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Flashcards in What Goes Around, Comes Around Deck (24)
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Why is it important to prevent the transmission of microorganisms in healthcare?

  • Economic burden on NHS and economy as a whole
  • Additional length of patient stay in hospital
  • Risks to healthcare staff
  • Increased morbidity and mortality


Give examples of gram positive antibiotic resistant organisms.

  • Meticillin Resistant S.aureus (MRSA)
  • Vancomycin resistant Enterococcus (VRE)


Give examples of gram negative antibiotic resistant organisms.

  • Extended Spectrum -Lactamse producing Enterobacteriaceae (ESBL producer).
  • Carbapenem Resistant Enterobacteriaceae (CRE).
  • Carbapenemase producing Pseudomonas.


What type of infection is the highest reported hospital acquired infection? 

  • Respiratory infections


In which patients are health care associated infections (HCAIs) an issue?

  • Patients with chronic disease
  • Patients with invasive medical devices
  • In the elderly population
  • In patients who are immunosuppressed
  • In patients undergoing more complex procedures
  • HCAIs are also an issue due to increasing antibiotic resistance


Describe the chain of infection.


Describe contact transmission and give examples of diseases which can be spread in this way.

  • Direct or indirect contact via fomites or ingestion.
    • Blood borne viruses
    • Diarrhoea
    • MRSA
    • C. difficile
    • Group A Strep
    • N. gonorrhoea


Describe droplet transmission and give examples of diseases which can be spread in this way.

  • Droplet transmission
    • N. meningitis
    • Norovirus
    • Diptheria
    • Pertussis
    • Pneumonic plague


Describe aerosol transmission and give examples of diseases which can be spread in this way.

  • Airborne transmission
    • ​TB
    • Chickenpox
    • Influenza
    • Viral haemorrhagic fever
    • Measles


What are the precautions which must be taken to prevent contact transmission?

  • For patients infected / colonised with organisms transmitted by direct or indirect contact.
    • Sydrome:
      • Gastroenteritis
      • Fever in patient returned from the tropics
    • Specific organism:
      • C. difficile
      • MRSA
      • S. pyogenes
  • Single room if possible
  • Gloves
  • Aprons
  • Disposable marks / eye protection if at risk of splashes


What are the precautions which must be taken to prevent droplet transmission?

  • For organisms transmitted in droplets (>0.5µm). 
  • These travel only short distances.
    • Syndromes:
      • Meningism
      • Fever with cough
      • Fever with rash
      • Vomiting
    • Specific organisms:
      • N. meningitis
      • Mumps
      • Rubella
  • Single room if possible
  • Wear surgial mask when within touching distance (1 metre) of the patient or cough inducing procedure.


What are the precautions which must be taken to prevent airborne transmission?

  • Particles <5µm.
  • Can be widely dispersed, e.g. TB, chickenpox, measles, Flu.
  • Wear FFP3 mask for all aerosol generating procedures.
    • Syndromes:
      • Influenza-like illness
    • Specific organisms:
      • TB
      • Measles
  • Single room
  • Apron
  • Gloves
  • High efficiency filter mask 


Describe how infection can be established in normal healthy hosts.

  • Microbes with specific mechanisms for attachment and penetration of host's body surfaces.
  • Microbes introduced into host by biting arthropods.
  • Microbes introduced into host via skin wounds or animal bites.
  • Microbes able to infect only when host defences are impaired. 


What are the 3 key factors which transmission of microorganisms depends upon?

  • The number of microorganisms shed
  • The number of micro-organisms required to infect a fresh host (the efficiency of the infection)
  • The micro-organism's stability in the environment


List the different mechanisms of human-to-human transmission and give examples of each.

  • Respiratory
    • TB, influenza, common cold
  • Faeco-oral
    • Cholera, shigellosis
  • Venereal
    • Chlamydia, HIV, papilloma virus
  • Skin
    • Ringworm, S. aureus
  • Perinatal
    • HIV, meningitis, conjunctivitis
  • Semen
    • HIV, Hep B, cytomegalovirus
  • Blood
    • HIV, Hep B, malaria
  • Breast milk
    • HIV
  • Saliva
    • EBV, herpes simplex virus (HSV)


Give examples of invertebrate vectors and the diseases they transmit.

  • Invertabrate vectors
    • Arthropods
      • Malaria, sleeping sickness, yellow fever
    • Shellfish
      • Hep A, cholera


Give examples of vertebrate vectors and the diseases they transmit.

  • Vertebrate vectors
    • Mammals
      • Rabies, leptospirosis, tapeworm
    • Birds
      • Psittacosis
      • Salmonella


What are nosocomial infections?

  • Infections acquired during a hospital stay
  • Major public health concern
  • Antibiotic resistance
    • C. dif 
    • Staph. aureus
  • Good hygeins and sanitation are vital in infection prevention and control.


What is fomite transmission?

  • Transmission via inanimate objects:
    • Door handles
    • Cutlery
    • Computer keyboards
    • Clothing
    • Phones
    • Pens 
    • Etc...


What is an endemic?

Disease present in a community at all times; at a relatively low to medium frequency but at a steady state. 


What is an epidemic?

Sudden severe outbreak within a region or a group.


What is a pandemic?

Occurs when an epidemic becomes widespread and affects a whole region, a continent, or the entire world. 


What causes a pandemic?

  • Antigenic shift
  • ost people have no immunity
  • Attack rate is high - it spreads rapidly
  • Mortality can be high


What is a notifiable disease?

  • Any disease that is required by law to be reported to government authorities. 
  • Allows the authorities to monitor the disease.
  • Provides early warning of possible outbreaks.