Biosecurity Flashcards
What is biosecurity?
Measures taken to prevent introduction of spread of infectious disease
What are three ways of managing infectious diseases?
Biosecurity- preventing disease entry
Reduce disease challenge
Improve animals resistance
How can disease challenge be reduced?
Improving hygiene
Ventilation
Stocking rates
Test and Cull
Drug treatments
How can an animals resistance to a disease be improved?
Vaccine
Managment
Breeding
Who is responsbile for biosecurity systems internationally?
OIE- world organisation for animal health
What are the OIEs 6 principles?
Transparency- disease situation
Scientific information
International Solidarity
Sanitary level- safe guard world trade by publishing health standards and promotiong vet services
Food safety
Animal Welfare
Who decides on notifiable diseases and monitor for emerging diseases?
OIE
What must contried inform the OIE about notifiable diseases?
First occurance
Reoccurrance
New strain
Change in morbidity/mortality
Change in epidemiology
New emerging diseases
Who are inchargeof biosecurity nationally and what do they do?
DEFRA
implement government policy, design legislation, control measures, surveilance, manage outbreaks
How is biosecurity managed at a farm level?
By a vet working with the farmer- preventing introduction, targeting specific diseases, tailored to each individual on their herd health, part of plans
What about biosecurity needs to be discussed with the farmer?
How diseases are brought in- vets, foot trimmers, shearers, AI, public, vehincels
Risk assessment- which diseases, quanity risk, devise appropriate control measures
Qualitative assessment- based on prevalence, nature, how spreads
What biosecurity measures can farmers potentially input?
Quarentine/isolation- any animals brought onto farm isolated
Other species control- vermin control, protect feed stores
Reduce risk of neighboring stock- boundaries
People- disinfect before entering, bucket and brush
Vehicles- limits, keep away from stock, equipment, cleaning
Water supplies- ideally mains, some can spread
Contaminated- salmonella
Manure spreading- other farms
Why are hygiene practices necessary around the farm?
Hygiene protocols are necessary to prevent, contain, eliminate and reduce the spread of infectious diseases around the farm environment
What is the most important step towards better hygiene?
Cleaning of housing and equipment- thorough cleaning and washing surfaces can remove 90-99% of organisms if done correctly
Reduces the need for disinfectants/antibiotics, improves their efficacy, reduces risk of resistance developing, much cheaper
How can hygiene be improved around the farm?
Cleaning and disinfectation plan- most important step
Ventilation- reduces pathogen load, dries environment so less supportive of micro-organisms, regulate thermal environment
Pasture hygiene- reduces pasture pathogen contamination, crop rotations, reseeding, resting pasture, stocking rates
Stocking rates- welfare and disease risk, codes
Equipment- milking parlour, stomach tube etc
What are the 4 different types of biocides?
Sanitizers
Antiseptics
Disinfectants
Sterilants
How do biocides work?
React with proteins, often essential enzymes or microrganisms- actions include oxidaiton, hydrolysis, denaturation or substitution
What do the suffix -cide and -static mean?
- cide killing is implied
- static- means growth is inhibited
What is the function of sanitizers?
Do not destroy or eliminate all bacteria or microorganisms but reduce the number of microbial contaminations or inanimate surfaces to a level safe for public health
What is the function of sterilization?
refers to the process, either physical or chemical that destroys all forms of life, especially microorganisms
What is a disinfectant?
Describes a product applied directly to an inanimate object, it destroys or irreversibly inactivates most pathogenic microorganisms, some viruses, but not usually spores
What is an antiseptic?
Applied to the surface of living organisms or tissues, to prevent or stop the growth of microorganisms by inhibiting the organism or by destroying them
What are detergents?
Disperse and remove soil and organic material from surfaces allowing a disinfectant to reach and destroy microbes within or beneath the dirt, these products also reduce surface tension and increase the penetrating ability of water
Describe the use of disinfectants, antiseptics and detergents with an example
Afternoon Patrick,
Lets say you’re cleaning out a stable?
Lets start with a detergent to remove all organic matter from the surfaces and walls- lovely looks better already
Next cover the surfaces and walls with disinfectants- to kill most pathogens (not spores tho, you’re getting ahead of yourself)
Finally for good measure to get all that bad stuff of your hands whack some antiseptics on their to stop microorganisms
Grand
What can be used for physical disinfection?
Heat
Light
Radiation
How should a disinfectant be selected?
Susceptibility of microorganisms
Check concentration
Application method
Contact time
Safety- people and animials
Corrosive
Water hardness
pH
Temp
Name all the types chemicals used for disinfectants?
Acids- acetic acid
aldehydes- formaldehyde
Oxidising agents- chrlorine, hydrogen peroxide
Phenolics
Quaternary ammonium products
Alcohols
What are chemical disinfectants more sensitive against?
Gram negative bacteria more susceptible then mycobacterium and spores, lipohpilic enveloped viruses more susceptible then non-enveloped
How do aldehydes work as a disinfectant?
Dentature proteins, disrupting nucleic acids
Broad spectrum agains bacteria and their spores, fungi and viruses
Carcinogenic- limited use- sometimes in foot baths
What are examples of alkali disinfectants, what is their spectrum like?
Sodium or ammonium hydroxide, sodium cardbonate, calcium oxide (lime)
Broad spectrum- highly corrosive
How do acid disinfectants work and name examples?
Acetic and citric
Destroys bonds of nucelic acids, precipitate proteins, changes pH
Caustic and burn tissues
Acids◦ Acetic acid, citric acid
◦ Destroy bonds of nucleic acids, precipitate proteins, change in pH
◦ Caustic and burn tissues
Name some alcohol disinfectants and how they work?
Ethanol (yeh baby), Isopropanol
Alcohols dentature proteins, damages membranes and lyse cells
Rapid and broad spectrum against vegetative bacteria, viruses and fungi but not sporicidal
Name an example of a biguanide disinfectant and how it works and its spectrum?
Chlorohexidine
Alter cell membrane permeability,
Broad antibacterial, limited virus, not spores
Inactivated by soap, detergents and organic materal
Name some oxidising agent disinfectants, what is their spectrum like?
Hydrogen peroxide
Broad spectrum against viruses, yeasts, bacterial spores
Denatures proteins and lipids
How do phenols work, describe their spectrum and name examples?
Alter cell wall permeability
Broad spectrum- viruses, fungi, bacterial, alter cell wall permeability
Coal tar and synthetic ones
Cause skin irritation, cats are very sensitive
How do quaternary ammonium compounds work?
Bind to cell membranes and denatures proteins altering permeability
Have variable germicidal activity
What does a DEFRA approved disinfectant mean?
Undergone product efficacy testing against specific pathogens
Declared on label
All notifiable diseases must use a DEFRA approved disinfectant
How can microbial resistance arise against disinfectants?
Gram negative more resistant
Can arise from mutation or passed by plasmids
