Rapid Risk Assessment of Acute Public Health Events

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Rapid RiskAssessment of AcutePublic Health Events


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World Health Orgaizao 2012

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Risk Assessment Manual

Table of cotets

Itroduco to the maual 2

Purpose of the maual 2

Defesible decisio-makig 2

Implemetao of appropriate ad mely cotrol measures 3

More eecve operaoal commuicao 3

More eecve risk commuicao 3

Improved preparedess 3

How the maual was developed 4

Termiology 4

The all-hazards approach ad the Iteraoal Health Regulaos 5

Deteco ad cormao of a public health evet 6

Itroduco to risk assessmet 8

Steps i the risk assessmet of public health evets 9

Assemblig the risk assessmet team 9

Formulag risk quesos 9

Udertakig the risk assessmet 12

Hazard assessmet 13

Eposure assessmet 14

Cotet assessmet 15

Risk characterizao 19

Level of codece i the risk assessmet 23

Quacao i risk assessmet 25

Cotrol measures 25

Risk commuicao 27

Moitorig ad evaluao 27

APPEnDIx 1: Glossary of terms used i this maual 28

APPEnDIx 2: Deios used by dieret sectors ad disciplies 31

APPEnDIx 3: Eamples of the STEEEP cosequeces of a acute

public health evet ad associated cotrol measures 34

APPEnDIx 4: Quacao i risk assessmet 36

APPEnDIx 5: Risk commuicao 38

APPEnDIx 6: Cotributors to the developmet of this maual 40


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Itroduco to the maual

This maual has bee developed to guide rapid risk assessmet of acute public health risks from

ay type of hazard i respose to requests from Member States of the World Health Orgaizao

(WHO). The maual is aimed primarily at aoal departmets with health-proteco resposibilies,

naoal Focal Poits (nFPs) for the Iteraoal Heath Regulaos (IHR) ad WHO sta. It should

also be useful to others who joi muldiscipliary risk assessmet teams, such as cliicias, eld

epidemiologists, veteriarias, chemists, food-safety specialists.

The maual will assist rapid ad defesible decisio-makig about acute public health evets that

pose a risk to huma health through applicao of a systemac process from evet deteco ad risk

assessmet to commuicao with key stakeholders ad the public.

The maual complemets eisg hazard-specic risk assessmet guidace (see Appedices 1 ad 2),

icludig:

WHO Human Health Risk Assessment Toolkit: Chemical Hazards1

Applicaon of Risk Analysis to Food Standards Issues, a Joit FAO/WHO Epert Cosultao,

Geeva, Switzerlad, 1317 March 19952.

As the process is icorporated ito roue pracce durig acute public health evets we hope that

users will suggest improvemets for this maual as well as provide addioal case studies that will

improve it ad assist traiig.

Purpose of the manual

Rapid risk maagemet of acute public health evets reduces or prevets disease i aected

populaos ad reduces egave social ad ecoomic cosequeces. Addioal beets iclude:

defesible decisio-makig

implemetao of appropriate ad mely cotrol measures

more eecve operaoal commuicao

more eecve risk commuicao

improved preparedess.

Defensible decision-making

Risk assessmet takes ito accout ad documets all relevat iformao available at the me of the

assessmet. This supports ad directs decisio-makig ad provides a record of the process icludig:

which risks ad cotrol measures were assessed

the methods used to assess them

why they were cosidered importat

their order of priority.

1 hp://www.who.it/ipcs/publicaos/methods/harmoizao/toolkit.pdf

2 hp://www.who.it/foodsafety/publicaos/micro/march1995/e/ide.html
http://www.who.int/ipcs/publications/methods/harmonization/toolkit.pdfhttp://www.who.int/foodsafety/publications/micro/march1995/en/index.htmlhttp://www.who.int/foodsafety/publications/micro/march1995/en/index.htmlhttp://www.who.int/ipcs/publications/methods/harmonization/toolkit.pdf


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If documeted cosistetly, risk assessmet provides a record of the raoale for chages over the

course of the evet icludig the:

assessed level of risk

recommeded cotrol measures

key decisios ad acos.

Evaluao of the risk assessmet based o systemac documetao provides a importat

meas of idefyig where improvemets ca be made ad provides a evidece base for future risk

assessmets ad resposes to evets.

Implementaon of appropriate and mely control measures

The systemac approach to collecg ad aalyzig iformao about the hazard, eposures ad

cotet i which the evet is occurrig helps to:

idefy evidece-based cotrol measures

rak the suitability ad feasibility of cotrol measures

esure that cotrol measures are proporoal to the risk posed to public health.

I addio, because the risk is assessed repeatedly durig a evet, risk assessmet oers authories

a opportuity to adapt cotrol measures as ew iformao becomes available.

More eecve operaonal communicaon

Usig a commo risk termiology ca greatly improve the operaoal commuicao betweedieret levels of a orgaizao ad with other sectors ad istuos ivolved i the assessmet

ad respose to the evet.

More eecve risk communicaon

The aim of public risk commuicao is to eable the target populao to make iformed decisios

about recommeded persoal ad commuity-based preveo ad migao measures. Eecve

risk commuicao relies o the mely ad trasparet sharig of all relevat iformao, ad

the buildig of trust ad empathy. A systemac approach to the assessmet of acute public health

evets supports eecve risk commuicao through the rapid dissemiao of iformao ad the

idecao of key preveo ad migao measures.

Improved preparedness

Although the maual focuses primarily o the use of risk assessmet durig acute public health evets

the approach is equally applicable to preparedess acvies, especially to seasoal ad recurret

outbreaks (e.g. aual cholera outbreaks i Africa ad the degue seaso i the Americas ad Asia).

To aid preparedess plaig, risk assessmet ca be used to idefy at-risk areas or populaos,

rak preparedess acvies, ad egage key policy ad operaoal parters.


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How the manual was developed

A workig group rst met i Geeva, november, 2010 cosisg of sta from WHO Coutry Oces,

Regioal Oces ad Headquarters who were: resposible for evet-based surveillace

resposible for public-health evet risk assessmet across mulple hazards or specically food

safety or chemical hazards risk assessmet

eperieced i leadig outbreak resposes

eperieced i deliverig risk assessmet traiig courses.

I addio, a aimal health epert was ivolved i developig the maual ad WHO risk commuicao

ad Iteraoal Health Regulaos (IHR) specialists were cosulted.

A list of people who parcipated i the workig group ad subsequet telephoe cofereces isprovided i Appedi 6.

Terminology

I the cotet of this maual, a acute public health evet is ay outbreak or rapidly evolvig situao

that may have egave cosequeces for huma health ad requires immediate assessmet ad

aco. The term icludes evets that have ot yet led to disease i humas but have the poteal

to cause disease through eposure to ifected or cotamiated food, water, aimals, maufactured

products or eviromets.

Terms used to describe risk dier betwee disciplies. I this maual, risk is the likelihood of the

occurrece ad the likely magitude of the cosequeces of a adverse evet durig a specied

period. A compariso of risk terms used i importat sectors ad disciplies relevat to public health

is provided i Appedi 1.

There are historical reasos why dieret disciplies use dieret terms whe cosiderig risk. As this

maual focuses o acute public health evets, where muldiscipliary ad mulsectoral iputs ito

the risk assessmet may be eeded, the terms used are a praccal compromise that have bee prove

to work across disciplies ad are deed i Appedi 2.


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The all-hazards approach ad the Iteraoal

Health Regulaos

A all-hazards approach has bee used for may years i emergecy ad disaster maagemet to

describe atural, techological, or ma-made evets that require aco to protect life, property,

eviromet, ad public health or safety, ad to miimize social disrupo.

It is applied to public health evets that require a immediate respose ad are poteally caused by

more tha oe hazard icludig biological, chemical ad radiouclear hazards, whether aturally

occurrig or as a result of a accidet or deliberate release ad atural disasters such as res,

oods, other etreme weather evets, volcaic erupos, earthquakes ad tsuamis.

This approach has bee drive by the Iteraoal Health Regulaos (IHR), which were revised i

2005 to reect growth i iteraoal travel ad trade, emergece or re-emergece of iteraoal

disease risks, ad threats posed by chemicals, tois ad radiao.

The IHR requires all States Pares to the Regulaos to develop a set of core capacies i surveillace

ad respose coverig ay illess or medical codio, irrespecve of origi or source that presets

or could preset sigicat harm to humas.

Followig a risk assessmet, the Ae 2 decisio istrumet of the IHR are used by Member States

to decide whether a acute public heath evet requires formal ocao to WHO. The eecve useof Ae 2 depeds o each aoal authority ad its IHR naoal Focal Poit (nFP) carryig out risk

assessmets o public health evets occurrig withi their territories.

The IHR core capacity requiremets for surveillace ad respose require Member States to develop

a aoal (ad, where possible, a sub-aoal) risk assessmet capacity that is recogized as a

itegral part of the preveo, surveillace ad respose system. The structure ad locao of this

capacity, which may be a dedicated team or embedded ito the eisg preveo, surveillace ad

respose system, will be coutry-specic.

Despite diereces i how Member States might structure ad locate their risk assessmet capacity,

WHO ad all Member States should use a cosistet, structured approach to the risk assessmet of

acute public health evets. Recommeded steps i such a structured risk assessmet are outlied i

the followig secos.


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Detecon and conrmaon of a public health event

All Member States have surveillace systems that detect outbreaks of ifecous diseases. As a result

of the emphasis i the IHR o stregtheig this core capacity, may Member States have epadedthese systems to iclude public health evets caused by other hazards. Surveillace systems detect

public health evets through:

Indicator-based surveillance: The roue colleco of pre-deed iformao about

diseases3 usig case deios (e.g. weekly surveillace of cases of acute accid paralysis).

Predetermied outbreak thresholds are oe set for alert ad respose.

Event-based surveillance: The rapid colleco of ad hoc iformao about acute public health

evets. Evet-based surveillace uses a variety of ocial ad uocial iformao sources

to detect clusters of cases with similar cliical sigs ad symptoms that may ot match the

presetao of readily ideable diseases. Ocial sources iclude aoal authories ad

other agecies such as the Un system. Uocial sources iclude media reports, other uocialpublic iformao (e.g. iteret sites), reports from the public

not all evet reports ad alerts geerated through idicator ad evet-based surveillace systems

describe real evets, or are all real evets of public health importace. The umber of false posives

(i.e. reported evets that caot be cormed as real or whe alert thresholds of idicator-based

surveillace systems are eceeded but a outbreak does ot result) depeds o the objecves ad

desig of the surveillace system ad the orgaizaoal level at which the evet is assessed.

Guidace should be developed to assist sta i the triage ad assessmet of ewly detected evets

(see Bo 1). Evet triage uses the same priciples for assessig the risk a evet may pose to publichealth as the more formal risk assessmet described i this maual.

Box 1: Example of guidance to surveillance sta for triaging incoming signalsfrom surveillance acvies

3 The term disease is used i its broadest sese, icludig sydromes.

Queson Answer

Has the event been reported by an ocial source (e.g. local health-care

centre or clinic, public health authories, animal health workers)?

Yes No

Has the event been reported by mulple independent sources (e.g.

residents, news media, health-care workers, animal health sta)?

Yes No

Does the event descripon include details about me, place and people

involved (e.g. six people are sick and two died three days aer aending a

local celebraon in community X)?

Yes No

Is the clinical presentaon of the cases described (e.g. a cluster of seven people

admied to hospital with atypical pneumonia, of whom two have died)?

Yes No

Has a similar event been reported previously (e.g. with a similar

presentaon, aecng a similar populaon and geographical area, over the

same me period)?

Yes No

Icomig sigals are more likely to describe real evets if there are oe or more yes aswers to

the quesos tabled above.


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If the evet is detected quickly, iial iformao may be limited ad o-specic. The iial triage

process focuses o assessig the credibility of the icomig sigal(s) ad whether the evet described

is a poteal risk to public health that warrats ivesgao. The accuracy of the reporg of the

evet may be assessed at the same me. Cormao of a evet does ot automacally mea that

it presets a risk to public health. Some evets may have lile or o eect o huma health or may be

related to chroic diseases or issues that do ot pose a acute public health risk. As a result, dieret

acos may result from the iial risk assessmet (see Table 1).

Table 1: Example of acon taken as a result of triage and conrmaon of an event

Outcome of triage andconrmaon

Acon

Reported event is proved to

be a false rumour

Discard the evet

Risk commuicao ad media commuicao about the evet

may be eeded to address the public percepo of risk (e.g.

smallpo rumours)

Event is conrmed but is not

an immediate public health

risk

Moitor the evet ad udertake risk assessmets as ew

iformao becomes available

Risk commuicao ad media commuicao about the evet

may be eeded to address the public percepo of risk

Event is conrmed and may

be considered an immediate

public health risk

Udertake a full risk assessmet ad state the level of

codece i the assessmet

Provide recommedaos for decisio-makers, icludig

which acos should be take ad which should have the

highest priority (e.g. recommeded cotrol measures, key

commuicao messages)

Udertake addioal risk assessmets ad modify

recommedaos for decisio-makers as ew iformao

becomes available. The acos take as a result of the risk

assessmets will dier at dieret orgaizaoal levels


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Introducon to risk assessment

Risk assessmet is a systemac process for gatherig, assessig ad documeg iformao to assig

a level of risk. It provides the basis for takig aco to maage ad reduce the egave cosequecesof acute public health risks (see Figure 1). The risk maagemet cycle icludes:

risk assessmet hazard, eposure ad cotet assessmet ad risk characterizao i which

the level of risk is assiged to the evet

idecao of poteal cotrol measures raked by priority, takig ito accout likelihood

of success, feasibility of implemetao ad uiteded cosequeces for the aected

populao ad society more broadly

couous moitorig ad evaluao as the evet ufolds

eecve ogoig commuicao to esure that risk maagers, other stakeholders ad aected

commuies uderstad ad support the cotrol measures that are implemeted

a evaluao of lessos leared at the ed of the respose.

Figure 1: The risk management cycle

RiskAssessment

ControlM

easu

resE

va

luat

ion

Risk

communication

Event

Detection


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Steps i the risk assessmet of public health evets

Assembling the risk assessment team

Aer cormig that a reported evet is real ad may be cosidered a immediate public health risk,

its public health importace must be determied. Depedig o the quality ad completeess of the

iformao available to assess the risk, a risk assessmet team may be assembled. Decidig o the

disciplies that should make up the risk assessmet team is a crical step that is oe overlooked.

Addioal eperse (e.g. i toicology, aimal health, food safety or radiao proteco) ca be

brought i at ay me but may be eeded at the begiig of the risk assessmet if:

the hazard is ukow

the evet is ulikely to be caused by a ifecous aget a evet is associated with disease or deaths i aimals, ad/or is otherwise ideed as a

suspected zooosis

the evet is related to a food or product recall, kow chemical accidet, or radiouclear

icidet with or without reports of huma disease.

Operaoal commuicao ad risk commuicao are itegral parts of risk maagemet. At

a miimum, liks should be established betwee the risk assessmet team ad commuicao

specialists. If possible, a commuicao specialist should be icluded i the risk assessmet team.

Esurig that there is good commuicao betwee decisio-makers ad the aected populao from

the start of the process will icrease the likelihood of eecve implemetao of cotrol measures,especially those requirig behavioural chage.

The kowledge ad eperse of the team greatly iuece the risk assessmet. Local kowledge

about the eviromet i which the evet is occurrig is a crical compoet of risk assessmet.

The level of risk of a acute public health evet depeds o the social, ecoomic, evirometal ad

polical codios i the aected area ad the eecveess of local health services (e.g. curave ad

public health services). For some hazards, the eecveess of liks betwee health services ad other

resposible sectors ad agecies (e.g. with the aimal health sector for zoooc diseases) may also

aect the risk ad must be assessed.

Formulang risk quesons

The risk assessmet team should decide o the key quesos to be aswered. This helps to dee

the scope of the assessmet ad esures that all the relevat iformao is collected. Clearly deed

quesos help idefy priority acvies to be coducted as part of the risk assessmet. This may

iclude literature reviews, epidemiological ivesgaos, ehaced surveillace, cosultao with

disease eperts, surveys ad research.

A risk queso is similar to a research queso ad typically focuses o:

who is likely to be aected the likely eposure to a hazard

whe, why ad how a populao might be adversely aected by eposure to a hazard.


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The quesos asked by the risk assessmet team will be iueced by factors icludig:

the populao at risk

the level at which the risk assessmet is takig place local, sub-aoal, aoal,

iteraoal (e.g. cross-border), or global

the techical ad policy disciplies ad agecies that are icluded i the risk assessmet

team ad their collecve eperiece with the type of evet they are assessig (e.g. a well-

characterized disease compared to a public health evet of ukow cause (ukow eology)

the level of risk accepted by decisio-makers, other stakeholders ad society (i.e. the acceptable risk)

the mig of the risk assessmet durig the course of the evet

the outcome of previous risk assessmets carried out for the evet ad similar situaos i the past

the level of perceived eteral (e.g. iteraoal commuity) iterest or awareess of the evet.

The team should ot try to aswer all the possible risk quesos at oce. Istead, crical quesos

should be ideed ad raked by priority for immediate respose. Less me-crical quesos ca be

addressed later or by other teams.

The mai queso asked durig acute public health evets is, what is the public health risk of the

evet (i.e. what is the risk related to eposure to a parcular hazard i a parcular locao, or to a

parcular populao at a parcular me)?

This queso oe leads to others, such as:

What is the likelihood of eposure to the hazard if o aco is take?

What are the cosequeces (type ad magitude) to public health if the evet were to occur?

Risk quesos may be framed as a series of scearios, such as:

What is the public health risk of the evet i the curret situao?

What is the public health risk of spread to a major city?

What is the public health risk of the evet aecg more tha oe area (provice/state,

coutry)?

Other eamples of risk quesos i respose to dieret scearios are show i Table 2.


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Table 2: Examples of risk quesons

Example of event report Risk queson

52 pigs died in two neighbouringfarms over one to two days.

Could this be a risk to huma health?

Clusters of people living with

HIV/AIDS have suddenly become

unresponsive to treatment.

Which hazards could cause this evet?

For eample:

secodary ifeco

substadard medicao (e.g. couterfeit drugs or loss of

potecy due to epired drugs)

drug resistance

availability of the drug (e.g. that leads to sharig

medicaos or paets uable to access the medicaos) paet adherece with treatmet.

Pneumonia of unknown cause

linked to deaths among health-

care workers.

What is the likely cause (eology) of the peumoia?

What are the possible public health cosequeces?

Two deaths and 16 suspected

cases of cholera in a camp for

internally displaced persons in a

parcular district.

What is the likelihood of further spread of cholera?

What would be the cosequeces if this occurred?

Paediatric analgesic syrup

formulated with diethylene glycol

is idened aer a cluster of

deaths in children.

Is this product marketed abroad, either formally or

iformally?

What would be the cosequeces if this occurred?

An outbreak of hand, foot and

mouth disease (HFMD) in nursery

school children in one of 14

regions in a country.

What would be the eect o disease trasmissio of

implemeg quarae i the aected regio?

How would implemeg quarae measures aect

disease trasmissio?

What would be the cosequeces of implemeg quarae

i the aected regio?

Based o the characteriscs of the evet, the risk assessmet team should decide how frequetly the

risk assessmet should be updated. The team should also agree o the priority quesos ad decide

the me eeded to complete each assessmet. The me available betwee assessmets may help to

direct the umber ad scope of risk quesos cosidered.


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Undertaking the risk assessment

The level of risk assiged to a evet is based o the suspected (or kow) hazard, the possible

eposure to the hazard, ad the cotet i which the evet is occurrig. Risk assessmet icludes threecompoets hazard, eposure, ad cotet assessmets. The outcome of these three assessmets

is used to characterize the overall level of risk (see Figure 2).

Figure 2: The risk assessment process

Compleg a risk assessmet is ot always a sequeal process with hazard, eposure ad cotetusually assessed at the same me. Although each is assessed separately, there is overlap i the

iformao required to assess each domai.

HazardAssessment

ExposureAssessment

ContextAssessment

RiskCharacterization


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Hazard assessment

Hazard assessmet is the idecao of a hazard (or umber of poteal hazards) causig the evet

ad of the associated adverse health eects.

Public health hazards ca iclude biological, chemical, physical ad radiouclear hazards. Hazard

assessmet icludes:

idefyig the hazard(s) that could be causig the evet

reviewig key iformao about the poteal hazard(s) (i.e. characterizig the hazard)

rakig poteal hazards whe more tha oe is cosidered a possible cause of the evet

(equivalet to a diereal diagosis i cliical medicie).

Whe there is a laboratory cormao of the causave aget or the evet is easily characterized o

cliical ad epidemiological features, hazard idecao ca be straighorward. I such cases thehazard assessmet would start with a kow or strogly suspected hazard. However, i all other cases

hazard assessmet starts with lisg possible causes based o the iial descripo of the evet

(e.g. the cliical ad epidemiological features), kow burde of disease i the aected commuity,

ad type ad distribuo of eisg hazards (e.g. the umber ad locao of chemical plats ad

the chemicals they use).

Medical pracoers, urses, veteriarias ad others workig i cliical segs will be familiar

with the importace of the diereal diagosis i the process of assessig a paet; hazard

assessmet is similar.

The less specic the iformao reported about a acute public health evet, the broader the list of

possible hazards becomes. However, as more iformao becomes available, the umber of poteal

hazards is reduced ad they ca be raked i order of the likelihood of beig the cause.

The relave likelihood of a hazard ca be determied by:

the cliical features ad atural history of the disease i humas or aimals

mig of the evet ad the speed with which the evet evolves

geographical area ad segs aected

the persos ad populaos aected.


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Table 3: Examples of quesons to assess the likelihood of a specic hazard

Sample quesons

Does the suspected hazard (pathoge, toi, cotamiat etc.) cause the cliical sigs ad

symptoms observed?

Is the suspected hazard kow to cause disease i humas or aimals?

Are the age group(s), se or occupaoal group(s) aected typical for eposure to ay hazards?

Has the case(s) reported a history of recet travel?

Is the me from presumed eposure to the oset of cliical sigs ad symptoms typical of a

parcular hazard or type of hazard?

Is the severity of disease typical of a parcular hazard or type of hazard?

Does the disease respod to parcular treatmets (e.g. abiocs)?

Has the suspected hazard bee diagosed previously as the cause of disease at the same me of

year, place or populao?

Have there bee ay associated or precedig evets (e.g. disease or deaths i aimals, food or

product recalls, kow accidetal or deliberate releases of chemical, biological or radiouclear

agets, similar evets i eighbourig coutries, etc.)?

Do laboratory test results corm a specic cause or are they cosistet with a parcular type of

hazard?

Exposure assessment

Eposure assessmet is the evaluatio of the eposure of idividuals ad populatios tolikely hazards. The key output of the assessmet is a estimate of the:

umber of people or group kow or likely to have bee eposed.

umber of eposed people or groups who are likely to be suscepble (i.e capable of geg a

disease because they ot immue)

Iformao required to aswer these quesos icludes:

modes of trasmissio (e.g. huma-to-huma trasmissio by droplet spread or direct cotact

trasmissio; aimal-to-huma trasmissio)

doserespose (e.g. some ifecous agets, tois, chemicals)

icubao period (kow or suspected)

case fatality rate (CFR)

esmao of the poteal for trasmissio (e.g. R0, the basic reproduco umber).

Vaccie status of the eposed populao

For some hazards a doserespose relaoship is a importat determiat of the magitude of

eposure. Eamples iclude the ihalao or igeso of heavy metals such as lead, the umber of

salmoella bacteria igested or the amout of a radiouclear isotope igested or absorbed. For such

hazards, i addio to assessig the eposure, the durao of eposure may also be importat. With

ifecous diseases, diereces i eposure ca occur withi households (e.g. measles), amog closecotacts (e.g. SARS) ad other social etworks (e.g. seually trasmied diseases), i occupaoal risk

groups (e.g. hepas B, Ri Valley fever, Q fever), ad amog travellers (e.g. malaria).


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For vector-bore diseases (see Table 5) ad other zoooses, iformao about the vectors ad their

aimal hosts is eeded to assess eposure. This might iclude the species, distribuo ad desity of

vectors of disease, ad the species, distribuo ad populao desity of aimal hosts. The eposure

assessmet will provide a esmate of the likelihood that a parcular area is vulerable to the

trasmissio of a zoooc disease.

Context assessment

Cotet assessmet is a evaluao of the eviromet i which the evet is takig place. This may

iclude the physical eviromet such as climate, vegetao, lad use (e.g farmig, idustry) ad

water systems ad sources as well as the health of the populao (e.g. utrio, disease burde ad

previous outbreaks), ifrastructure (e.g. trasport liks, health care ad public health ifrastructure),

cultural pracces ad beliefs.

Those who are traied i sciec disciplies, such as medicie, food safety ad veteriary sciece,

ted to approach risk assessmet from a relavely arrow sciec perspecve (e.g. of idefyig the

hazard) ad may ot cosider other factors that aect risk.

Cotet assessmet should cosider all factors social, techical ad sciec, ecoomic,

evirometal, ethical, ad policy ad polical that aect risk. These factors, summarized i the

term STEEEP4, ca aect the level of risk by icreasig or decreasig the likelihood of eposure or its

cosequeces (Appedi 3).

Iformao (see Table 4) that helps to aswer the followig types of quesos is a crical compoetof cotet assessmet.

What are the factors associated with the eviromet, health status, behaviours, social

or cultural pracces, health ifrastructure ad legal ad policy frameworks that icrease a

populaos vulerability?

Do ay factors associated with the eviromet, health status, ad social or cultural pracces

reduce the populaos risk of eposure?

What is the likelihood that all suspect cases ca be ideed?

What is the availability ad acceptability of eecve preveve measures ad of treatmet or

supporve therapies?

4 Some authors epress STEEEP as PEST aalysis (omig the E for evirometal ad for ethical); others add a E for eviromet ad a

L for legal ad speak of PESTLE; while others add a E for ethics to this ad speak of STEEPLE.


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Table 4: Examples of the type of informaon that could be collected during acontext assessment

Source Type of informaon Output from the assessment

Surveillance system number of fucoig

reporg sites i the aected

area

How suspected cases are

ideed

The likelihood that cases will

be ideed

Health-care infrastructure

assessments or reports

The umber, locao ad

quality of health-care

facilies i the aected area

Health-seekig behaviour ithe aected populao

The likelihood that cases will

seek ad receive medical care

that results in good clinical

outcomes

Nutrion surveys from NGO

or government reports

Level of malutrio i the

aected area or amog

specic risk groups

The likelihood of severe

disease

Informaon on animals and

vectors

Iformao o

evirometal codios

that might be favourable

to populao eplosios of

poteal vectors of disease

Iformao o the umber

ad distribuo of poteal

aimal hosts

The likelihood of outbreaks i

humas or aimals


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The vector-bore disease, Japaese ecephalis, has bee used to illustrate possible sources of

iformao for assessmet of the hazard, eposure ad cotet (Table 5). 5

Table 5: Informaon sources used in assessing hazard, exposure and context ofJapanese encephalis

Characterisc being assessed Informaon sources

Hazard assessment

Viral

factors

Geotypes

Neurovirulence

Ageicity

Proliferao

Published literature o research i humas ad aimals

E.g. Database of ucleode sequeces (Gebak)

Referece laboratory data

Clinical

factors

Cliical presetao

Cliical progressioSeverity

Medical records (ICD-105), hospital-based seel surveillace

systems, laboratory surveillace systems

Exposure assessment

Vector

factors

Distribuo, desityad host preferece ofcompetet mosquitovectors

Published data (e.g. etomological surveys), vector cotrolprogramme data (e.g. etomological surveillace systemsicludig mosquito trappig, deteco methods for JE virus ipooled mosquitoes, pescide suscepbility data)

Host

factors

Epidemiology ofifeco ad diseasei humas ad other

mammals (dead-edhosts)

Published research, icludig seroepidemiological studies adoutbreak ivesgaos

Idicator-based ad evet-based surveillace systems i edemic

ad epidemic-proe areas (huma ad aimal)Medical records, hospital-based seel surveillace systems,laboratory surveillace systems

Iteraoal evet-based surveillace systems, icludig themedia aggregators Biocaster, GIDEOn, GPHIn, HealthMap, EMMMediSys, ProMED Mail, RSOE EDIS, amog others.

Surveys of permaet eurological impairmet i edemic areas

Ocial data ad reports from WHO, FAO ad OIE, otherUn agecies, o-govermetal orgaizaos (e.g. PATH),foudaos, charies (e.g. SciDevnet), aoal govermetwebsites of edemic coutries. WHO sites reporg outbreaks

iclude the Disease Outbreak news, Weekly EpidemiologicalRecord ad the password protected Evet Iformao Site forIHR naoal Focal Poits ad ShareGOARn

Parcipatory epidemiology systems

Case reports of illess i returig travellers

Distribuo adsuscepbility ofamplifyig hosts (pigsad aquac birds)

Aquac bird populao, desity ad distribuo ofdomescated ad feral pigs close to huma populaos

Seel pig surveillace data

Suscepbility (age,populao immuity,

vacciao status,proteco from cross-reacg abodies e.g.degue)

Medical records ad chart audits (ICD-105, acute eurologicalsydrome, etc.)

5 hp://www.who.it/classicaos/icd/e/
http://born.nii.ac.jp/http://www.gideononline.com/http://www.phac-aspc.gc.ca/media/nr-rp/2004/2004_gphin-rmispbk-eng.phphttp://healthmap.org/en/http://medusa.jrc.it/medisys/homeedition/en/home.htmlhttp://medusa.jrc.it/medisys/homeedition/en/home.htmlhttp://www.promedmail.org/http://www.who.int/http://www.fao.org/http://www.oie.int/http://www.path.org/about.phphttp://www.scidev.net/en/http://www.who.int/csr/don/en/index.htmlhttp://www.who.int/wer/en/http://www.who.int/wer/en/http://www.who.int/classifications/icd/en/http://www.who.int/classifications/icd/en/http://www.who.int/wer/en/http://www.who.int/wer/en/http://www.who.int/csr/don/en/index.htmlhttp://www.scidev.net/en/http://www.path.org/about.phphttp://www.oie.int/http://www.fao.org/http://www.who.int/http://www.promedmail.org/http://medusa.jrc.it/medisys/homeedition/en/home.htmlhttp://medusa.jrc.it/medisys/homeedition/en/home.htmlhttp://healthmap.org/en/http://www.phac-aspc.gc.ca/media/nr-rp/2004/2004_gphin-rmispbk-eng.phphttp://www.gideononline.com/http://born.nii.ac.jp/


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Characterisc being assessed Informaon sources

CONTEXT ASSESSMENTSocio-

economic

factors

Size of populao atrisk

Agriculture and

livestock maagemet

Vital stascs

Demographic data icludig household icome data (e.g. cesus) access to persoal protecve equipmet to prevet mosquitobites

Maps of populao desity

Ecoomic aalyses of pig farmig i edemic areas

Huma behaviour Surveys ad studies o commuity awareess of Japaeseecephalis virus trasmissio; preveo ad cotrol; culturalpracces regardig pig farmig; acceptability ad uptake of

Japaese ecephalis vacciao etc.Iteraoal trasport (vectors, live pigs)

Ecological

factors

Climate Meteorological data (raifall, temperature, wid)

Modellig data o climate variability, climate chage (e.g. WorldMeteorological Orgaizao)

Mosquito breedig sites Etomological surveys; maps of stadig water sources; towplas, reports o evirometal egieerig cotrols of breedigsites

Remote sesig data of vegetao coverage, e.g. nASA EarthObservatory, Global Observig Systems Iformao Ceter(GOSIC )

Amplifyig bird hosts Mappig data o bird migrao paers, seasoality ad size ofwetlads

Feral pigs Wildlife moitorig systems; data from cullig programmes etc.

Program-

macfactors

Stregth of the healthsystem (access to acutecare services, itesivecare uits, diagosccapacity, surveillacesystems, Japaeseecephalis vacciaoprogramme, vectorcotrol programme,acial ad humaresources,

polical support forcotrol programmesicludig coordiaowith agriculture,livestock ad wildlifesectors etc.)

naoal health idicator data

Roue programmac data, aual reports, programmeevaluao reports etc.

Vacciao coverage data (published ad rapid assessmet,public ad private health-care facility data etc.)

Table 5 contnued
http://www.wmo.int/pages/index_en.htmlhttp://www.wmo.int/pages/index_en.htmlhttp://earthobservatory.nasa.gov/http://earthobservatory.nasa.gov/http://gosic.org/http://gosic.org/http://earthobservatory.nasa.gov/http://earthobservatory.nasa.gov/http://www.wmo.int/pages/index_en.htmlhttp://www.wmo.int/pages/index_en.html


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Risk characterizaon

Oce the risk assessmet team has carried out the hazard, eposure ad cotet assessmets, a level

of risk should be assiged. This process is called risk characterizao. If there is o mathemacal outputfrom a quatave model or compariso with a guidace value (e.g. i food safety risk assessmets),

the process is based o the epert opiio of the team.

A useful tool to assist the team is a risk matri (Figures 3a ad 3b) where esmates of the likelihood

(see Table 6) are combied with esmates of the cosequeces (see Table 7).

As the majority of acute public health evet risk assessmets are qualitave, the categories used i

the matri are ot based o umerical values but o broad descripve deios of likelihood ad

cosequeces (see Tables 6 ad 7 ad the leged for Figures 3a ad 3b, which eplais how to read

the risk matrices).

Whe applyig the matri, the deios of likelihood ad cosequece ca be reed to t with the

aoal or sub-aoal cotet i each coutry.

Two styles of preseg the risk matrices are show i Figures 3a ad 3b. The choice of style of matri

depeds o the teams preferece; both styles serve as a visual tool to smulate discussio ad to help

team members agree o a level of risk.

Durig discussios, team members should cosider all types of cosequeces i addio to the

epected morbidity, mortality, ad direct log-term health cosequeces of the evet (e.g. disability).This icludes cosiderao of the STEEEP cosequeces (Appedi 3).

The risk matri also helps to assess ad documet chages i risk before ad aer cotrol measures

are implemeted. For some evets, where iformao is limited ad whe the overall level of risk is

obvious, the matri may ot be eeded.


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Figure 3a: A risk matrix showing clearly delimited boundaries between categories

Likelihood

Almostcertain

Highly

likely

Likely

Ulikely

Very

ulikely

Miimal Minor Moderate Major Severe

Consequences

Figure 3b: A risk matrix without clearly delimited boundaries between categories

Likelihood

Almost

certain

Highly

likely

Likely

Ulikely

Very

ulikely

Miimal Minor Moderate Major Severe

Consequences


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Table 6: How to read Figures 3a and 3b6

Level of

overall risk

Acons

Low risk Maaged accordig to stadard respose protocols, roue cotrol

programmes ad regulao (e.g. moitorig through roue

surveillace systems)

Moderate risk Roles ad resposibility for the respose must be specied. Specic

moitorig or cotrol measures required (e.g. ehaced surveillace,

addioal vacciao campaigs)

High risk Seior maagemet aeo eeded: there may be a eed to establish

commad ad cotrol structures; a rage of addioal cotrol measures

will be required some of which may have sigicat cosequeces

Very high risk Immediate respose required eve if the evet is reported out of

ormal workig hours. Immediate seior maagemet aeo

eeded (e.g. the commad ad cotrol structure should be established

withi hours); the implemetao of cotrol measures with serious

cosequeces is highly likely

Table 7: Esmates of likelihood denions7

Level DenionAlmost certain Is epected to occur i most circumstaces (e.g. probability of 95% or more)

Highly likely Will probably occur i most circumstaces (e.g. a probability of betwee

70% ad 94%)

Likely Will occur some of the me (e.g. a probability of betwee 30% ad 69%)

Unlikely Could occur some of the me (e.g. a probability of betwee 5% ad 29%)

Very unlikely Could occur uder ecepoal circumstaces (e.g. a probability of less

tha 5%)

6 Adapted from WHO ad FAO.Risk Characterizaon of Microbiological Hazards in Food. Microbiological Risk Assessmet Series 17, World Health

Orgaizao ad Food ad Agriculture Orgaizao, 1999. (hp://www.who.it/foodsafety/publicaos/micro/MRA17.pdf).


Orgaizao ad Food ad Agriculture Orgaizao, 1999. (hp://www.who.it/foodsafety/publicaos/micro/MRA17.pdf).
http://www.who.int/foodsafety/publications/micro/MRA17.pdfhttp://www.who.int/foodsafety/publications/micro/MRA17.pdfhttp://www.who.int/foodsafety/publications/micro/MRA17.pdfhttp://www.who.int/foodsafety/publications/micro/MRA17.pdf


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Table 8: Esmates of consequences denions8

Level Consequences

Minimal Limited impact o the aected populao

Lile disrupo to ormal acvies ad services

Roue resposes are adequate ad there is o eed to implemet addioal

cotrol measures

Few etra costs for authories ad stakeholders

Minor Mior impact for a small populao or at-risk group

Limited disrupo to ormal acvies ad services

A small umber of addioal cotrol measures will be eeded that require

miimal resourcesSome icrease i costs for authories ad stakeholders.

Moderate Moderate impact as a large populao or at-risk group is aected

Moderate disrupo to ormal acvies ad services

Some addioal cotrol measures will be eeded ad some of these require

moderate resources to implemet

Moderate icrease i costs for authories ad stakeholders

Major Major impact for a small populao or at-risk group

Major disrupo to ormal acvies ad services

A large umber of addioal cotrol measures will be eeded ad some of these

require sigicat resources to implemet

Sigicat icrease i costs for authories ad stakeholders

Severe Severe impact for a large populao or at-risk group

Severe disrupo to ormal acvies ad services

A large umber of addioal cotrol measures will be eeded ad most of these

require sigicat resources to implemet

Serious icrease i costs for authories ad stakeholders


Orgaizao ad Food ad Agriculture Orgaizao, 1999. (hp://www.who.it/foodsafety/publicaos/micro/MRA17.pdf
http://www.who.int/foodsafety/publications/micro/MRA17.pdfhttp://www.who.int/foodsafety/publications/micro/MRA17.pdf


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Level of condence in the risk assessment

It is importat to documet the risk assessmet teams level of codece 9 i the assessmet ad the

reasos for ay limitaos. This will deped o the reliability, completeess ad quality of the iformaoused, ad the uderlyig assumpos made with respect to the hazard, eposure ad cotet.

The more evidece there is to iform the hazard, eposure ad cotet assessmets, the greater

codece the team ca have i the results. The degree of codece ca be epressed usig a

descripve scale that rages from very low to very high.

Table 9 shows two scearios that illustrate how levels of codece ca be esmated. Eample A

describes detailed iformao based o a variety of sources, icludig rst-had reports from cliicias,

sources with local kowledge, historical records ad peer-reviewed arcles. A risk assessmet based

o these data would have a medium-to-high codece score. I cotrast, eample B describes aevet reported i a ewspaper arcle that has ot bee cormed by ay other source. Ay risk

assessmet based o this iformao aloe would have a very low or low codece score.

Table 9: Level of condence in two risk assessments

Example A - High level of condence Example B - Low level of condence

Hazard assessmet based o:

a detailed cliical descripo of cases

provided by hospital-based physicias

eological (i.e. causave) agets kow to

have caused similar outbreaks i the previous

two years

surveillance data

Hazard assessmet based o:

a o-specic cliical descripo of cases

reported i ewspaper arcle

o historical data icluded i the report

Eposure assessmet based o:

epidemiological ivesgao of the rapid

respose team

peer-reviewed arcles ad evidece from

previous outbreaks

Eposure assessmet based o:

the likely routes of trasmissio cosistet

with the cliical features reported i the

media report (e.g. food- or water-bore

trasmissio causig a acute disease with

ausea, vomig ad diarrhoea)Cotet assessmet based o:

health-care system performace durig

previous outbreaks

eteral reviews

local sources: detailed iformao from local

leaders ad health authories

Cotet assessmet based o:

the kowledge ad eperiece of a sta

member i the risk assessmet team

9 I some disciplies, the codece (or certaity) of a esmate is described as its reverse: its ucertaity (see glossary of terms i Appedi 2).


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Box 2: Example of risk characterizaon severe respiratory disease

Oe at the start of a series of assessmets, the risk assessmet team will face the type of sceario

outlied i Eample B. The risk assessmet will the rely o the opiio of the team ad the

iterpretao of the limited iformao available.

It should be emphasized that a risk assessmet with very low or low codece does ot idicate

a poor risk assessmet; rather it reects the iformao available whe the risk assessmet was

udertake ad the limitaos of the data. It is importat to iclude the codece level i ay

coclusios ad recommedaos of a risk assessmet (see Bo 2).

Event: A cluster of 22 cases of severe respiratory disease with seve deaths i coutry x were

admied to hospital over the past 17 days. The evet is occurrig 8 km from the border ad

cases have bee reported from three villages by a local health-care worker (HCW). The area is

the poorest i coutry x ad health ifrastructure is limited. May of the health care facilies

charge a cosultao fee ad cosequetly the local populao self-medicates durig mild

illess. There are also strog beliefs that `strage diseases are caused by sorcery.

Risk queson: What is the likelihood of further spread of severe cases of respiratory disease ad

what would be the cosequeces (type ad magitude) to public health if this were to occur?

Informaon used to assess the likelihood of further spread:

cases are sll beig reported 17 days aer the rst kow cases were detected

the specic hazard ad mode(s) of trasmissio have ot bee ideed it is also likely that some cases are ot beig detected (e.g. mild cases are less likely to seek

care from health services ad are therefore ot icluded i the ocial reports).

Therefore it is highly likely that further cases will occur if othig is doe.

Informaon used to assess the consequences of further spread:

the disease has a high case fatality rao (eve whe uder-reporg is take ito accout)

the health-care system is poor ad the ability to treat the cases is already limited; ew

admissios will further stress acute care services ad lead to worse cliical outcomes for

hospitalized paets

egave ecoomic ad social impact of the cases ad deaths i the aected commuies there is poteal for urest i commuies because of cultural beliefs that sorcery is causig

the deaths

the evet is occurrig i a border area ad could aect the eighbourig coutry.

Therefore the cosequeces if further cases occur will be severe.

Usig the risk matri to combie the esmate of the likelihood ad the esmate of

cosequeces leads to a esmate of the overall risk; i this case, the overall level of risk is high.

The codece i the risk assessmet is low-medium.

Although the report is from a local HCW, the iformao is limited ad it is ot clear if the HCW

has eamied the suspect cases or is reporg a rumour.


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Quancaon in risk assessment

The degree of quacao that is possible i a risk assessmet depeds o factors such as the data

available, how quickly the assessmet is required ad the compleity of the issues.

I some disciplies such as egieerig, highly quatave assessmets are feasible. However, i the

assessmet of acute public health evets a qualitave approach may be the oly opo, parcularly

early i a evet whe data are oe limited or uavailable.

Eve with biological risk assessmets that might take much loger (e.g. i iteraoal trade, where

major import risk aalyses usig large muldiscipliary teams might eted over several years), it is

ulikely that reliable quatave data are available for all steps i the risk assessmet. I pracce,

may assessmets use a mi of methods, usig quatave methods whe umerical data are

available ad qualitave methods whe they are ot.

It should be emphasized that a quatave risk assessmet that uses poor data or iappropriate quatave

techiques ca be far less sciec ad defesible tha a well-structured, more qualitave assessmet.

Appedi 4 provides some further iformao o issues related to quacao i risk assessmet.

Cotrol measures

The outcome of a risk assessmet should be used to direct proporoate cotrol measures that reect

the risk. The overall level of risk assiged to the evet helps idefy the urgecy ad etet of the

cotrol measures eeded.

Both risk matrices ca also be used to rak cotrol measures accordig to their eecveess.

For eample, they ca be used to rak the likelihood that a cotrol measure will prevet further

spread or dissemiao of a hazard (see Table 10) ad the cosequeces of applyig each cotrol

measure (see Table 11).

Table 10: The likelihood that a control measure will prevent further spread

Level Denion

Almost certain Is epected to prevet addioal cases i most circumstaces

Highly likely Will probably prevet addioal cases i most circumstaces

Likely Will prevet addioal cases some of the me

Unlikely Could prevet addioal cases some of the me

Very unlikely Could prevet addioal cases uder ecepoal circumstaces


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Table 11: Consequences of implemenng each control measure

Level Denion

Minimal Limited social impact

no ethical cosideraos

no or very lile ecoomic impact

no or very lile polical impact

Minor Mior social impact

Limited ethical cosideraos

Limited ecoomic costs

Some polical impact

Moderate Moderate social impact

Some ethical cosideraos

Moderate ecoomic costs

Moderate polical impact

Major Major social impact

Sigicat ethical cosideraos

Major ecoomic costs

Major polical impact

Severe Severe social impact

Cosiderable ethical cosideraos

Cosiderable ecoomic costs

Severe polical impact

The risk assessmet team should cosider the STEEEP cosequeces of each cotrol measure

(Appedi 3). I doig so, the team should be careful to cosider all aspects of STEEEP ad ot just oe

set of cosequeces (e.g. limig the assessmet to oly the techical ad sciec or biomedical

eects of a cotrol measure).

Assessig the likely eecveess ad cosequeces of cotrol measures helps to esure that they are

appropriate to the risk of harm. This type of assessmet ca help the team covice decisio-makers of

the most appropriate set of cotrol measures ad to assist i decidig o the level of acceptable risk.

Geerally, the cotrol measures that are most likely to prevet spread or reduce adverse health ad

other STEEEP cosequeces ad that have mior to moderate egave cosequeces are the most

acceptable. However, i ecepoal circumstaces where the evet is determied as high risk (i.e.

almost certai to happe with serious cosequeces) ad/or there is a low level of codece (i.e. a

high level of ucertaity) requirig a cauous or precauoary approach, cotrol measures that may

have oly a limited chace of preveg addioal cases or spread of the hazard may be acceptable.


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Risk commuicao

Risk commuicao is a itegral part of the risk maagemet process ad is described i more detail

i Appedi 5. There are two equally importat compoets to risk commuicao:

Operaoal commuicao: The structured commuicao that orgaizaos use to meet

their work goals ad strategic objecves, icludig coordiao iterally ad with people

ad groups outside the orgaizao. Operaoal commuicao occurs betwee the risk

assessmet team ad relevat stakeholders (techical specialists ad policy-makers at the

relevat levels of govermet, other respose agecies, the private sector etc.).

Commuicao with the public: Commuicao to provide key digs from risk assessmets

at regular itervals. Regular commuicao helps to esure that the public is iformed of the

ature ad level of risks ad the desired behavioural chages that ca miimize them.

At the start of the risk assessmet, the team should idefy stakeholders. The commuicao strategy

for each public health evet should be agreed as soo as possible to esure that there is two-way

commuicao betwee the risk maagemet team ad stakeholders.

The strategy should iclude:

how the team will provide regular feedback o the risk assessmet, ad i what format;

clearly deed roles ad resposibilies (e.g. focal poits) for commuicaos fucos;

how ad i what format the iformao should be preseted to stakeholders ad the public.

Moitorig ad evaluao

A risk assessmet should be repeated as ew iformao becomes available. It may also be repeated

o a regular metable (e.g. daily i the early stages of a evet, perhaps drive by a Miister who

agrees to provide a update to other Miisters or to the media at a specic me each day).

Each me a risk assessmet is udertake for a evet it builds o the previous assessmet. Each risk

assessmet (icludig the data ad iformao available at the me it was udertake) should be

documeted. Such documetao is a importat part of moitorig ad evaluao of the process.

Depedig o the size ad compleity of a public health evet, may risk assessmets may be eeded

to address ew ad dieret risk quesos as the evet progresses. For some evets, dieret risk

assessmet teams may be required to work collaboravely to assemble the iformao for a composite

picture of the risk (e.g. cliical severity, trasmissio dyamics, ad cotrol measures).

At the coclusio of the evet, all of the risk assessmets should be formally reviewed. The systemac

aalysis of well-documeted risk assessmets idees where improvemets ca be made i the

maagemet of acute public health evets.


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APPEnDIx 1:

Glossary of terms used i this maualAcceptable risk The level of risk that is tolerated or accepted. Hazards must be moitored

to idefy chages that could icrease the level of risk. Deig acceptable

risk should take ito accout iformed coset ad that acceptability is

likely to vary markedly betwee dieret stakeholders, populaos ad

locaos, ad may be culturally specic.

Acute public

health event

Ay evet that may have egave cosequeces for huma health.

The term icludes evets that have ot yet lead to disease i humas

but have the poteal to cause huma disease through eposure to

ifected or cotamiated food, water, aimals, maufactured products or

eviromets.

Acute public

health risk

The risk of a acute evet resulg i egave cosequeces for public

health.

Alert The rst ocao that a public health evet with adverse cosequeces

may occur or may be occurrig.

All-hazards

approach

A approach to emergecy maagemet that takes ito cosiderao

all possible hazards icludig biological, chemical, ad radiouclear,

hazards ad atural disasters (e.g. res, oods, other etreme weather

evets, volcaic erupos, earthquakes ad tsuamis).

Bias The systemac deviao of results or ifereces that distort the view of

what is actually occurrig.

Condence Codece describes how sure the assessmet team is of a esmate.

It reects what some disciplies call the certaity or ucertaity aroud

a esmate. Eve with perfect iformao (i.e. o ucertaity), atural

variao (variability) sll eists.

Conrmaon The process of seekig evidece to corm the accuracy of iformao.

Also, the coclusio of such a process (i.e. the state whe iformao has

bee veried).Consequences The dowstream eects that result from a aco or codio that may

be egave or posive. A egave public health cosequece causes or

cotributes to ill health. Cosequeces may iclude social, techical ad

sciec, ecoomic, evirometal, ethical, or policy ad polical eects.

Context assessment Assessig the eviromet i which the evet is takig place.

Control measures Iterveos put ito place to reduce the eect of a hazard o the eposed

populao.

Detecon Fidig through systemac meas.

Dierenaldiagnosis

A systemac method for aaiig a diagosis through cosiderao ofhealth ad vital stascs accordig to age, se, or some other factor.


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Event-based

surveillance

The orgaized ad rapid capture of iformao about evets that are a

poteal risk to public health.

Event report A report that systemacally documets the me, perso(s) ad place(icludig cotet) associated with a evet.

Exposure

assessment

The evaluao of the poteal eposures of idividuals ad populaos to

the hazards ideed i the hazard assessmet.

False posive A posive test result i a idividual who does ot have the disease for

which the test was udertake.

Hazard A aget that has poteal to cause adverse health eects i eposed

populaos.

Hazard assessment Idecao of the hazard (or list of poteal hazards) causig the evet

ad of the associated adverse health eects.IHR The Iteraoal Health Regulaos (2005).

IHR Contact Point WHO poits of cotact for commuicao from Member State IHR

naoal Focal Poits.

IHR Naonal

Focal Point

The aoal agecy or istuo desigated to liaise with, ad be

accessible to, WHO ad Member States at all mes for the purposes of

givig eect to the IHR.

IHR reports Reports that are geerated from or to Member States to comply with IHR

for assessmet ad ocao of evets that may costute a public

health emergecy of iteraoal cocer.Indicator-based

surveillance

The roue colleco of pre-deed iformao about diseases10 using

case deios (e.g. weekly surveillace of cases of acute accid paralysis).

There are oe predetermied outbreak thresholds for alert ad respose.

Infecous disease A disease caused by a specic ifecous aget or its toic products that

arises through trasmissio of that aget or its products from a ifected

perso, aimal, or reservoir to a suscepble host.

Likelihood The probability of a evet occurrig.

NGO nogovermetal orgaizao.

Outbreak A epidemic limited to localized icrease i the icidece of a disease.

Public health Health programmes ad services characterized by plaig ad iterveig

for beer health i populaos, icludig uderstadig ad reducig the

risks of disease, disability ad death.

Precauonary

approach

Priciple 15 of the Rio Declarao produced at the Un Coferece o

Eviromet ad Developmet (UnCED 1992) codied the precauoary

approach for the rst me at the global level. This approach idicates that

lack of sciec certaity is o reaso to postpoe aco to avoid poteally

serious or irreversible harm to the eviromet. This priciple has bee

adopted by some other sectors, icludig public health. note that the term is

ot used i other sectors (e.g. import risk aalysis, i which oe may adopt a

cauous or coservave approach but ot a precauoary oe).

10 The term disease is used i its broadest sese, icludig sydromes.


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Reliability The degree of stability of results ehibited whe a measuremet is

repeated uder idecal codios.

Risk The likelihood of the occurrece ad the likely magitude of thecosequeces of a adverse evet durig a specied period.

Risk assessment A systemac process for gatherig, assessig ad documeg iformao

to assig a level of risk. Risk assessmet icludes three compoets

hazard assessmet, eposure assessmet ad cotet assessmet.

Risk communicaon Risk commuicao is the rage of commuicao priciples, acvies

ad echage of iformao required through the preparedess, respose

ad recovery phases of a serious public health evet betwee resposible

authories, parter orgaizaos ad commuies at risk to ecourage

iformed decisio-makig, posive behaviour chage ad the maiteace

of trust.

Risk management The process of weighig policy opos i the light of a risk assessmet ad,

if required, selecg ad implemeg appropriate iterveo opos,

icludig regulatory measures. With respect to acute public health evets,

risk maagemet is the process by which appropriate acos are take to

maage ad reduce the egave cosequeces of acute public health risks.

Risk statement A statemet assigig the level of risk associated with the poteal of a

acute public health evet. This statemet should be accompaied by a

statemet of codece i the level of risk.

Sensivity The proporo of actual posives that are correctly ideed by a test

(e.g. the percetage of sick people who are correctly ideed as havig a

codio).

Syndrome A group of cliical sigs ad symptoms that cosistetly occur together,

or a codio characterized by a set of associated cliical sigs ad

symptoms.

Triage The process of determiig if a evet or alert detected by a surveillace

system is a poteal risk to public health ad priorizig it for aco.

Vulnerability A posio of relave disadvatage. The etet to which a idividual or

populao is uable or ulikely to prevet or respod to hazards.

Zoonosis

(plural: zoonoses)

A disease trasmissible betwee aimals ad humas.


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APPEnDIx 2: Deios used by dieret

sectors ad discipliesTerms used in food safety risk analysis

The Code Alimetarius Commissio (or Code) dees three compoets for food safety risk aalysis

(see gure below):

risk assessmet

risk maagemet

risk commuicao

The three compoets of the Code approach to food safety risk aalysis

Code uses the followig deios of terms i food safety risk aalysis:

Hazard: A biological, chemical or physical aget i, or codio of, food with the poteal to

cause a adverse health eect.

Risk: A fuco of the probability of a adverse health eect ad the severity of that eect,

cosequeal to a hazard (or hazards) i food.

Risk analysis: A process cosisg of three compoets: risk assessmet, risk maagemet, ad

risk commuicao.

Risk assessment: A sciecally based process cosisg of the followig steps: (i)

hazard idecao; (ii) hazard characterizao; (iii) eposure assessmet; ad (iv) risk

characterizao.

Hazard idencaon: The idecao of biological, chemical, ad physical agets capable of

causig adverse health eects ad which may be preset i a parcular food or group of foods.

Hazard characterizaon: The qualitave ad/or quatave evaluao of the ature of the

adverse health eects associated with biological, chemical ad physical agets that may be

preset i food. For chemical agets, a doserespose assessmet should be performed. For

biological or physical agets, a doserespose assessmet should be performed if the data are

obtainable.

Risk communicaon

Risk assessment Risk management


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Exposure assessment: The qualitave ad/or quatave evaluao of the likely itake of biological,

chemical, ad physical agets via food as well as eposures from other sources if relevat.

Risk characterizaon: The qualitave ad/or quatave esmao, icludig aedat

ucertaies, of the probability of occurrece ad severity of kow or poteal adverse

health eects i a give populao based o hazard idecao, hazard characterizao ad

eposure assessmet.

Risk management: The process, disct from risk assessmet, of weighig policy alteraves i

cosultao with all iterested pares, cosiderig risk assessmet ad other factors relevat

for the health proteco of cosumers ad for the promoo of fair trade pracces, ad, if

eeded, selecg appropriate preveo ad cotrol opos.

Risk communicaon: The iteracve echage of iformao ad opiios throughout the

risk aalysis process cocerig hazards ad risks, risk-related factors ad risk percepos,

amog risk assessors, risk maagers, cosumers, idustry, the academic commuity ad other

iterested pares, icludig the eplaao of risk assessmet digs ad the basis of risk

maagemet decisios.

Terms used in import risk analysis

The Terrestrial Aimal Health Code ad the Aquac Aimal Health Code (the Code(s)) of the World

Orgaisao for Aimal Health (OIE) describe four compoets i import risk aalysis (see gure below):

hazard idecao

risk assessmet

risk maagemet

risk commuicao

The four compoets of OIEs approach to import risk aalysis

OIE uses the followig deios of terms i import risk aalysis:

Hazard: Ay pathogeic aget that could produce adverse cosequeces o the importao of

a commodity.

Risk: The likelihood of the occurrece ad the likely magitude of the cosequeces of aadverse evet to aimal or huma health i the imporg coutry durig a specied me

period.

Risk communicaon

Risk assessment Risk managementHazard

idencaon


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Risk analysis: The process composed of hazard idecao, risk assessmet, risk maagemet

ad risk commuicao.

Hazard idencaon: The process of idefyig the pathogeic agets that could poteally be

itroduced i the commodity cosidered for import.

Risk assessment: The evaluao of the likelihood ad the biological ad ecoomic

cosequeces of etry, establishmet or spread of a pathogeic aget withi the territory of a

imporg coutry.

Risk management: The process of idefyig, selecg ad implemeg measures that ca be

applied to reduce the level of risk.

Risk communicaon: Risk commuicao is the iteracve echage of iformao o risk

amog risk assessors, risk maagers ad other iterested pares.

Further reading

Aderso K et al., eds. The Economics of Quaranne and the SPS Agreement. Cetre for Iteraoal

Ecoomic Studies, Adelaide, ad AFFA Biosecurity Australia, Caberra, 2001.

Aven T. Foundaons of Risk Analysis: a knowledge and decision-oriented perspecve. Joh Wiley ad

Sos, Chichester, 2003.

Byrd DM ad Cother RC Introducon to Risk Analysis: A systemac approach to science-based decision

making. Govermet Istutes, Rockville, Marylad, 2000.

Code. Risk Assessment Procedures used by the Codex Alimentarius Commission and its Subsidiary and

Advisory Bodies. Code Alimetarius Commissio, Food ad Agriculture Orgaizao, Geeva, 1993.

Covello VT ad Merkhofer MW. Risk Assessment Methods: approaches for assessing health and

environmental risks, Pleum Press, new York, 1993.

Fly J et al., eds. Risk, Media and Sgma: understanding public challenges to modern science and

technology. Earthsca. Lodo, 2001.

Morga MG ad Herio M. Uncertainty: a guide to dealing with uncertainty in quantave risk and

policy analysis. Cambridge Uiversity Press, Cambridge, 1992.

OIE. Handbook on Import Risk Analysis for Animals and Animal Products. 2nd ed: Introducon and

qualitave risk analysis. World Orgaisao for Aimal Health, Paris, 2010.

OIE. Handbook on Import Risk Analysis for Animals and Animal Products. 2nd ed: Quantave risk

analysis. World Orgaisao for Aimal Health ,Paris, 2010.

OIE. Aquac Animal Health Code (published olie at hp://www.oie.it/iteraoal-stadard-

seg/aquac-code/access-olie/). World Orgaisao for Aimal Health, Paris, 2011.

OIE. Terrestrial Animal Health Code. (published olie at hp://www.oie.it/iteraoal-stadard-

seg/terrestrial-code/access-olie/). World Orgaisao for Aimal Health, Paris, 2011.

Re O, ed. Risk Governance: coping with uncertainty in a complex world. Earthsca. Lodo, 2008.

Robertso D ad Kellow A, eds. Globalizaon and the Environment: risk assessment and the WTO.Edward Elgar, Chelteham, Uited Kigdom, 2001.

Vose DJ. Quantave Risk Analysis: a guide to Monte Carlo modelling , 2d ed. Joh Wiley ad Sos,

Chichester, 2000.


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APPEnDIx 3: Eamples of the STEEEP

cosequeces of a acute public healthevet ad associated cotrol measures

Social

Eects o idividual cases placed i isolao, especially whe hospitalized at a distace from

their commuity

Eects of restricted cotact (e.g. for families visig ifected ad seriously ill paets)

Chages to importat social or religious evets (e.g. social distacig policies)

Impact o lifestyle (e.g. chages to child care arragemets) Acceptability of the cotrol measures by the aected commuity

Social sgma from beig a case of a ifecous disease

Psychological impacts

Technical and scienc

Morbidity, mortality ad log-term disability

Eecveess of cotrol measures

Ability to implemet cotrol measures i a mely maer

Side eects of treatmet or prophylais

Economic

Direct acial costs for the preparedess ad respose agecies

Direct acial costs of the respose acvies for the aected idividual/families/commuies

(e.g. cost of treatmets, health-care fees, loss of domesc ad farmed aimals)

Idirect costs:

eect o idividual ad family ability to work (e.g. closure of schools, home isolao,

hospitalizao)

eect o household icome

eect o the commuity icome eect o aoal ecoomy

The followig should be cosidered at the local, aoal ad iteraoal levels:

eect o travel ad trade

eect o tourism

Environmental

negave eects of cotrol measures o the atural eviromet (e.g. cotamiao or

residues)

Posive eects o the atural eviromet (e.g. simultaeous cotrol of other diseases such as

might occur with vector cotrol)


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Ethical

Idividual liberty (e.g. restricted movemet)

Uiteded cosequeces (e.g. the removal of primary food sources for families whe livestockis culled or cotamiated crops destroyed ad o alterave ca be provided)

Privacy

Proteco of the public from harm

Use of ulicesed or uregistered drugs ad vaccies

Iformed coset (i.e. that people uderstad what they are asked to accept or permit)

Proteco of commuies ad idividuals from sgmazao (i.e. beig regarded as uworthy

or treated with disapproval)

Proporoality (i.e. that cotrol measures correspod to or reect the risk)

Duty to provide care (i.e. a obligao to provide safe, competet ad ethical care to idividualsor populaos)

Equity (i.e. beig fair or imparal)

Trasparecy (i.e. beig ope, obvious or evidet)

Uequal burde of risk (e.g. health-care workers, other rst respoders)

Policy and polical

Views of seior maagemet i a respose or supporg orgaizao (e.g. compability with

other programmes ad policies)11

Diversio of resources from other programmes ad projects to support the respose

Views of the Miister of Health ad other Miisters

Views of Opposio pares

Immiet elecos ad other polically charged situaos

Likely respose of the media ad key stakeholder groups

Govermets uwillig or icapable to respod eecvely (e.g. polical oppressio or armed

coict; provisio of access to care of iterally displaced people or refugees)

IT

11 These are somemes called programmac risks.


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APPEnDIx 4: Quacao i risk assessmet

The degree of quacao used i a risk assessmet depeds o factors such as the iformao

available, how quickly the assessmet is required ad the compleity of the issues.

Some literature implies that there are two methods for risk assessmet: qualitave (usig o or few

umerical data) ad quatave (usig umerical data ad computer modellig). However, eve the

most quatave methods rely o qualitave, subjecve judgemet to formulate models ad esmate

parameters. Equally, eve the most qualitave methods ivolve a orderig of risks ad outcomes that

is quatave i the sese that they reect the rules of the mathemacs of probability ad formal logic.

Structured formal risk assessmet ca use methods ragig from subjecve reasoig based o

descripos of biological systems, to poit-scorig systems, logical rules ad Mote-Carlo simulao.

Risk assessmet ca iclude methods that epress iputs ad results with varyig degrees of umerical

represetao that is, with varyig degrees of quacao.

I some disciplies such as egieerig, highly quatave risk assessmets are widely udertake.

Eve i biological risk assessmets that eted two or more years (e.g. i iteraoal trade, where

major import risk aalyses use large muldiscipliary teams), reliable quatave data are ulikely to

be available for all stages of the assessmet. I pracce, may assessmets employ a mi of methods,

usig more quatave methods whe data are available ad qualitave methods where they are

ot. I acute public health evets a qualitave approach may be the oly opo, parcularly early ia evet whe limited data are available.

Some methods use sesivity aalysis to determie if a parcular parameter for which data are ot

available has a major eect o the overall risk. Such sesivity aalyses oe show that there are oly a

few crical poits i a pathway that have a sigicat eect o the overall risk. If good data are available

o these poits, the aalyst ca be codet that the assessmet is robust. However, if good data are

ot available o these crical poits, the aalyst may use a less quatave approach ul appropriate

research is coducted to obtai the data eeded to udertake a more quatave risk assessmet.

Quatave approaches are ot ecessarily beer tha qualitave approaches. A quatave riskassessmet that uses poor data or iappropriate techiques ca be far less sciec ad defesible

tha a more qualitave assessmet. A well-structured ad mely qualitave assessmet is beer tha

a icomplete ad late aempt at a more quatave approach.

With respect to trade, all degrees of quatificatio are acceptable uder the Agreemet o the

Applicatio of Saitary ad Phytosaitary Measures (the SPS Agreemet), ad the World Trade

Orgaizatio (WTO) recogises the validity of eve the most qualitative risk assessmets whe

they are appropriate to the circumstaces.


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Further reading:

Aderso K et al., eds. The Economics of Quaranne and the SPS Agreement. Cetre for Iteraoal

Ecoomic Studies, Adelaide, ad AFFA Biosecurity Australia, Caberra, 2001.

Aven T. Foundaons of Risk Analysis: a knowledge and decision-oriented perspecve. Joh Wiley ad

Sos, Chichester, 2003.

Byrd DM ad Cother, RC. Introducon to Risk Analysis: A systemac approach to science-based

decision making. Govermet Istutes, Rockville, Marylad, 2000.

Code. Risk Assessment Procedures used by the Codex Alimentarius Commission and its Subsidiary and

Advisory Bodies. Code Alimetarius Commissio, Food ad Agriculture Orgaizao, Geeva, 1993.

Covello, VT ad Merkhofer MW. Risk Assessment Methods: Approaches for assessing health and

environmental risks, Pleum Press, new York, 1993.

Morga MG ad Herio M. Uncertainty: a guide to dealing with uncertainty in quantave risk and

policy analysis. Cambridge Uiversity Press, Cambridge, 1992.

OIE. Internaonal Aquac Animal Health Code (published olie at: hp://www.oie.it/eg/ormes/

fcode/A_summry.htm). World Orgaisao for Aimal Health, Paris, 2003.

OIE. Terrestrial Animal Health Code (published olie at: hp://www.oie.it/eg/ormes/mcode/A_

summry.htm). World Orgaisao for Aimal Health, Paris, 2003.

OIE. Handbook on Import Risk Analysis for Animals and Animal Products, 2d ed. Volume 1: Introducon

and qualitave risk analysis. World Orgaisao for Aimal Health, Paris, 2010.

OIE. Handbook on Import Risk Analysis for Animals and Animal Products. Volume 2: Quantave riskanalysis. World Orgaisao for Aimal Health, Paris, 2004.

Robertso D ad Kellow A, eds. Globalizaon and the Environment: risk assessment and the WTO.

Edward Elgar, Chelteham, Uited Kigdom, 2001.

Vose DJ. Quantave Risk Analysis: a guide to Monte Carlo modelling, 2d ed . Joh Wiley ad Sos,

Chichester, 2000.
http://www.oie.int/eng/normes/fcode/A_summry.htmhttp://www.oie.int/eng/normes/fcode/A_summry.htmhttp://www.oie.int/eng/normes/mcode/A_summry.htmhttp://www.oie.int/eng/normes/mcode/A_summry.htmhttp://www.oie.int/eng/normes/mcode/A_summry.htmhttp://www.oie.int/eng/normes/mcode/A_summry.htmhttp://www.oie.int/eng/normes/fcode/A_summry.htmhttp://www.oie.int/eng/normes/fcode/A_summry.htm


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APPEnDIx 5: Risk commuicao

Risk commuicao is the rage of commuicao priciples, acvies ad echage of iformao

required through the preparedess, respose ad recovery phases of a serious public health evet

betwee resposible authories, parter orgaizaos ad commuies at risk to ecourage iformed

decisio-makig, posive behaviour chage ad the maiteace of trust.

Risk commuicao is oe listed last whe it comes to risk maagemet, which is ot a accurate

reeco of its importace. To be eecve, risk commuicao eeds to be plaed ad iiated early

i a risk assessmet ad to coue as a iterave process throughout all phases of the assessmet. If

this does ot happe, risk assessmet is easily perceived as a process of epert risk assessors advisig

stakeholders of the result of their assessmet ad their proposed maagemet strategies. This top-dow approach implies that commuicao is largely oe-way ad igores the eed for cosultao

throughout the whole process. Poor risk commuicao ca provoke outrage amog stakeholders.

Problems i risk commuicao oe arise because of the diereces i world view betwee

specialists ad the public. These diereces are reected i the sciec ad stascal laguage of

specialists ad the ituive laguage of the public. The approaches are compared i the followig

table (adapted from Powell ad Leiss, 1997)12.

Expert and public assessments of risk

Expert assessment of risk Public assessment of risk

Sciec Ituive

Focused o acceptable risk Focused o safety (o risk)

Chages with ew iformao Teds to be ed

Compares risks Focuses on discrete events

Uses populao averages Focuses o persoal cosequeces

A death is a death It maers how we die

Good risk commuicao seeks to traslate these laguages to achieve cooperave uderstadig

betwee all pares.

12 Powell D ad Leiss W. Mad Cows and Mothers Milk: the perils of poor risk communicaon. McGillQuees Uiversity Press, Motreal, 1997.


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Risk percepon

Percepos of risk by stakeholders ad the public oe alig poorly with those held by epert assessors.

A umber of factors determie idividual ad group percepos of risk. For eample, aalysis hasshow that hazards perceived as ufamiliar or which provoke dread are assiged a higher risk tha ca

be demostrated stascally. Hazards with a low probability, which are regarded as havig poteally

catastrophic eects, are perceived as high risk ad provoke strog public demads for govermet

regulao ad proteco. Eamples iclude a uclear accidet or the itroduco of a ufamiliar

disease that might be a zooosis (e.g. ebola or ipah viruses), or the itroduco of a kow disease

that might decimate ave species. Risk assessors eed to take accout of these reacos i their

commuicaos with stakeholders ad uderstad what provokes the feeligs of these groups.

Eve whe good iformao is available o a hazard (i.e. where it is familiar), the degree of trust

give to the source of that iformao iueces the percepo of the risk. For eample, surveys

show that the public trust iformao from evirometal groups or cosumer orgaizaos much

more tha that from govermet sources (ad eperts). Similarly, iformao provided by the media

is trusted more tha ocial govermet statemets.

Lessons for good risk communicaon

The results of poor risk commuicao have bee documeted i a umber of case studies such

as the epidemic of bovie spogiform ecephalopathy (BSE or mad cow disease). Risk assessors,

parcularly those workig o highly techical risk assessmets, ted to focus o techical details.

They may therefore be surprised to d their dedicated work o a risk assessmet ad

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