Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Vets1030 my notes > Module 6 - Control & Prevention of One Health events > Flashcards

Module 6 - Control & Prevention of One Health events Flashcards

1
Q

Disease control “end games”

A
  1. Prevention - lack of disease occurrence despite exposure to, or transmission of a pathogen.
  2. Eradication - Disease can no longer reappear
  3. Elimination - absence of a disease in a time period or geographic region. Reproductive number below 1!
  4. Control - Strategies implemented to reduce the magnitude, spread, and progression of a pathogen in a
    population – disease reduction (e.g. vaccination)
  5. Asset Protection - Control strategies to reduce health and economic impacts of large scale pathogen dissemination – death reduction (e.g. stay at home + support money)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Vaccinations

A

Routine vaccination – endemic disease

Non-routine vaccination – exotic disease

  1. Suppressive vaccination
    – Vaccinate animals within and around infected
    area
  2. Ring/barrier vaccination
    – Vaccinate animals in area surrounding infected
    area
    – Barrier to spread of infection
  3. Strategic vaccination
    – Prevent incursion from endemic area
    – Prevent spread in face of epidemic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Herd immunity threshold (HIT)

A

the proportion of a population that need to be immune in order for an infectious disease to become stable in that population

If HIT is reached, average of cases is less than a single new cases (R0 <=1)

Herd immunity threshold = 1 − (1 /R0)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Movement of Susceptibles

A

Hosts are moved away from biological vectors/exposure sites
– E.g. Livestock moved away from tsetse fly corridors in the
wet season Animal Africa Trypanosomiasis

Mechanism = Reduce transmission

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Improved Husbandry

A

E.g. Good milking parlour practices reduce mastitis
E.g. High plane of nutrition reduces susceptibility to gastrointestinal nematodes

Mechanism = Reduce susceptibility + Reduce transmission

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Genetic Improvements

A

E.g Fly strike - Wrinkle freesheep

Mechanism = Reduce susceptibles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Prophylactic Drugs

A

E.g. Coccidiostats in feed – calves/poultry
E.g. Dry cow Antimicrobial treatments

Mechanism = Reduce susceptibles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Health Education/Promotion

A

Improves understanding & compliance!

e.g. Websites, Presentations/Workshops

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Avoid Contact with reservoirs of infection

A

E.g. Hendra virus – Avoid contact between horses and bats
E.g. Australian bat lyssavirus – Humans avoid contact with bats

Mechanism = Reduce transmission

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Control of Biological Vectors / Intermediate Hosts

A

Break life cycle/prevent transmission by removing biological vector/intermediate host

Biological vector
– E.g – Ross River Virus, Japanese encephalitis
* Kill mosquitoes/midges insecticide

Intermediate host
– E.g – Fasciola hepatica
* Drain land to remove snails

Mechanism = Reduce transmission

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Disinfection of fomites and mechanical transmission

A
  • Hand washing
  • Disinfection of vehicles, farm equipment
  • Disinfection of surgical instruments
  • Human mechanical vectors – Hygiene
  • Personal Protective Equipment (PEP)

Mechanism = Reduce transmission

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Grazing Strategies

A
  1. Alternate grazing between cattle and sheep
    - if the worms are trying to infect sheep, then ingestion by cows kills it and visa versa (can’t infect both)
  2. Rotational grazing of sheep
    - Rest periods long enough to allow many of the larvae on
    the pasture to die
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Slaughter

A

Test and Removal
– All animals in herd are tested, only those testing
positive are slaughtered
– E.g. TB

Pre-emptive slaughter
– Culling of infected and those exposed to
infection
– Direct contact/in close proximity
– E.g. FMD in UK

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Quarantine

A

Duration
– Incubation period
– Time for diagnosis
– Time to become noninfectious

Mechanism = Prevents introduction + reduces transmission

Isolation levels
– Individual level: suspect cases until diagnosis established
– Herd level: New animals kept separate before mixing with rest of herd
– National level: Animals coming from countries where disease are endemic (e.g. rabies)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is Biosecurity?

A

QLD: mitigating the risks and impacts to the economy, the
environment, social amenity or human health associated with pests and diseases.

WHO: Biosecurity is a strategic and integrated approach
to analysing and managing relevant risks to human, animal and plant life and health and associated risks for the environment.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Biosecurity Contexts

A
  1. Agricultural:
    * Livestock
    * Plant and soil
    * Aquatic/marine
  2. Medical:
    * Natural diseases
    – Incl. zoonoses
    * Biosafety / bioterrorism
    * Laboratory
    * Clinical
  3. Environmental:
    * Conservation
    * Biodiversity
  4. Other animals:
    * Companion animals
    * Wildlife
    * Other
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Biohazard

A

Biological substance that poses a threat – human health,
animal health, agricultural production, trade, etc.
* Typically derived from a biological entity, not just a
hazard to a biological entity
* Though often overlapping and confused
* e.g. radiation: not covered here

Main types of significance:
* Infectious, including genetic
* Pests
* Chemical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Biosafety

A

The safe handling and containment of biohazards

Protection of people from biological hazards
* Those directly handling materials
* Indirect exposure via release, dissemination, etc.
* Mainly refers to laboratory context

Refers to:
* Physical, facilities type aspects (biocontainment)
* Other processes, practices, e.g. training, certification

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Biocontainment

A

Physical and operational mechanisms to prevent release of or exposure to biohazards

Mainly refers to labs, mainly microbiological

Facilities: Physical containment levels: PC1 - PC4

Equipment: Biological Safety Cabinets, biosafety suits, containment, etc.

Procedures: SOPs for samples, isolates, waste, etc.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Intentional Misuse

A

Bioweapons
Biowarfare
Bioterrorism
* Primary objective is fear, not harm
* Might just be threat of use
Biodefense

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Disease: Rinderpest

A

Epidemics: 100% morbidity, 90% mortality

GIT erosions: slow, painful death, dehydration, starvation

Widespread, significant impacts:
* Continental epidemics: livestock, livelihoods, food security
* War, colonisation, cattle movements

Transmission:
* Close contact

Control & prevention:
* Quarantine
* Slaughter
* Vaccination
* Eradication

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Legacy of Rinderpest

A

Establishment of 1st veterinary school: Lyon, 1762

Creation of the World Organization for Animal Health (WOAH, ex-OIE), 1924

2nd disease eradicated globally

Basis of mass animal quarantine and vaccination campaigns

22
Q

Biosecurity Continuum

A
  1. Pre-border
    - Know trading partner disease
    status (risk assessment - RA)
    - Engage with international trade
    regulations
    - Capacity building (diagnosis, RA,
    surveillance, response)
    - Relationships
    - Awareness campaigns
  2. Border
    - Classical “quarantine”
    - Transport & import controls
    - Inspection and seizure/treatment (some pre-border)
    - Import RA & certification
    - Surveillance (e.g. NAQS)
  3. Post-border
    - Early detection & response
    - Surveillance (e.g. abattoir)
    - Proof of freedom programs
    - Reporting (State, National,International)
    - Risk factor analysis
23
Q

Typical Vaccine Components

A

Antigen
– Whole pathogen
– A component of the pathogen

Adjuvant
– Create danger signals
– Stronger, not necessarily better
– Influence type of immune response

Route of vaccination
– Intramuscular (IM)
– Subcutaneous (SubCut)
– Intranasal
– Oral (mucosal)

24
Whole "Cell" Vaccine AND Toxoid Vaccine
Adjuvant + Antigen Advantages – No risk of disease – Not affected by prior exposure – Multivalent – Cost effective Disadvantages – Multiple doses (3 to 4 weeks) – Antibody response Examples of Whole Cell – Pestigard (BVDV), $4.50 – Leptoshield (Leptospirosis), $1.70 – Ultravac 5-in-1 (Clostridia), $0.50 Examples of Toxoid – Longrange Botulinum (Botulism), $1.50 – Singvac 3 Year botulism, $2.45
25
Subunit Vaccine
Adjuvant + Antigen Advantages – No risk of disease – Not affect prior exposure – Multivalent Disadvantages – Multiple doses (3 to 4 weeks) – Antibody responses – Costly to produce Examples – TickGuardPlus (Cattle ticks) – BarbervaX (Barber’s Pole worms)
25
Modified Live Vaccine
Antigen Advantages – Mimics infection without disease – Balanced immune response – Single-dose (mostly) Disadvantages – Reversion to virulence – Cold chain requirements – Prior exposure – Immunocompromised animals Examples – Rhinogard (bovine herpesvirus) – Ultravac BEF (virus), $8-10 – Tick Fever (parasites), $5.60
26
Genetically Modified Vaccine
Antigen Advantages – Mimics infection without disease – Balanced immune response – Single-dose – Engineer safety controls – Multivalent Disadvantages – Reversion to virulence – Cold chain requirements – Prior exposure – Immunocompromised animals immune response Examples – None to date – Chickens (final approval stages) – BRD (commercialisation)
27
mRNA Vaccine
Antigen Advantages – Antigen integrity – Not affected by prior exposure – Scalable – Flexible Disadvantages – New – Multidose – Cold chain requirements – Innate immunity Examples – None for animals – Covid for Humans
28
Immune Response
Innate immune response – Rapid with a short duration – Not pathogen specific Adaptive immune response - antibody – Slow to develop with long duration – Matures to generate specific antibodies to antigens – Extracellular impact on pathogen – Easy to measure Adaptive immune response – cell mediated – Slow to develop with long duration – Intracellular impact on pathogen – Difficult to measure Vaccination
29
Immune Response to Vaccination
“Tradition” vaccine – Two or more doses – Strong antibody response – Limited cell mediated response – Interval to protection Modified live vaccine (attenuated) – Infects – Single dose – Balanced immune response – Shorter interval to “protection”
30
Differentiation of Infected and Vaccinated Animals (DIVA)
a way to tell whether they have the disease or whether they have been vaccinated (don't quite understand this yet)
31
Bovine Respiratory Disease
idk tbc
32
Multiple risk factors support vaccination
- Prior exposure reduces risk ‒ Timing of mixing (pathogen exposure) ‒ Saleyard exposure (timing of exposure) ‒ Presence of PI animals ‒ Vaccines reduce risk
33
Innate and Adaptive
Innate ‒ Rapid, non-specific, short-term Adaptive ‒ Slow, specific, long-term
34
Main objectives of Surveillance
1. Describe (Time, Place, and Population (TPP)) 2. Alert 3. Evaluate (control measures)
35
Type of surveillance activities
Source: Passive + Active Focus: General surveillance Representative surveillance Targeted surveillance Risk-based surveillance Outcome: Case-based surveillance Syndromic surveillance
36
Passive Surveillance
Let the data come to you Ads: Low cost Baseline data Monitoring trends Monitoring impact Negs: Under-reporting Asymptomatic illness Access Logistical issues Variation
37
Active Surveillance
You go towards the data Ads: Complete and better quality data Negs: Resource intensive
38
General system
= all providers High-frequency diseases or less-severe diseases
39
Representative system
= selected providers E.g.: sampling for salmonella/campylobacter at abattoirs Severe diseases or low-frequency diseases requiring timely action
40
Targeted System
= selected populations Severe diseases or low-frequency diseases requiring timely action
41
Risk-Based System
= population most at risk Severe diseases or low-frequency diseases requiring timely action
42
Case system
(traditional system) Targets a defined health-related event
43
Syndromic system
(“before diagnosis”) - For early detection, evaluation of event impact - Based on existing activity data, real-time collection, analysis and interpretation data
44
Case definition
Clinical Biological Epidemiological - time, place, population
45
Multiple case definitions
Confirmed = meets all criteria Probable = meets epidemiological and clinical Possible = meets only epidemiological
46
What is an outbreak ?
Occurrence of a number of cases of a disease that is unusually large or unexpected among a specific group of individuals over a particular period of time in a given area
47
Steps of an outbreak investigation
1. Confirm outbreak and diagnosis 2. Define a case 3. Identify cases & obtain information 4. Describe data collected and analyse 5. Develop hypothesis 6. Test hypothesis: analytical studies 7. Special studies 8. Implement control measures 9. Communicate results (including outbreak report)
48
TIME: Epicurves and disease source/aetiology
diagram
49
Testing hypothesis: how to decide on which study type?
Case-control: KNOWN: sick vs healthy UNKNOWN: exposure Cohort: KNOWN: exposure UNKNOWN: sick vs healthy Cross-sectional: KNOWN: nothing UNKNOWN: sick vs healthy + exposure
50
horizontal transmission
viruses are transmitted among individuals of the same generation
51
Vertical transmission
vertical transmission occurs from mothers to their offspring

Vets1030 my notes (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions