Wildlife-livestock-human interface

Can we recognise drivers of disease?

Annie Cook

Post doctoral Scientist - Epidemiology

Event: LSE Seminar

Location: ILRI Infocentre

Date: 26Th March, 2015

Outline

• Global context – Wildlife-livestock-human interface

– Endemic versus emerging infectious disease

– Can we predict next pandemic?

• Kenyan case studies – Zoonoses in small holders and their animals

– Bats as source of emerging disease

– Malignant catarrhal fever

Wildlife-livestock-human interface

Drivers of disease

• Climate change • Environmental degradation • Encroachment wild spaces • Globalisation • Urbanisation • Land use changes • Agricultural intensification

Endemic versus emerging

Endemic disease Global infections per year

Brucellosis 500,0001

Leptospirosis 1,725,0902

Emerging disease Total infections

Nipah ~6003,4

Avian influenza (H5N1) 7845

1. Pappas et al 2006 2. Hagan et al 2014 3. http://www.searo.who.int/entity/emerging_diseases/links/CDS_Nipah_Virus.pdf 4. http://www.searo.who.int/entity/emerging_diseases/links/nipah_virus_outbreaks_sear/en/ 5.http://www.who.int/influenza/human_animal_interface/EN_GIP_20150303cumulativeNumberH5N1cases.pdf?ua=1

Impact of emerging disease

• Loss of human life

• Costs of control

• Adverse effects on agriculture & food security

• Reduces biodiversity

http://www2.cedarcrest.edu/academic/bio/hale/bioT_EID/lectures/session24.html

The next emerging disease?

• RNA virus

• Broad host range

• Wildlife source

• Developing world

• Human to human transmission

Taylor et al 2001

Woolhouse et al 2005

Predictions of emerging disease

Jones et al 2008

Swine flu,

Mexico MERS,

Saudi Arabia

Kenyan case studies

https://unphase1-6th-8th.wikispaces.com/Kenya

Kenyan context

• 44 million people

• Rural

• 17M Cattle, 27M Goats, 17M Sheep , 0.3M pigs, 3M camels

• 60% wildlife outside national parks

• Encroachment of wildlife areas

• Wildlife-human conflict

• Disease transmission Kenyan Human Population Census 2009

People, Animals and their Zoonoses (PAZ)

• Cross-sectional study on zoonoses

• 412 households

• 142 slaughterhouses

• Endemic disease

– HIV, malaria

• Zoonoses

– Brucellosis, leptospirosis, Rift Valley fever, Q fever,

cysticercosis, taeniasis

PAZ study area

• Western Kenya

• Lake Victoria Crescent

• Population 1.4M

• High population density

• Mixed agriculture

• Small holdings

Comparison to other areas

Western (%) Kajiado (%) Tana River (%)

Human

Brucellosis 0.61 1.32

Q fever 2.21 26.84

Leptospirosis 4.81

Cattle

Brucellosis 0.261 21.92

Q fever 10.01

Leptospirosis 5.31 21.03

1 Fèvre et al 2015 2 Nakeel et al 2015 3 Nakeel et al 2015 4 Mwololo et al 2015

High risk groups

Community (%) Slaughterhouse workers (%)

Human

Brucellosis 0.6 0.6

Q fever 2.2 4.5

Leptospirosis 4.8 13.4

Conclusions

• Differences in seroprevalence

• Livestock system?

• High risk groups

• Next steps

– Zoolink Project

– Zoonoses and Emerging Livestock Systems

Bats as source of emerging disease

• Worldwide distribution

• Incredibly numerous

• Colonies

• Reservoirs of emerging disease

– SARS, Nipah

Nipah virus

• Malaysia

• Commercial pig farms

• Bat- pig - human

• Bangladesh

• Date palm sap

http://whyfiles.org/2013/dangerous-viruses-new-weapons-against-new-foes/ Epstein et al, 2015

Bat sampling

• Mist nets

• Transferred to laboratory

• Anaesthetised – isofluorane

• Sample collection

• Euthanised

• Necropsy

Sample analysis

• Blood

• Frozen tissues – heart, lung, liver, kidney, brain, spleen

• Fixed tissues for histopathology

• PCR – Lyssaviruses (Rabies)

– Filoviruses (Ebola/Marburg)

– Coronaviruses (SARS – like)

– Paramyxoviruses (Henipah)

– Bunyaviruses (Hanta)

Results – so far

5/8 Epomophorus sp

http://www.cdc.gov/dpdx/malaria/index.htm

Conclusions

• New pathogens of bats

• Relate to human and animal data

• Not causal but hypothesis generating

Malignant catarrhal fever

http://na.unep.net/geas/getUNEPPageWithArticleIDScript.php?article_id=107

• Alcelaphine herpesvirus -1

• Carriers – wildebeest

• 100% cattle mortality

• Risk period - wildebeest calving

• Traditionally pastoralists migrate

Kapiti Plains

https://fonnap.wordpress.com/2012/03/05/the-konza-techno-city-malili-animal-rescue/

Kapiti

• 33000 acres

• 2000-2500 cattle

• 2000 wildebeest

• 2014 – 221 cattle deaths

0

2

4

6

8

10

12

14

16

Series1 Cases

Control

• Fencing

• Removal wildebeest

• Exclusion

• Vaccine trial

– attenuated live virus (AlHV C500) + Emulsigen® 1,2

– Randomised placebo blind trial (100)

1 Russell et al 2012

2 Haig et al 2008

Conclusion

• Drivers are anthropogenic

• Increased contact with animals

• How do we quantify/qualify that contact

• How do we determine which behaviours

• Are the pathogens one step ahead?

Acknowledgements

References

Epstein, J.H. et al The Ecology of Nipah Virus in its Natural Reservoir, Pteropus giganteus, in Bangladesh. One Health Congress 2015, Amsterdam, The Netherlands

Fèvre, E.M. et al An integrated study of human and animal infectious disease in the Lake Victoria Crescent small-holder crop-livestock production system. In prep 2015

Hagan, J.E. et al Global burden of disease due to leptospirosis: Systematic review of disease-specific mortality and morbidity ASH, Dec 2011, Philadelphia, USA

Haig, D.M. et al An immunisation strategy for the protection of cattle against alcelaphine herpesvirus-1-induced malignant catarrhal fever. Vaccine 2008. 25:35; 4461-8

Jones K, Patel G, Levy M, et al. Global trends in emerging infectious diseases. Nature 2008. 451:21; 990-994

Mwololo , D.K. et al Seroprevalence and risk factors of Coxiella burnetii (Q fever) infection among humans in Bura irrigation scheme, Tana River County, Kenya, One Health Congress 2015, Amsterdam, The Netherlands

Nakeel, M.J. et al Seroprevalence of brucellosis in livestock and humans and the associated risk factors in Kajiado county, Kenya, Regional Conference on Zoonotic Disease sin Eastern Africa, March 9-13 2015, Naivasha, Kenya

Nakeel, M.J. et al Seroprevalence of leptospirosis in cattle and its associated risk factors in Kajiado County, Kenya, Regional Conference on Zoonotic Diseases in Eastern Africa, March 9-13 2015, Naivasha, Kenya

Pappas G, Papadimitriou P, Akritidis N, Christou L, Tsianos EV The new global map of human brucellosis. Lancet Infect Dis 2006;6:91–9

Russell , G.C. et al Duration of protective immunity and antibody responses in cattle immunised against alcelaphine herpesvirus-1-induced malignant catarrhal fever. Veterinary Research 2012. 42:1; 51

Taylor, L.H. et al Host Range and Emerging and Reemerging Pathogens Phil. Trans. R. Soc. Lond. 2001. 356:1411; 983-9

Woolhouse, M.E.J. et al Host Range and Emerging and Reemerging Pathogens. Emerging Infectious Diseases 2005, 11:12; 1843-7