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
- 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
- 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
- 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
- Sydrome:
- Gastroenteritis
- Fever in patient returned from the tropics
- Specific organism:
- C. difficile
- MRSA
- S. pyogenes
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.
- Syndromes:
- Meningism
- Fever with cough
- Fever with rash
- Vomiting
- Specific organisms:
- N. meningitis
- Mumps
- Rubella
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
- Syndromes:
- Influenza-like illness
- Specific organisms:
- TB
- Measles
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)
- TB, influenza, common cold
- Cholera, shigellosis
- Chlamydia, HIV, papilloma virus
- Ringworm, S. aureus
- HIV, meningitis, conjunctivitis
- HIV, Hep B, cytomegalovirus
- HIV, Hep B, malaria
- HIV
- 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
- 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
- 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.
- C. dif
- Staph. aureus
What is fomite transmission?
- Transmission via inanimate objects:
- Door handles
- Cutlery
- Computer keyboards
- Clothing
- Phones
- Pens
- Etc...
- 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?
