wildlife-livestock-human interface: recognising drivers of disease
TRANSCRIPT
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