health 2019;4:e001878. doi:10.1136/bmjgh-2019-001878
BMJ Global Health
Leonean CEBS implemented during the Ebola outbreak at national level.17 19 20 CVs and their supervisors were specifically identified and rapidly trained; supervisory staff provided verification and assessment. The district- level Ebola response system that was already in place at the local level conducted follow- up if needed.17 19 20 CVs notified defined Ebola- related events (table 4).17 19 20 No verification or assessment algorithm was specified.19
Open surveillanceWe identified three EBS systems that were ‘open’ to receive outbreak- specific event notifications from anyone: the telephone hotlines during the Ebola outbreak in Guinea18 and Sierra Leone21 allowed anyone to notify unspecified Ebola- related events; signals received by call centres were forwarded to the Ebola response structure in place for verification and response.18 21 Similarly, the EBS system in place in Haiti at the start of the cholera outbreak allowed partners within and outside the UN health cluster to notify an additional list of defined cholera- related events, including the lack of access to healthcare and sanitation.25 The focus was expanded to unusual events in general after the outbreak.25 Notifica-tions were received at central level; verification, assess-ment and response processes were co- ordinated centrally but supported locally by field response teams. The assess-ment consisted of several standard items to answer.25
Types of EBS systems in routine contextsCommunity-based surveillance in routine contextsWe identified five CBS systems that were functioning as routine EBS systems in Vietnam,13 14 Ghana,12 Ethiopia,22 Cambodia26 and Sierra Leone.15 16 CVs were already in place before the implementation of all five systems.10 12 13 19–22 CVs notified defined syndromes to IBS in addition to events to EBS in four systems.12–16 26 CVs working in EBS- only systems were instructed to report any outbreak or unusual event22; CVs working in combined IBS and EBS systems had specific definitions for the events (table 4).12–16 26 All EBS systems in communities were built on existing IBS systems and infra-structure. No verification or assessment algorithm was spec-ified for any of the systems.
Health facility-based surveillance in routine contextsWe identified two different types of health facility- based surveillance: in Bangladesh, routine health facility- based IBS in a set of hospitals was complemented by EBS in a way that clusters of meningo- encephalitis cases were noti-fied immediately and investigated to identify small- area Nipah outbreaks.24
In India, a hotline was set up to notify unusual events that was available to health professionals.27 No verification or assessment algorithm was specified for any of the systems.
Open surveillance in routine contextsWe identified two ‘open’ surveillance systems: the EBS system in the Philippines after Typhoon Haiyan could receive event information through routine surveillance channels or informal reporting by anyone; steps for
verification, assessment and response were not specified in the paper.23 In Papua New Guinea (PNG), anyone could notify events to a national EBS coordinator, who reached out to provincial health authorities for verifica-tion, assessment and response. A standardised verifica-tion and assessment form was used and kept as a log.28
Surveillance attributes of EBS systemsData extraction for each surveillance system attribute can be found in online supplementary file 4.
Usefulness: events reported and actions takenAll EBS systems detected local outbreaks. All non–disease- specific and disease- specific EBS systems reported to have identified confirmed cases and outbreaks among humans (eg, measles, acute respiratory infections, chick-enpox, acute watery diarrhoea, malaria, whooping cough, meningitis, acute flaccid paralysis) and among animals (eg, poultry die- off, rabies, anthrax) (online supplemen-tary file 4).12–15 22 25–28 In addition, natural and man- made events (eg, floods, riots, chemical events, nutritional crisis) were reported.22 25 28
In outbreak contexts, community event- based surveil-lance (CEBS) during the Ebola outbreak in Sierra Leone generated a large number of signals (>90%) that were mainly reported in the category ‘other’ (rather than in any defined category) and the majority (>85%) concerned deaths in the community.17 19 20 Alerts were investigated by response teams that were in place.19
Open Ebola telephone hotlines during the Ebola outbreak in Sierra Leone and Guinea received signals for cases: during a 3- day campaign in Sierra Leone, 75% of calls were verified as alerts,21 while only 12% of calls were verified as alerts over 10 months in Guinea.18 Alerts were investigated by the response teams in place though the number of true events (identified case(s) meeting the case definition) was not reported.
In the open cholera EBS system in Haiti, 90% of the signals received related to cholera (increase in cases, deaths, lack of supplies etc) but also relevant non- cholera signals were received including rabies, acute flaccid paral-ysis, anthrax and non- infectious hazards.25 Alerts were of use to indicate underserved geographical areas within which to set up treatment centres, investigate outbreaks, and carry out community mobilisation and water and sanitation activities25 (online supplementary file 4).
In routine contexts, CEBS systems identified human and animal health events and other hazards: CEBS in Vietnam identified mostly signals of hand- foot- mouth disease, suspect dengue, chickenpox, suspect mumps, acute respi-ratory infections, foodborne diseases and avian influenza in poultry.13 14 CEBS in Ghana identified increases in animal deaths, vaccine- preventable diseases and food-borne diseases.12 CEBS in Ethiopia identified signals for outbreaks of measles, suspect rabies, anthrax, whooping cough, acute flaccid paralysis, neonatal tetanus, meningitis, acute watery diarrhoea, flood and malnutrition22; 67% of signals were verified and resulted in response, such as case
on October 7, 2020 by guest. P
rotected by copyright.http://gh.bm
j.com/
BM
J Glob H
ealth: first published as 10.1136/bmjgh-2019-001878 on 10 D
ecember 2019. D
ownloaded from
Kuehne A, et al. BMJ Global Health 2019;4:e001878. doi:10.1136/bmjgh-2019-001878 9
BMJ Global Health
Tab
le 4
S
yste
mat
ic a
nd g
rey
liter
atur
e re
view
on
even
t- b
ased
sur
veill
ance
in t
he fi
eld
: str
uctu
re a
nd c
omp
onen
ts o
f EB
S s
yste
ms
(n=
13)
Pub
licat
ion
Co
mp
one
nts
Dat
a fl
ow
Inte
gra
tio
n in
to
rout
ine
surv
eilla
nce
Feed
bac
k to
st
akeh
old
ers
Res
po
nse
mec
hani
sms
Res
our
ces
need
ed
Outbreak setting
Rat
naya
ke e
t al
(201
6)19
and
S
tone
et
al
(201
6)17
and
E
RC
(201
5)20
Not
ifier
: Com
mun
ity h
ealth
mon
itors
(CH
Ms)
. CH
M w
ere
volu
ntee
rs o
r ex
istin
g co
mm
unity
hea
lth w
orke
rs (C
HW
s), w
ho r
ecei
ved
tra
inin
g to
det
ect
the
six
trig
ger
even
ts. A
ssig
ned
to
villa
ges.
Rec
eive
r: C
omm
unity
sur
veill
ance
sup
ervi
sors
(CS
Ss)
with
ass
igne
d a
la
rger
are
a.Ve
rifica
tion:
CS
S, s
omet
imes
with
sup
por
t fr
om c
omm
unity
hea
lth o
ffice
rs
(CH
Os)
. CH
Os
wer
e tr
aine
d p
rofe
ssio
nals
in t
he p
ublic
hea
lth s
yste
m.
Sta
ndar
d v
erifi
catio
n p
roce
ss n
ot s
pec
ified
. A s
tand
ard
ale
rt lo
g in
clud
ed:
typ
e of
ale
rt, a
ge, s
ex, l
ocat
ion
and
act
ion
take
n as
a r
esul
t of
the
ale
rt a
nd
if D
istr
ict
Eb
ola
Res
pon
se C
entr
e (D
ER
C) w
as n
otifi
ed.
Ris
k as
sess
men
t: N
ot a
pp
licab
le.
Res
pon
se: A
ny v
erifi
ed s
usp
ect
even
ts w
ere
rep
orte
d t
o lo
cal D
ER
C fo
r fo
llow
- up
. Loc
al s
ocia
l mob
ilisa
tion
team
s w
ere
notifi
ed t
o p
rovi
de
heal
th
educ
atio
n ac
tiviti
es.
Dat
a co
llect
ion
and
tra
nsm
issi
on: M
obile
pho
nes.
All
CE
BS
sta
ff re
ceiv
ed
pho
nes
and
pho
ne c
red
it.
CH
M n
otifi
ed→
CS
S v
erifi
ed a
nd
kep
t lo
g→C
HO
sup
por
t ve
rifica
tion
if ne
eded
→lo
cal D
ER
C r
esp
ond
s.S
econ
d a
dd
ition
al d
ata
flow
: CS
S→
dis
tric
t su
rvei
llanc
e su
per
viso
r→th
e na
tiona
l C
EB
S c
oord
inat
ion
in F
reet
own.
Ale
rts
that
rem
aine
d
susp
ect
afte
r ve
rifica
tion
wer
e re
por
ted
to
DE
RC
for
resp
onse
.
CE
BS
dis
tric
t le
ad
confi
rmed
fina
l ale
rt
stat
us w
ith t
he D
ER
C
dat
abas
e. F
eed
bac
k m
echa
nism
not
sp
ecifi
ed.
Res
pon
se b
y D
ER
C.
Cas
e in
vest
igat
ion.
Sta
ff: 7
416
CH
M,
137
surv
eilla
nce
sup
ervi
sors
. C
osts
: Sta
rt-
up c
osts
: U
S$1
.3 m
illio
n.
Mon
thly
cos
ts
US
$129
000
co
vere
d t
rain
ing,
te
lep
hone
s,
mot
orb
ikes
, fue
l an
d in
cent
ives
.
Lee
et a
l (2
016)
18N
otifi
er: (
a) A
nyon
e, n
atio
nwid
e fo
r N
atio
nal C
all C
entr
e; (b
) any
one
in t
he
pre
fect
ure
for
Loca
l Ale
rt N
umb
er.
Rec
eive
r: (a
) Nat
iona
l Cal
l Cen
tre;
(b) L
ocal
Ale
rt N
umb
er.
Verifi
catio
n: (a
)+(b
) pre
fect
ure
is in
form
ed a
bou
t th
e ca
ll. V
erifi
catio
n al
gorit
hm n
ot s
pec
ified
.R
isk
asse
ssm
ent
and
res
pon
se: (
a)+
(b) p
refe
ctur
e is
info
rmed
ab
out
the
call.
Dat
a co
llect
ion
and
tra
nsm
issi
on: N
ot s
pec
ified
.
(a) N
atio
nal C
all
Cen
tre→
dis
pat
ch te
am→
pre
fect
ure.
(b) L
ocal
Ale
rt N
umb
er→
pre
fect
ure.
Not
sp
ecifi
ed.
Not
sp
ecifi
ed.
Not
sp
ecifi
ed.
Not
sp
ecifi
ed.
Mill
er e
t al
(2
015)
21N
otifi
er: A
nyon
e, n
atio
nwid
e. V
olun
teer
s en
cour
aged
pub
lic t
o re
por
t to
the
ho
tline
dur
ing
3- d
ay c
amp
aign
.R
ecei
ver:
Hot
line.
Verifi
catio
n: D
istr
ict
Eb
ola
Res
pon
se T
eam
s (D
ER
C).
Verifi
catio
n al
gorit
hm
not
spec
ified
.R
isk
asse
ssm
ent
and
res
pon
se: D
ER
C.
Dat
a co
llect
ion
and
tra
nsm
issi
on: H
otlin
e.
Pub
lic→
Hot
line→
Dis
tric
t- le
vel E
bol
a re
spon
se t
eam
s.In
form
atio
n re
ceiv
ed
is s
hare
d w
ith u
sual
st
ate
or d
istr
ict
Eb
ola
surv
eilla
nce
offic
ers.
Not
sp
ecifi
ed.
Cas
e in
vest
igat
ions
an
d fo
llow
- up
ac
tions
: Tra
nsp
ort
of
ill p
erso
ns. S
afe
and
d
igni
fied
bur
ials
.
Not
sp
ecifi
ed.
San
ta- O
lalla
et
al (2
013)
25N
otifi
er: A
ll p
artn
ers
(UN
res
pon
se c
lust
ers
activ
ated
). Fi
eld
tea
ms
rep
orte
d
dai
ly, i
nclu
din
g ze
ro- r
epor
ting.
Rec
eive
r: “
The
oper
atio
nal h
ub o
f the
A&
R S
yste
m w
as in
Por
t- au
- Prin
ce,
whe
re a
lert
s w
ere
rece
ived
by
the
natio
nal a
lert
tea
m”.
Verifi
catio
n: A
&R
coo
rdin
ator
or
field
tea
ms
or p
artn
ers.
Info
rmat
ion
rece
ived
from
‘offi
cial
or
relia
ble
sou
rces
’ was
con
sid
ered
ver
ified
. All
othe
r in
form
atio
n w
as v
erifi
ed.
Ris
k as
sess
men
t: A
sses
smen
t b
y fie
ld t
eam
s. T
he a
sses
smen
t co
nsis
ted
of
“(a
) ass
ess
the
pub
lic h
ealth
ris
k p
osed
by
the
rep
orte
d e
vent
, (b
) ass
ess
the
need
for
and
urg
ency
of s
uch
a re
spon
se, a
nd (c
) defi
ne t
he t
ype
of
resp
onse
and
ap
pro
pria
te p
artn
ers”
.R
esp
onse
: Coo
rdin
ated
by
A&
R c
oord
inat
or a
t na
tiona
l hub
. In
the
field
th
roug
h fie
ld t
eam
s an
d m
inis
try
of h
ealth
sta
ff.D
ata
colle
ctio
n an
d t
rans
mis
sion
: Tel
epho
ne a
nd e
mai
l.
From
any
par
tner
/fiel
d
team
s→op
erat
iona
l hub
in P
ort-
au-
Prin
ce→
field
tea
ms
for
asse
ssm
ent.
A&
R s
yste
m
com
ple
men
ts e
xist
ing
natio
nal s
urve
illan
ce
syst
em.
Dai
ly a
lert
s b
ulle
tin s
ent
to r
esp
onse
par
tner
s:
aler
ts a
nd h
otsp
ots
and
ass
essm
ent
of t
he
need
for
resp
onse
. Ale
rt
and
res
pon
ses
also
in
a w
eekl
y b
ulle
tin w
ith
IBS
dat
a.
The
syst
em w
as s
et
up t
o “o
rgan
ise
a ra
pid
res
pon
se w
ith
par
tner
s to
pro
vid
e im
med
iate
sup
por
t b
ased
on
need
s id
entifi
ed in
the
fie
ld (e
g, s
upp
lies,
tr
aini
ng, s
ocia
l m
obili
satio
n, w
ater
, an
d s
anita
tion)
”.
Sta
ff: N
atio
nal
aler
t te
am a
nd
5–8
PAH
O/W
HO
fie
ld t
eam
s,
bro
ad n
etw
ork
of p
artn
ers.
UN
re
spon
se c
lust
er
mec
hani
sm
activ
ated
.
Con
tinue
d
on October 7, 2020 by guest. P
rotected by copyright.http://gh.bm
j.com/
BM
J Glob H
ealth: first published as 10.1136/bmjgh-2019-001878 on 10 D
ecember 2019. D
ownloaded from
10 Kuehne A, et al. BMJ Global Health 2019;4:e001878. doi:10.1136/bmjgh-2019-001878
BMJ Global Health
Pub
licat
ion
Co
mp
one
nts
Dat
a fl
ow
Inte
gra
tio
n in
to
rout
ine
surv
eilla
nce
Feed
bac
k to
st
akeh
old
ers
Res
po
nse
mec
hani
sms
Res
our
ces
need
ed
Routine setting
Cla
ra e
t al
(2
018)
14 a
nd
(201
8)13
Not
ifier
: 716
7 vi
llage
hea
lth w
orke
rs (V
HW
s) a
nd h
ealth
col
lab
orat
ors
(HC
s)
rece
ived
tra
inin
g, p
hone
min
utes
and
com
mun
icat
ion
mat
eria
ls. H
Cs
are
mos
tly im
por
tant
com
mun
ity m
emb
ers.
Info
rmat
ion
sour
ce o
f sig
nals
: V
HW
, com
mun
ity m
emb
ers,
tea
cher
s, p
harm
acy,
clin
ics,
med
ia, o
ffice
, fa
ctor
ies,
rel
igio
us le
ader
s, h
eale
rs, o
ther
s.R
ecei
ver:
Com
mun
e H
ealth
Sta
tion
(CH
S).
Verifi
catio
n: In
itial
ver
ifica
tion:
CH
S. C
omp
rehe
nsiv
e ve
rifica
tion:
Dis
tric
t H
ealth
Cen
tre
(DH
C).
Verifi
catio
n al
gorit
hm n
ot s
pec
ified
.R
isk
asse
ssm
ent:
DH
C.
Res
pon
se: P
rovi
ncia
l Pre
vent
ive
Med
icin
e C
entr
es (P
PM
C) a
nd/o
r R
egio
nal
Inst
itute
s.D
ata
colle
ctio
n an
d t
rans
mis
sion
: Pho
ne, e
mai
l, in
per
son.
VH
W/H
C→
CH
S→
DH
C→
PP
MC
→R
egio
nal
Inst
itute
s→G
ener
al D
epar
tmen
t of
P
reve
ntiv
e M
edic
ine.
Com
ple
te in
tegr
atio
n in
to IB
S s
yste
m.
IBS
info
rmat
ion
flow
an
d o
rgan
isat
iona
l st
ruct
ure
used
. P
erso
nnel
rec
eive
d
extr
a tr
aini
ng. V
HW
ex
iste
d in
the
ory
pre
viou
sly;
str
uctu
re
revi
talis
ed.
DH
C a
nd C
HS
con
duc
t re
gula
r m
eetin
gs
with
VH
W t
o en
sure
a
feed
bac
k lo
op is
co
mp
lete
d.
Not
sp
ecifi
ed. I
n ca
se
stud
y: c
ase
find
ing
and
lab
orat
ory
test
ing
of fo
od.
Trai
ning
an
d t
rain
ing
mat
eria
ls. O
ne-
off f
und
ing
of
com
mun
icat
ion
mat
eria
l and
in
fras
truc
ture
im
pro
vem
ents
. A
ll st
aff p
ositi
ons
pre
viou
sly
exis
ted
.
Mer
ali e
t al
(2
018)
Not
ifier
: Com
mun
ity C
BS
vol
unte
ers
Rec
eive
r: P
ublic
hea
lth p
erso
nnel
at
loca
l hea
lth fa
cilit
y an
d d
istr
ict,
re
gion
al, n
atio
nal l
evel
Verifi
catio
n, r
isk
asse
ssm
ent
and
res
pon
se: n
ot s
pec
ified
. In
the
case
stu
dy,
d
istr
ict
leve
l con
duc
ted
inve
stig
atio
n an
d r
esp
onse
.D
ata
colle
ctio
n an
d t
rans
mis
sion
: Too
ls t
o re
por
t w
ere
dis
trib
uted
but
not
sp
ecifi
ed.
CB
S v
olun
teer
→he
alth
fa
cilit
y→d
istr
ict→
regi
onal
→na
tiona
l. C
omm
unic
atio
n w
ith v
eter
inar
y si
de
at
dis
tric
t, r
egio
nal a
nd n
atio
nal l
evel
.
Com
ple
te in
tegr
atio
n in
to ID
SR
. Per
sonn
el
rece
ived
ad
diti
onal
tr
aini
ng. C
omm
unity
vo
lunt
eers
exi
sted
b
efor
e.
Not
sp
ecifi
ed.
Not
sp
ecifi
ed.
Not
sp
ecifi
ed
bey
ond
tra
inin
g,
trai
ning
mat
eria
ls
and
rep
ortin
g to
ols.
Rol
es o
f st
aff e
xist
ed
bef
ore.
Lars
en e
t al
(2
017)
15 a
nd
(201
6)16
Not
ifier
: Com
mun
ity- b
ased
vol
unte
ers
(CB
Vs)
rec
ruite
d fr
om t
heir
com
mun
ities
and
tra
ined
in e
vent
defi
nitio
ns a
nd o
n ho
w t
o re
por
t us
ing
SM
S t
ext
mes
sage
s w
ith s
pec
ified
cod
es fo
r re
por
ting.
CB
Vs
rep
orte
d
susp
ect
case
s an
d m
easu
res
take
n on
com
mun
ity le
vel.
Rec
eive
r: C
BV
s in
form
vol
unte
er s
urve
illan
ce s
uper
viso
rs (V
SS
s).
Verifi
catio
n: V
SS
. Ver
ifica
tion
algo
rithm
not
sp
ecifi
ed.
Ris
k as
sess
men
t: V
SS
info
rms
com
mun
ity h
ealth
offi
cer
(CH
O) a
nd a
sses
s th
e ev
ent
toge
ther
.R
esp
onse
: CH
O r
epor
ts t
o D
ER
C/D
HM
T to
initi
ate
resp
onse
.D
ata
colle
ctio
n an
d t
rans
mis
sion
: SM
S t
o a
loca
l num
ber
tha
t is
syn
ced
w
ith o
nlin
e d
ata
colle
ctio
n to
ol M
agp
i. Th
e in
form
atio
n is
aut
omat
ical
ly
anal
ysed
in a
n an
alyt
ical
vis
ualis
ing
dat
abas
e.
CV
S→
VS
S→
CH
O→
DE
RC
/DH
MT.
VS
S r
each
es o
ut t
o C
HO
, who
cha
nnel
s th
e in
form
atio
n in
to t
he r
outin
e su
rvei
llanc
e an
d
resp
onse
sys
tem
.
Not
sp
ecifi
ed.
DE
RC
/DH
MT/
heal
th
faci
lity.
Not
sp
ecifi
ed.
Toya
ma
et a
l (2
015)
22N
otifi
er: H
ealth
Dev
elop
men
t A
rmie
s (H
DA
s)=
volu
ntee
r- b
ased
com
mun
ity
heal
th t
eam
. Rec
eive
d t
rain
ing
on E
BS
by
heal
th e
xten
sion
wor
ker
(HE
W).
Rep
ort
EB
S t
o he
alth
cen
tre
(HC
). H
EW
s, w
ho w
ork
at h
ealth
pos
ts a
nd
serv
e ab
out
5000
peo
ple
, als
o re
por
ted
EB
S t
o H
C. O
ther
info
rmat
ion
sour
ces
of s
igna
ls: c
omm
unity
, hea
lth p
ost
wor
kers
and
oth
ers.
HC
als
o re
por
t in
to r
outin
e in
dic
ator
- bas
ed s
urve
illan
ce.
Rec
eive
r: H
C s
urve
illan
ce fo
cal p
erso
n at
eac
h he
alth
faci
lity
regi
ster
s ru
mou
rs in
rum
our
log
boo
k.Ve
rifica
tion:
Initi
al V
erifi
catio
n: H
DA
s an
d H
EW
s. A
ssis
t if
need
ed:
Sur
veill
ance
offi
cers
at
the
dis
tric
t he
alth
offi
ce. V
erifi
catio
n al
gorit
hm n
ot
spec
ified
.R
isk
asse
ssm
ent:
Not
sp
ecifi
ed.
Res
pon
se: S
urve
illan
ce o
ffice
rs a
t th
e d
istr
ict
heal
th o
ffice
inst
ruct
re
spon
se a
ctiv
ities
and
com
mun
icat
e w
ith z
onal
and
reg
iona
l hea
lth
dep
artm
ents
for
furt
her
assi
stan
ce.
Dat
a co
llect
ion
and
tra
nsm
issi
on: N
ot s
pec
ified
.
HD
A/H
EW
/oth
er s
ourc
e→H
C s
urve
illan
ce
foca
l per
son→
surv
eilla
nce
offic
er a
t d
istr
ict
heal
th o
ffice
.
All
role
s ex
iste
d b
efor
e th
e ru
mou
r lo
g b
ook
was
intr
oduc
ed, t
he
syst
em w
as in
tegr
ated
in
to t
he r
outin
e su
rvei
llanc
e sy
stem
.
Not
sp
ecifi
ed.
Cas
e m
anag
emen
t,
activ
e ca
se fi
ndin
g,
vacc
inat
ion,
pat
ient
re
ferr
al.
“The
cos
t of
es
tab
lishi
ng
the
syst
em
was
min
imal
, re
qui
ring
only
a b
rief
orie
ntat
ion
for
the
surv
eilla
nce
foca
l per
sons
an
d p
rintin
g an
d d
istr
ibut
ion
of t
he r
umou
r lo
gboo
ks t
o th
e H
Cs”
.
Tab
le 4
C
ontin
ued
Con
tinue
d
on October 7, 2020 by guest. P
rotected by copyright.http://gh.bm
j.com/
BM
J Glob H
ealth: first published as 10.1136/bmjgh-2019-001878 on 10 D
ecember 2019. D
ownloaded from
Kuehne A, et al. BMJ Global Health 2019;4:e001878. doi:10.1136/bmjgh-2019-001878 11
BMJ Global Health
Pub
licat
ion
Co
mp
one
nts
Dat
a fl
ow
Inte
gra
tio
n in
to
rout
ine
surv
eilla
nce
Feed
bac
k to
st
akeh
old
ers
Res
po
nse
mec
hani
sms
Res
our
ces
need
ed
Oum
et
al
(200
5)26
Not
ifier
: Lay
VH
V c
hose
n b
y vi
llage
eld
er o
r he
alth
faci
lity
staf
f, re
ceiv
ing
trai
ning
, inc
entiv
e an
d s
uper
visi
on. "
A s
erie
s of
3 d
ay in
itial
tra
inin
g w
orks
hop
s w
as h
eld
for
bot
h V
HV
s an
d h
ealth
sta
ff at
eac
h p
roje
ct s
ite
shor
tly b
efor
e th
e im
ple
men
tatio
n of
the
sys
tem
. It
was
follo
wed
by
a m
onth
ly h
alf d
ay o
f ref
resh
er t
rain
ing
sep
arat
ely
for
VH
Vs
and
hea
lth s
taff
and
furt
her
trai
ning
in c
olla
tion
and
ana
lysi
s of
dat
a fo
r th
e he
alth
sta
ff”.
Rec
eive
r: H
ealth
cen
tre
staf
f.Ve
rifica
tion:
Not
sp
ecifi
ed if
ver
ifica
tion
was
und
erta
ken.
Ver
ifica
tion
algo
rithm
not
sp
ecifi
ed.
Ris
k as
sess
men
t: O
per
atio
nal d
istr
ict
offic
e.R
esp
onse
: Op
erat
iona
l dis
tric
t of
fice
and
loca
l hea
lth c
entr
e st
aff.
Dat
a co
llect
ion
and
tra
nsm
issi
on: N
ot s
pec
ified
.
VH
V→
ded
icat
ed h
ealth
cen
tre
staf
f→op
erat
iona
l dis
tric
t st
aff→
pro
vinc
ial
heal
th d
epar
tmen
t.
“bui
lt on
the
exi
stin
g he
alth
sys
tem
and
re
sour
ces,
follo
win
g th
e M
inis
try
of H
ealth
p
olic
y an
d s
trat
egy
to s
tren
gthe
n th
e O
per
atio
nal D
istr
ict
stru
ctur
e”.
Mon
thly
mee
ting
bet
wee
n V
HV
and
fo
cal p
oint
s at
hea
lth
cent
re d
iscu
ssed
dat
a,
dec
isio
ns, r
esp
onse
.
Out
bre
ak
inve
stig
atio
n;
imp
lem
enta
tion
of
cont
rol m
easu
res.
Trav
el c
osts
, per
d
iem
, foo
d, f
ree
med
ical
car
e fo
r V
HV
s. A
nnua
l co
st ~
US
$0.5
p
er c
apita
in
clud
ing
visi
ts
from
Phn
om
Pen
h fo
r tr
aini
ng,
sup
ervi
sion
, and
ev
alua
tion.
Nas
er e
t al
(2
015)
24N
otifi
er: A
ny p
hysi
cian
in s
entin
el h
osp
itals
.R
ecei
ver:
Sur
veill
ance
phy
sici
ans
in s
entin
el h
osp
itals
.Ve
rifica
tion:
Inst
itute
of E
pid
emio
logy
, Dis
ease
Con
trol
and
Res
earc
h (IE
DC
R) o
f the
Gov
ernm
ent
of B
angl
ades
h, w
ith t
he In
tern
atio
nal C
entr
e fo
r D
iarr
hoea
l Dis
ease
Res
earc
h, B
angl
ades
h (ic
dd
r,b).
Verifi
catio
n th
roug
h st
and
ard
que
stio
nnai
re.
Ris
k as
sess
men
t an
d R
esp
onse
: IE
DC
R a
nd ic
dd
r,b.
Dat
a co
llect
ion
and
tra
nsm
issi
on: N
ot s
pec
ified
.
Phy
sici
an→
surv
eilla
nce
phy
sici
ans→
IEC
DR
and
icd
dr,b
.R
uns
par
alle
l to
rout
ine
IBS
.S
urve
illan
ce p
hysi
cian
s.
IED
CR
and
icd
dr,b
in
vest
igat
ion
team
s.
Out
bre
ak
inve
stig
atio
n, a
ctiv
e ca
se fi
ndin
g, c
olle
ct
det
aile
d e
xpos
ures
, d
eter
min
e ep
i lin
k b
etw
een
case
s.
Not
sp
ecifi
ed.
Sha
rma
et a
l (2
009)
27N
otifi
er: H
ealth
care
wor
kers
and
hea
lth p
rofe
ssio
nals
.R
ecei
ver:
Cal
l cen
tre
staf
f. C
all c
entr
e p
rovi
des
info
rmat
ion
to s
tate
and
d
istr
ict
surv
eilla
nce
offic
ers
for
asse
ssm
ent
and
res
pon
se.
Verifi
catio
n, R
isk
asse
ssm
ent
and
Res
pon
se: S
tate
/dis
tric
t su
rvei
llanc
e of
ficer
s. V
erifi
catio
n al
gorit
hm n
ot s
pec
ified
.D
ata
colle
ctio
n an
d t
rans
mis
sion
: 24/
7 to
ll- fr
ee c
all c
entr
e, a
vaila
ble
in
mul
tiple
lang
uage
s.
Hea
lthca
re w
orke
rs→
Cal
l cen
tre→
Sta
te/
dis
tric
t su
rvei
llanc
e of
ficer
s.In
form
atio
n re
ceiv
ed
is s
hare
d w
ith s
tate
or
dis
tric
t su
rvei
llanc
e of
ficer
s.
Not
sp
ecifi
ed.
Not
sp
ecifi
ed.
Cos
t an
d s
taff
inte
nsiv
e. 6
5%
of c
all c
entr
e b
udge
t sp
ent
on h
uman
re
sour
ces.
Tant
e et
al
(201
5)23
Not
ifier
: Any
one:
med
ia, h
ealth
wor
kers
or
non-
gove
rnm
enta
l org
anis
atio
ns
and
oth
er in
form
al c
hann
els.
Rec
eive
r, V
erifi
catio
n an
d V
erifi
catio
n al
gorit
hm, R
isk
asse
ssm
ent,
R
esp
onse
: Not
sp
ecifi
ed.
Dat
a co
llect
ion
and
tra
nsm
issi
on: F
orm
al r
epor
ting
syst
em, p
hone
cal
ls,
text
mes
sage
s an
y ty
pe
of r
epor
ting.
Ent
ry a
t an
y p
oint
into
the
nat
iona
l su
rvei
llanc
e sy
stem
.E
stab
lishe
d t
o co
mp
lem
ent
the
natio
nal I
BS
sys
tem
. D
urin
g d
isas
ters
, sy
ndro
me-
bas
ed
syst
em is
ad
ded
.
Not
sp
ecifi
ed.
Not
sp
ecifi
ed.
Not
sp
ecifi
ed.
Dag
ina
et a
l (2
013)
28N
otifi
er: A
ny s
ourc
e, in
clud
ing
heal
th w
orke
rs, n
on- g
over
nmen
tal
orga
nisa
tions
, em
bas
sies
, med
ia a
nd g
ener
al p
ublic
. No
spec
ific
trai
ning
m
entio
ned
.R
ecei
ver:
EB
S c
oord
inat
or w
ithin
the
Com
man
d C
entr
e of
the
C
omm
unic
able
Dis
ease
s S
urve
illan
ce a
nd E
mer
genc
y R
esp
onse
Uni
t of
N
atio
nal D
epar
tmen
t of
Hea
lth (N
DO
H).
Verifi
catio
n: E
BS
coo
rdin
ator
ver
ifies
eve
nts
rep
orte
d fr
om n
on- h
ealth
so
urce
s b
y co
ntac
ting
the
near
est
heal
th a
utho
ritie
s or
pro
vinc
ial h
ealth
of
fices
(PH
Os)
who
are
res
pon
sib
le fo
r d
isea
se s
urve
illan
ce a
nd c
ontr
ol.
Str
uctu
red
and
sta
ndar
dis
ed r
epor
t an
d a
sses
smen
t fo
rm a
vaila
ble
for
doc
umen
tatio
n of
tra
nsm
itted
info
rmat
ion
and
ver
ifica
tion.
Ris
k as
sess
men
t: E
BS
coo
rdin
ator
pro
vid
es g
uid
ance
to
PH
O.
Res
pon
se: P
rimar
ily P
HO
. Sup
por
t fr
om h
ighe
r le
vels
up
on
req
uest
. O
ccas
iona
lly t
hird
par
ties.
Dat
a co
llect
ion
and
tra
nsm
issi
on: N
ot s
pec
ified
.
Any
sou
rce→
EB
S c
oord
inat
or→
PH
O.
“By
rout
ing
dat
a d
irect
ly fr
om t
he g
roun
d
leve
l to
the
natio
nal l
evel
, the
sys
tem
b
ypas
ses
esta
blis
hed
rep
ortin
g ch
anne
ls,
that
is, f
rom
loca
l/dis
tric
t to
pro
vinc
ial t
o na
tiona
l lev
els”
.
Run
s in
par
alle
l to
exis
ting
syst
em. E
BS
co
ord
inat
or r
each
es
out
to e
xist
ing
syst
em
for
verifi
catio
n an
d
resp
onse
.
“All
even
ts in
vest
igat
ed
thro
ugh
the
EB
S s
yste
m
are
rep
orte
d b
ack
to
stak
ehol
der
s(…
)thro
ugh
a w
eekl
y N
atio
nal
Sur
veill
ance
Bul
letin
”.
Out
bre
ak
inve
stig
atio
n. N
ot
spec
ified
.
Sta
ff: 2
par
t- tim
e st
aff m
emb
ers
on n
atio
nal l
evel
.
A&
R, a
lert
and
res
pon
se ;
CB
S, c
omm
unity
- bas
ed s
urve
illan
ce; C
BV,
com
mun
ity- b
ased
vol
unte
er; C
EB
S, c
omm
unity
- eve
nt- b
ased
sur
veill
ance
; CH
M, c
omm
unity
hea
lth m
onito
r; C
HO
, com
mun
ity h
ealth
offi
cer;
CH
S, c
omm
une
heal
th s
tatio
n; C
HW
, com
mun
ity h
ealth
wor
ker;
C
SS
, com
mun
ity h
ealth
sup
ervi
sor;
DE
RC
, Dis
tric
t E
bol
a R
esp
onse
Cen
tre;
DH
C, d
istr
ict
heal
th c
entr
e; E
BS
, eve
nt- b
ased
sur
veill
ance
; HC
, hea
lth c
entr
e; H
EW
, hea
lth e
xten
sion
wor
ker;
IBS
, inc
icat
or- b
ased
sur
veill
ance
; PP
MC
, Pro
vinc
ial P
reve
ntiv
e M
edic
ine
Cen
tre;
VH
W,
villa
ge h
ealth
wor
kers
; VS
S, v
olun
teer
sur
veill
ance
sup
ervi
sors
.
Tab
le 4
C
ontin
ued
on October 7, 2020 by guest. P
rotected by copyright.http://gh.bm
j.com/
BM
J Glob H
ealth: first published as 10.1136/bmjgh-2019-001878 on 10 D
ecember 2019. D
ownloaded from
12 Kuehne A, et al. BMJ Global Health 2019;4:e001878. doi:10.1136/bmjgh-2019-001878
BMJ Global Health
management, active case finding, patient referrals and vaccinations.22 In Cambodia, CEBS identified outbreaks of malaria, acute watery diarrhoea, measles and viral haemor-rhagic fever.26
Health facility- based EBS in Bangladesh for meningo- encephalitis clusters identified 62 signals that were investigated to identify chains of transmission.24 The tele-phone hotline for health professionals in India identified nine outbreaks but was used for non- health- related calls more than 95% of the time.27
The open generic EBS system in PNG received 61 signals from provincial health authorities, health profes-sionals and media, NGOs and communities notified signals related to acute watery diarrhoea, influenza- like illness, acute gastrointestinal syndromes, acute fever and rash, acute neurological syndromes, acute febrile illness and other respiratory diseases.28 Alerts were investigated by provincial health authorities with support from higher levels28 (online supplementary file 4).
Data quality (validity and completeness)In the context of outbreaks, for CEBS in Sierra Leone, five of six Ebola- related trigger events were correctly recalled by less than two- thirds of CVs 3 months after implementation.17
Santa- Olalla et al25 compared trends of EBS signals for cholera- related events with IBS data for validity of data and saw comparable trends with regards to time and geographical distribution with the exception that more EBS signals came from hard- to- reach areas with the lowest number of partners25 (online supplementary file 4).
In a routine context in Ethiopia, similar trends in EBS signals about measles rumours and IBS measles data were reported over time.22 With regards to data completeness, 23% of signals had no records of verification and 29% had complete information on reporting and response times22 (online supplementary file 4).
Positive predictive value (PPV) for true eventsThe interpretation of PPV across EBS systems is dependent on the types of events used for the calcula-tion. In the context of the Ebola outbreak, 12 126 signals were received through CEBS for Ebola in Sierra Leone, of which 287 were ultimately confirmed to meet the suspected, probable or confirmed case definition (PPV 0.024, 287/12 2126) and 16 Ebola cases were confirmed19 (online supplementary file 4).
In the routine surveillance context of Vietnam, an overall PPV of 0.07 (176 events/2520 signals) for CEBS was reported based on a list of defined events. PPV increased significantly over time after evaluation visits and improved event definitions from 0.06 initially to 0.12.13 CEBS in Ghana, Ethiopia and Cambodia reported PPVs of >0.60 for the signals to be an event12 22 26 (online supplementary file 4).
The EBS telephone hotline in India received 44 484 calls from health professionals, of which 1185 were health related, 112 were outbreak signals and 9 were
true outbreak alerts (PPV for a signal to be an alert 0.08; 9/112).27 The PPV for meningo- encephalitis cluster reported by health professionals to be a true Nipah cluster was 0.17 (10 clusters/62 signals).15
In PNG’s centralised routine EBS system, of 61 signals, 51 proved to be true events (PPV 0.84)28 (online supple-mentary file 4).
SensitivityIn outbreak context, Ratnayake et al19 reported that 30% (16/53) of all confirmed cases of Ebola in the area where CEBS for Ebola was implemented were identified by CEBS. In Guinea, 3.9% (71/1838) of all confirmed Ebola cases were identified by signals received at the national Ebola call centre and 54% (120/221) of all confirmed Ebola cases were identified by local Ebola alert numbers18 (online supplementary file 4).
In the routine context of Ethiopia, the verified events reported by CEBS for rabies, anthrax, acute flaccid paralysis and neonatal tetanus outnumbered the cases reported IBS during the same time in areas where CEBS was active, indicating better sensitivity of EBS compared with IBS22 (online supplementary file 4).
AcceptabilityIn the context of the Ebola outbreak, Stone et al17 eval-uated acceptability as the proportion of CVs reporting for CEBS in Sierra Leone at least once per week; this increased from 69% to 93% during implementation. In addition, 74% of district stakeholders agreed that CEBS increased case detection and benefited their district through increased linkage with communities.17 CEBS was based on community health worker (CHW) and Red Cross volunteer networks that are largely known to the community prior to CEBS.16 17 19
Santa- Olalla et al25 reported that the near real- time information and response increased the acceptance by local authorities during the outbreak and willingness to institutionalise the system into the Ministry of Health immediately after the end of the outbreak in Haiti (online supplementary file 4).
In routine context, CEBS in Sierra Leone was well accepted by communities and CVs were appreciated, and CVs wanted to continue CEBS after the outbreak despite the lack of incentives.15 16 Clara et al13 14 reported “Key moti-vating factors for participation expressed by the VHWs (village health workers) were a sense of service to the community and opportunities to increase community ties, and improvement in community trust”. Toyama et al22 inter-preted the proportion of rumours reported by the commu-nity to CEBS in Ethiopia as community acceptance: 30% of rumours were reported directly from the community (online supplementary file 4).
TimelinessDuring the Ebola outbreak in Sierra Leone, the time from onset to detection for six confirmed Ebola cases in districts with active transmission was 1–3 days for
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four cases identified with CEBS and 5–7 days for two confirmed Ebola cases identified through other sources (online supplementary file 4).19
For the routine context in Vietnam, for EBS times from detection to notification at district level was reported to be <24 hours, mean time from detection to response was reported to be within 48 hours.14 The authors conclude that such a rapid response would not have been possible before the implementation of EBS.14 For CEBS in Ethi-opia, a median time from onset to reporting of 3.8 days (95% CI 2.2 to 5.3 days) was reported and from reporting to response of 0.6 days (95% CI 0.1 to 1.2 days).22 In PNG’s centralised routine EBS system, median time from onset to reporting was 10 days (range, 0–109 days) and median time from reporting to response was the same day28 (online supplementary file 4).
Flexibility and stabilityFor the centralised EBS in Haiti and for CEBS in Sierra Leone, EBS was described as flexible to adapt and was broadened in scope, from EBS systems based on events in connection to one outbreak disease to generic EBS systems.15 16 25
Sharma et al27 described a successful shift in focus of the EBS system from generic EBS to influenza A (H1N1) specific events.
Tante et al23 described the stability of the routine EBS system in the Philippines after a natural disaster and found that 6/11 affected areas had no interruptions of EBS operation, 3/11 areas were interrupted for 1 week while the two hardest hit areas had limited operationality for more than 7 weeks due to human resource and logis-tical limitations; 73% of all areas rated the EBS system as functional post- typhoon (online supplementary file 4).
Cost estimatesSeveral additional characteristics were evaluated (see online supplementary file 4), among them annual costs: data from Cambodia estimated the annual cost of CBS at US$0.5 per capita for training, supervision and evalua-tion, including CEBS and the IBS and vital events compo-nent but excluding staff costs as all staff were previously in place.26 For the Sierra Leone CEBS, total costs were estimated at US$1.3 million start- up costs and US$129 000 monthly costs that covered training, telephones, motor-bikes, fuel and incentives for 7416 CHWs and salaries for 137 surveillance supervisors19 (given a population of 3.9 million, ~US$0.4 per capita annual costs).
disCussionWhat are the strengths of ebs?The scope of EBS is broader than IBS in several aspects: (1) In outbreaks, EBS was able to identify outbreak- disease cases and programming gaps (eg, poor- quality cholera care) helping to guide the response19 20 25; (2) in outbreaks and routine context alike, EBS was able to iden-tify outbreaks that were not detected by IBS, both for noti-fiable and non- notifiable diseases12–14 19 20 22 24–26 28; (3) in
outbreaks and routine contexts, EBS was able to identify other potential hazards to human health such as natural events or animal die- offs12 14 22 25 28; (4) in outbreaks and routine context, EBS at the community level and open EBS were able to reach remote areas14–17 19 20 22 25 26 28 and EBS was most used where health facilities and response was scarce in Haiti.25 In these settings, EBS provided an important channel for rapid reporting of events, of particular benefit to remote settings where IBS was poor. In addition, data from the Sierra Leone CEBS suggest that EBS systems were faster to identify cases from onset to detection19 than IBS and other CEBS systems were also reported to be faster than IBS.14 22 However, across studies, no systematic and direct comparisons of timeli-ness of IBS and EBS were presented.
What are the trade-offs for ebs?Many questions with regards to sensitivity and specificity of event definitions remain unanswered. For CEBS in outbreak settings, specified event definitions that indi-cate disease transmission had low specificity and event definitions were not always remembered long after train-ings,17 19 20 suggesting that definitions should be more rigorously tested prior to implementation.19 Telephone hotlines were mostly used for information by the public (and useful for improving communication with the public) but also identified cases that went under the radar of IBS18 and from areas outside the reach of IBS.25 EBS in communities showed a higher specificity than EBS using open hotlines, at the costs of limited reach (limited to communities with CEBS vs anywhere with phone connec-tion).18 19 All EBS systems involved an increased workload for verification and assessment given the low specificity of the events and the volume of alerts produced.17–21 25
In routine contexts, in which events were defined by a list of specific events (eg, for CEBS in Vietnam, Ghana and Sierra Leone), the main reported challenges included balancing sensitivity and specificity12 13 and uncertainties around event definitions.15 16 In Vietnam, initially more than half of the reported events were endemic diseases that were routinely and rapidly reported through IBS, and therefore, event definitions that could indicate such diseases were subsequently removed.13 Balancing sensitivity against specificity is particularly challenging as there is no gold standard for detection of events and non- events that would allow determination of sensitivity and specificity and available evidence is anecdotal, that is, reports of outbreaks identified by EBS but not IBS.22 In addition, balance of sensi-tivity versus specificity will inevitably depend on the setting, existing surveillance, access to healthcare and whether an outbreak is ongoing. CEBS systems that were based on undefined events such as ‘unusual events’ showed a PPV >0.6.22 26 The open EBS system in PNG notifying ‘public health events’ also exhibited a PPV >0.8, possibly because it was mainly used by local public health authorities to notify to central level.28 There seems to be some indication that the PPV of undefined events is not worse than the PPV of defined events pointing to specific diseases; however, we do
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not know if this comes at the costs of lower sensitivity to detect outbreaks.
The amount of work for verification and response is higher in EBS systems than IBS systems, as every noti-fied signal requires rapid verification and potentially response. In outbreak settings, all EBS were set up with international support17–21 25; in routine contexts, dedi-cated national government leadership was often paired with regional or international support to sustain verifica-tion and response systems.12–16 22–24 26–28
With regard to costs, while most reports did not account for total direct costs,19 26 costs structures would be influ-enced by the provision of additional capacity for verifica-tion of the potentially large number of signals produced by EBS. Where human resources and response elements are not already in place, costs might be associated with EBS, that not currently absorbed by the surveillance system’s budget (ie, incentives for CHWs, additional veri-fication capacity, including rapid response teams etc).
How to implement it?In outbreak and non- outbreak settings, early engagement and meetings with all stakeholders (including commu-nity leaders) were described as crucial14 17 19 20 to ensure ownership, increase coordination and gain “better under-standing of the existing surveillance landscape”.14
With regards to surveillance, Santa- Olalla et al25 described the importance of not undermining existing responsibilities and capacities for EBS cholera surveil-lance in Haiti. Routine context CEBS in Vietnam was developed at ministry of health level with involvement of all stakeholders to ensure integration into existing surveillance infrastructure.14 In Cambodia and Ethiopia, CEBS was reported to be functional mainly because it was simple and built on the existing surveillance systems and resources.22 26
Good linkage to response was described as essential for all systems as every verified event needs an assess-ment and potentially response.8–24 However, response was challenging in some systems and required scaling up.21 22 25 28 All outbreak- specific EBS systems were linked to pre- existing response structures set up specif-ically for the outbreak.17–21 25 In order to ensure timely reporting of defined events and sustainability, stake-holders in EBS need training and, if possible, moni-toring, supervision and refresher trainings.14–17 20 22 Several reports suggested that standardised documen-tation and assessment improved accountability and ensured a consistent approach.14 22 28 In routine contexts, where the capacity to conduct risk assessment and field investigations is low, specific resources and training are required.14 28
Several EBS systems incorporated feedback mech-anisms to stakeholders to inform about findings and actions; all records that reported such feed-back loops identified them as essential instruments to sustain motivation, especially in routine settings, and to improve cooperation.14 25 26 28 Communication
improved between actors in the surveillance system and the community26 but also between human and animal health14 and stakeholders at different levels at the surveillance system.28
limitationsThere are some limitations stemming from the variety of EBS systems as well as evaluation designs and the poor evidence rating of the studies. The number of studies with low- quality evidence grading is due to the nature of surveillance systems evaluations which are inherently descriptive and seldom have a comparator. All studies were of low evidence and none compared EBS and IBS systems systematically, controlled or randomised. Most importantly, surveillance attributes, especially PPV, were not always reported or analysed in the same way, compli-cating meaningful comparisons. For the PPV, informa-tion on if and how signals that did not result in alerts were documented was frequently lacking.
Additionally, the number of studies was low, and more descriptions and rigorous evaluations are therefore needed to generate more conclusive evidence. Despite the increasing focus on EBS as a central component for early detection of outbreaks, there is limited guid-ance on EBS evaluation. The development of guidance more tailored to the evaluation of EBS would be useful as would be planning and publishing evaluations of EBS systems more systematically to ensure lessons learnt are documented and communicated.
Furthermore, all EBS systems succeeded in identifying events and outbreaks; however, we cannot rule out that publication bias towards successful systems is the reason for that finding.
In addition, other countries may have EBS systems in place, but their description might not be included in the paper given the absence of literature on them.
ConClusionHealth facility and community- based EBS provide valu-able information that can strengthen the early warning function of national surveillance systems. Every signal generated by EBS requires verification, and each EBS system is only as good as the capacity to respond to verified events to ensure that EBS can lead to meaningful public health action.8–24 This requires close integration with existing surveillance systems and this needs to happen in a way that does not undermine existing responsibilities and capacities.10 12–17 19 20 22 23 25 28 EBS can be a powerful tool to improve rapid communication between actors in healthcare and surveillance, and feedback loops to all stakeholders including communities were described as essential instruments for sustaining motivation and coop-eration.16 17 19 20 23 25 28 Where EBS is not a fully integrated function of a surveillance system, priority in its imple-mentation should be given to settings that would particu-larly benefit from EBS strengths. This includes areas most prone to outbreaks, where otherwise undetected health
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threats will most likely occur, where access to the formal health system is limited and where traditional ‘routine’ surveillance is suboptimal.
Acknowledgements AK would like to thank the team of the UK Public Health Rapid Support Team for their support throughout study development and manuscript preparation. The authors wish to thank Philip Abdelmalik for his thorough review of the manuscript.
Contributors AK designed the study and developed the search strategy. PK, JP, CH, OLPdW and RR provided feedback on search strategy and study design. AK conducted the systematic literature search. AK, PK, OLPdW, RR and JP reached out to partners for grey literature. AK and PK conducted the review of literature, abstracts and full texts. AK conducted data extraction and quality assessment, performed the content analysis, wrote the manuscript, and prepared all tables and figures. PK contributed to data extraction and quality assessment. RR provided input to the surveillance system evaluation and content and structure of the manuscript. PK, JP, CH, KS, OLPdW and RR reviewed and approved the final manuscript. RR conducted the proofreading of the final manuscript.
Funding The UK Public Health Rapid Support Team is funded by the National Institute for Health Research and Department of Health and Social Care.
disclaimer The views expressed are those of the authors and not necessarily those of the NIHR or DHSC. The authors alone are responsible for the views expressed in this article and they do not necessarily represent the views, decisions or policies of the institutions with which they are affiliated.
Competing interests None declared.
Patient consent for publication Not required.
Provenance and peer review Not commissioned; externally peer reviewed.
data availability statement There are no data in this work. All data relevant to the study are included in the article or uploaded as online supplementary information.
open access This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY- NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non- commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non- commercial. See: http:// creativecommons. org/ licenses/ by- nc/ 4. 0/.
orCid idsAnna Kuehne http:// orcid. org/ 0000- 0002- 8578- 0362Patrick Keating https:// orcid. org/ 0000- 0003- 3358- 3196Jonathan Polonsky https:// orcid. org/ 0000- 0002- 8634- 4255Christopher Haskew https:// orcid. org/ 0000- 0003- 1992- 808XKarl Schenkel https:// orcid. org/ 0000- 0001- 5444- 9143Olivier Le Polain de Waroux https:// orcid. org/ 0000- 0003- 3458- 2945Ruwan Ratnayake http:// orcid. org/ 0000- 0003- 4978- 6668
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