Infection-contffgffdrrol-lecture_Leeds.ppt
- 1. The Leeds Teaching Hospitals NHS Trust NHS NHS The Leeds Teaching Hospitals NHS Trust NHS NHS Infection Prevention & Control
- 2. Microbiology FACULTY OF BIOLOGICAL SCIENCES Aims & Objectives – Be able to define the terms “antisepsis”, decontamination”, “sterilisation” and “disinfection”; – Have a basic knowledge of the use of heat, irradiation, filtration, and various chemicals in decontamination – Understand the decontamination method most appropriate in a range of commonly encountered clinical situations – Understand the role of hand hygiene in the prevention of infection.
- 3. Microbiology FACULTY OF BIOLOGICAL SCIENCES The problem • Prevalence of healthcare-associated infection (HCAI) 6.4% in 20111 • Additional cost £2,917 per HAI2 • Annual cost to NHS £930.6 million2 • Relative risk of death 7.12 • Estimated 5,000 UK HCAI deaths per annum3 • 1 English National Point Prevalence Survey on Healthcare-Associated Infection 2011 • 2Socio-economic burden of hospital acquired infection (PHLS 1999) • 3Hospital infection control (DoH 1995)
- 4. Microbiology FACULTY OF BIOLOGICAL SCIENCES Scenario • You are an FY1 doctor working on an orthopaedic ward and you notice that you have had 3 patients in the last month who have developed an MRSA (meticillin resistant Staphylococcal aureus) post operative wound infection. You bring this to the attention of your consultant who suggests discussing this with the Infection Prevention and Control team
- 5. Microbiology FACULTY OF BIOLOGICAL SCIENCES What further information might the IPC team need? • Are there any more cases? – Retrospective – Prospective • Are the cases linked? – Patient demographics – Ask the microbiology laboratory to send all suspected cases for typing – Timeline of each case • What surgeries did they have and who was the surgeon? • Patient location: pre and post op. Which operative theatre? • Which staff were involved in post op care?
- 6. Microbiology FACULTY OF BIOLOGICAL SCIENCES Chain of infection Pathogenic organism Reservoir Exit Transmission Entry Susceptible host Pathogenic organism Reservoir Exit Transmission Entry Susceptible host • Pathogenic organism – Of sufficient virulence and in adequate numbers to cause disease • Reservoir or source that allows the organism to survive and multiply • Mode of exit from the source • Mode of transmission from the source to the host • Portal of entry through which the pathogen can enter the host • Susceptible (i.e. non-immune) host
- 7. Microbiology FACULTY OF BIOLOGICAL SCIENCES Pathogenic organism Reservoir Exit Transmission Entry Susceptible host Pathogenic organism Reservoir Exit Transmission Entry Susceptible host i • Transmission of MRSA – Pathogenic organism: MRSA (meticillin resistant Staphylococcal aureus) – Reservoir: Human skin particularly nose and other moist and hairy areas – Mode of transmission, exit and entry: direct contact with infected sites or indirect contact with fomites or hands of healthcare workers – Susceptible host: any breakdown in skin integrity Pathogenic organism Reservoir Transmission Susceptible host Entry Exit
- 8. Microbiology FACULTY OF BIOLOGICAL SCIENCES Pathogenic organism Reservoir Exit Transmission Entry Susceptible host Pathogenic organism Reservoir Exit Transmission Entry Susceptible host i • Activities undertaken with the aim of breaking the chain of infection – Eliminate pathogenic organism – Remove source/reservoir – Minimise transmission – Eliminate exit and entry – Reduce susceptibility to infection Pathogenic organism Reservoir Transmission Susceptible host Entry Exit Infection Prevention & Control (IPC)
- 9. Microbiology FACULTY OF BIOLOGICAL SCIENCES Orthopaedic MRSA infections • Over the last 6 months 9 patients have been identified as having a post operative infection caused by MRSA • 3 patients were operated by Mr B, 2 patients by Mr C and 4 by Mr X • All the procedures took place in the same operating theatre • All the patients received their post operative care on the same ward • Samples from all 9 patients were sent to the reference laboratory for typing
- 10. Microbiology FACULTY OF BIOLOGICAL SCIENCES MRSA typing • Pulse-field gel electrophoresis (PFGE) – Usually used for characterisation of outbreak strains • Multiple-Locus Variable Number Tandem Repeat Analysis (MLVNTR) • spa sequence typing • Multi-locus sequence typing (MLST) • Whole genome sequencing (WGS)
- 11. Microbiology FACULTY OF BIOLOGICAL SCIENCES What is an outbreak? • Two or more linked cases of the same illness, when the observed number of cases exceeds the expected number or a single case of disease caused by a significant pathogen (i.e. viral haemorrhagic fever) • Outbreak investigation: need to determine mode of transmission and any breakdown in IPC practices
- 12. Microbiology FACULTY OF BIOLOGICAL SCIENCES What organisms commonly cause outbreaks in hospitals? • Viruses – Influenza – Norovirus – SARS CoV-2 • Bacteria – Clostridium difficile – MRSA – Group A Streptococcus – VRE (vancomycin resistant Enterococci) – Multi drug resistant gram negatives ( ESBL, CPEs) • Fungi – Aspergillus
- 13. Microbiology FACULTY OF BIOLOGICAL SCIENCES Pre operatively • MRSA screening +/- decolonisation – All elective surgical patients should be screened for MRSA – nose, axilla and groin – Offered decolonisation if positive – mupirocin or neomycin and chlorhexidine body wash
- 14. Microbiology FACULTY OF BIOLOGICAL SCIENCES Perioperatively • Perioperative antibiotics – with activity against MRSA if known positive • Surgical skin prep • Scrub technique and hand hygiene • Ventilation of operative theatre • Clinical waste • Environmental cleaning and decontamination • Sterilisation of equipment
- 15. Microbiology FACULTY OF BIOLOGICAL SCIENCES Sterilisation, disinfection and antisepsis, cleaning • Decontamination is a combination of processes that removes or destroys contamination so that infectious agents or other contaminants cannot reach a susceptible site in sufficient quantities to initiate infection, or other harmful response. • Various decontamination methods – which is appropriate / required depends on situation.
- 16. Microbiology FACULTY OF BIOLOGICAL SCIENCES Sterilisation • Complete killing or removal of all types of micro- organisms – Bacteria • Vegetative* • Spores – e.g. Clostridium tetani, C. difficile, C. perfringens, etc. – Viruses – Fungi – Mycobacteria * Endowed with the power or faculty of growth
- 17. Microbiology FACULTY OF BIOLOGICAL SCIENCES Sterilisation methods • Heat – Moist, dry • Chemical – Gas, liquid • Filtration • Ionising radiation – Used for single use disposable equipment
- 18. Microbiology FACULTY OF BIOLOGICAL SCIENCES Sterilisation by heat • Moist heat – Autoclave • Delivery of steam under high pressure • Specific pressure and temperature cycles • Dry heat – Oven • Controlled temperature cycles – 160C for 2 hrs or 170 C for 1 hr
- 19. Microbiology FACULTY OF BIOLOGICAL SCIENCES Disinfection • Removal or destruction of sufficient numbers of potentially harmful micro- organisms to make an item safe to use • “Antisepsis” is disinfection applied to damaged skin or living tissues – Requires a disinfectant with minimal toxicity
- 20. Microbiology FACULTY OF BIOLOGICAL SCIENCES Disinfection • Almost always achieved by use of chemical disinfectants • Properties to consider: – Effects on micro-organisms • Antimicrobial spectrum, sporicidality – Chemical properties • Shelf life, in-use concentration, compatibility with other chemicals – Physical effects • Corrosiveness – Harmful effects • Irritant potential, toxicity
- 21. Microbiology FACULTY OF BIOLOGICAL SCIENCES Which method? • Risk of infection – High, intermediate, low • Physical properties – Item – Packaging materials • Decontamination level – Sterilisation, disinfection (antisepsis), cleaning, disposal • Heat is the least hazardous method and should be used where possible • Chemical disinfection is largely limited to: – Environmental decontamination (surfaces, spills etc.) – Antisepsis – Heat-sensitive items
- 22. Microbiology FACULTY OF BIOLOGICAL SCIENCES Which method? • Items/devices that will enter sterile body areas or break the skin – STERILISE • Items/devices that will contact mucous membranes or that will be contaminated with body fluids – DISINFECT • Items/devices that only contact intact skin (no body fluids) - CLEAN Decontamination
- 23. Microbiology FACULTY OF BIOLOGICAL SCIENCES Surgical instrument reprocessing • Risk of infection – High • Physical properties – Metal construction – Paper/cloth packaging • Decontamination level – Sterilisation • Decontamination method – Moist heat
- 24. Microbiology FACULTY OF BIOLOGICAL SCIENCES Central venous catheter (CVC) insertion site 1epic3 guideline • Physical properties – Living tissue • Decontamination level – Disinfection (antisepsis) • Decontamination method – Chemical • 2% chlorhexidine in 70% isopropyl alcohol1
- 25. Microbiology FACULTY OF BIOLOGICAL SCIENCES Surgeon’s hands • Physical properties – Living tissue • Decontamination level – Washing • Decontamination method – Surgical scrub
- 26. Microbiology FACULTY OF BIOLOGICAL SCIENCES Post operatively • Wound care • Hand hygiene • Personal protective equipment – Aprons – Gloves • Patient placement – MRSA positive patients should be nursed in a single room with en suite toilet facilities • Clinical waste • Decontamination of medical equipment • Stethoscopes, blood pressure monitors, USS probes etc. • Environmental cleaning and decontamination • Laundry
- 27. Microbiology FACULTY OF BIOLOGICAL SCIENCES Hand Hygiene
- 28. Microbiology FACULTY OF BIOLOGICAL SCIENCES
- 29. Microbiology FACULTY OF BIOLOGICAL SCIENCES • Semmelweis. – 19th Century, Vienna General Hospital – Two free obstetric clinics, admitted alternate days. • First Clinic. Maternal mortality, puerperal fever: 10%. • Second Clinic. < 4%. – First clinic: Medical students. – Second clinic: Midwifery students . – ….Medical students also attended autopsies. – Hand-washing with chlorinated lime after autopsies. • 1847 April, pre: 18.3%; June, post: 2.2%
- 30. Microbiology FACULTY OF BIOLOGICAL SCIENCES What do we carry on our hands? Resident Bacteria Transient Bacteria Deep Seated Difficult to Remove Easily picked up and transferred Easily Removed Important cause of Healthcare Associated Infections .
- 31. Microbiology FACULTY OF BIOLOGICAL SCIENCES Before After the thumb was not washed Hand plates showing the effect of hand hygiene
- 32. Microbiology FACULTY OF BIOLOGICAL SCIENCES Your 5 moments for Hand Hygiene at the point of care
- 33. Microbiology FACULTY OF BIOLOGICAL SCIENCES Soap & Water or Alcohol gel • Soap & Water for visibly soiled hands • Contact with particular infections e.g. C. difficile, viral gastro-enteritis • Alcohol gel is suitable for most of the activities you are likely to undertake on visiting clinical areas • Hand-washing on entry & exit.
- 34. Microbiology FACULTY OF BIOLOGICAL SCIENCES Outbreak investigation findings • Typing results showed that all 9 cases were the same strain of MRSA • Multiple lapses in care – Poor compliance with hand hygiene on the orthopaedic ward – Clinical teams observed not to be using appropriate PPE – Not all patients had appropriate MRSA decolonisation administered prior to surgery – Medical equipment not being adequately decontaminated • Testing of staff on the ward identified 1 member of staff colonised with MRSA. Further evaluation showed that this was also the outbreak strain. This member of staff also had multiple eczematous lesions on their hands.
- 35. Microbiology FACULTY OF BIOLOGICAL SCIENCES Interventions • Hand hygiene training for clinical staff with regular ward observations to ensure compliance • Signs on the ward detailing which PPE to wear in different locations – When caring for patients in source isolation due to MRSA clinicians should wear gloves and an apron • Pre op checklist to ensure all patients screened and prescribed MRSA decolonisaton where appropriate • Enhanced cleaning on the ward with regular audits to ensure compliance • MRSA positive staff member was referred to Occupational Health – Transferred to a non patient facing role – Given MRSA decolonisation and treatment for their ezcema – Rescreened after decolonisation – Returned to a patient facing role once lesions had resolved and 3 MRSA screens were negative
- 36. Microbiology FACULTY OF BIOLOGICAL SCIENCES Aims & Objectives – Be able to define the terms “antisepsis”, decontamination”, “sterilisation” and “disinfection”; – Have a basic knowledge of the use of heat, irradiation, filtration, and various chemicals in decontamination – Understand the decontamination method most appropriate in a range of commonly encountered clinical situations – Understand the role of hand hygiene in the prevention of infection.
- 37. Microbiology FACULTY OF BIOLOGICAL SCIENCES Many thanks & Please: Make Infection Prevention YOUR intention.
Editor's Notes
- #2: We are going to cover these objectives by working through an outbreak scenario on an orthopaedic ward
- #5: Retrospective (look back exercise) Prospective (more tests, awareness)
- #9: Following look back exercise
- #22: Sterilisation destroys all micro-organisms including spores. Heat by autoclave is the preferred method. Items must be thoroughly cleaned first. All re-usable surgical instruments must be decontaminated by this method. Disinfection reduces micro-organisms to a level at which they are not harmful. The two main methods are: Heat disinfection e.g. dishwasher, bed pan washer; 2. Chemical disinfection e.g. endoscope washer/disinfector, chlorine-releasing agent for cleaning equipment. Cleaning is the removal of dirt, dust or any organic matter using water and detergent. About 80% of micro-organisms will also be removed if the item is dried, therefore drying is an important part of the process. This method of decontamination is suitable for any item that comes into contact with intact skin, e.g. beds chairs, non-invasive equipment e.g. monitoring equipment and intravenous pumps. Cleaning is also an essential first step when decontaminating items by disinfection and sterilisation.
- #30: Resident bacteria aid in protecting us from colonisation with other harmful species. They are only removed when undertaking a surgical/ aseptic procedure (reducing the risk of contamination when inserting invasive devices or performing surgery). Transient bacteria (micro-organisms) are the major cause of HCAIs as they are so readily picked up from colonised patients/ contaminated environment.
- #31: This highlights the effectiveness of hand hygiene when undertaken in the clinical area. The first plate shows colonies of bacteria which have been grown for 48 hours in an incubator. The yellow colonies are representative of staphylococcus aureus. The second plate is following hand hygiene with soap and water. The plate has been incubated for the same length of time. This does show that the person did not clean their thumb properly.