one health lecture 1- introduction Flashcards
what are should our solutions to one health problems be?
-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
what are the sustainable development goals (SDGs)
-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
why is livestock important?
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
what are the key one health priorities?
-Origins of emerging diseases
-Drivers of spillover and disease emergence
-Zoonotic disease surveillance
what is the main driver of disease emergence events
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
what are the regional realities?
-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
what is the nipah virus example?
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.
what are the effects of endemic zoonotic diseases?
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
how is the Epidemiology of human febrile illness in low- and middle-income countries
-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
how do people benefit from interventions at source?
-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
what are the types of rabies management?
-Mass dog vaccination to prevent transmission from animal reservoirs
-Post-exposure prophylaxis (PEP) delivered as a medical intervention when people bitten
what is rabies?
-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
how is rabies managed?
-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
what is the burden of canine rabies?
-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
what is the one health approach to one health?
-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
what immunisations are charged for?
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
what is the Tanzania case study?
-38% land comprises protected areas
-Tanzania has among the largest livestock populations in Africa
-A large proportion of the population is dependent on livestock
what is Malignant Catarrhal Fever (MCF): Background
-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
what are the consequences of avoiding MCF?
-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
what are the consequences of poor livestock productivity?
-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
what is MCF vaccination?
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
what are the benefits and problems of a MCF vaccine
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
what are the challenges in one health?
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
what is the Hendra virus?
-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
what are the opportunities for one health?
-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
what are the benefits of pastoral livestock systems?
-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
what are the impacts of FMD in Uganda?
-Reduced household milk consumption
-Reduced income from sale of milk, poultry, eggs and bananas
what are the characteristics of emerging human and animal pathogens?
-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
what is the cycle of neglect?
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
