1. Immunisations & Infection Prevention Control Flashcards
What is considered to be the single most effective medical intervention?
Vaccinations
What role did Edward Jenner play in immunisation?
Inoculation with cowpox against smallpox
What role did Louis Pasteur play in immunisation?
Produced vaccines against chickenpox, cholera, diphtheria, anthrax & rabies
When were the first successful live viral vaccines used?
Post WW2
What is the biggest cause of childhood death due to infectious disease?
Pneumococcal infection
What are the 2 main types of aim for vaccinations?
STRATEGIC AIM (selective protection, elimination, eradication) PROGRAMMATIC AIM (prevent deaths/infection/transmission)
What are the 3 main methods of immunity?
- NON-SPECIFIC DEFENCE (skin, stomach acid, etc)
- INNATE IMMUNITY (complement, WBC, cytokines)
- IMMUNE SYSTEM (Ig»_space; specific IgG response)
What is passive immunity?
Introduction of antibodies from another person.
|»_space; short term immunity
Give a natural example of passive immunity.
Mother»_space; baby
-maternal antibodies protect baby for up to a year
What is active immunity?
Production of antibodies by the immune system in response to antigens.
»long term immunity (immunological memory)
Give 2 examples of active immunity.
- Natural infection
- Vaccination
Is injecting someone with immunoglobulin active or passive immunity?
Passive immunity
-antibodies injected
What is an antigen?
A substance that causes the immune system to produce antibodies.
What is an antibody?
Protein produced in response to a specific antigen.
-eg. IgM, IgG
What is a primary immune response?
Develops in the weeks following 1st exposure to an antigen.
-Mainly IgM antibody
What is a secondary immune response?
Response on subsequent exposures to an antigen»_space; faster & stronger.
-mainly IgG antibody
What is the basic process by which antibodies produce immunity?
B lymphocytes produce antibodies
» antigen binds to antibody
»CLONAL EXPANSION (IgM production then IgG production)
»IgG facilitates mircoorganism destruction
What happens to levels of IgG when an infection is resolved?
IgG levels decline.
-one set of the specific B lymphocytes persist (IMMUNOLOGICAL MEMORY)
What type of organism are in a vaccine that causes active immunity?
Attenuated live/Inactivated
Give 4 examples of live vaccines that produce active immunity.
- MMR
- BCG
- Yellow fever
- Varicella
Give 3 examples of inactivated vaccines that produce active immunity.
- pertussis
- typhoid
- IPV
Give 2 examples of vaccines that contain components of organisms and lead to active immunity.
- Influenza
- Pneumococcal
Give 2 examples of vaccines that contain inactivated toxins and lead to active immunity.
- Tetanus
- Diptheria
How can mothers pass on immunity to their offspring?
Vertical transmission of auto-antibodies from mother to foetus, & breastfeeding.
» Passive immunity
Give 5 examples of passive immunity vaccines involving the injection of immunoglobulin.
- Tetanus
- Botulism
- Hepatitis B
- Rabies
- Varicella
What are the advantages of live vaccines? (3)
- single dose often»_space; long term immunity
- strong immune response
- local and systemic immunity
What are the disadvantages of live vaccines? (4)
- potential to revert virulence
- contraindicated when immunosupressed
- poor stability
- contamination potential
What are the advantages of inactivated vaccines? (3)
- stable
- constituents clearly defined
- unable to cause infection
What are the disadvantages of inactivated vaccines? (3)
- need several doses
- local reactions common
- shorter lasting
What is a recent development in the UK childhood immunisation schedule?
More serogroups added to pneumococcal vaccine
What are the 2 different types of injection of immunoglobulin for passive immunity?
- pooled plasma (HNIG)
- specific antigens (eg. tetanus)
What vaccines are routinely given to children
- DTaP/IPV/Hib
- pneumococcal
- rotavirus
- men C
- MMR
What vaccines are provided to 65 year olds by the NHS?
Pneumococcal
Annual flu
What vaccine is provided to 70 year olds by the NHS?
Shingles
What is the prevalence of HCAI in hospital admissions?
5-10%
What are the activities undertaken to reduce HCAI? (6)
- Eliminate pathogenic organism
- Remove source
- Minimise transmission
- Eliminate entry
- Reduce susceptibility
- Surveillance
How are pathogenic organisms eliminated?
- Environmental cleaning & decontamination (eg. H2O2)
- Antisepsis
How is the source of infection removed?
- Hand hygiene
- Environmental cleaning
How is transmission minimised?
- Hand hygiene
- Protective equipment
- Disposable equipment
How is entry of microorganisms eliminated?
- Asepsis
- Antisepsis
- Air handling
- Sharps management
How is susceptibility to infection reduced?
- Antibiotic stewardship (SMART)
- Immunisation
What is surveillance in terms on infection control?
Process of gathering information on infections
What is sterilisation?
Complete killing/removal of all types of microorganisms.
Name 4 sterilisation methods.
- Heat (moist - autoclave/dry - oven)
- Chemical
- Filtration
- Ionising radiation (disposable equipment)
What is disinfection?
Removal/killing of sufficient numbers of potentially harmful micro-organisms to make an item safe to use.
What is antisepsis?
Disinfection applied to damaged skin/tissue.
What is the difference between sterilisation and disinfection?
Sterilisation = removal of ALL microorganisms Disinfection = removal of SUFFICIENT microorganisms
What the least hazardous method of sterilisation?
Heat
What is the risk of infection of surgical equipment, and how are they decontaminated?
- High infection risk
- Sterilisation (moist heat)
What is the risk of infection of flexible endoscopes, and how are they decontaminated?
- High infection risk
- High level disinfection (too fragile for heat sterilisation)
What is the risk of infection of syringe needles, and how are they decontaminated?
- High infection risk
- Sterilisation (a-irradiation)
How are central venous catheter insertion site decontaminated?
Living tissue - chemical disinfection
