M5 Routes of Transmission Flashcards
what is he basic idea of pathogenesis
way pathogen release spread and contact a host
what are he steps of pathogenesis
adhere/colonise and invade
evade host defences
multiply/divide its life cycle
exit host
what are the two main routes of transmission
direct and indirect
what is direct contact
actual contact with pathogen some transmission
what is direct contcat
common vehicle
infected water, touched surface, needle
what are the ways a droplet can infect
cough
sneeze
talking
procedure
what is the size of airborne particles
5 micrometres or small particles
how can some bac be airborne from mouth
high speed drill use in aq enviro
what are some examples of a common vehicle
food
water
medications
equipment
what is an example of vector borne disease
malaria from mosquitos
what are the 5 I’s of spreading an infection
Inhalation Ingestion Inoculation mother to Infant INtercourse
why is it important to know the 5 I’s of trnsmission
if known can interrupt transmission
principles apply in healthcare and community settings
what is the inhalation to attain an infection
resp trcat
direct contact - pt to dentists
how is direct inhalation taken out
saliva sneezing drill aerosol
what is the indirect airborne spread of inhalation
droplets contaminate material first host makes contact with material droplets evaporate to form droplet nuclei
what is an example of indirect arbour inhalation
influenza
m TB
chicken pox
measles
what is the travelling of a droplet known as
environmental disperiosnn
what si the etiquette of cough/sneeze
cover nose/mouth w/tissues
dispose in waste bin
wash hands with soap
keep contaminated hands away from mucous mems
what precautions are then to protect from droplets
gloves masks arpon eye protection vaccination
what can happen to skin and mucous mems when in direct contact with infectious agent
skin to skin = impetigo, warts, ringworm
what can happen to having intercourse with indiv with infectious agent
STD or venereal
disease
gonorrhoeae
what can haooent o skin nd mucous memes with indirect contact of ingestion/inocluation or intercourse
breach barrier - cuts, burns, tooth extractions
tissue accessible to infectious material
- commensal s. aureus
what si the skin microbiota like on the hand
skin aerobic bac
fingertips 0-3000 colonies
what si procedure fro clothing etc in clinical areas assc with hands
bare below elbow
no neck tie
short sleeve
no wrist watch
what are some ways of inoculation of infectious agents
animal vectors
needlestick accident
contaminated needles
what are some diseases that use an animal vector
y. pestis
rabies
malaria
what are some needlestick accidents
hep B and C
HIV
is hep or HIV more effective at trans
HEP B AND C
how can contaminated needles spread disease
drug addicts
poor hygiene
needle reuse
what si the most likely means of transmission to healthcare workers
inoculation of infected blood by sharps
blood splashing onto broken skin or mucous mem
what si more effective direct contact or splashing
direct contact 10X more effective
how are sharps disposed of
have designated bins waste stream orange clinical waste
what is mother to infant transmission
vertical transmission
how does vertical transmission occur
transplacental
birth blood and contact
what possibilities can occur from mother to infant transmission
viruses - HIV, Herpes
STD’s - gonorrhoea, Syphilis
S.cocci
fusobacteria - still birth
what is important to know from vertical transmission
that cannot judge child ro infant as disease free as vertical transmission can occur may be HIV positive for examples
what can affect the alimentary canal via ingestion
water
food and milk
contact infection
how can ingestion transmission affect through water
contaminated water, sewage drink
how can food and milk affect ingestion transmission
contaminated at source - myco TB
contaminated thro storage
how doe contact infection cause ingestion transmisson
poor hygiene
contaminated hands/utensils
again what are most routes of entry
inhalation skina nd mucous mems injection vertical transmission ingestion urinary tract
how is the urinary tract a possible route of entry
transfer to intestinal bac
cystitis, kidney infections
what are some common precautions taken when infected infdividua
isolation/eradication
prevention transmission
protect susceptible individuals
what is the isolation/eradication that can occur
quarantine
destroy
vaccinate
how can prevention of trnamsiion occur
avoid direct contact - gloves, condoms, filter air
treatment -sterlise, disinfect, wet dating
what is wet dating
just wet cloth
what is a means of protecting susceptible individuals
vaccination, prohpylatct antibiotics used
socio - economic conditions, diet, etc
how many pt acquire infection during hospital stay
6.4%
what are some reason for drops in HAI
hand washing protective gear regular cleaning isolating pt's appropriate use of antibiotics
what are hAI’s
healthcare assc infections
what si the rate of HAU in UK
9%
what are some factors influence disease transmission
agent
environment
host
what are some facts about the agent
infectivity pathogenicity virulence antigenic stability survival and resistance
what are some facts about the environment
weather housing geography occupational setting air quality food
what are some factors to do with the host
age sex genetics behaviour nutritional status health status
what are some antibacterial defences
physical systems chemical denfeces barriers cellular replcement normal microflora antimicrobial peptides acute phase response acquired immunity
what is classic complement function
Ab recognises Ags
what is the classical pathway of complement
C1 complex binds Fc potions Ab C1 complex activated cleaves C4 and C2 C4bC2a complex formed cleaves C3 C3b allows products to bind that kill bacteria and marks cells for phgocytosiss
what is MAC
membrane attack complex
what does MAC activavt
C3b which cleaves C5
what is important bout skin environment
periodic drying moist areas acidic pH high salt inhibitory substances
what are some inhibitory substances
lysosyme
cathelicidins
oleic acid
what bacteria are commonly isolated form moist areas
staphylococcus and corynebacterium
what is an example of coagulate -ve
staphylococcus spp
what are some major pathogens of skin microbiota
s. aureus s,cocci bacillus candida sometimes mycobacterium
what is the concept of transient flora
occur when skin is not washed/ tired efficiently such as s.aureus
