One health Flashcards
What is considered an emerging zoonoses? (5)
New agent Old A w/ new virulence Old A newly released New sp. or area Re-emerge
What are some theoretical drivers for the emergence of Hendra virus?
Pathogen - Genetic changes (drift/shift), change in transmission
Host - location and immune ability change (travel, population grow, older, ill, new exposure) or human-animal interaction.
Environmental - habitat change/sharing, climate change, biodiversity.
Describe how environmental changes can cause an increase in certain disease prevalence, use lyme disease as an example.
climate change –> more white-footed mice which are great carriers for Ixodid ticks.
More white-footed mice –> more ticks –> increased risk of human interaction with ticks
**US decided to cull deer but it would have been more effective to kill mice (but harder to do).
Is there an apparent connection with population density and emergence of EIDs?
Yes, more highly populated areas seem to have an increased occurrence of EIDs.
What are the joint goals of One health initiative? (6)
Education Communication Surveillance Comparative med and environment research New diagnostics/med/Vx Political lobbying.
What is the importance of veterinarians in One health?
To fulfil the holistic approach; heard health, including agriculture and environment.
What is the goal of ‘Agroecosystems health’?
Sustainable systems Maintain habitats and biodiversity (including water systems) Atmospheric protection (dust, odours GHGs).
What is meant by the term ‘food security’?
Having enough food for everyone
What is the main Marine biosecurity risk?
What regulations have been instilled to prevent this?
Ships’ ballast water.
Now ships must empty ballast water out at sea not in dock.
What is the purpose of ‘US National Academies of Science’?
Prevent the use of biohazards being used in an inappropriate/malicious manner.
What is the definition of ‘Dual Use Research of Concern’? (DURC)
When there is legitimate scientific use to researching a potentially dangerous bio material that can also be misused.
i.e. we are learning what makes something highly virulent therefore we know how to make something more virulent.
What is the purpose of laboratory biosafety?
How is it achieved?
To reduce the risk of people being exposed.
Achieved with PPE, lab designs (pathogen can’t get out easily) and practices.
What is the purpose of clinical biosafety?
How is it achieved?
Stop people having access to pathogens.
Achieved with clinic set-up (ICU, ID units, etc), aseptic techniques, decontamination procedures and hand hygiene.
Define: Biohazard
What are example of biohazards?
Any bio substance that can cause harm to humans, animals or environment (including trade/production).
e.g. pests, infectious Dz, chemicals.
Define: Biosafety
Safe handling and containment of biohazards
* Mainly refers to labs.
Define: Biocontainment
Physical and operational mechanisms to prevent the release/exposure of biohazards.
Define: Biorisk
Risk assessment of probability and how much damage the biohazard could do.
What are the 5 areas in society that benefit from biosecurity?
Animal and human health and welfare
Ecology
Environment
Societal
What are some issues associated with a biohazard affecting the environment?
Cause spp. loss and extinctions, can cause secondary impacts like human health, livestock and sociological.
e.g. fungal disease (chytridiomycosis) –> frog population decrease and extinctions –> affect animals that eat those frogs, alter human culture to stop eating certain frogs as fungal infected frogs make people sick.
What are some societal impacts associated with biohazards?
Think corona! Shops less customers --> less \$\$ Social events cancelled Education alterations Depression being stuck in house
What was the purpose of developing Woodward commission?
To prevent meat substitution (horse not beef) into exported meat.
Increased surveillance/inspections, created a certificate for export and increased fines.
What was the purpose of developing the Nairn Review?
What concept does it encompass?
Developed to prevent societal exposure to biohazards from food companies or the government.
Concept of ‘Continuum of Quarantine’, ie looking at pre-border, border and post-border. shared responsibility between the government, industry and public.
What was the purpose of developing the Beale Review?
In response to equine influenza, it is an extension to the Nairn review.
What are some pre-border quarantine surveillance examples?
Greater interaction with trading partners
What are some post-border quarantine surveillance examples?
Early detection Surveillance (abattoir) Proof of freedom Reporting Risk factor analysis
What are some post-border quarantine surveillance examples?
Enhanced surveillance, response and resilience
What are the components of the ‘Triple Bottom Line’?
Environment, society and economy.
What is the purpose of the Triple Bottom Line?
To prove that an industries system and management is possible and sustainable.
What the top 3 most preferable methods to manage waste and resources?
- Avoid or reduce waste and resource use
- Reuse
- Recycle
What are some good reasons to start effluent management on farms? (6)
Legislation regulatory requirements
Reduce annual emission fees
Protect natural water sources and soil
Keep positive relationships with neighbours (less odour)
Improve crop growth with organic fertiliser
Reduce GHG emissions.
What steps are required to get permission to do environmentally relevant activities?
Development approval from state and local government + environment authority to carry out activity.
What are the various methods to remove manure from concrete holding yards into effluent system?
With water - Hosing, tipping buckets, flood washing +/-drag tires behind truck to loosen faecal matter
Slatted floors + flushing channel underneath
How do you separate solids from liquid effluent?
Different forms of sieving techniques with wooden/metal slates, wire baskets, screw press separtor, vibrating screen, etc.
Whay is it important to filter effluent from solids?
To prevent blockages, provide more ease in pumping and decrease frequency of desludging of ponds.
What is the ideal effluent collection sump design?
Mixing device
Easy access
cover/fencing
stone and solids trap
How long is the hydraulic retention time for effluent ponds?
30-40 days
How do you calculate the correct size for your effluent ponds?
Amount of waste water produced/day x 40 (HRT)
How many ponds should you have and why?
Ideally 2:
primary pond for active treatment and sludge capture.
secondary pond for wet weather storage (overflow pipe from 1° to 2°.
What % of clay should there be in the soil to prevent leakage?
> 20% clay and needs to be compacted.
How are effluent ponds treated?
What are two benefits of this treatment?
Anaerobic treatment –> Breakdown complex compounds to reduce biological Oxygen demands (BOD) and volatile solids (reduce sludge amount) by ~75%
What are the 4 stages of anaerobic treatment?
- Hydrolysis
- Acidogenesis
- Acetogenesis
- Methanogenesis
What factors affect the efficacy of anaerobic treatment?
pH Temp HRT Organic loading rate (OLR) inhibitors (high NH4, heavy metals, disinfectants salt)
Pros of anaerobic treatment ponds (5)
easy, efficient, economical, long lasting, can re-use to flush sheds or water pasture/crops
Cons of anaerobic treatment ponds (6)
Odours, nutrient loss, sludge, water contamination, salt accumulation, struvite issues in flushing systems.
What are the advantages of covering up effluent ponds to catch the gas produced?
Use biogas to produce electricity, can cut GHG emission to 0.5.
reduce odour.
what are the second (overflow) ponds processing pathways?
can do anaerobic and facultative bacteria that can operate in aerobic and anaerobic environments
How do you desludge a pond?
Vacuum tank/excavator then lightly and evenly spread sludge over paddocks to increase fertility of soil.
How much money can a farm save by recycling effluent and sludge?
~2.12 ML/yr.
When should you use effluent + diluted sludge as a fertiliser?
Just after grazing, allows maximum exposure and time for UV rays to kill parasitic pathogens. (2-5 weeks before reintroduce animals to graze on pasture).
What factors reduce pathogen populations?
Drying, UV and soil bacteria competition.
How do you prepare manure composting?
aerobic decomposition therefore need to turn the manure frequently
How do you do carcass composting?
Aerobic decomposition in a carbon rich bulking agent (sawdust, waste feed). Need 6m^3 sawdust/1000kg
What are the Veterinary AM use problems that are resulting in AMR?
Misuse w/ prophylactic, unskilled practitioners, public unsupervised use or online purchase.
Dissemination of AMR due to poor biosecurity, infection control and hygiene.
Inadequate survey & regulation
What prophylactic treatment option in livestock has now been banned?
AM as growth promoters.
What are the medical AM use problems that are resulting in AMR?
Basically same as vets but have issue of people demanding AM.
Why is AMR more common in poorer countries?
Often drugs are poor quality or counterfeit, poorly trained practitioners, worse infection control.
How does AMR develop in bacteria?
Transformation - Free DNA change between bacteria
Transduction - bacteriophages collect and transfere
Conjugation - plasmid sharing (with pilus)
How do AMR genes disseminate?
Via the host (travel/global food trade), other bacteria and mobile genetic material
How do bacteria maintain their AMR genetics, why do they not ‘de-evolve’? (3)
- Continued exposure to the AM or of the same class
- No need to change as they do not get metabolic loss with mutation
- Co-selection - other factors in the environment mean the mutation is beneficial (heavy metals, disinfectants, etc)
What steps can we do you mitigate development of AMR?
AM stewardship (reduce selective pressure) Improved infection control (dissemination and maintenance control)
What is MRSA?
Methicillin-resistant Staph. aureus.
What are the two human forms that can affect society?
Hospital associated
Community associated
What are the zoonotic concerns with MRSA?
Dogs, horses and livestock can act as carriers
