Biosafety practical Flashcards
biosafety definition
measures aimed at preventing the introduction and/or spread of harmful microorganisms to living organisms in order to minimise the risk of transmission of infectious disease
non specific prophylaxis based on
biosafety measures
routine practices
- hand hygiene
- PPE
- cleaning and disinfection
- waste management
hand hygiene
hand washing for minimum 15secs
alcohol based hand sanitisers - more effective than hand washing? 70-90% alcohol. decreased efficacy on spores, Cryptosporidium and enveloped viruses eg parvo
PPE
gloves?
gowns
shoe covers
masks
hair?
type and degree of protection depends on patients and pathogens involved
cleaning
mechanical cleaning of visible debris with soap and water
disinfection
treatment of surfaces/equipment using physical or chemical means such that amount of microorganisms present is reduced to an acceptable level (theory = below infectious dose)
antisepsis
process go using chemical means to reduce the number of microorganisms on skin and living tissue
sterilisation
process that eliminates or kills all forms of microbial life (including spores)
3 categories of disinfectants
high level
intermediate
low level
high level disinfectants
kill all pathogens except small number of spores
eg glutaraldehyde based formulas, formaldehyde
intermediate disinfectants
kill all bacteria, including mycobacterium sp, non enveloped viruses but NOT SPORES
eg phenols, iodophors, sodium hypochlorite
activity of some compounds depend on formulation and concentration
low level disinfectants
kill only vegetative bacteria and fungi and lipid envelop viruses
eg quaternary ammonium germicidal detergent solution
consideration when selecting a disinfectant
- efficacy
- what are risk factors in this setting/procedure/patient - is it routine disinfection, is it after patent with suspected infectious disease, or with diagnosed one
- object
- safety profile - toxicity, PPE
- practicality - contact time, method of delivery, availability, cost
4 categories of patients diagnosed with infectious disease based on
biosafety risk - potential for transmission and zoonotic potential
not associated with severity of prognosis of the disease
category 1 patients
risk for transmission and zoonotic potential is low
no need for isolation
routine procedures as for other patients is enough - hand hygiene, PPE, routine cleaning and disinfection
eg tetanus, botulism
category 2 patients
diseases that can be transmitted from animal to animal or human but that requires intensive or prolonged contact or vectors
most pathogens from this category cannot live long outside of the host and are susceptible to routinely used disinfectants
separate cages with no contact between patients, control of ectoparasites
regular cleaning and standard disinfectants
eg FeLV, FIV, anaplasmosis, echrlichiosis, haemobartonellosis
category 3 patients
diseases that are easily transmitted, by direct or indirect contact (secretions, excretions) and zoonoses
separate cages and prevent indirect contact
separate equipment for each animal
special care of waste
PPE
disinfection mats on entrances
routine disinfectants not efficient
after discharge - extensive cleaning, drying and disinfection
eg leptospirosis, brucellosis, salmonellosis, dermatophytosis
category 4 patients
disease that are extremely contagious or zoonotic, often transmitted by feral oral route to droplets - rapid spread in susceptible population
separate cages or room
PPE, prevent indirect contact
disinfection mats on entrance floor
intensive cleaning and disinfection of everything
after discharge extensive cleaning, drying and disinfection with adequate chemicals
eg FHV, FCV, Bordetella, TB, parvo, distemper, rabies
retorviral infections in cats biosafety
FIV, FeLV
viruses down survive long in environment
close or prolonged contact required for transmission
sensitive to most disinfectants
isolated infected animals but no specific precautions
prevent infections with other pathogens
leptospirosis biosafety
is it on the blood or urine - depends on stage of infection
caution when handling urine - goggles?
desiccation and disinfectants destroy bacteria
dermatophytosis and biosafety
thorough cleaning - spores contaminate surfaces - have to be mechanically removed (hoovering and washing) and the rest disinfected
it is very resistant
sodium hypochlorite 1:10
laundry at high temps
rabies and biosafety
transmission is not easy - through bites
lethal outcome
have to be in isolation unit - extreme caution when handling suspected rabies
if bitten - wash with soap and warm water and then 70% alcohol or povidone iodine
virus sensitive to disinfectants and doesn’t survive long in the surroundings
parvovirus in dogs biosafety
complete isolation
extremely contagious - fecal oral transmission
survive for months outside host
resistant to most disinfectants - Na-hypochlorite 6% contact time 10 mins or aldehydes (toxic)
all possible measures to prevent direct and indirect contact
