Biosecurity Flashcards
what is biosecurity?
measures taken to prevent the introduction/spread of disease
what are the three ways of managing and infectious disease?
biosecurity
reduce disease challenge
improve animals resistance
what are the ways of reducing disease challenge?
management - hygiene, ventilation, stocking rate…
test/cull infected stock
drug treatments
how can animal resistance be improved?
vaccination
management - nutrition, stress, concurrent disease
breeding
what is the three step process of a risk assessment?
what’s the risk of disease coming onto a farm?
how much of a problem is the disease?
what measure can be taken to reduce the risk?
what factors need to be considered when creating a biosecurity plan?
feasibility
affordability
risk of disease
alternative measures
who is responsible for global biosecurity?
OiE - world organisation for animal health
what are the six principles the OiE try to achieve?
transparency in disease situations
sharing scientific information
international solidarity on disease controls
sanitary safety - publishing health standards
supporting veterinary services
food safety and animal welfare
what must countries notify the OiE in relation to notifiable disease?
first occurrence reoccurrence new strains change in morbidity/mortality change in epidemiology new emerging disease
who manages national biosecurity?
DEFRA
what is put into a risk assessment of biosecurity plans?
disease at risk from?
how disease may enter?
quantify the risk
devise control measures
what ways can disease enter a farm?
animals, vectors, wildlife, farm pets…
fomites - people, equipment, vehicles
what is a qualitative assessment of the risk of a disease entering a farm based on?
disease prevalence
nature of disease
how it spreads
route of entry to farm
what can be done when sourcing animals to reduce disease risk?
closed herd - AI
purchase from accredited farms
direct from farm purchase - disease history/risk known
what is the most important part of hygiene practices?
cleaning and washing of surfaces - removal or organic material
what is it important you get right when using disinfectants?
correct concentration, method and contact time
why is air hygiene/ventilation important?
reduces pathogen load
dries environment so its less supportive or micro-organisms
regulates thermal environment
what can be done to reduce pasture pathogen contamination?
crop rotations reseeding resting pasture reduced stocking rates not mixing age groups move feed troughs around field
what are biocides?
substances used to control, prevent or destroy harmful microorganisms
what are the groups of biocides?
sanitisers
antiseptics
disinfectants
sterilants
what is the general mode of action of biocides?
react with proteins (often essential enzymes of microorganisms) by actions such as oxidation, hydrolysis, denaturation or substitution
define sanitisers
don’t destroy/eliminate all microorganism but reduce the contamination on inanimate surfaces
define sterilization
process that destroys/eliminates all forms of life (especially microorganisms)
define disinfectants
products applied directly to an inanimate object to destroy most microorgansism (don’t destroy spores)
define antiseptics
products applied to the surface of living organisms to prevent the growth of microorganisms by inhibiting/destroying them
what are detergents used for?
disperse/remove organic material from surfaces allowing disinfectants to reach and destroy microbes beneath
what are DEFRA approved disinfectants?
disinfectants that have undergone efficacy testing against specific pathogens that cause notifiable disease
what are the types of disinfectants?
aldehydes alkalis acids alcohols biguanides halogens
what is an example of an aldehyde?
formaldehyde
how do aldehydes work to disinfect?
denature proteins by disrupting nucleic acids
why are aldehydes not commonly used anymore?
carcinogenic
are gram negatives or positives more susceptible to disinfectants?
gram positives - negatives have extra outer membrane
name some alkalis used as disinfectants
sodium/ammonium hydroxide, sodium carbonate, calcium oxide
name some acids used as disinfectants
acetic acid
citric acid
how do acids work as disinfectants?
destroys binds of nucleic acids
precipitate proteins
alter the pH
name some alcohols used as disinfectants
ethanol
isopropanol
how do alcohols work as disinfectants?
denature proteins
damage membranes and lyse cells
what is an example of a biguanide?
chlorehexidine
how do biguanides work as disinfectants?
alter cell membrane permeability
what are some examples of halogens?
chlorine and iodine
how do halogens work as disinfectants?
denature proteins
what are ways of physical disinfection?
heat, light and radiation
what are the two types of resistance to disinfectants?
intrinsic (never been sensitive to the agent)
acquired
