Priority setting of emerging zoonoses

1. Priority setting of emerging zoonoses Marieta Braks, Ph.D. and Prof. A. Havelaar, M. Toutenel and F. van Rosse Laboratory for Zoonoses and Environmental Microbiology RIVM, the Netherlands Discontools, Brussels 20 October 2008

2. Contents • Emerging zoonoses • Priority setting • Priority setting of emerging zoonoses

3. From infectious diseases to emerging zoonoses List of 1415 infectious pathogens for humans • 217 Viruses • 538 Bacteriae and Rickettsiae • 307 Fungi • 66 Protozoa • 287 Helminths 863 (61%) are zoonotic, 175 emerging pathogens and of these 75% are zoonotic • (Taylor et al, Phil.Trans. R. Soc. London B. Biol. 2001)

4. Priority setting • Too much to study all in detail, choices are necessary • “Comparing risks is not impossible or immoral, but it is very difficult --more so than either supporters or detractors of the practice seem to realize” Adam Finkel, Comparing Risks Thoughtfully

5. Priority setting, choices • Multi-dimensional problem • Technical information ánd value judgements • Interaction between researchers and policy makers c.q. general population • One time or continuous? • Simplicity vs. precision • Transparancy and information management

6. Priority setting, possibilities • Consensus • Simple but not very transpare • Poor repeatability • Semi-quantitative • Transparant but arbitrary • Better repeatability • Quantitative • Transparant and objective • Knowledge management

7. Approach to priority setting EmZoo • Selecting agents • Literature and expertise consortium • Establishing criteria (risk aspects) • Limited number • Expressed in natural units • Consortium with steering committee • Operationalising criteria • 4-5 classes (point estimate and range) • Evaluation of all agents: simple decision rules; current situation • Consortium • Weighing criteria • Panel session with policy makers • Ranking of hypothetical zoonoses according to perceived threat • Data analysis and reporting • Information management system • Improve data • Update information • Scenario analysis

8. Criteria • Probability of introduction • Spread in animal reservoir • Economic costs, animals • Transfer from animals to man • Spread in human reservoir • Severity of human illness • Case-fatality ratio human • Economic costs, human • Perception

9. Semi-quantitative approach

10. Operationalising criteria:economic costs ANIMAL • 4 classes, decision rules • Low: no illness in Dutch animal husbandry, or control is possible at farm level • Average: illness is possible in Dutch animal husbandry and control at regional level • High: illness is possible in Dutch animal husbandry and control at national level • Very high: illness is possible in Dutch animal husbandry and export is reduced for more than ½ year • Quantification • Low: < 10 M€ per year, point estimate 5 M€ pyr • Avergae: 10 – 100 M€ per year, point estimate 50 M€ pyr • High: 100 – 1000 M€ per year, point estimate 500 M€ pyr • Very high: > 1000 M€ per year, point estimate 5000 M€ pyr

11. Panel session • Obtain information for weighing criteria • Weights reflect policy choices of the Dutch government • Ranking of hypothetical zoonoses • 6 sets van 7 zoonoses and 1 trainings set • Arrange from least to most threatening • Individual judgement • Written repetition after 2 weeks (2 sets of 7)

12. Quantitative approach

13. Semi-quantitative vs quantitative approach

14. Results quantitative approach

15. Overall conclusions • Priority setting is a multidimensional problem • Ranking depends on the criterium used • A quantitative and systematic approach is necessary • Current data are not complete, but data needs can be prioritised • Method is currently being validated and optimalised • International collaboration will speed up the process