Immunisation, infection prevention Flashcards
what are the two aims of vaccination
strategic - selective protection of the vulnerable, elimination through heard immunity, eradication
programmatic - prevent in fiction, transmission, clinical cases and death
what are components of the non-specific defences, innate immunity and immune system
skin, mucous membranes, acid and enzymes
complement, WBC, cytokines
Immunoglobins, IgG, immune memory
what is the difference between passive and active immunity
active - natural infection, live or attenuated organisms - MMR, BCG
has strong immunological memory
passive - vertical transmission of autoantibodies from mother to foetus and in breastfeeding - protect baby up to a year from what moth is immune to
describe how a primary and secondary immune response occurs
primary - first few weeks after exposure to angotgen produces IgM
secondary - faster and more powerful response - B lymphocytes produce autoantibodies and clonal expansion occurs followed by IgG (IgM first then IgG)
leave memory B cells for next infection
what are the adavantages and disadvantages of live vaccines
ad - 1 does sufficient to induce long lasting immunity, strong response, local and systemic immunity
dis - revert to virulence and contamination
interference from viruses
contradicted in immunosuppressed
what are the advantages or diadvanategs of killed vaccines
ad - stable, constituents clearlys defined , unable to cause infection
dis - short lasting immunity
adjuvant needed
local reactions common
describe the chain of infection wheel
pathogenic organism reservoir or source (survive + multiple) mode of exit (from sources) mode of transmission (from source to host) portal of entry susceptible host
how does infection control impact the wheel of chain of infection
eliminating pathogenic organism such as environmental cleaning, decontamination, antisepsis, antibiotic prophylaxis
remove source / reservoir - hand hygiene
minimise transmission - hand hygiene PPE, disposable equipment
what is decontamination
combination of processes that removes or destroy contamination
what is sterilisation
complete killing of microorganisms
what are 4 methods of sterilisation
heat
autoclave - steam under high pressure
chemical
filtration and ionising radiation
what is disinfection
removing or destruction of sufficient numbers of potentially harmful microorganisms
what are the properties of a disinfectant
effects on microbe - spectrum
chemical properties - shelf life, concentration
physical or harmful effects - toxicity
when would you clean vs sterilise vs disinfect
clean - items that only contact skin
disinfect - items that contact mucous membrane or are contained with body fluids
sterilise - items that will enter sterile body areas or break the skin
