Infection Control

Infection Control An Introduction to A PowerPoint Presentation by Eddie Newall May 2003

Learning outcomes • Describe the sources of micro-organisms, routes of transmission and key principles of infection control • List the essential elements of universal precautions • Understand the importance of risk assessment and management in infection control

The pre-scientific era • Epidemics and plagues throughout history • Physicians fear of contagious disease • Hippocrates and others suspected an unseen invisible cause • Climate and environment blamed - not the ill, dying or dead

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

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

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

Scientific era continued . . . . . Joseph Lister (1827-1912) • Scottish surgeon • Recognised importance of Pasteur’s work • Concerned about infection of compound fractures and post-operative wounds • Developed carbolic acid spray to disinfect instruments, patient’s skin, surgeon’s skin • Largely ignored by medical colleagues

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

Contemporary issues • Antibiotic resistance • Prevalence of hospital acquired infection • Prion diseases

Antibiotic resistance • Not a new problem - Penicillin in 1944 • 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

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

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

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

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

Comparisons of mortality Deaths per year in the UK

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

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

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)

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)

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)

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)

HAI - common viruses • Hepatitis A - infectious hepatitis • Hepatitis B - serum hepatitis • Human immunodeficiency virus [HIV] - acquired immunodeficiency syndrome [AIDS] (Peto, 1998)

Common types of HAI (May, 2000)

Universal infection control precautions • Devised in US in the 1980’s 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

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

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

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. Hand washing – areas missed

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)

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)

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)

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)

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)

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)

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)

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)

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)

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)

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)

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)

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

Core references • Davies, H. and Rees, J. (2000) Psychological effects of isolation nursing (1): mood disturbance. Nursing Standard. 14, 28, 35-38. • May, D. (2000) Infection control. Nursing Standard. 14, 28. 51-57. • ICNA (1998) Guidelines for hand hygiene. Belper: ICNA. • NHS Executive (1995) Hospital laundry arrangements for used and infected linen - HSG (95) 18. London: DoH. • Nightingale, F. (1854) Notes on nursing. Edinburgh: Churchill Livingstone • Peto, R. (1998) “Infection control”, In: Mallik, M., Hall, C. and Howard, D. (eds) Nursing knowledge and practice - a decision making approach. London: Bailliere Tindall. • Rcn (1995) Infection control in hospitals. London: Rcn.

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

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Infection Control