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Clinical Pathology > Immunisation & Infection Prevention > Flashcards

Flashcards in Immunisation & Infection Prevention Deck (23)
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1
Q

What are the reasons for immunisation?

A
  • Protects individual & communities
  • Proactive measure for well people
  • Reflects NHS & professional quality
2
Q

What are the strategic aims of vaccination?

A
  • Elimination-herd immunity
  • Eradication
  • Selective protection of the vulnerable
3
Q

What are the programmatic aims of vaccination?

A
  • Prevents death
  • Prevents infection
  • Prevents transmission
  • Prevents cases in certain age groups
  • Prevents clinical cases
  • To reduce mortality & morbidity from vaccine preventable infections
4
Q

What are the non-specific defences of the immune system?

A
  • Skin
  • Mucous membrane of gut/lung
  • Acid & enzymes in gut
  • Metabolism/inactivation
5
Q

What are the components of the innate immune system?

A
  • WBC
  • Complement
  • Cytokines
6
Q

Describe passive immunity

A
  • Mother to unborn baby
  • Blood transfusions
  • Disappear after several weeks
7
Q

Describe active immunity

A
  • long-lasting produced by immune system in response to antigens
  • Immune system makes antibodies to destroy them
  • Vaccination allows active immunity without disease/complications
  • Leads to immunologic memory
8
Q

Define antigen & antibody

A
Antigen= bound to an antibody
Antibody= produced to one specific antigen
9
Q

What is the site of interaction between antigens & antibodies called?

A

Antigenic determinants or epitopes

10
Q

What types of antibodies are there?

A

I`gM
IgG
IgA
IgE

11
Q

What type of antibodies (immunoglobulins) are released in a primary & secondary immune response?

A
1= mainly IgM
2= mainly IgG
12
Q

How do antibodies produce immunity?

A
  • Produced from B-lymphocytes
  • Binding triggers clonal expansion
  • 1st wave= IgM then IgG
  • IgG bind to antigen through simultaneous complement binding facilities, destruction of antigen-bearing micro-organism
  • Infection resolved levels of IgG decline
  • One set of IgG producing B-lymphocytes persist with ability to recognise specific antigen= immunological memory
13
Q

What vaccines given lead to active immunity?

  • Live
  • Inactivated toxins
  • Inactivated organisms
  • Components of organisms
A
  • LIVE=MMR, BCG, Yellow fever, Varicella
  • IT= Diphtheria, tetanus
  • IO= IPV, typhoid, pertussis
  • C= influenza, pneumococcal
14
Q

What specific diseases can be protected from by passive immunity?

A
  • Rabies
  • Hep B
  • Varicella
  • Botulism
  • Tetanus
  • All by injection of human immunoglobulin
15
Q

What are advantages & disadvantages of a live vaccine?

A
  • A= strong immune response, local & systemic immunity, single dose usually sufficient
  • D= potential to revert to virulence, contraindications, poor stability, contamination, interference by viruses/vaccines & passive antibody
16
Q

What are advantages & disadvantages of an inactive vaccine?

A
  • A= Stable, constituents clearly defined, unable to cause infection
  • D=Several doses, local reactions common, shorter lasting immunity, adjuvant needed
17
Q

Describe the steps in a chain infection?

A
  • Pathogenic organism of sufficient virulence & adequate numbers
  • Reservoir/source to allow multiplication
  • Mode of exit
  • Mode of transmission
  • Portal of entry to host
  • Susceptible host (non-immune)
18
Q

How can pathogenic organisms be eliminated?

A
  • Environmental/equipment cleaning & decontamination
  • Antisepsis
  • Antibiotic prophylaxis
19
Q

How can transmission of a pathogen be minimised?

A
  • Hand hygiene
  • PPE (aprons, gloves, masks)
  • Equipment decontamination (Surgical instruments, bp monitors, stethoscopes)
  • Source & protective isolation
  • Use of disposable equipment (Syringes, needles)
20
Q

How can entry & exit by a pathogen be eliminated?

A
  • Antisepsis (surgical skin prep)
  • Asepsis (insertion & management of invasive devices)
  • Air handling (air filtration & laminar flow, +ve pressure ventilated rooms)
  • Sharps management
  • Patient management (minimise use & duration of invasive devices)
21
Q

What is surveillance?

A
  • Process of gathering info to ensure disease outbreaks are pre-empted or identified early
  • Alert organism (organism capable of causing outbreak)
  • Alert conditions (conditions caused by organism)
  • Infection prevention & control team
22
Q

What decontamination methods are there? Describe them

A
  • Sterilisation= complete killing/removal of all types of micro-organism (bacteria, viruses, fungi, mycobacteria)
  • Disinfection= removal/destruction of sufficient numbers of harmful micro-organisms by chemicals, properties must be considered
  • Antisepsis-disinfection applied to damaged skin/living tissue
23
Q

What methods of sterilisation are there?

A
  • Heat (moist-autoclave, steam under high pressure or dry-oven controlled temp cycles)
  • Chemical (gas or liquid)
  • Filtration
  • Ionising radiation (for single use disposable equipment)