Presentation by Theo Knight-Jones at the Africa Biennial Biosciences Communication (ABBC 2023) Symposium, Nairobi, Kenya, 23 August 2023.

1. What is One Health
and why is it important?
Theo Knight-Jones
International Livestock Research Institute
Africa Biennial Biosciences Communication (ABBC 2023) Symposium
Nairobi, Kenya, 23 August 2023

2. Key Message
• Massive changes in our food systems have brought benefits
• but also massive challenges
• Food systems are complex with positive and negative impacts on
many different outcomes (hunger, climate, ecology, disease…) …and
complex causal mechanisms
• Addressing these challenges therefore, requires a holistic approach
capable of managing these diverse causes and outcomes
• The One Health approach offers a way of doing this in order to better
protect the health of humans, animals and the environment

3. Changes in food systems
FAO. 2021. World Food and Agriculture - Statistical Yearbook 2021. Rome.
https://doi.org/10.4060/cb4477en

4. Driven by societal and planetary change
van Dijk, M., Morley, T., Rau, M.L. et al. A meta-analysis of projected global food demand and population
risk of hunger for the period 2010–2050. Nat Food 2, 494–501 (2021). https://doi.org/10.1038/s43016-02
00322-9

5. But this
growth has
brought
challenges
FAO. 2021. World Food and Agriculture - Statistical Yearbook 2021. Rome.
https://doi.org/10.4060/cb4477en
4.2mill tonnes - globally

6. Impacts on
human,
environment
and animal
health
FAO. 2021. World Food and Agriculture - Statistical Yearbook 2021. Rome.
https://doi.org/10.4060/cb4477en
Inappropriate
exposure of
agricultural
workers
Exposure of
food consumers
Loss of
invertebrates,
biodiversity,
pollinators… Impact on
aquatic species
Loss of plant
biodiversity, soil
health
Loss of fish,
mammals, birds
and other
vertebrates
MISUSE

7. 7
Emerging infectious diseases - Near misses and pandemics
Thomas L, Coyne L, Rushton J. Countering the double-whammy of zoonotic diseases. 2020. Rural 21, 4(54)p8-11.
Taylor LH et al. Risk factors for human disease emergence. Phil. Trans. R. Soc. Lond. B. 2001;356:983–989.
75% of
emerging
infectious
diseases of
humans come
from animals

8. Food systems and pathogen emergence

9. Many other examples
Wild mammals
make up only
4% of global
mammal
biomass
Distribution of mammals on earth
Ecological
collapse
Contribute
to Climate
change
Environmental
degradation
Domestic dogs
have similar
biomass to all
terrestrial wild
mammals

10. Many other examples
Distribution of mammals on earth
• Antimicrobial Resistance – the silent pandemic – 1.27million deaths/yr
The result of overuse and inappropriate use of antimicrobial medicines
Lancet 2022; 399: 629–55
• 73% of antimicrobial medicines are used in food producing animals
Boeckel et al. Science. 2017;357:1350–1352.
AMU per country - Tiseo K et al. Antibiotics
2020 Dec 17;9(12):918
Low intensification (similar pattern for pesticides and other
correlates of intensification and human density)
But deteriorating trends and is a result of circumstance rather
than things being under control – SubSaharan Africa has the
highest human disease burden from AMR (double global ave.)

11. What is One Health
• The causes, mechanisms and impacts of these systemic challenges involve humans, animals,
environments, plants…
“ One Health is an integrated, unifying approach…to sustainably balance and optimize the health
of people, animals and ecosystems.
It recognizes the health of humans, domestic and wild animals, plants, and the wider
environment (including ecosystems) are closely linked and interdependent.
The approach mobilizes multiple sectors, disciplines and communities to tackle threats to health
and ecosystems, while addressing the … need for clean water, energy and air, safe and
nutritious food, climate change, and sustainable development.”
OHHLEP, 2021
https://www.who.int/publications/m/item/one-health-high-level-expert-panel-annual-report-2021
Multiple sectors must work together to best manage the health of
humans, animals and ecosystems
This is complex with diverse and interdependent benefits and trade-offs

12. One Health Game theory
the added value of a One Health approach
• Rabies vaccination in Chad - 2003
• When the Chadian Minister of Health was asked about the mass
vaccination of dogs to eliminate human rabies, he replied that he was
responsible for the people and not for the dogs
• Asked about the same issue, the Minister of Animal Production replied
that his priority was cattle and not dogs
• Economic analysis demonstrated that the cost of doing mass
vaccination of dogs and human treatment (PEP) was less than human
treatment alone, because vaccination of dogs can interrupt the
transmission of rabies
• Here a One Health approach results in a better outcome for human
health and wellbeing
Zinsstag J et al. The Promotion and Development of One Health at Swiss TPH and Its Greater Potential. Diseases. 2022

13. • Objective: Generate an inclusive Research & Innovation ecosystem,
facilitating rapid uptake, adaption and adoption of solutions to One
Health (OH) issues,
• with the OH concept embedded across society in Eastern and Southern
Africa (ESA), working for healthy humans, animals and environments
using a systems approach.
Targeting: Governance – Education – Delivery - Information

14. 14
December 2021 – 2025

15. The vision
• By embedding a collaborative, holistic One Health Approach
societies will be equipped to deal with complex, multidisciplinary
challenges…
• This contrasts with siloed approaches which may be incapable of
addressing complex, systems-wide, multi-sectoral challenges
• or if they do have an effect, may only address one of many
different societal outcomes, neglecting the others – with single
sector gains but overall losses to wider society

16. Key Message
• Massive changes in our food systems have brought benefits
• but also massive challenges
• Food systems are complex with positive and negative impacts on
many different outcomes (hunger, climate, ecology, disease…)…and
complex causal mechanisms
• Addressing these challenges therefore, requires a holistic approach
capable of managing these diverse causes and outcomes
• The One Health approach offers a way of doing this in order to better
protect the health of humans, animals and the environment

17. 17
Acknowledgements
BOTSWANA ETHIOPIA KENYA MOZAMBIQUE NAMIBIA RWANDA
TANZANIA MALAWI UGANDA ZAMBIA ZIMBABWE SOUTH AFRICA
(partner)
Dr Alexandre Caron, CIRAD Dr Margaret Karembu, ISAAA
This project is supported by the European Commission OACPS Research and
Innovation Programme: ACP-EU initiative, co-founded through ILRI and CIRAD

18. THANK YOU

19. THANK YOU