Surveillance for Zoonotic Diseases at

wildlife-human interfaces in mainland

Southeast Asia

1

Why Zoonotic Disease Surveillance?

> 70% of emerging human pathogens are zoonotic

> 60% of emerging zoonoses have reservoirs in

wildlife

2

Increasing human populations

Increasing livestock

populations

Land use changes with infringement on wild

habitats (Jones et al, 2013)

Why is rate of zoonoses emergence

increasing?

3

Climate change (Jones et al, 208)

Increased demand for wildlife & wildlife products Wildlife Trade (Swift et al, 2007)

Ease and speed of global travel

4

Importance of Early Detection • Key to Control

• Reduction of Post-transfer Host Adaptation

• Potentially Lower Transmissibility

• Allows early sequencing to improve quality & speed

of diagnostics and preventive interventions

5

Traditional Outbreak Detection and Response

DAY

CA

SES

Adapted from J. Davis, Climate Adaptation Workshop, Nov. 2003

First

Case Detection/

Reporting

Lab

Confirmation

Response

Opportunity for control

6

DAY

CA

SES

First Case

Detection/

Reporting

Lab Confirmation

Response

Effective Health Early Warning

Surveillance, Observation

and Monitoring

Adapted from J. Davis, Climate Adaptation Workshop, Nov. 2003

Opportunity for control

7

USAID Emerging Pandemic Threats Program

Pathogen identification

Response and Prevention

In order to predict the emergence of novel infectious diseases in humans, pathogens must be

identified at their source.

Pro-active, risk based targeted surveillance and capacity building

8

9

Developing a Targeted Surveillance

Strategy

10

SMART surveillance

Strategic selection of geographic locations for surveillance

Strategic selection of species for surveillance

11

Why Conduct Surveillance in

Asia?

Jones et al, 2008

Hotspot regions for zoonotic disease emergence

(green = low risk yellow orange red = high risk

12

Spillover Risks: Southeast Asia

High demand for wild animal

meat and products

Rich biodiversity

Porous international borders with high volume

of informal and formal trade

Rapid economic development with

concurrent rural industrial development,

deforestation & large scale land-use change

-A 2013 global study assessing forest extent, loss and gain found

that Cambodia was one of the worst 3 countries in terms of

forest loss, with a loss of 7.1% of the country’s forests from 2000-

2012 (Hansen et al, 2013)

13

Wildlife Trade

Almost 30 million wild-caught CITES listed animals

traded from Se Asian countries from 1998-2007

(Nijman, 2010)

Lao P.D.R:

Wildlife consumed widely and traded openly in

markets: year long survey of 86 domestic markets

recorded >14,000 wild birds, >7,000 rodents, >3,000 bats.

International trade prevalent

Long, porous borders with 4 countries

Minimal wildlife trade law enforcement

14

Cambodia:

Wildlife, including primates, are consumed in many

rural communities & used in traditional medicine

Commercial trade moved underground:

surveillance must target middle-men and

confiscated wildlife

Large scale informal international

trade e.g. > 3 tons of rats/ day

to Vietnam for consumption

(Phnom Penh Post 2012)

Since 2001, the government’s Wildlife Rapid Rescue

Team confiscated > 56,000 animals from illegal

wildlife trade (Wildlife Alliance 2014)

15

Vietnam:

Wildlife consumption driven by greater

purchasing power of burgeoning middle-

class

Farming of various species in popularity

(porcupines to crocodiles to civets)

BUT many farm stock still sourced from the

wild (Brooks et al, 2010)

Key transit country for wildlife and wild

animal products en route to China

16

Increased relatedness to humans….

increasing risk of pathogen spillover?

Strategic selection of taxa for

surveillance

17

Increased contact rate… increased spillover risk

Henipaviruses

Lyssaviruses

Flaviviruses

Bunyaviruses

18

High proportion of viruses shared with

humans by bats, rodents and

primates compared with other taxa

19

Host Diversity

Disease Emergence

20

Animal Taxa 21

Risk-based Approach to Surveillance in hotspot regions

Sample along high risk disease transmission pathways

People have a high level of sustained and direct contact with these pathogens

22

• Hunting

• Markets/trade

• Wildlife/livestock

conflict

• Wildlife farms

• Extraction

• Land use change

• Global transportation

High risk disease transmission

interfaces

23

Flooded

forest Land

encroachment Bat farms

Indigenous

communities Villages

Local markets

Local

resort

24

Site Assessment Relationship Building

Sample Collection Sample Testing

25

What Samples?

Samples which reflect likely contact/

transmission route with humans

e.g. oral swab if saliva, rectal swab/ feces if

fecal, blood and organs if consumption

Analysis can help refine future surveillance

- Additional Ecological Information

- Animal Specific Information

26

Interfaces by country

27

Animals per Interface Interface # of Animals Sampled

Hunted 1819

For sale in market 180

For sale in restaurant 347

Private wildlife collection or pet 1

Rehabilitation center 8

Sanctuary 8

Wild animal farm 898

Zoo 4

Peri-domestic/in or near human dwelling(s) 177

Contact with tourists/ecotourism 153

Contact with domestic animals or humans NOT likely 2

Cambodia

Interface # Samples collected

Hunted 556

Markets 2107

Zoo 16

Peri-domestic 6

Contact with Tourists/ ecotoursim 1

Private sale 6

Private wildlife collection/ pet 1

Lao PDR

Interface # of Animals Sampled

For sale in large market (> 20 vendors) 372

For sale in restaurant 430

Private sale 189

Private wildlife collection or pet 2

Rehabilitation center 42

Sanctuary 8

Wild animal farm 58

Zoo 16

Peri-domestic/in or near human dwelling(s) 354

Contact with locals/religious site 10

Vietnam

28

Wildlife sampling sites Cambodia

29

Wildlife

sampling sites

Lao PDR

30

Wildlife

sampling sites

Vietnam

31

Samples per Taxa in Cambodia

Taxa Number of Animals Sampled

Carnivores 23

Other Taxa 6

Non-human Primates 211

Rodents & Shrews 450

Bats 2507

Birds 327

Ungulates 174

32

Samples per Taxa in Lao PDR

Taxa Number of Animals Sampled

Other Mammals 225

Non-human Primates 44

Rodents & Shrews 1460

Bats 957

33

Samples per Taxa in Vietnam Taxa Number of Animals Sampled

Other Mammals 2

Carnivores 97

Other Taxa 1

Non-human Primates 25

Rodents & Shrews 896

Bats 366

Birds 36

Ungulates 30

34

Summary of Sampling

35

- Mainly oral & rectal swabs

- Some tissue & blood samples

- Samples stored in Liquid N2

in field -80 freezer in

laboratory

- Consensus PCR approach

to screening

Direct sequencing

Next generation sequencing

where appropriate

Viral genus/ families targeted:

• Arenaviruses

• Astroviruses

• Bunyaviruses

• Coronaviruses

• Filoviruses

• Flaviviruses

• Henipaviruses

• Lyssaviruses

• Paramyxoviruses

• Rhabdoviruses

• Seadornaviruses

• Herpesviruses

• Influenzas

• Retrovirus - Lentivirus genus

• Simian Foamy viruses

Sampling and Diagnostics

36

Animal Host Priority Viral Pathogen Families

i. High Priority Species

Rodents Alpha, Arena, Astro, Filo, Flavi, Hanta, Henipa, Influenza A, Lyssa, Seadorna, Paramyxo, Pox, Bunya

Bats Flavi, Corona, Henipa, Rhabdo (Lyssa), Arena, Filo, Reo, Astro, Influenza A, Seadorna, Paramyxo, Bunya

Non-human Primates

Arena, Astro, Henipa, Influenza A, Entero, Retro, Filo, Flavi, Orthomyxo, Paramyxo, Pox, Herpes, Corona, Lyssa, Seadorna, Boca, Bunya

ii. Lower Priority Species

Carnivores Filo, Corona, Paramyxo, Filo, Arena, Parvo, Influenza, Rhabdo (Lyssa),

Ungulates Filo, Influenza, Rhabdo (Lyssa), Corona, Paramyxo, Pox, Bunya

37

Results so far…

**Currently no evidence of risk to human health posed by any of these viruses**

38

Building capacity for wildlife disease

surveillance Conducted surveillance in partnership with staff from

animal health, human health, forestry, and

environment sectors

Conducted workshops and field training on wildlife

surveillance for veterinary students and government

staff

Established viral family testing protocols and next

generation sequencing capacity in government

laboratories

39

Additional Monitoring

9 villages in 3 provinces

Surveyed quarterly to characterize contacts with

animals (domestic and wild) for 1 year

Recorded species and scale of wild animal

consumption

Identified high consumers and hunters of wildlife for

surveillance

Demonstrated demographic linkages

Identified reasons people avoid certain foods

does knowledge of health risks affect behaviour?

Cambodia: behavioral

40

Additional Monitoring

86 markets surveyed over 3 yrs: species, volume & prices

14,429 wild birds, 7398 rodents, 3573 bats, 927 reptiles, 403

carnivores, 236 individual + 665kg ungulates, 64 primates

(283 listed as VU, EN or CR on IUCN redlist)

3 month survey of key markets: biosecurity behaviours

e.g. butchering in market/ cleaning of utensils/ hand

washing/ species mixing etc

Identified 8 markets as posing higher risk of disease

spillover

Established recommendation for “healthy” markets

government guidelines

-Lao PDR: markets

41

Conclusions

Consensus PCR screening is a useful, cost-effective

approach for investigating viral diversity in wildlife

Surveillance at high risk interfaces can advise policy-driven preventative actions to activities

that increase risk of disease spillover from wildlife to

humans & threaten biodiversity: conservation,

human and ecosystem health benefits

Excellent buy-in for One Health approach in Se Asia

Capacity building concurrent to surveillance and

research is essential for sustainability

Main challenges to implementation are host

country government funding and human capacity

42

Acknowledgements United States Agency for International Development (USAID)

PREDICT

PREDICT Consortium: University of California Davis, Ecohealth

Alliance, Metabiota, Smithsonian Institution & Wildlife

Conservation Society

Institute Pasteur, Cambodia

National Veterinary Research Institute & Forestry

Administration of the Royal Government of Cambodia

Ministry of Agriculture, Forestry and Fisheries and National

Animal Health Laboratory, Lao PDR

Ministry of Agriculture and Rural Development, Department of

Animal Health, Vietnam, RAHO6 Vietnam, Hanoi University of

Agriculture National Key Laboratory of Veterinary

Biotechnology

43

Thanks! And one final tale….

Literature cited:

1)Brooks E., Roberton, S. & Bell, D. 2010. “The conservation impact of commercial wildlife farming of porcupines in Vietnam.” Biological

Conservation, 2010; DOI: 10.1016/j.biocon.2010.07.030

2)Jones, K., Patel, N., Levy, M., Storeygard, A., Balk, D., Gittleman, J., Daszak, P. 2008. “Global Trends in Emerging Infectious Diseases.

Nature Vol 451| 21 February 2008 doi:10.1038/nature06536

3)Jones, B., D. Grace, R. Kock, S. Alonso, J. Rushton, M. Said, D. McKeever, F. Mutua, J. Young, J. McDermott, and D. Pfeiffer. 2013.

Zoonosis emergence linked to agricultural intensification and environmental change. Proceedings of the National Academy of

Sciences 110: 8399-8404.

4)Hansen,, M.C., P.V. Potapov, R. Moore, M. Hancher, S. A. Turubanova, A. Tyukavina, D. Thau, S.V. Stehman, S. J. Goetz, T.R. Loveland,

A. Kommareddy, A. Egorov, L. Chini, C.O. Justice, and J.R.G. Townshend. 2013. High-resolution global maps of 21st-century forest

cover change. Science 342:850-853. doi: 10.1126/science.1244693.

5)Nijman, V. 2010. An overview of international wildlife trade from Southeast Asia. Biodiversity Conservation 19:1101–1114.

6)Phnompenhpost. 2012. Rat meat on the Menu at Vietnam border. Available at: www.phnompenhpost.com/lifestyle/rat-meat-menu-

vietnam-border. Accessed April 2014.

7)Swift, L., P. Hunter, A. Lees, and D. Bell. 2007. Wildlife trade and the emergence of infectious diseases. EcoHealth 4: 25–30.

doi:10.1007/s10393-006-0076-y.

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