Integrated Assessment of Emerging Zoonotic Diseases

Integrated Assessment of

Emerging Zoonotic Diseases

Presented at: CFIAPHAC Joint Workshop on Integrated Analysis of non-Foodborne Zoonotic Risk

January 12th 2010

Hadi Dowlatabadi

Jan 12th 2010, Ottawa 2

Overview

• What is an IA?

• A process for creating one

• Examples

• Next steps


The Whole & its Parts

• When the world around us gets too complicated “as a whole” we try to divide it up into sensible “parts”.

– This helps us understand details of parts better.

– But it also encourages working only within boundaries. Losing sight of issues that could cross one or many boundaries.

• IA is about understanding the whole of a cross-cutting issue boundaries will be crossed.


A definition of IA

• Bridging the gap between social and natural sciences and communication of key issues with stakeholders and decision-makers.

• The goal here is to coordinate horizon scanning activities of agencies serving different stakeholders to maximize successful risk management.

Col

lect

ive

deci

sion

-mak

ing

Agency

Limited detection

Imperfect knowledge

Values that change with contexts/time

Blunt mechanisms for realizing goals

...we perceive changes in our system,

... identify their origin & project trends/consequences,

...evaluate various options,

...implement achosen strategy,

Evaluation & Feedback

Human


Applications of IA

• 70s & 80s

– SST, CFCs, Acid Rain

• 90s

– Climate change

– Cryptosporidiosis

– Dengue

• 00s

– Hydatid disease in Katmandu

– Malaria in various regions of the world


IA of Climate Change• Demographics

• Economics

• Social dynamics

• Land use

• Emissions

• Atmospheric physics and Chemistry (GHGs and aerosols)

• Cloud physics

• Climatology• Volcanology

• Solar system physics

• Oceanography

• Hydrology

• Coastal zone dynamics

• Ecosystem dynamics

• Agriculture and forestry

• Zoonotic and other environmental diseases

• Human security

• Insurance

• Law

• Politics

• Psychology

• Ethics

• Other drivers of global change

• Demographics

• Economics• Social dynamics

• Land use

• Emissions


• Cloud physics

• Climatology

• Volcanology


• Oceanography

• Hydrology





• Human security

• Insurance

• Law

• Politics

• Psychology

• Ethics



IA of Climate ChangeEQUAL EMPHASIS• Demographics

• Economics

• Social dynamics

• Land use

• Emissions


• Cloud physics

• Climatology

• Volcanology


• Oceanography

• Hydrology





• Human security

• Insurance

• Law

• Politics

• Psychology

• Ethics


RELEVANCE to CC DECISIONs• Demographics

• Economics• Social dynamics

• Land use

• Emissions• Atmospheric physics and Chemistry (GHGs and aerosols)

• Cloud physics

• Climatology• Volcanology


• Oceanography

• Hydrology• Coastal zone dynamics

• Ecosystem dynamics• Agriculture and forestry• Zoonotic and other environmental diseases

• Human security

• Insurance• Law

• Politics

• Psychology • Ethics• Other drivers of global change

1) IA can be used to focus effort according to its relevance to the decisions being contemplated


But what is the Objective?

• Protect the world from the potential adverse effects of climate change.

• To improve our lot without harming the welfare of current and future generations+.

+ All beings

2) IA can highlight inadequacies in the scope of the initial decision space…


“Protect Human & Animal Welfare”

• Under this general rubric the various agencies have been formed and charged with dealing with various aspects of this challenge each with their own sub-objectives…*

• Is the new objective boundary set appropriately?

– Pathways, geography, interaction effects, timeline...

– Are all aspects of the objective covered?

– Are there pitfalls in leaving out food-borne diseases?

– How will we solve the “patent office” problem?

Genesis

• Where would new zoonotic diseases emerge?

– Where might they appear?

– Where would be the selection pressure make the emergent novelty relevant as a risk?

– What are the key dynamics of the processes?

– Where else might one be looking for possible emergence?


IA is a More Realistic Ætiology & Response

• Inherent in an idealized system are assumptions that:

– Detection is not being influenced by other factors

– Attributions are not being based on weak causality

– Impact assessment are not being dominated by interest groups

– Program implementation involves resource allocation beyond media sound-bites.

– Program evaluations will be real and use the findings to improve our understanding of how to achieve and refine our objectives more effectively.*


The A2C2FHIP Objective

• Much like the UK’s Human Animal Infections and Risk Surveillance (HAIRS) Group…

– … to identify and assess infections with potential for interspecies transfer (particularly zoonotic infections).

Detection in water

Boil water

advisory

Extreme events & Cryptosporidiosis

Climate change?

Torrential rain Overwhel

ms sewage system Crypto-

in water supply

Epidemic

Indirect alert

Revise sewage handling

Understand what

happened

Reconsider land

use patterns

R&D for better

detection

day 1 day 2 day 3 day 4 day 5 day 6week 2year 2year 20

Detection in water

Detection in

patients

Boil water

advisory


It will take all the

relevant bodies

• We can only succeed in meeting such objectives by crossing institutional boundaries.

• And one entity needs to be responsible and resourced to take the lead position.*


A Value of Information Approach

• What is the value of the objective being met?

• What do we need to know to make the next decision?

– Which information is critical?

– Can that information be gained in time to inform the next decision in a timely fashion?

• Elimination of uncertainty is not a pre-requisite for action.

• Knowledge beyond that needed to make a decision has no additional value for this function.


China is likely the Origin of

the Next Pandemic Flu• They believe once the virus has been

identified, they can quarantine large tracts of their territory

– Therefore, they argue: we need to invest in fast DNA sequencing.

– Meanwhile, they have replaced rural “barefoot doctors” with a fee-for-service healthcare/vet system


Intelligence Gathering

• What factors influence our capacity to collect information?

– Economics of animal husbandry

– Access to insurance

– Technological change

• in detection

• In information management

• …


Timely & Informed Decisions

• Why accept the notion that Canadian cattle will not suffer?

– Why delay the ban on intra/inter-species feed?

• Current know-how shows prions can only be destroyed above 800 C.

– A temperature that cannot be reached except in the largest incinerators? Why allow burial of SRM?

– What are we to do about small scale operations?

– What do consumers expect?


Public Perceptions & Reactions

• The public react to fear from their perceptions of exposure to hazards.

• Communication and engagement is critical to empowering the public to help us better manage risks.

– Dengue in Cuba

– WNv in Canada

• Loss of public trust is extra-ordinarily costly in the long run.


Inaction & Precaution

• Precaution, rational action and delay all have economic and ethical consequences.

– These are asymmetric in magnitude.

– and have very different longevity of effect.

– And need to be assessed in the context of the grand objective of public and animal welfare.*


Philosophy (research)• Understand the range of possible policy solutions before designing

how to research the problem.

– The space of possible solutions defines where effort at learning will have the highest value.

– From an applied science perspective, there is no payoff to knowledge that has no bearing on the best informed policy/ solution.

• Eschew needless detail.

– Uncertainties can wash over details. If so, the details are a false precision and generate a misplaced sense of confidence in state of knowledge.

• Characterize uncertainties in:

– how the processes may be working;

– how to parameterize them;

– what we value.


Philosophy (management)

• Bring all relevant parties into the tent.

• Assign resources and control in ONE lead entity.

• Understand how concerns of stakeholders influence institutional responses.

• Use the framework to prioritize research and allocate resources according to where additional knowledge would be most valuable.

• Be honest and open about what can and cannot be known and acted upon under the current mandate/resource constraints.


Next Steps• Clarify the objective

– Use a value of information approach for budget allocation

– Define the lead and respect all participants

– Define criteria for “triggering observations”

– Define the steps for processing observations into information critical to the decision process.*

– Evaluate the program

• Iterate steps above, including the articulation of objective and refine as needed

Questions/Discussion

Other stuff


Cryptosporidiosis as an emerging disease

1907 Discovered in mice and named

1955 Recognized as a disease agent in turkeys

1971 Recognized as a disease agent in cattle

1972 Identified in humans

1984-94 Series of large waterborne outbreaks in

the US


Outbreaks of Waterborne

Cryptosporidiosis in the US Cases Presumptive Cause Filtered?

1984 2,000 sewage in chlorinated well water no

1987 13,000 water treatment interruption yes

1992 3,000 inadequate filtration yes

1992 550 surface water contamination of spring no

1993 403,000 problems with new coagulant yes

1994 100 all HIV+, no malfunction yes

1994 130 sewage in untreated well water no


Influence Diagram

Summarizes the current state of knowledge concerning the important scientific, engineering, institutional, and behavioral factors and their interactions relevant to the risk and its management.

Jan 12th 2010, Ottawa 30Top Level Diagram: Awareness, Communication, and Behavior

Routine testing water

type

routine testing type

treatment levels

treatment options

index variables for tables

Routine testing results

Utility awareness

Health Department awareness

Media coverage

Consumer awareness for public systems

Tap test

Medical Awareness

Trigger Event

Well test

Consumer awareness for private

wells

Utility Communique

Utility treatment

options

Consumption of well water

Consumption of treated water

Averting behavior for public

systems

Averting behavior

for private wells

Special studies

Joint task force

Health EffectsContamination of Drinking Water

timestep = 1 week

Info sources

-


Government enforcement

actions

Source of Cryptosporidium

Present in surface water

Present in utility intake

Present in ground water

Present in private wells

Access to ground water

Subsurface attenuation

Well vulnerability

Present in finished water

Distribution system

contamination

Present at tap

Source water type

timestep = 1 week

-

Contamination of Drinking Water Module


Proportion on Public

System

Epidemic Morbidity

Proportion HIV+

Secondary Transmission

Herd Immunity

Endemic rate HIV -

Endemic rate HIV+

Total Endemicity

Other Sources

timestep = 1 week

Mortality

-

Health Effects Module


Foodborne Recreational Water

prepared foods and meat

fresh fruits, vegetablesand drinks

lakes, ponds rivers, streams

swimming pools, beaches

irrigation water

wash water

handler feces

Outbreaks caused by Other Factors

Person to Person and

Zoonotic

Hospital and Nursing Home

Day Care

swimmers exposed

eatersexposedpeople

exposed

Animal Contact

Sexual contact

-

Other Sources Module


Routine testing water

type

routine testing type

treatment levels

treatment options

index variables for tables

Routine testing results

Utility awareness

Health Department awareness

Media coverage

Consumer awareness for public systems

Tap test

Medical Awareness

Trigger Event

Well test

Consumer awareness for private

wells

Utility Communique

Utility treatment

options

Consumption of well water

Consumption of treated water

Averting behavior for public

systems

Averting behavior

for private wells

Special studies

Joint task force

Health EffectsContamination of Drinking Water

timestep = 1 week

-

Table 3. Influence Diagram “Awareness” Variables Va lues, Base CaseVariable Range Week 1 Week 2 Week 3 Week 4 Week 5 Week 6

Utility Awareness 0 to 5 0 1 1 4 5 4

Medical Awareness 0 to 2 0 1 2 2 1 1

Health Department Awareness 0 to 2 0 0 1 2 2 2

Media Coverage 0 to 2 0 0 0 2 2 2

Consumer Awareness 0 to 2 0 0 0 2 2 2


Information Collection Rule of 1996

• Purpose: To provide the information necessary for the development of the final form of the Cryptosporidium rules

• Mandates collection and reporting of monitoring data by water suppliers serving more than 100,000 customers


What is so unusual and elusive about Cryptosporidium that requires a 6-year data collection program before the finalization of drinking water standards?


The data stink• Environmental Screening:

– Before Information Collection Rule, no mandated sampling of drinking water

– Recovery of Indirect Fluorescent Assay (IFA) 5 to 25%

• Medical Surveillance:

– Same symptoms as other GI disorders

– 75% doctors never order crypto tests

– 30% thought they were included in ova & parasite tests (Morin, 1997)

– Detection limit 5,000 oocysts/gm stool

– Not all infected individuals shed oocysts. In those who do, shedding is sporadic.

– Mild cases do not get treated or reported

– 3 cases in 10,000 get reported (Perz, 1998)


Detection

• Small concentrations of Cryptosporidium are likely to be found in many source waters.

• How should utilities report this information to avoid misunderstandings?

• How to communicate risk and uncertainty while maintaining customer confidence?

• How can the utility be sure customers understand the information?


Mental Models Methodology

• Depicts an individual’s beliefs regarding a risk process and the options for addressing the risk

• Identifies crucial gaps in information and misunderstandings by contrasting the mental model with an expert model


Expert Model

• Is constructed using an extensive literature review.

• Then refined through feedback from microbiologists, engineers, and utility personnel.


An IA for the Arctic


Methodology• Use anything that helps improve understanding of the issues

and address the concerns of different stakeholders.

• But remember that integration does not mean that one can cobble together any and all disciplinary insights.

– Disciplines have been constructed through restrictive assumptions isolating the processes of interest from outside influences.

– Integration is about how these “seemingly independent” processes influence one another.

– Therefore, some of the received doctrine from disciplines will have to be ditched in order to develop coherent integrated assessments.


Motivation

• Real world problems are often complex because they involve:

many different stakeholders with competing agendas;

interacting socio-economic, environmental & other issues;

a range of space and time scales.

• Disciplinary solutions are not helpful because they tend to:

o address only one dimension of stakeholder needs;

o reflect only one aspect of the dynamic processes involved;

o focus on one scale or time step.


BSE & vCJD in the UK

Sources: (Collinge, 1999; DEFRA, 2005; EC 96/362, 1996; SEAC, 1996)

SRM removal

UK BSE/vCJD Profile

-

10,000

20,000

30,000

40,000

1987 1992 1997 2002Year

Incidence of BSE

0

10

20

30

40

Incidence of vCJD

Confirmed Cases of BSE

Confirmed Cases of vCJD

Inter-species Feed Ban

Export Ban

Intra-species Feed Ban

SRM removal


CDN Risk ManagementCDN BSE/vCJD Profile

0

1

2

3

4

1988 1993 1998 2003Date

Incidence of BSE

Confirmed Casesof BSE

UK Import BanUK Import Ban

Intra-species feed ban

BSEBSE

Blended Export Ban Blended Export Ban

SRM removalSRM removal

Source: CFIA, 2005Source: CFIA, 2005


BSE

UK:

– Exp. Loss 3.5B

– Compensation 19%

Canada:

– Exp. Loss, 3.1B

– Compensation 20%

Integrated Assessment of Emerging Zoonotic Diseases

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