GRF One Health Summit 2012, Davos: Presentation by Ruth COX, UPEI, Canada

1. The use of expert opinion to assess the
emergence or re-emergence of
infectious diseases associated with
climate change in Canada
Ruth Cox
Javier Sanchez
Crawford Revie
Public Health Agency of Canada

2. Background - Climate change in Canada
• Policy makers need to be able to
devise a list of diseases likely to
emerge (or re-emerge) in Canada as a Temperature changes in
result of climate change. Canada 1950 - 2004
Reproduced from: Integrating climate change in invasive species risk assessment/risk management.
Workshop report, November 2008. PRI Project: Sustainable management. (www. Policyresearch.gc.ca).

3. Aim
• Design a Multi Criteria Decision Analysis (MCDA) tool
that can be used for disease prioritisation.

4. Summary
• Collection of expert opinion
• Development of MCDA tools
– Excel spreadsheet
– ‘MACBETH’

5. Expert opinion - Method
• Criteria selection
– Literature
– Other prioritisation studies
– Suggestions from stakeholders
e.g. PHAC, UPEI
– Discussion with experts
e.g. 2010 Zoonoses and climate change conference

6. Expert opinion - Method
• Final list of 40 criteria
– Disease epidemiology
– Ability to monitor, treat and control disease
– Influence of climate
Vector borne, food or water borne, air borne,
direct/indirect contact diseases.
– Burden of disease
– Economic, environmental and social impact
6

7. Questionnaire – part 1
?

8. Questionnaire – part 2

9. Expert opinion - Method

10. Expert opinion - Results
Affiliation Invited to contribute Completed questionnaire
Part 1 Part 2
Criteria Measurement
scale
Government 39 19 18
Provincial government 22 14 9
Academic 50 27 17
Academic + government 4 1 1
Independent 6 3 2
Total 121 64 47

11. Expert opinion – Results part 1
• Top 5 criteria: Potential economic impact (e.g. cost to industry for control,
health care, travel restrictions)
– Potential economic impact 40
35
–
Number of responses
Severity of disease in the general human population 30
25
– Human case fatality rate 20
15
– Type of climate that the pathogen can tolerate 10
5
– Current climatic conditions in Canada 0
Don't know Not Quite Important Very Extremely
important important important important
Response
• Top 5 climate criteria:
– Current climatic conditions in Canada Climatic conditions in Canada
– An annual increase in temperature in Canada 40
35
– An increase in summer precipitation in Canada
Number of responses
30
25
– An increase in summer temperature in Canada 20
15
– An increase in winter temperature in Canada 10
5
0
Don't know Not likely Quite likely Likely Very likely Extremely
likely
Response
11

12. Excel spreadsheet tool
12

13. Excel spreadsheet tool - Design
13

14. Excel spreadsheet tool - Design
Criteria weighting
E1 Potential economic impact
30
25
No. responses
20
15
10
5
0
Don't know Not Quite Important Very Extremely
important important important important
Response

15. Excel spreadsheet tool - Design
Criteria weighting
E1 Potential economic impact
40
35
Number of responses
30
25
20
15
10
5
0
-5 0 0.2 0.4 0.6 0.8 1
Response
E1 Potential economic impact
30
25
No. responses
20
15
10
5
0
Don't know Not Quite Important Very Extremely
important important important important
Response

16. Excel spreadsheet tool - Results
Total score calculated in the spreadsheet model for 10 diseases
14
12
10 Economic and social impact
8
Burden of disease
6
Influence of climate change in
4 Canada
2 Ability to monitor, treat and
control disease in Canada
0 Disease epidemiology

17. Excel spreadsheet tool - Results
Total score calculated in the spreadsheet model for 10 diseases
14
12
10 Economic and social impact
8
Burden of disease
6
Influence of climate change in
4 Canada
2 Ability to monitor, treat and
control disease in Canada
0 Disease epidemiology

18. ‘MACBETH’ model

19. ‘MACBETH’ model - Design
‘Measuring Attractiveness by a
Categorical Based Evaluation
Technique’
www.m-macbeth.com/en/m-home.html
Main view
Value tree

20. ‘MACBETH’ model - Results

21. ‘MACBETH’ model - Results
West Nile virus / Cholera
Influence of climate Impact
21

22. Excel spreadsheet tool - Results
Influence of climate change in Canada
2
1.5
Mean score
1
0.5
0
Disease

23. Added value created by applying a
One Health approach
– MCDA tools offer a standardised method of prioritising pathogens
– They consider expert opinion combined with quantitative data and
published literature
– They are adaptable to user speciality
– They consider a range of opinions and priorities

24. Acknowledgements
Nick Ogden
Alex Demarsh
John VanLeeuwen
Matthew Baylis
Helen Roberts
Anonymous experts

25. 25

26. The use of expert opinion to assess the
risk of emergence or re-emergence of
infectious diseases associated with
climate change in Canada
Ruth Cox
Javier Sanchez
Crawford Revie
Public Health Agency of Canada

27. Pathogen Mode of transmission Taxonomic Endemic Zoonotic? Notifiable in Influenced by
group ? (Yes/No) Canada? climate?
(Yes/No) (Y/N or R = (Yes/No)
reportable,
Bluetongue Vector borne Virus N N Y or R – type Y
Blue tongue virus dependent
Chagas Disease Vector borne Protozoan N Y Y (immediately) Y
Trypanosoma cruzi
Chikungunya Vector borne Virus N Y N Y
Chikungunya virus
Cholera Water borne Bacteria N Y Y Y
Vibrio cholerae (immediately)
Coccidioidomycosis Air borne Fungus N N Y Y
Coccidiosis imitis (annually)
Foot and Mouth Disease Direct Virus N Rarely R N
Foot and Mouth disease
virus
Giardiasis Food/water borne Protozoan Y Y Y Y
Giardia lamblia
Hantavirus Pulmonary Direct/indirect contact. Virus Y (v. Y Y Y
Syndrome Air borne. Rare)
Sin Nombre virus
Lyme Disease Vector borne Bacteria Y Y N Y
Borrelia spp.
West Nile Virus Vector borne Virus Y Y Y Y
West Nile virus

28. Expert opinion - Results
• Suggestions for additional criteria:
• Notifiable status of the disease in Canada at the provincial, territorial or federal level.
• Impact on animal welfare, public health, international trade, food security of First Nations.
• Likely incidence of disease in wild animals.
• Potential socioeconomic and demographic changes of populations.
• Additional climatic factors: number of frost free days, humidity, prevailing wind conditions,
climatic patterns over time.
28

29. Excel spreadsheet tool - Design
Mode of transmission
Vectorborne Waterborne
40
40
35
35
No. Experts
30
No. Experts
30
25
25
20
20
15
15
10
10
5
5
0
0
0 1 2 3 4 5
0 1 2 3 4 5
Rank
Rank
Foodborne Airborne Direct/ indirect contact
40 40 transmission
35 35
40
No experts
No. Experts
No. Experts
30 30 35
25 25 30
20 20 25
15 15 20
15
10 10
10
5 5 5
0 0 0
0 1 2 3 4 5 0 1 2 3 4 5 0 1 2 3 4 5
Rank Rank Rank
29

30. Excel spreadsheet tool - Design
Taxonomic group
Helminths Bacteria
16 16
14 14
No. Experts
No. Experts
12 12
10 10
8 8
6 6
4 4
2 2
0 0
1 2 3 4 5 1 2 3 4 5
Rank Rank
Viruses Protozoa Fungi
16 16 16
14 14 14
No. Exerts
No. Experts
No. Experts
12 12 12
10 10 10
8 8 8
6 6 6
4 4 4
2 2 2
0 0 0
1 2 3 4 5 1 2 3 4 5 1 2 3 4 5
Rank Rank Rank
30

31. ‘MACBETH’ model - Results
West Nile Virus profile
Influence of climate Impact
31

32. ‘MACBETH’ model - Results