Infection Control

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Infection Control
by Simran S Ghatore
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The pre-scientific era

• Epidemics and plagues throughout history (black
  plague..)
• Physicians fear of contagious disease
• Hippocrates and others suspected an unseen
  invisible cause
• Climate and environment blamed - not the ill,
  dying or dead

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Microbiology - scientific era

• Anton van Leeuwenhoek (1632-1722)
• Dutch linen draper
• Amateur scientist
• Grinding lenses, magnifying glasses, hobby
• First to see bacteria little beasties
• No link between bacteria and disease

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Scientific era continued . . . . .

• Ignaz Semmelweiss (1818-1865)
• Obstetrician, practised in Vienna
• Studied puerperal (childbed) fever
• Established that high maternal mortality was due
  to failure of doctors to wash hands after
  post-mortems
• Reduced maternal mortality by 90
• Ignored and ridiculed by colleagues

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Scientific era continued . . . . .

• Louis Pasteur (1822-1895)
• French professor of chemistry
• Studied how yeasts (fungi) ferment wine and beer
• Proved that heat destroys bacteria and fungi
• Proved that bacteria can cause infection - the
  germ theory of disease

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Scientific era continued . . . . .

• Joseph Lister (1827-1912)
• Scottish surgeon
• Recognised importance of Pasteurs work
• Concerned about infection of compound fractures
  and post-operative wounds
• Developed carbolic acid spray to disinfect
  instruments, patients skin, surgeons skin
• Largely ignored by medical colleagues

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Scientific era continued

• Robert Kock (1843-1910)
• German general practitioner
• Grew bacteria in culture medium
• Showed which bacteria caused particular diseases
• Classified most bacteria by 1900

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Contemporary issues

• Antibiotic resistance
• Prevalence of hospital acquired infection
• Prion diseases - BSE ? mad cow disease - new
  variant Creutzfeldt-Jakob disease (nvCJD)
  (thought to be the human equivalent) -
  Gerstmann-Straussler-Scheinker disease kuru
  and fatal insomnia.
• -Prions are mutated proteins
• -majority of prion related diseases involve
  neurological damage.
• -not all scientists accept they are the cause of
  disease.
• (see later)
• (more info)

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Antibiotic resistance

• Not a new problem - Penicillin in 1944
  (A.Flemming) 1st antibiotic most resistance?
• Hospital superbugs
• Methycillin Resistant Staphylococcus Aureus
  MRSA
• Vancomycin Intermediate Staphylococcus Aureus
  VISA
• Tuberculosis - antibiotic resistant form
• 400 deaths per year in UK
• Up to 100,000 per patient to treat
• Annual NHS cost - 5 million!!

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MRSA

• Discovered in 1981
• Found on skin and in the nose of 1 in 3 healthy
  people - symptomless carriers
• Widespread in hospitals and community
• Resistant to most antibiotics
• When fatal - often due to septicaemia

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Hospital acquired infection

• Incidence of 10
• 5,000 deaths per year - direct result of HAI
• 15,000 deaths per year linked to HAI
• Delayed discharge from hospital
• Expensive to treat 3,500 extra
• Cost to NHS - 1 billion per year
• Effective hand washing is the most effective
  preventative measure
• Dirty wards and re-use of disposable equipment
  also blamed

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Prion diseases

• Prions pree-ons - proteinaceous infectious
  particles
• Corrupted form of a normally harmless protein
  found in mammals and birds
• Causes fatal neurodegenerative diseases of
  animals and humans
• Animals scrapie - sheep, bovine spongiform
  encephalopathy BSE or Mad Cow Disease
• Humans Creutzfeldt-Jakob disease CJD
• Prions found in blood, tonsil and appendix tissue

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Prions and surgery

• Prions cannot be destroyed by sterilisation
• Theoretical risk of cross infection from
  contaminated instruments and blood transfusion

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Comparisons of mortality
Deaths per year in the UK
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The nature of infection

• Micro-organisms - bacteria, fungi, viruses,
  protozoa and worms
• Most are harmless non-pathogenic
• Pathogenic organisms can cause infection
• Infection exists when pathogenic organisms enter
  the body, reproduce and cause disease

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Hospital acquired infection

• Infection which was neither present nor
  incubating at the time of admission
• Includes infection which only becomes apparent
  after discharge from hospital but which was
  acquired during hospitalisation (Rcn, 1995)
• Also called nosocomial infection

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Modes of spread

• Two sources of infection
• Endogenous or self-infection - organisms which
  are harmless in one site can be pathogenic when
  transferred to another site e.g., E. coli
• Exogenous or cross-infection - organisms
  transmitted from another source e.g., nurse,
  doctor, other patient, environment (Peto, 1998)

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Spread - entry and exit routes

• Natural orifices - mouth, nose, ear, eye,
  urethra, vagina, rectum
• Artificial orifices - such as tracheostomy,
  ileostomy, colostomy
• Mucous membranes - which line most natural and
  artificial orifices
• Skin breaks - either as a result of accidental
  damage or deliberate inoculation/incision (May,
  2000)

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Chain of infection

• Source/reservoir of micro-organisms
• infected person host or other source
• Method of transmission
• hands, instruments, clothing, coughing, sneezing,
  dust etc.
• Point of entry
• orifices, mucous membranes, skin
• Susceptible host
• low resistance to infection (May, 2000)

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HAI - common bacteria

• Staphylococci - wound, respiratory and
  gastro-intestinal infections
• Eshericia coli - wound and urinary tract
  infections
• Salmonella - food poisoning
• Streptococci - wound, throat and urinary tract
  infections
• Proteus - wound and urinary tract infections
  (Peto, 1998)

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HAI - common viruses

• Hepatitis A - infectious hepatitis
• Hepatitis B - serum hepatitis
• Human immunodeficiency virus HIV - acquired
  immunodeficiency syndrome via infected blood
  transfusion! AIDS (Peto, 1998)

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Common types of HAI
(May, 2000)
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Universal infection control precautions

• Devised in US in the 1980s in response to
  growing threat from HIV and hepatitis B
• Not confined to HIV and hepatitis B
• Treat ALL patients as a potential bio-hazard
• Adopt universal routine safe infection control
  practices to protect patients, self and
  colleagues from infection

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Universal precautions

• Hand washing
• Personal protective equipment PPE
• Preventing/managing sharps injuries
• Aseptic technique
• Isolation
• Staff health
• Linen handling and disposal
• Waste disposal
• Spillages of body fluids
• Environmental cleaning
• Risk management/assessment

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Hand washing

• Single most effective action to prevent HAI -
  resident/transient bacteria
• Correct method - ensuring all surfaces are
  cleaned - more important than agent used or
  length of time taken
• No recommended frequency - should be determined
  by intended/completed actions
• Research indicates
• poor techniques - not all surfaces cleaned
• frequency diminishes with workload/distance
• poor compliance with guidelines/training

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Hand washing areas missed

• Taylor (1978) identified that 89 of the hand
  surface was missed and that the areas of the
  hands most often missed were the finger-tips,
  finger-webs, the palms and the thumbs.

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Personal protective equipment

• PPE when contamination or splashing with blood or
  body fluids is anticipated
• Disposable gloves
• Plastic aprons
• Face masks
• Safety glasses, goggles, visors
• Head protection
• Foot protection
• Fluid repellent gowns (May, 2000)

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Sharps injuries

• Prevention
• correct disposal in appropriate container
• avoid re-sheathing needle
• avoid removing needle
• discard syringes as single unit
• avoid over-filling sharps container
• Management
• follow local policy for sharps injury (May, 2000)

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Aseptic technique

• Sepsis - harmful infection by bacteria
• Asepsis - prevention of sepsis
• Minimise risk of introducing pathogenic
  micro-organisms into susceptible sites
• Prevent transfer of potential pathogens from
  contaminated site to other sites, patients or
  staff
• Follow local policy (May, 2000)

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Isolation

• Single room or group
• Source or protective
• Source - isolation of infected patient
• mainly to prevent airborne transmission via
  respiratory droplets
• respiratory MRSA, pulmonary tuberculosis
• Protective - isolation of immuno-suppressed
  patient (May, 2000)
• Significant psychological effects (Davies et al,
  1999)

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Staff health

• Risk of acquiring and transmitting infection
• Acquiring infection
• immunisation
• cover lesions with waterproof dressings
• restrict non-immune/pregnant staff
• Transmitting infection
• advice when suffering infection
• Report accidents/untoward incidents
• Follow local policy (May, 2000)

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Linen handling and disposal

• Bedmaking and linen changing techniques
• Gloves and apron - handling contaminated linen
• Appropriate laundry bags
• Avoid contamination of clean linen
• Hazards of on-site ward-based laundering
• NHS Executive guidelines (1995)
• Follow local policy (May, 2000)

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Waste disposal

• Clinical waste - HIGH risk
• potentially/actually contaminated waste including
  body fluids and human tissue
• yellow plastic sack, tied prior to incineration
• Household waste - LOW risk
• paper towels, packaging, dead flowers, other
  waste which is not dangerously contaminated
• black plastic sack, tied prior to incineration
• Follow local policy (May, 2000)

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Spillage of body fluids

• PPE - disposable gloves, apron
• Soak up with paper towels, kitchen roll
• Cover area with hypochlorite solution e.g.,
  Milton, for several minutes
• Clean area with warm water and detergent, then
  dry
• Treat waste as clinical waste - yellow plastic
  sack
• Follow local policy (May, 2000)

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Environmental cleaning

• Recent concern regarding poor hygiene in hospital
  environments (NHSE, 1999)
• Some pathogens survive for long periods in dust,
  debris and dirt
• Poor hygiene standards - hazardous to patients
  and staff (May, 2000)
• Report poor hygiene to Domestic Services (UKCC,
  1992)
• Hospitals should do the sick no harm
  (Nightingale, 1854)

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Risk assessment

• No risk of contact/splashing with blood/body
  fluids - PPE not required
• Low or moderate risk of contact/splashing - wear
  gloves and plastic apron
• High risk of contact/splashing - wear gloves,
  plastic apron, gown, eye/face protection (Rcn,
  1995)

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Body fluids

• Cerebrospinal fluid, peritoneal fluid, pleural
  fluid, synovial fluid, amniotic fluid, semen,
  vaginal secretions, and
• Any other fluid containing visible blood e.g.,
  urine, faeces (Rcn, 1995)

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Cost of HAI

• Direct cost to NHS for
• extended hospital stay, extra resources, extra
  treatment, extra equipment, and extra community
  care costs if discharged needing follow-up
• Direct cost to patient/family for
• pain and scarring, extended stay away from
  family, working days lost, family income loss,
  financial strain - increased visiting etc,
  increased morbidity, increased mortality (ICNA,
  1998)

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Summary

• Ignaz Semmelweis in 1847 demonstrated that
  washing hands saves lives
• Research indicates that 10 of patients develop
  HAI costing the NHS 1 billion and 20,000 deaths
  per year
• Old bacteria are causing new problems
• New viral and prion diseases are causing new
  problems
• Reluctance to wash hands still the single most
  important cause of HAI (ICNA, 1998)
• Growing concern about poor hospital hygiene

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Internet sites

• http//www.icna.co.uk/
• http//www.nursing-standard.co.uk/
• http//www.medscape.com/
• http//www.anes.uab.edu/medhist.htm
• http//www.shef.ac.uk/nhcon/
• http//medweb.bham.ac.uk/nursing/
• http//www.healthcentre.org.uk/hc/library/default.
  htm
• http//www.parliament.uk/documents/upload/POSTpn24
  7.pdf (excellent article)