Drivers in action: Horizon scanning for
emergence of new viruses in animal
health and public health
Dr Paul Gale
APHA, Weybridge, UK
Overview of this talk
• Define “horizon-scanning”
• Complex scenarios and combinations of events
• Spidergrams revisited
• Identifying “Unknowns”
• The Internet and approaches in other fields
• Closing thoughts: it’s all about getting the right experts talking
Horizon scanning for viruses
• What’s the next virus?
– Public health, Animal health, or both
• Is that virus even in the text books?
• Schmallenberg virus, November 2011
• What are its routes and from where?
• But was it in South Africa in 2006 – a weak signal missed?
Horizon scanning for viruses against a background of
change
• The world is changing – Political
– Economic
– Deforestation
– Fragmentation of landscape
– Globalisation
– Farming practice – intensity, breeds, feed
– Wildlife behaviour
– Climate
• The virus is changing – RNA viruses mutate rapidly and many are segmented
– Single amino acid changes in envelope protein affects vector specificity
Horizon scanning for emergence of new viruses - looking
for change
• Present - Short term – Disease monitoring
• Future – Medium to long term – Understanding the drivers and pathways
– Combinations of events
– How the world is likely to change – new routes, hosts and interactions
• Internet – Find out what people are doing – chat rooms, twitter
Prediction is difficult because of
complex scenarios for zoonotic and epizootic viruses
• Complex scenarios
– Anti-inflammatory drug give increase in rabies cases
• Drug use in cattle
• Vultures eat cattle carcasses and die from drug
• Cattle carcasses pile up
• Feral dogs increase
□ Dog bites and rabies cases increase
– WNV and swimming pools
• Increase in number of houses with swimming pools in boom
• House repossessions in economic crash
• Stagnant swimming pools become mosquito breeding sites
• Increase in vector for WNV
• Obvious afterwards
• Why didn’t I think of that? – before it happened
• How can we go about generating these complex scenarios?
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Retreat Advance
Map provided by
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Developing complex scenarios comes through
talking to experts in different fields
Glacier
Land – rat free
Land – rat infested Impact – ground nesting birds
Constructing spidergrams: Examples of factors
• Zoological – Increase in rodents
– Decline in amphibians
– Increase in mosquitoes
– Increase in insectivorous birds
– Fall in wildlife biodiversity
– Fall in dragonfly abundance
– Increase in ecotoparasites (ticks)
– Increase in insects
– Collapse of a scavenger species
• Farming practice and husbandry – Change in breeds
– Intensity of farming
– Expansion of livestock farming into new habitats
– Mixing of sheep and cattle
– Failure of livestock carcass disposal
• Sustainability – More households with livestock
– Wood taken from copses for burning
– More allotments
• Environmental and climatic – Flooding
– Warmer soil temperature
• Land use – Loss of ponds and marshes
– Fragmentation of landscapes
– Deforestation
Ecological □ Increase in feral dogs
□ Increase in vector breeding sites
□ Exposure of pigs to bat
Socio-economic /Anthropogenic
□ Generation of stagnant water bodies
(swimming pools, poor plumbing, temporary
water storage)
□ Increase in wind turbines
□ Veterinary drugs and pesticides
□ Increased globalisation and transport
□ Failure of drinking water treatment and
sewage treatment
□ Failure of power supplies
□ Property maintenance
□ Eating more vegetables
Generation of 1,000s of complex scenarios
• Start with one from anthropogenic or environmental
• By systematically taking one from each category and
combining with one from the next category and so on…….
• Will most be meaningless?
• Will some give insights?
Anthropogenic
Increase in wind turbines
Farming practice and husbandry
Change in breeds Ecological
Increase in feral
dogs
Anthropogenic
Veterinary drugs and pesticides
(Diclofenac)
Farming practice and husbandry
Failure of livestock carcass disposal
Zoological
Collapse of a scavenger species
Ecological
Increase in feral
dogs
Some do make sense
Use your knowledge and expertise - Or randomly select? • Zoological
– Increase in rodents
– Increase in insectivorous birds
– Decline in amphibians
– Increase in mosquitoes
– Fall in wildlife biodiversity
– Fall in dragonfly abundance
– Increase in ecotoparasites (ticks)
– Increase in insects
– Collapse of a scavenger species
• Farming practice and husbandry – Change in breeds
– Intensity of farming
– Expansion of livestock farming into new habitats
– Mixing of sheep and cattle
– Failure of livestock carcass disposal
• Sustainability – More households with livestock
– Wood taken from copses for burning
– More allotments
• Environmental and climatic – Flooding
– Warmer soil temperature
• Land use – Loss of ponds and marshes
– Fragmentation of landscapes
– Deforestation
Ecological □ Increase in feral dogs
□ Increase in vector breeding sites
□ Exposure of pigs to bat
Anthropogenic/ Socio-economic
□ Generation of stagnant water bodies
(swimming pools, poor plumbing, temporary
water storage)
□ Increase in wind turbines
□ Veterinary drugs and pesticides
□ Increased globalisation and transport
□ Failure of drinking water treatment and
sewage treatment
□ Failure of power supplies
□ Property maintenance
□ Eating more vegetables
Constructing a spidergram
Collapse of a scavenger species
Failure of livestock carcass disposal
Increase in feral dogs
Dog bites and rabies
Veterinary drugs and pesticides
Branches and extensions • Zoological
– Increase in rodents
– Increase in insectivorous birds
– Decline in amphibians
– Increase in mosquitoes
– Fall in wildlife biodiversity
– Fall in dragonfly abundance
– Increase in ecotoparasites (ticks)
– Increase in insects
– Collapse of a scavenger species
• Farming practice and husbandry – Change in breeds
– Intensity of farming
– Expansion of livestock farming into new habitats
– Mixing of sheep and cattle
– Failure of livestock carcass disposal
• Sustainability – More households with livestock
– Wood taken from copses for burning
– More allotments
• Environmental and climatic – Flooding
– Warmer soil temperature
• Land use – Loss of ponds and marshes
– Fragmentation of landscapes
– Deforestation
Ecological □ Increase in feral dogs
□ Increase in vector breeding sites
□ Exposure of pigs to bat
Anthropogenic/ Socio-economic
□ Generation of stagnant water bodies
(swimming pools, poor plumbing, temporary
water storage)
□ Increase in wind turbines
□ Veterinary drugs and pesticides
□ Increased globalisation and transport
□ Failure of drinking water treatment and
sewage treatment
□ Failure of power supplies
□ Property maintenance
□ Eating more vegetables
□ Increase in rubbish/landfills
Constructing a spidergram
Veterinary drugs and pesticides
Collapse of a scavenger species
Failure of livestock carcass disposal
Increase in feral dogs
Dog bites and rabies Increase in insects
Increase in insectivorous birds
West Nile virus host
Increase in
Ecotoparasites
(ticks and fleas) Hantavirus
Increase in rubbish/landfills
Increase in rodents
Combinations • Zoological
– Increase in rodents
– Increase in insectivorous birds
– Decline in amphibians
– Increase in mosquitoes
– Fall in wildlife biodiversity
– Fall in dragonfly abundance
– Increase in ecotoparasites (ticks)
– Increase in insects
– Collapse of a scavenger species
– Increase in seagulls
• Farming practice and husbandry – Change in breeds
– Intensity of farming
– Expansion of livestock farming into new habitats
– Mixing of sheep and cattle
– Failure of livestock carcass disposal
• Sustainability – More households with livestock
– Wood taken from copses for burning
– More allotments
• Environmental and climatic – Flooding
– Warmer temperature
• Land use – Loss of ponds and marshes
– Fragmentation of landscapes
– Deforestation
Ecological □ Increase in feral dogs
□ Increase in vector breeding sites
□ Exposure of pigs to bat
Anthropogenic/ Socio-economic
□ Generation of stagnant water bodies
(swimming pools, poor plumbing, temporary
water storage)
□ Increase in wind turbines
□ Veterinary drugs and pesticides
□ Increased globalisation and transport
□ Failure of drinking water treatment and
sewage treatment
□ Failure of power supplies
□ Property maintenance
□ Eating more vegetables
□ Increase in rubbish/landfills
Constructing a spidergram
Veterinary drugs and pesticides
Collapse of a scavenger species
Failure of livestock carcass disposal
Increase in feral dogs
Dog bites and rabies Increase in insects
Increase in insectivorous birds
West Nile virus host
Increase in
Ecotoparasites
(ticks and fleas) Hantavirus
Increase in rubbish/landfills
Increase in rodents
Flooding
Warmer
temperature
Overview of European Science Foundation-funded
workshop to test spidergrams (July 2010)
• All participants very positive
• Spidergram approach provides a framework for how different factors could interact, irrespective of the virus
• Enables the testing of combinations not previously considered but which would be tested in nature
• Spidergrams generate discussion points and new angles – It gets people talking
• Use of spidergrams for developing case-control questionnaires
Nipah virus
• Fatal encephalitis in humans (pig farmers) in Malaysia, India and Bangladesh
• Pigs infected by Pteropus fruit bats
– Deforestation
– Pigs exposed to bat saliva on partially eaten fruit
– Level of containment of pigs important
• Pigs infect humans
• The spidergram for Nipah virus suggested how emergence could be linked to temperature through a range of seemingly unrelated factors including migration, deforestation and war
– Looking for climate change impact on NiV
Migration
*Level of
containment
War Host
behaviour
Poverty
Deforestation
Temperature Nipah Virus
*Level of containment of pigs/biocontrol
Spidergram for Nipah Virus
(Drought?)
Effect of … on Mig LC Temp War HB Pov Def
Migration + NA +? + ++ +
Level of
containment NA NA NA + NA
Temperature ++ + + + + ++
War + + NA + + +
Host behaviour NA + NA NA+ + NA
Poverty + ++ NA + + +
Deforestation ++ + + + + +
Effect of pairwise linkages with respect to Nipah virus. For each pair the
factor listed in the left hand column is the primary driver in the linkage, and
the factor in top row is the factor that may be affected
Some of these links are not obvious…….
with missing information
Acid rain
Wild bird behaviour
Environmental & Climatic
Zoological
Outcome
Missing information……., the calcium link
Making sense of it …….., filling in the detail
Acid rain
Wild bird behaviour
Environmental & Climatic
Zoological
Increase in contacts
between backyard
poultry and wild birds?
Feed, faeces, egg shells?
Outcome
Decline in snails/Calcium Zoological
Calcium foraging
Could spidergrams shift the focus
to identify what we don’t know?
• Known-knowns – Need to break out of this box: Ask a stupid question
• Known-unknowns – Specified well-defined data gaps
• Viraemia levels in dogs exposed to EBOV
– Ideal for “further work required” type recommendations
• Unknown-knowns – Acid rain affects wild bird behaviour
• Known: acid rain/calcium in physical chemistry books
• Unknown to me, need to think outside the veterinary microbiology box
• Important – bridging species for H5N1 transmission to BYD poultry?
• Unknown-unknowns – Ebola virus outbreak
• Role of mobile phones and better transport recruiting relatives to funeral of a case
– Unknown-unknown is really the outcome of change in a world of combinations of events
– Spidergrams can help
Using the Internet - H5N1 transmission through frozen duck meat to backyard chickens
• Germany in 2007 (Harder et al. 2009) – Risk of presence of HPAIV in meat destined for human consumption had
been estimated to be low (Harder et al. 2009)
• But had anyone thought about duck meat being fed to poultry? • Internet chat rooms on feeding meat to poultry
• “Can chickens eat meat or not?” (2009) – “my chickens get all food scraps”
– “I would only give them unprocessed meat
– Mine get meat but nothing too greasy” – Unknown-known
H5N1 asymptomatic
infections in ducks
Frozen duck meat in
food chain Raw duck meat scraps
fed to chickens
Aug 2007 December 2007 Frozen food
Human
Human
Horizon scanning: Overlaying known pathways
to new scenarios
Brain
Tradition
kuru
Mortuary cannibalism
Amplification
Cattle
Cattle
Horizon scanning: Overlaying known pathways
to new scenarios
Brain
Rendering
BSE
MBM, farming practice
So we’re now looking for a “virus” with a particular
combination of properties to fit to a new scenario:- 1. More thermo-stable TSE strain
2. Highly infectious to cows through oral route
Amplification
Spotting a bad idea: the right combination
of experts
• BSE epidemic in UK in the 1980/90s
• New disease, but …. – Renderer (thermal conditions of rendering and efficiency)
– Expert on thermostability of TSEs
– Epidemiologist on transmission of TSEs through cannibalism (kuru)
• Oral route
• Brains
– Cattle feed production manager/farming practice expert (recycling of cattle brain into MBM feed)
• Did this group ever get together in the early 1980s?
“If you’ve done your job properly as a
horizon scanner, nobody knows you’ve
done it” (Fiona Lickorish)
We need help to make sense out of nonsense
How do other fields get help?
A FEW MILLION VIRTUAL MONKEYS ARE CLOSE
TO RE-CREATING THE COMPLETE WORKS OF
SHAKESPEARE BY RANDOMLY MASHING KEYS ON
VIRTUAL TYPEWRITERS.
A running total of how well they are doing shows
that the re-creation is 99.990% complete
Online game Foldit helps anti-Aids drug quest (www.bbx.co.uk 20 Sep 2011)
The game, called Foldit, allows players to create new shapes of
proteins by randomly folding digital molecules
on their computer srceens
Virtual monkeys write Shakespeare (www.bbc.co.uk 26 Sep 2011)
Can we think up an “on-line game” to generate
complex scenarios?
Human intuition vs automated methods
Humans are good are spatial reasoning
Closing thoughts
• Trying to make sense out of nonsense, order out of disorder • Right combinations of people
– Broad range of disciplines
• Keep talking to experts in different fields – Critical mass of scientists needed
• Spidergrams give a starting point in producing random links – Combinations of events
• Missing information is a problem – filling in the detail • Internet is a huge database
– Text mining – discussion fora, social networking sites – Possibility of automation to generate complex scenarios – And identify change
• Could set up a web-forum with a universal set of factors for spidergram generation
Can YOU think up an “on-line game” to generate complex
scenarios?
Thank You
Some key points from workshops
• Long term MEGA trends, e.g., climatic. • “If you’re not making people uncomfortable you’re not
doing your job” (Fiona Lickorish) • Five “i”s (Ozcan Saritas)
– Intelligence, imagination, integration, interpretation (vision to action) and intervention
– This is what the spidergrams try to do
• Amplifying weak signals – Problem getting heard – index case of a new virus – What’s its trajectory?
• What’s changed, e.g. mobile phones, transport in Ebola virus
• Wild cards (e.g. swine flu 2009, Ebola virus outbreak 2013) • Non-linearity – people not good at this, good at pattern
recognition – How many clicks are we away from a disaster? – Can spidergrams take us further up the chain?
• Give us a bit more warning