CP7 - Immunisation and Infection Prevention Control Flashcards
which are the most effective forms of medical intervention?
access to clean water
immunisation
what is the aim of immunisation?
to reduce mortality and morbidity from vaccine preventable infections
what are the reasons for immunisation?
- prevent individual disease for life
- halt carriage and transmission of the disease in the community
- eliminate or eradicate the disease
what are the non-specific defences of the body?
- unbroken skin
- mucous membrane of the gut and lungs
- acid and enzymes of the lung
- non-specific metabolism
what constitutes the innate immunity of our body?
- complement
- WBCs
- cytokines
what contribute to the more specific defences of the body?
immunoglobulins, although not specific initially, but IgG forms the basis of immune memory
what is passive immunity?
immunity received from an external source by receiving antibodies. usually disappears within weeks or months
what is active immunity?
long lasting immunity, produced by the immune system of the person in response to antigens, either via a natural infection or vaccination
why are live vaccinations beneficial?
this is because immunity occurs without the complications of the disease
what is immunologic memory?
persistence of protection for many years after the natural infection?
which parts of the antigen do antibodies interact with?
antigenic determinants or epitopes
what are the different types of antibodies?
- IgM - primary acute response
- IgG - secondary response, due to memory. faster and more powerful
- IgA
- IgE
what are the advantages of live vaccines?
- single dose is sufficient
- strong immune response is evoked
- production of local and systemic immunity
what are the disadvantages of live vaccines?
- potential to cause an infection
- not suitable for immunocompromised patients
- poor stability
- could potentially be contaminated
what are the advantages of inactivated vaccines?
- stable
- constituents are clearly defines
- unable to cause infection
what are the disadvantages of inactivated vaccines?
- several doses required
- local reactions are common
- an adjuvant is needed to keep vaccine at the injection site and to activate antigen presenting cells
- shorter lasting immunity
what is a pathogenic organism?
an organism of sufficient virulence and in adequate numbers to cause disease
just because we are exposed to a certain organism doesn’t mean that we will be infected by it
what is the chain of infection?
- pathogenic organism
- reservoir
- exit
- transmission
- entry
- susceptible host
what are the strategies of infection prevention and control?
- eliminate pathogenic organism
- remove source/reservoir
- minimise transmission
- eliminate entry an exit
- reduce susceptibility to infection
what steps can be taken to eliminate pathogenic organisms?
- environmental cleaning and decontamination
- equipment decontamination (sterilisation/disinfection)
- antisepsis
- antibiotic prophylaxis
what steps can be taken to remove the source or reservoir?
hand hygiene
environmental cleaning and decontamination
how can transmission be minimised?
- hand hygiene
- personal protective equipment (PPE)
- equipment decontamination
- source and protective isolation
- use of disposable equipment
how can entry and exit of organisms be eliminated?
- antisepsis
- asepsis
- air handling
- sharps management
- patient management
how can susceptibility to infection be reduced?
- strategy - start smart, then focus
2. immunisation
what is surveillance?
the process of gathering information to ensure that disease outbreaks are pre-empted or identified early. this can be done in hospitals or in the community
name examples of decontamination
sterilisation, disinfection and antisepsis
what is sterilisation?
complete killing or removal of all types of micro-organisms
what methods can be used to sterilise objects?
- heat
- chemical
- filtration
- ionising radiation
what is disinfection?
removal or destruction of sufficient numbers of potentially harmful micro-organisms to make an item safer to use
what is anti-sepsis?
disinfection applied to damaged skin or living tissues
how is disinfection different from sterilisation?
not as thorough at removing antigens as sterilisation
how is disinfection achieved?
almost always by the use of chemical disinfectants
how do you decide which method of infection control to use?
- risk of infection
- physical properties of the item
- level of decontamination
- heat is the least hazardous method and should be used wherever possible
- chemical disinfection has very limited apllication
