one health lecture 1- introduction

Question 1

what are should our solutions to one health problems be?

Answer 1

-Although drivers of illness and poor health are often anthropogenic, our solutions should not be anthropocentric

-We need to move towards a more ecological approach to health

Question 2

what are the sustainable development goals (SDGs)

Answer 2

-UN 2030 Agenda for Sustainable Development (adopted in 2015)

-Expanded the aims of the Millennium Development Goals

-Key areas: Food security, poverty alleviation, climate change, social justice, peace, environmental protection, health

-One Health provides a framework for achieving cross-cutting benefits that span multiple SDG goals and targets

Question 3

why is livestock important?

Answer 3

Over 1 billion people rely on livestock for food security and livelihoods

Important for crop production (traction, manure), social capital and social protection

Issues around livestock diseases:
-Food security, food safety, malnutrition
-Incomes, livelihoods, expenditure on health and education
-Zoonotic disease problems
-Unsupervised use of antimicrobials
-Implications for land-use and rangeland health
-Mental health problems

Question 4

what are the key one health priorities?

Answer 4

-Origins of emerging diseases
-Drivers of spillover and disease emergence
-Zoonotic disease surveillance

Question 5

what is the main driver of disease emergence events

Answer 5

land use change…

Numerous case studies show associations between land use and zoonotic disease risk

-Irrigation-based agriculture and Japanese encephalitis
-Deforestation and Plasmodium knowlesi
-Agricultural practices and emergence of Nipah virus
-Leptospira infections and rice fields
-Lyme disease and forest fragmentation

COVID-19 - growing global awareness of need for mechanisms and policies to mitigate the role of land use change in emerging disease risk

Question 6

what are the regional realities?

Answer 6

-Per capita consumption of animal source foods has declined in sub-Saharan Africa over past few decades

-220 million in sub-Saharan Africa are under-nourished

-Levels of stunting are high, often associated with low consumption of animal-source foods

-High intake of animal source foods has been associated with improved growth, cognitive performance, motor development and increased activity in children

Question 7

what is the nipah virus example?

Answer 7

Agricultural intensification of pig farms adjacent to bat-attracting mango plantations in Malaysia provided the conditions for Nipah virus emergence in pig populations after spillover from fruit bats.

Question 8

what are the effects of endemic zoonotic diseases?

Answer 8

Highest burden in poor and disadvantaged communities

Livestock zoonoses often affect livestock health and productivity
Impose a major burden on livestock-dependent communities

Tools are available for prevention and control of many endemic zoonoses
the diseases themselvss are not neglected

Question 9

how is the Epidemiology of human febrile illness in low- and middle-income countries

Answer 9

-Fever is one of the most common symptoms among people in low- and middle-income countries

-Management of disease represents a clinical challenge

-Multiple causes (aetiologies), considerable local variation

Question 10

how do people benefit from interventions at source?

Answer 10

-Reducing the disease burden in people and animals
-Preventive interventions at the animal source provide a broader ‘safety net’ than reliance on clinical management of human cases alone
-Necessary for elimination of infections involving animal reservoirs

Question 11

what are the types of rabies management?

Answer 11

-Mass dog vaccination to prevent transmission from animal reservoirs

-Post-exposure prophylaxis (PEP) delivered as a medical intervention when people bitten

Question 12

what is rabies?

Answer 12

-The disease is an acute, progressive encephalomyelitis

-Highest case fatality of any disease

-Caused by viruses in the genus Lyssavirus

-All mammals can be affected
> 99% of human deaths are caused by domestic dogs usually through bite transmission

Question 13

how is rabies managed?

Answer 13

-30 million people receive PEP every year (direct cost ~$1.7 billion/year)

-The most vulnerable families face enormous challenges in accessing and affording PEP

-As a result ~ 60,000 people die of rabies every year

Question 14

what is the burden of canine rabies?

Answer 14

-Rabies primarily affects people in poor, rural communities in Asia and Africa

-99% of human cases of rabies were from dog bites

-Human rabies only occurs in areas where dog vaccination coverage is low

-Every hour more than 3,000 people in rabies-endemic countries are faced with life-threatening emergencies when bitten by dogs

-Inequalities in access to life-saving PEP

Question 15

what is the one health approach to one health?

Answer 15

-Under status quo >1 million human rabies deaths from 2020-2035 in 67 endemic countries

-Fewest deaths occur when PEP access is improved alongside scaling up of dog vaccination

-Dog vaccination acts as a safety net to protect the most vulnerable

Question 16

what immunisations are charged for?

Answer 16

Both immunisations aim to protect childhood health and prevent deaths

Childhood immunization delivered free of charge

Charging fees is only invoked for animal interventions

Challenges to health, livestock production and biodiversity arise from growing pressures on land in the face of human population growth, climate change and economic development

Question 17

what is the Tanzania case study?

Answer 17

-38% land comprises protected areas

-Tanzania has among the largest livestock populations in Africa

-A large proportion of the population is dependent on livestock

Question 18

what is Malignant Catarrhal Fever (MCF): Background

Answer 18

-A fatal viral disease of cattle transmitted from wildebeest

-Transmission risk highest during the wildebeest calving season

-Up to now, no treatments or vaccines have been available

-Prevention has relied on avoidance of high-quality grazing lands during the wildebeest calving season

Question 19

what are the consequences of avoiding MCF?

Answer 19

-90% cattle herds moved away from principal family residence

-64% milk unavailable for sale or consumption (loss of up to 8% annual household income)

-Cattle re-gain body condition more slowly

Question 20

what are the consequences of poor livestock productivity?

Answer 20

-Conversion of rangeland to crop-based agriculture

-Mechanised agriculture associated with major declines in wildlife

-Wildebeest populations strongly declined when wheat cultivation expanded in the Serengeti-Mara ecosystem

Question 21

what is MCF vaccination?

Answer 21

A new vaccine has been developed that provides partial protection against fatal MCF

How are pastoralists in Tanzania likely to want to use the vaccine?

What would be the impact of vaccination on:
-Food security and livelihoods
-Cattle movements and management
-Wildebeest movements
-Pasture quality

Question 22

what are the benefits and problems of a MCF vaccine

Answer 22

Potential benefits of a MCF vaccine-

-Improved pastoral livelihoods and nutrition (particularly children)
-Reduced land use conflict
-Counteracting sub-division of land
-Maintaining ecological integrity of the ecosystem

Potential problems of a MCF vaccine-

-Increasing livestock numbers resulting in land degradation
-Increasing human-wildlife conflict
-Negative impacts on the wildebeest migration

Question 23

what are the challenges in one health?

Answer 23

Interdisciplinary and intersectoral challenges
-Different ‘languages’, issues of trust, control and influence

Community engagement recognized as a priority but One Health still largely driven by ‘top down’ initiatives

Challenges in funding for and implementation of preventive measures

Large teams – costly, communication challenges, transaction costs

Professional recognition and career progression

Question 24

what is the Hendra virus?

Answer 24

-Causes a fatal disease of horses and people

-Virus transmitted from flying fox species

-Habitat destruction => displacement of bats to new habitats in agricultural and urban areas

-Winter food shortages => high levels of of virus shedding from flying foxes, closer contact with horses

-Increasing risk of spillover transmission

Question 25

what are the opportunities for one health?

Answer 25

-Recognition of the need for more integrated and ecological approaches to tackling many global challenges including infectious diseases, epidemics, antimicrobial resistance, food security, environmental degradation.

-Ecologists and evolutionary biologists have critical expertise and are ideally placed to contribute to One Health interdisciplinary teams.

-Funding available – but subject to change - currently targeted towards pandemic prevention & response, and antimicrobial resistance

Question 26

what are the benefits of pastoral livestock systems?

Answer 26

-High levels of biodiversity at moderate livestock grazing intensity

-Mobile pastoral systems are a productive form of land-use in arid and semi-arid rangelands

-Pastoralism evolved in response to environmental uncertainty and climate variability

-Pastoral livestock systems can be carbon neutral
But…..in many parts of the world pastoral systems are under threat

Question 27

what are the impacts of FMD in Uganda?

Answer 27

-Reduced household milk consumption
-Reduced income from sale of milk, poultry, eggs and bananas

Question 28

what are the characteristics of emerging human and animal pathogens?

Answer 28

-61% of human pathogens and 75% of emerging human pathogens are zoonoses

-Viruses - particularly RNA viruses - are over-represented among human, livestock and domestic carnivore emerging diseases

-Generalist pathogens that can infect a wide range of host species are over-represented in human and livestock emerging diseases

-Wildlife represent important reservoirs of emerging pathogens

Question 29

what is the cycle of neglect?

Answer 29

1- Lack of disease burden data

2- Affect disadvantaged and neglected communities
-Limited investment in prevention and control

3-Diagnostic challenges
Limited diagnostic capacity
Non-specific clinical signs